Programs & Examples On #Ess

ESS (Emacs Speaks Statistics) is an emacs add-on for editing scripts and interacting with statistical programs such as R, Stata or SAS.

How to get AIC from Conway–Maxwell-Poisson regression via COM-poisson package in R?

I figured out myself.

cmp calls ComputeBetasAndNuHat which returns a list which has objective as minusloglik

So I can change the function cmp to get this value.

Monitoring the Full Disclosure mailinglist

Two generic ways to do the same thing... I'm not aware of any specific open solutions to do this, but it'd be rather trivial to do.

You could write a daily or weekly cron/jenkins job to scrape the previous time period's email from the archive looking for your keyworkds/combinations. Sending a batch digest with what it finds, if anything.

But personally, I'd Setup a specific email account to subscribe to the various security lists you're interested in. Add a simple automated script to parse the new emails for various keywords or combinations of keywords, when it finds a match forward that email on to you/your team. Just be sure to keep the keywords list updated with new products you're using.

You could even do this with a gmail account and custom rules, which is what I currently do, but I have setup an internal inbox in the past with a simple python script to forward emails that were of interest.

Under what circumstances can I call findViewById with an Options Menu / Action Bar item?

I am trying to obtain a handle on one of the views in the Action Bar

I will assume that you mean something established via android:actionLayout in your <item> element of your <menu> resource.

I have tried calling findViewById(R.id.menu_item)

To retrieve the View associated with your android:actionLayout, call findItem() on the Menu to retrieve the MenuItem, then call getActionView() on the MenuItem. This can be done any time after you have inflated the menu resource.

I am receiving warning in Facebook Application using PHP SDK

You need to ensure that any code that modifies the HTTP headers is executed before the headers are sent. This includes statements like session_start(). The headers will be sent automatically when any HTML is output.

Your problem here is that you're sending the HTML ouput at the top of your page before you've executed any PHP at all.

Move the session_start() to the top of your document :

<?php    session_start(); ?> <html> <head> <title>PHP SDK</title> </head> <body> <?php require_once 'src/facebook.php';    // more PHP code here. 

programming a servo thru a barometer

You could define a mapping of air pressure to servo angle, for example:

def calc_angle(pressure, min_p=1000, max_p=1200):     return 360 * ((pressure - min_p) / float(max_p - min_p))  angle = calc_angle(pressure) 

This will linearly convert pressure values between min_p and max_p to angles between 0 and 360 (you could include min_a and max_a to constrain the angle, too).

To pick a data structure, I wouldn't use a list but you could look up values in a dictionary:

d = {1000:0, 1001: 1.8, ...}  angle = d[pressure] 

but this would be rather time-consuming to type out!

Uninitialized Constant MessagesController

Your model is @Messages, change it to @message.

To change it like you should use migration:

def change   rename_table :old_table_name, :new_table_name end 

Of course do not create that file by hand but use rails generator:

rails g migration ChangeMessagesToMessage 

That will generate new file with proper timestamp in name in 'db dir. Then run:

rake db:migrate 

And your app should be fine since then.

How to implement a simple scenario the OO way

You might implement your class model by composition, having the book object have a map of chapter objects contained within it (map chapter number to chapter object). Your search function could be given a list of books into which to search by asking each book to search its chapters. The book object would then iterate over each chapter, invoking the chapter.search() function to look for the desired key and return some kind of index into the chapter. The book's search() would then return some data type which could combine a reference to the book and some way to reference the data that it found for the search. The reference to the book could be used to get the name of the book object that is associated with the collection of chapter search hits.

How to make a variable accessible outside a function?

Your variable declarations and their scope are correct. The problem you are facing is that the first AJAX request may take a little bit time to finish. Therefore, the second URL will be filled with the value of sID before the its content has been set. You have to remember that AJAX request are normally asynchronous, i.e. the code execution goes on while the data is being fetched in the background.

You have to nest the requests:

$.getJSON("https://prod.api.pvp.net/api/lol/eune/v1.1/summoner/by-name/"+input+"?api_key=API_KEY_HERE"  , function(name){   obj = name;   // sID is only now available!   sID = obj.id;   console.log(sID); }); 


Clean up your code!

  • Put the second request into a function
  • and let it accept sID as a parameter, so you don't have to declare it globally anymore! (Global variables are almost always evil!)
  • Remove sID and obj variables - name.id is sufficient unless you really need the other variables outside the function.


$.getJSON("https://prod.api.pvp.net/api/lol/eune/v1.1/summoner/by-name/"+input+"?api_key=API_KEY_HERE"  , function(name){   // We don't need sID or obj here - name.id is sufficient   console.log(name.id);    doSecondRequest(name.id); });  /// TODO Choose a better name function doSecondRequest(sID) {   $.getJSON("https://prod.api.pvp.net/api/lol/eune/v1.2/stats/by-summoner/" + sID + "/summary?api_key=API_KEY_HERE", function(stats){         console.log(stats);   }); } 

Hapy New Year :)

How to use a global array in C#?

Your class shoud look something like this:

class Something {     int[] array; //global array, replace type of course     void function1() {        array = new int[10]; //let say you declare it here that will be 10 integers in size     }     void function2() {        array[0] = 12; //assing value at index 0 to 12.     } } 

That way you array will be accessible in both functions. However, you must be careful with global stuff, as you can quickly overwrite something.

Crop image to specified size and picture location

You would need to do something like this. I am typing this off the top of my head, so this may not be 100% correct.

CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); CGContextRef context = CGBitmapContextCreate(NULL, 640, 360, 8, 4 * width, colorSpace, kCGImageAlphaPremultipliedFirst); CGColorSpaceRelease(colorSpace);  CGContextDrawImage(context, CGRectMake(0,-160,640,360), cgImgFromAVCaptureSession);  CGImageRef image = CGBitmapContextCreateImage(context); UIImage* myCroppedImg = [UIImage imageWithCGImage:image]; CGContextRelease(context);       

python variable NameError

Your if statements are checking for int values. raw_input returns a string. Change the following line:

tSizeAns = raw_input() 

to

tSizeAns = int(raw_input()) 

Pass PDO prepared statement to variables

Instead of using ->bindParam() you can pass the data only at the time of ->execute():

$data = [   ':item_name' => $_POST['item_name'],   ':item_type' => $_POST['item_type'],   ':item_price' => $_POST['item_price'],   ':item_description' => $_POST['item_description'],   ':image_location' => 'images/'.$_FILES['file']['name'],   ':status' => 0,   ':id' => 0, ];  $stmt->execute($data); 

In this way you would know exactly what values are going to be sent.

Why my regexp for hyphenated words doesn't work?

This regex should do it.

\b[a-z]+-[a-z]+\b 

\b indicates a word-boundary.

My eclipse won't open, i download the bundle pack it keeps saying error log

Make sure you have the prerequisite, a JVM (http://wiki.eclipse.org/Eclipse/Installation#Install_a_JVM) installed.

This will be a JRE and JDK package.

There are a number of sources which includes: http://www.oracle.com/technetwork/java/javase/downloads/index.html.

Implement specialization in ER diagram

So I assume your permissions table has a foreign key reference to admin_accounts table. If so because of referential integrity you will only be able to add permissions for account ids exsiting in the admin accounts table. Which also means that you wont be able to enter a user_account_id [assuming there are no duplicates!]

getting " (1) no such column: _id10 " error

I think you missed a equal sign at:

Cursor c = ourDatabase.query(DATABASE_TABLE, column, KEY_ROWID + "" + l, null, null, null, null);  

Change to:

Cursor c = ourDatabase.query(DATABASE_TABLE, column, KEY_ROWID + " = " + l, null, null, null, null); 

Accessing AppDelegate from framework?

If you're creating a framework the whole idea is to make it portable. Tying a framework to the app delegate defeats the purpose of building a framework. What is it you need the app delegate for?

OS X Sprite Kit Game Optimal Default Window Size

You should target the smallest, not the largest, supported pixel resolution by the devices your app can run on.

Say if there's an actual Mac computer that can run OS X 10.9 and has a native screen resolution of only 1280x720 then that's the resolution you should focus on. Any higher and your game won't correctly run on this device and you could as well remove that device from your supported devices list.

You can rely on upscaling to match larger screen sizes, but you can't rely on downscaling to preserve possibly important image details such as text or smaller game objects.

The next most important step is to pick a fitting aspect ratio, be it 4:3 or 16:9 or 16:10, that ideally is the native aspect ratio on most of the supported devices. Make sure your game only scales to fit on devices with a different aspect ratio.

You could scale to fill but then you must ensure that on all devices the cropped areas will not negatively impact gameplay or the use of the app in general (ie text or buttons outside the visible screen area). This will be harder to test as you'd actually have to have one of those devices or create a custom build that crops the view accordingly.

Alternatively you can design multiple versions of your game for specific and very common screen resolutions to provide the best game experience from 13" through 27" displays. Optimized designs for iMac (desktop) and a Macbook (notebook) devices make the most sense, it'll be harder to justify making optimized versions for 13" and 15" plus 21" and 27" screens.

But of course this depends a lot on the game. For example a tile-based world game could simply provide a larger viewing area onto the world on larger screen resolutions rather than scaling the view up. Provided that this does not alter gameplay, like giving the player an unfair advantage (specifically in multiplayer).

You should provide @2x images for the Retina Macbook Pro and future Retina Macs.

How to get parameter value for date/time column from empty MaskedTextBox

You're storing the .Text properties of the textboxes directly into the database, this doesn't work. The .Text properties are Strings (i.e. simple text) and not typed as DateTime instances. Do the conversion first, then it will work.

Do this for each date parameter:

Dim bookIssueDate As DateTime = DateTime.ParseExact( txtBookDateIssue.Text, "dd/MM/yyyy", CultureInfo.InvariantCulture ) cmd.Parameters.Add( New OleDbParameter("@Date_Issue", bookIssueDate ) ) 

Note that this code will crash/fail if a user enters an invalid date, e.g. "64/48/9999", I suggest using DateTime.TryParse or DateTime.TryParseExact, but implementing that is an exercise for the reader.

Parameter binding on left joins with array in Laravel Query Builder

You don't have to bind parameters if you use query builder or eloquent ORM. However, if you use DB::raw(), ensure that you binding the parameters.

Try the following:

$array = array(1,2,3);       $query = DB::table('offers');             $query->select('id', 'business_id', 'address_id', 'title', 'details', 'value', 'total_available', 'start_date', 'end_date', 'terms', 'type', 'coupon_code', 'is_barcode_available', 'is_exclusive', 'userinformations_id', 'is_used');             $query->leftJoin('user_offer_collection', function ($join) use ($array)             {                 $join->on('user_offer_collection.offers_id', '=', 'offers.id')                       ->whereIn('user_offer_collection.user_id', $array);             });       $query->get(); 

Generic XSLT Search and Replace template

Here's one way in XSLT 2

<?xml version="1.0" encoding="UTF-8"?> <xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">   <xsl:template match="@*|node()">     <xsl:copy>       <xsl:apply-templates select="@*|node()"/>     </xsl:copy>   </xsl:template>   <xsl:template match="text()">     <xsl:value-of select="translate(.,'&quot;','''')"/>   </xsl:template> </xsl:stylesheet> 

Doing it in XSLT1 is a little more problematic as it's hard to get a literal containing a single apostrophe, so you have to resort to a variable:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">   <xsl:template match="@*|node()">     <xsl:copy>       <xsl:apply-templates select="@*|node()"/>     </xsl:copy>   </xsl:template>   <xsl:variable name="apos">'</xsl:variable>   <xsl:template match="text()">     <xsl:value-of select="translate(.,'&quot;',$apos)"/>   </xsl:template> </xsl:stylesheet> 

Are all Spring Framework Java Configuration injection examples buggy?

In your test, you are comparing the two TestParent beans, not the single TestedChild bean.

Also, Spring proxies your @Configuration class so that when you call one of the @Bean annotated methods, it caches the result and always returns the same object on future calls.

See here:

Use NSInteger as array index

According to the error message, you declared myLoc as a pointer to an NSInteger (NSInteger *myLoc) rather than an actual NSInteger (NSInteger myLoc). It needs to be the latter.

I need to know how to get my program to output the word i typed in and also the new rearranged word using a 2D array

  1. What exactly doesn't work?
  2. Why are you using a 2d array?
  3. If you must use a 2d array:

    int numOfPairs = 10;  String[][] array = new String[numOfPairs][2]; for(int i = 0; i < array.length; i++){     for(int j = 0; j < array[i].length; j++){         array[i] = new String[2];         array[i][0] = "original word";         array[i][1] = "rearranged word";     }    } 

Does this give you a hint?

Is it possible to change the content HTML5 alert messages?

Yes:

<input required title="Enter something OR ELSE." /> 

The title attribute will be used to notify the user of a problem.

Read input from a JOptionPane.showInputDialog box

Your problem is that, if the user clicks cancel, operationType is null and thus throws a NullPointerException. I would suggest that you move

if (operationType.equalsIgnoreCase("Q")) 

to the beginning of the group of if statements, and then change it to

if(operationType==null||operationType.equalsIgnoreCase("Q")). 

This will make the program exit just as if the user had selected the quit option when the cancel button is pushed.

Then, change all the rest of the ifs to else ifs. This way, once the program sees whether or not the input is null, it doesn't try to call anything else on operationType. This has the added benefit of making it more efficient - once the program sees that the input is one of the options, it won't bother checking it against the rest of them.

strange error in my Animation Drawable

Looks like whatever is in your Animation Drawable definition is too much memory to decode and sequence. The idea is that it loads up all the items and make them in an array and swaps them in and out of the scene according to the timing specified for each frame.

If this all can't fit into memory, it's probably better to either do this on your own with some sort of handler or better yet just encode a movie with the specified frames at the corresponding images and play the animation through a video codec.

Hadoop MapReduce: Strange Result when Storing Previous Value in Memory in a Reduce Class (Java)

It is very inefficient to store all values in memory, so the objects are reused and loaded one at a time. See this other SO question for a good explanation. Summary:

[...] when looping through the Iterable value list, each Object instance is re-used, so it only keeps one instance around at a given time.

How can compare-and-swap be used for a wait-free mutual exclusion for any shared data structure?

The linked list holds operations on the shared data structure.

For example, if I have a stack, it will be manipulated with pushes and pops. The linked list would be a set of pushes and pops on the pseudo-shared stack. Each thread sharing that stack will actually have a local copy, and to get to the current shared state, it'll walk the linked list of operations, and apply each operation in order to its local copy of the stack. When it reaches the end of the linked list, its local copy holds the current state (though, of course, it's subject to becoming stale at any time).

In the traditional model, you'd have some sort of locks around each push and pop. Each thread would wait to obtain a lock, then do a push or pop, then release the lock.

In this model, each thread has a local snapshot of the stack, which it keeps synchronized with other threads' view of the stack by applying the operations in the linked list. When it wants to manipulate the stack, it doesn't try to manipulate it directly at all. Instead, it simply adds its push or pop operation to the linked list, so all the other threads can/will see that operation and they can all stay in sync. Then, of course, it applies the operations in the linked list, and when (for example) there's a pop it checks which thread asked for the pop. It uses the popped item if and only if it's the thread that requested this particular pop.

Access And/Or exclusions

Seeing that it appears you are running using the SQL syntax, try with the correct wild card.

SELECT * FROM someTable WHERE (someTable.Field NOT LIKE '%RISK%') AND (someTable.Field NOT LIKE '%Blah%') AND someTable.SomeOtherField <> 4; 

Image steganography that could survive jpeg compression

Quite a few applications seem to implement Steganography on JPEG, so it's feasible:

http://www.jjtc.com/Steganography/toolmatrix.htm

Here's an article regarding a relevant algorithm (PM1) to get you started:

http://link.springer.com/article/10.1007%2Fs00500-008-0327-7#page-1

how to put image in a bundle and pass it to another activity

So you can do it like this, but the limitation with the Parcelables is that the payload between activities has to be less than 1MB total. It's usually better to save the Bitmap to a file and pass the URI to the image to the next activity.

 protected void onCreate(Bundle savedInstanceState) {     setContentView(R.layout.my_layout);     Bitmap bitmap = getIntent().getParcelableExtra("image");     ImageView imageView = (ImageView) findViewById(R.id.imageview);     imageView.setImageBitmap(bitmap);  } 

FragmentActivity to Fragment

first of all;

a Fragment must be inside a FragmentActivity, that's the first rule,

a FragmentActivity is quite similar to a standart Activity that you already know, besides having some Fragment oriented methods

second thing about Fragments, is that there is one important method you MUST call, wich is onCreateView, where you inflate your layout, think of it as the setContentLayout

here is an example:

    @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {     mView       = inflater.inflate(R.layout.fragment_layout, container, false);       return mView; } 

and continu your work based on that mView, so to find a View by id, call mView.findViewById(..);


for the FragmentActivity part:

the xml part "must" have a FrameLayout in order to inflate a fragment in it

        <FrameLayout             android:id="@+id/content_frame"             android:layout_width="match_parent"             android:layout_height="match_parent"  >         </FrameLayout> 

as for the inflation part

getSupportFragmentManager().beginTransaction().replace(R.id.content_frame, new YOUR_FRAGMENT, "TAG").commit();


begin with these, as there is tons of other stuf you must know about fragments and fragment activities, start of by reading something about it (like life cycle) at the android developer site

vagrant primary box defined but commands still run against all boxes

The primary flag seems to only work for vagrant ssh for me.

In the past I have used the following method to hack around the issue.

# stage box intended for configuration closely matching production if ARGV[1] == 'stage'     config.vm.define "stage" do |stage|         box_setup stage, \         "10.9.8.31", "deploy/playbook_full_stack.yml", "deploy/hosts/vagrant_stage.yml"     end end 

500 Error on AppHarbor but downloaded build works on my machine

Just a wild guess: (not much to go on) but I have had similar problems when, for example, I was using the IIS rewrite module on my local machine (and it worked fine), but when I uploaded to a host that did not have that add-on module installed, I would get a 500 error with very little to go on - sounds similar. It drove me crazy trying to find it.

So make sure whatever options/addons that you might have and be using locally in IIS are also installed on the host.

Similarly, make sure you understand everything that is being referenced/used in your web.config - that is likely the problem area.

Laravel 4 with Sentry 2 add user to a group on Registration

Somehow, where you are using Sentry, you're not using its Facade, but the class itself. When you call a class through a Facade you're not really using statics, it's just looks like you are.

Do you have this:

use Cartalyst\Sentry\Sentry; 

In your code?

Ok, but if this line is working for you:

$user = $this->sentry->register(array(     'username' => e($data['username']),     'email' => e($data['email']),      'password' => e($data['password'])     )); 

So you already have it instantiated and you can surely do:

$adminGroup = $this->sentry->findGroupById(5); 

How do I show a message in the foreach loop?

You are looking to see if a single value is in an array. Use in_array.

However note that case is important, as are any leading or trailing spaces. Use var_dump to find out the length of the strings too, and see if they fit.

Xcode 12, building for iOS Simulator, but linking in object file built for iOS, for architecture arm64

After trying and searching different solutions, I think the most safest way is adding the following code at the end of the Podfile

post_install do |pi|
   pi.pods_project.targets.each do |t|
       t.build_configurations.each do |bc|
          bc.build_settings['ARCHS[sdk=iphonesimulator*]'] =  `uname -m`
       end
   end
end

This way you only override the iOS simulator's compiler architecture as your current cpu's architecture. Compared to others, this solution will also work on computers with Apple Silicon.

iPhone is not available. Please reconnect the device

Steps I used to fix it:

  1. Updated macOS to 10.15.5.
  2. Updated Xcode to 11.5

It still showed the same error so,

  1. I disconnected the iPhone and reconnected again.
  2. Removed Apple ID and added Apple ID again.

And it worked.

SessionNotCreatedException: Message: session not created: This version of ChromeDriver only supports Chrome version 81

Steps I took to make it work

  1. Check your current Chrome version e.g. 81
  2. Goto tools/nuget package manager
  3. Select selenium chrome driver
  4. upgrade/downgrade to the same Chrome-version you have.

Restarting the application should work.

error TS1086: An accessor cannot be declared in an ambient context in Angular 9

These issue arise generally due to mismatch between @ngx-translate/core version and Angular .Before installing check compatible version of corresponding ngx_trnalsate/Core, @ngx-translate/http-loader and Angular at https://www.npmjs.com/package/@ngx-translate/core

Eg: For Angular 6.X versions,

npm install @ngx-translate/core@10 @ngx-translate/http-loader@3 rxjs --save

Like as above, follow below command and rest of code part is common for all versions(Note: Version can obtain from( https://www.npmjs.com/package/@ngx-translate/core)

npm install @ngx-translate/core@version @ngx-translate/http-loader@version rxjs --save

TS1086: An accessor cannot be declared in ambient context

I think that your problem was emerged from typescript and module version mismatch.This issue is very similar to your question and answers are very satisfying.

Could not load dynamic library 'cudart64_101.dll' on tensorflow CPU-only installation

Tensorflow 2.1+

What's going on?

With the new Tensorflow 2.1 release, the default tensorflow pip package contains both CPU and GPU versions of TF. In previous TF versions, not finding the CUDA libraries would emit an error and raise an exception, while now the library dynamically searches for the correct CUDA version and, if it doesn't find it, emits the warning (The W in the beginning stands for warnings, errors have an E (or F for fatal errors) and falls back to CPU-only mode. In fact, this is also written in the log as an info message right after the warning (do note that if you have a higher minimum log level that the default, you might not see info messages). The full log is (emphasis mine):

2020-01-20 12:27:44.554767: W tensorflow/stream_executor/platform/default/dso_loader.cc:55] Could not load dynamic library 'cudart64_101.dll'; dlerror: cudart64_101.dll not found

2020-01-20 12:27:44.554964: I tensorflow/stream_executor/cuda/cudart_stub.cc:29] Ignore above cudart dlerror if you do not have a GPU set up on your machine.

Should I worry? How do I fix it?

If you don't have a CUDA-enabled GPU on your machine, or if you don't care about not having GPU acceleration, no need to worry. If, on the other hand, you installed tensorflow and wanted GPU acceleration, check your CUDA installation (TF 2.1 requires CUDA 10.1, not 10.2 or 10.0).

If you just want to get rid of the warning, you can adapt TF's logging level to suppress warnings, but that might be overkill, as it will silence all warnings.


Tensorflow 1.X or 2.0:

Your CUDA setup is broken, ensure you have the correct version installed.

Message: Trying to access array offset on value of type null

This happens because $cOTLdata is not null but the index 'char_data' does not exist. Previous versions of PHP may have been less strict on such mistakes and silently swallowed the error / notice while 7.4 does not do this anymore.

To check whether the index exists or not you can use isset():

isset($cOTLdata['char_data'])

Which means the line should look something like this:

$len = isset($cOTLdata['char_data']) ? count($cOTLdata['char_data']) : 0;

Note I switched the then and else cases of the ternary operator since === null is essentially what isset already does (but in the positive case).

Template not provided using create-react-app

Such a weird problem because this worked for me yesterday and I came across the same error this morning. Based on the release notes, a new feature was added to support templates so it looks like a few parts have changed in the command line (for example, the --typescript was deprecated in favor of using --template typescript)

I did manage to get it all working by doing the following:

  1. Uninstall global create-react-app npm uninstall create-react-app -g.
  2. Verify npm cache npm cache verify.
  3. Close terminal. I use the mac terminal, if using an IDE maybe close and re-open.
  4. Re-open terminal, browse to where you want your project and run create-react-app via npx using the new template command conventions. For getting it to work, I used the typescript my-app from the documentation site to ensure consistency: npx create-react-app my-app --template typescript

If it works, you should see multiple installs: one for react-scripts and one for the template. The error message should also no longer appear.

Array and string offset access syntax with curly braces is deprecated

It's really simple to fix the issue, however keep in mind that you should fork and commit your changes for each library you are using in their repositories to help others as well.

Let's say you have something like this in your code:

$str = "test";
echo($str{0});

since PHP 7.4 curly braces method to get individual characters inside a string has been deprecated, so change the above syntax into this:

$str = "test";
echo($str[0]);

Fixing the code in the question will look something like this:

public function getRecordID(string $zoneID, string $type = '', string $name = ''): string
{
    $records = $this->listRecords($zoneID, $type, $name);
    if (isset($records->result[0]->id)) {
        return $records->result[0]->id;
    }
    return false;
}

Visual Studio Code PHP Intelephense Keep Showing Not Necessary Error

To those would prefer to keep it simple, stupid; If you rather get rid of the notices instead of installing a helper or downgrading, simply disable the error in your settings.json by adding this:

"intelephense.diagnostics.undefinedTypes": false

dyld: Library not loaded: /usr/local/opt/openssl/lib/libssl.1.0.0.dylib

If you don't have Homebrew or don't know what is it

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
brew update && brew upgrade
brew uninstall openssl; brew uninstall openssl; brew install https://github.com/tebelorg/Tump/releases/download/v1.0.0/openssl.rb

Or if you already have Homebrew installed

brew update && brew upgrade
brew uninstall openssl; brew uninstall openssl; brew install https://github.com/tebelorg/Tump/releases/download/v1.0.0/openssl.rb

This works for me on Mac 10.15

SyntaxError: Cannot use import statement outside a module

simple just change it to : const uuidv1 = require('uuid'); it will work fine.

What's the net::ERR_HTTP2_PROTOCOL_ERROR about?

I also faced this error and I believe there can be multiple reasons behind it. Mine was, ARR was getting timed-out.

In my case, browser was making a request to a reverse proxy site where I have set my redirection rules and that proxy site is eventually requesting the actual site. Now for huge data it was taking more than 2 minutes 5 seconds and Application Request Routing timeout for my server was set to 2 minutes. I fixed this by increasing the ARR timeout by below steps: 1. Go to IIS 2. Click on server name 3. Click on Application Request Routing Cache in the middle pane 4. Click Server Proxy settings in right pane 5. Increase the timeout 6. Click Apply

Has been compiled by a more recent version of the Java Runtime (class file version 57.0)

This is a setting in IntelliJ IDEA ($JAVA_HOME and language level were set to 1.8):

File > Settings > Build, Execution, Deployment > Gradle > Gradle JVM

Select eg. Project SDK (corretto-1.8) (or any other compatible version).

Then delete the build directory and restart the IDE.

How to resolve the error on 'react-native start'

https://github.com/facebook/metro/issues/453

for who still get this error without official patch in react-native , expo

use yarn and add this setting into package.json

{
  ...
  "resolutions": {
    "metro-config": "bluelovers/metro-config-hotfix-0.56.x"
  },
 ...

Why powershell does not run Angular commands?

I solved my problem by running below command

Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser

Server Discovery And Monitoring engine is deprecated

Add the useUnifiedTopology option and set it to true.

Set other 3 configuration of the mongoose.connect options which will deal with other remaining DeprecationWarning.

This configuration works for me!

const url = 'mongodb://localhost:27017/db_name';
mongoose.connect(
    url, 
    { 
        useNewUrlParser: true, 
        useUnifiedTopology: true,
        useCreateIndex: true,
        useFindAndModify: false
    }
)

This will solve 4 DeprecationWarning.

  1. Current URL string parser is deprecated, and will be removed in a future version. To use the new parser, pass option { useNewUrlParser: true } to MongoClient.connect.
  2. Current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option { useUnifiedTopology: true } to the MongoClient constructor.
  3. Collection.ensureIndex is deprecated. Use createIndexes instead.
  4. DeprecationWarning: Mongoose: findOneAndUpdate() and findOneAndDelete() without the useFindAndModify option set to false are deprecated. See: https://mongoosejs.com/docs/deprecations.html#-findandmodify-.

Hope it helps.

Element implicitly has an 'any' type because expression of type 'string' can't be used to index

This is what it worked for me. The tsconfig.json has an option noImplicitAny that it was set to true, I just simply set it to false and now I can access properties in objects using strings.

dotnet ef not found in .NET Core 3

See the announcement for ASP.NET Core 3 Preview 4, which explains that this tool is no longer built-in and requires an explicit install:

The dotnet ef tool is no longer part of the .NET Core SDK

This change allows us to ship dotnet ef as a regular .NET CLI tool that can be installed as either a global or local tool. For example, to be able to manage migrations or scaffold a DbContext, install dotnet ef as a global tool typing the following command:

dotnet tool install --global dotnet-ef

To install a specific version of the tool, use the following command:

dotnet tool install --global dotnet-ef --version 3.1.4

The reason for the change is explained in the docs:

Why

This change allows us to distribute and update dotnet ef as a regular .NET CLI tool on NuGet, consistent with the fact that the EF Core 3.0 is also always distributed as a NuGet package.

In addition, you might need to add the following NuGet packages to your project:

"Permission Denied" trying to run Python on Windows 10

save you time : use wsl and vscode remote extension to properly work with python even with win10 and dont't forget virtualenv! useful https://linuxize.com/post/how-to-install-visual-studio-code-on-ubuntu-18-04/

"UserWarning: Matplotlib is currently using agg, which is a non-GUI backend, so cannot show the figure." when plotting figure with pyplot on Pycharm

In my case, the error message was implying that I was working in a headless console. So plt.show() could not work. What worked was calling plt.savefig:

import matplotlib.pyplot as plt

plt.plot([1,2,3], [5,7,4])
plt.savefig("mygraph.png")

I found the answer on a github repository.

Typescript: No index signature with a parameter of type 'string' was found on type '{ "A": string; }

Don't Use Any, Use Generics

// bad
const _getKeyValue = (key: string) => (obj: object) => obj[key];
    
// better
const _getKeyValue_ = (key: string) => (obj: Record<string, any>) => obj[key];
    
// best
const getKeyValue = <T extends object, U extends keyof T>(key: U) => (obj: T) =>
      obj[key];

Bad - the reason for the error is the object type is just an empty object by default. Therefore it isn't possible to use a string type to index {}.

Better - the reason the error disappears is because now we are telling the compiler the obj argument will be a collection of string/value (string/any) pairs. However, we are using the any type, so we can do better.

Best - T extends empty object. U extends the keys of T. Therefore U will always exist on T, therefore it can be used as a look up value.

Here is a full example:

I have switched the order of the generics (U extends keyof T now comes before T extends object) to highlight that order of generics is not important and you should select an order that makes the most sense for your function.

const getKeyValue = <U extends keyof T, T extends object>(key: U) => (obj: T) =>
  obj[key];

interface User {
  name: string;
  age: number;
}

const user: User = {
  name: "John Smith",
  age: 20
};

const getUserName = getKeyValue<keyof User, User>("name")(user);

// => 'John Smith'

Alternative syntax

const getKeyValue = <T, K extends keyof T>(obj: T, key: K): T[K] => obj[key];

Access blocked by CORS policy: Response to preflight request doesn't pass access control check

You have to set the http header at the http response of your resource. So it needs to be set serverside, you can remove the "HTTP_OPTIONS"-header from your angular HTTP-Post request.

origin 'http://localhost:4200' has been blocked by CORS policy in Angular7

Follow these steps

  1. Add cors dependency. type the following in cli inside your project directory

npm install --save cors

  1. Include the module inside your project

var cors = require('cors');

  1. Finally use it as a middleware.

app.use(cors());

Module 'tensorflow' has no attribute 'contrib'

If you want to use tf.contrib, you need to now copy and paste the source code from github into your script/notebook. It's annoying and doesn't always work. But that's the only workaround I've found. For example, if you wanted to use tf.contrib.opt.AdamWOptimizer, you have to copy and paste from here. https://github.com/tensorflow/tensorflow/blob/590d6eef7e91a6a7392c8ffffb7b58f2e0c8bc6b/tensorflow/contrib/opt/python/training/weight_decay_optimizers.py#L32

How to fix missing dependency warning when using useEffect React Hook?

These warnings are very helpful for finding components that do not update consistently: https://reactjs.org/docs/hooks-faq.html#is-it-safe-to-omit-functions-from-the-list-of-dependencies.

However, If you want to remove the warnings throughout your project, you can add this to your eslint config:

  {
  "plugins": ["react-hooks"],
  "rules": {
    "react-hooks/exhaustive-deps": 0
    }
  }

Unable to load script.Make sure you are either running a Metro server or that your bundle 'index.android.bundle' is packaged correctly for release

you can also downgrade node js to version less than 12 and remove nodemodule then run npm install again

Module not found: Error: Can't resolve 'core-js/es6'

After Migrated to Angular8, core-js/es6 or core-js/es7 Will not work.

You have to simply replace import core-js/es/

For ex.

import 'core-js/es6/symbol'  

to

import 'core-js/es/symbol'

This will work properly.

Updating Anaconda fails: Environment Not Writable Error

Deleting file .condarc (eg./root/.condarc) in the user's home directory before installation, resolved the issue.

Browserslist: caniuse-lite is outdated. Please run next command `npm update caniuse-lite browserslist`

I had same problem too this command works for me

npm i autoprefixer@latest

It automatically added need dependency in package.json and package-lock.json file like below:

package.json

"autoprefixer": "^9.6.5",

package-lock.json

"@angular-devkit/build-angular": {

...

"dependencies": {
    "autoprefixer": {
      "version": "9.4.6",
      "resolved": "https://registry.npmjs.org/autoprefixer/-/autoprefixer-9.4.6.tgz",
      "integrity": "sha512-Yp51mevbOEdxDUy5WjiKtpQaecqYq9OqZSL04rSoCiry7Tc5I9FEyo3bfxiTJc1DfHeKwSFCUYbBAiOQ2VGfiw==",
      "dev": true,
      "requires": {
        "browserslist": "^4.4.1",
        "caniuse-lite": "^1.0.30000929",
        "normalize-range": "^0.1.2",
        "num2fraction": "^1.2.2",
        "postcss": "^7.0.13",
        "postcss-value-parser": "^3.3.1"
      }
    },

...

  }

...

"autoprefixer": {
    "version": "9.6.5",
    "resolved": "https://registry.npmjs.org/autoprefixer/-/autoprefixer-9.6.5.tgz",
    "integrity": "sha512-rGd50YV8LgwFQ2WQp4XzOTG69u1qQsXn0amww7tjqV5jJuNazgFKYEVItEBngyyvVITKOg20zr2V+9VsrXJQ2g==",
    "requires": {
      "browserslist": "^4.7.0",
      "caniuse-lite": "^1.0.30000999",
      "chalk": "^2.4.2",
      "normalize-range": "^0.1.2",
      "num2fraction": "^1.2.2",
      "postcss": "^7.0.18",
      "postcss-value-parser": "^4.0.2"
    },

...

}

Uncaught Invariant Violation: Too many re-renders. React limits the number of renders to prevent an infinite loop

I suspect that the problem lies in the fact that you are calling your state setter immediately inside the function component body, which forces React to re-invoke your function again, with the same props, which ends up calling the state setter again, which triggers React to call your function again.... and so on.

const SingInContainer = ({ message, variant}) => {
    const [open, setSnackBarState] = useState(false);
    const handleClose = (reason) => {
        if (reason === 'clickaway') {
          return;
        }
        setSnackBarState(false)

      };

    if (variant) {
        setSnackBarState(true); // HERE BE DRAGONS
    }
    return (
        <div>
        <SnackBar
            open={open}
            handleClose={handleClose}
            variant={variant}
            message={message}
            />
        <SignInForm/>
        </div>
    )
}

Instead, I recommend you just conditionally set the default value for the state property using a ternary, so you end up with:

const SingInContainer = ({ message, variant}) => {
    const [open, setSnackBarState] = useState(variant ? true : false); 
                                  // or useState(!!variant); 
                                  // or useState(Boolean(variant));
    const handleClose = (reason) => {
        if (reason === 'clickaway') {
          return;
        }
        setSnackBarState(false)

      };

    return (
        <div>
        <SnackBar
            open={open}
            handleClose={handleClose}
            variant={variant}
            message={message}
            />
        <SignInForm/>
        </div>
    )
}

Comprehensive Demo

See this CodeSandbox.io demo for a comprehensive demo of it working, plus the broken component you had, and you can toggle between the two.

session not created: This version of ChromeDriver only supports Chrome version 74 error with ChromeDriver Chrome using Selenium

I encountered the same issue today and found this post and others from Google. I think I may have a more direct solution as a modification of your code. The previous answer is correct in identifying the mismatch in versions.

I tried the proposed solutions to no avail. I found that the versions were correct on my computer. However, this mismatch error was not resulting from the actual versions installed on the computer, but rather the RSelenium code is seeking the "latest" version of Chrome/ChromeDriver by default argument. See ?rsDriver() help page for the arguments.

If you run the code binman::list_versions("chromedriver") as specified in the help documentation, then you can identify the versions of compatible with the function. In my case, I was able to use the following code to establish a connection.

driver <- rsDriver(browser=c("chrome"), chromever="73.0.3683.68", extraCapabilities = eCaps)

You should be able to specify your version of Chrome with the chromever= argument. I had to use the closest version, though (my chrome version was "73.0.3683.75").

Hope this helps!

The POST method is not supported for this route. Supported methods: GET, HEAD. Laravel

I know this is not the solution to OPs post. However, this post is the first one indexed by Google when I searched for answers to this error. For this reason I feel this will benefit others.

The following error...

The POST method is not supported for this route. Supported methods: GET, HEAD.

was caused by not clearing the routing cache

php artisan route:cache

Tensorflow 2.0 - AttributeError: module 'tensorflow' has no attribute 'Session'

TF v2.0 supports Eager mode vis-a-vis Graph mode of v1.0. Hence, tf.session() is not supported on v2.0. Hence, would suggest you to rewrite your code to work in Eager mode.

react hooks useEffect() cleanup for only componentWillUnmount?

To add to the accepted answer, I had a similar issue and solved it using a similar approach with the contrived example below. In this case I needed to log some parameters on componentWillUnmount and as described in the original question I didn't want it to log every time the params changed.

const componentWillUnmount = useRef(false)

// This is componentWillUnmount
useEffect(() => {
    return () => {
        componentWillUnmount.current = true
    }
}, [])

useEffect(() => {
    return () => {
        // This line only evaluates to true after the componentWillUnmount happens 
        if (componentWillUnmount.current) {
            console.log(params)
        }
    }

}, [params]) // This dependency guarantees that when the componentWillUnmount fires it will log the latest params

How can I solve the error 'TS2532: Object is possibly 'undefined'?

With the release of TypeScript 3.7, optional chaining (the ? operator) is now officially available.

As such, you can simplify your expression to the following:

const data = change?.after?.data();

You may read more about it from that version's release notes, which cover other interesting features released on that version.

Run the following to install the latest stable release of TypeScript.

npm install typescript

That being said, Optional Chaining can be used alongside Nullish Coalescing to provide a fallback value when dealing with null or undefined values

const data = change?.after?.data() ?? someOtherData();

The iOS Simulator deployment targets is set to 7.0, but the range of supported deployment target version for this platform is 8.0 to 12.1

Instead of specifying a deployment target in pod post install, you can delete the pod deployment target, which causes the deployment target to be inherited from the podfile platform.

You may need to run pod install for the effect to take place.

platform :ios, '12.0'

  post_install do |installer|
    installer.pods_project.targets.each do |target|
      target.build_configurations.each do |config|
        config.build_settings.delete 'IPHONEOS_DEPLOYMENT_TARGET'
      end
    end
  end

How to Install pip for python 3.7 on Ubuntu 18?

The following steps can be used:


sudo apt-get -y update
---------
sudo apt-get install python3.7
--------------
 python3.7
-------------
 curl -O https://bootstrap.pypa.io/get-pip.py
-----------------
sudo apt install python3-pip
-----------------
sudo apt install python3.7-venv
-----------------
 python3.7 -m venv /home/ubuntu/app
-------------
 cd app   
----------------
 source bin/activate

Flutter Countdown Timer

Here is an example using Timer.periodic :

Countdown starts from 10 to 0 on button click :

import 'dart:async';

[...]

Timer _timer;
int _start = 10;

void startTimer() {
  const oneSec = const Duration(seconds: 1);
  _timer = new Timer.periodic(
    oneSec,
    (Timer timer) {
      if (_start == 0) {
        setState(() {
          timer.cancel();
        });
      } else {
        setState(() {
          _start--;
        });
      }
    },
  );
}

@override
void dispose() {
  _timer.cancel();
  super.dispose();
}

Widget build(BuildContext context) {
  return new Scaffold(
    appBar: AppBar(title: Text("Timer test")),
    body: Column(
      children: <Widget>[
        RaisedButton(
          onPressed: () {
            startTimer();
          },
          child: Text("start"),
        ),
        Text("$_start")
      ],
    ),
  );
}

Result :

Flutter countdown timer example

You can also use the CountdownTimer class from the quiver.async library, usage is even simpler :

import 'package:quiver/async.dart';

[...]

int _start = 10;
int _current = 10;

void startTimer() {
  CountdownTimer countDownTimer = new CountdownTimer(
    new Duration(seconds: _start),
    new Duration(seconds: 1),
  );

  var sub = countDownTimer.listen(null);
  sub.onData((duration) {
    setState(() { _current = _start - duration.elapsed.inSeconds; });
  });

  sub.onDone(() {
    print("Done");
    sub.cancel();
  });
}

Widget build(BuildContext context) {
  return new Scaffold(
    appBar: AppBar(title: Text("Timer test")),
    body: Column(
      children: <Widget>[
        RaisedButton(
          onPressed: () {
            startTimer();
          },
          child: Text("start"),
        ),
        Text("$_current")
      ],
    ),
  );
}

EDIT : For the question in comments about button click behavior

With the above code which uses Timer.periodic, a new timer will indeed be started on each button click, and all these timers will update the same _start variable, resulting in a faster decreasing counter.

There are multiple solutions to change this behavior, depending on what you want to achieve :

  • disable the button once clicked so that the user could not disturb the countdown anymore (maybe enable it back once timer is cancelled)
  • wrap the Timer.periodic creation with a non null condition so that clicking the button multiple times has no effect
if (_timer != null) {
  _timer = new Timer.periodic(...);
}
  • cancel the timer and reset the countdown if you want to restart the timer on each click :
if (_timer != null) {
  _timer.cancel();
  _start = 10;
}
_timer = new Timer.periodic(...);
  • if you want the button to act like a play/pause button :
if (_timer != null) {
  _timer.cancel();
  _timer = null;
} else {
  _timer = new Timer.periodic(...);
}

You could also use this official async package which provides a RestartableTimer class which extends from Timer and adds the reset method.

So just call _timer.reset(); on each button click.

Finally, Codepen now supports Flutter ! So here is a live example so that everyone can play with it : https://codepen.io/Yann39/pen/oNjrVOb

Python: 'ModuleNotFoundError' when trying to import module from imported package

FIRST, if you want to be able to access man1.py from man1test.py AND manModules.py from man1.py, you need to properly setup your files as packages and modules.

Packages are a way of structuring Python’s module namespace by using “dotted module names”. For example, the module name A.B designates a submodule named B in a package named A.

...

When importing the package, Python searches through the directories on sys.path looking for the package subdirectory.

The __init__.py files are required to make Python treat the directories as containing packages; this is done to prevent directories with a common name, such as string, from unintentionally hiding valid modules that occur later on the module search path.

You need to set it up to something like this:

man
|- __init__.py
|- Mans
   |- __init__.py
   |- man1.py
|- MansTest
   |- __init.__.py
   |- SoftLib
      |- Soft
         |- __init__.py
         |- SoftWork
            |- __init__.py
            |- manModules.py
      |- Unittests
         |- __init__.py
         |- man1test.py

SECOND, for the "ModuleNotFoundError: No module named 'Soft'" error caused by from ...Mans import man1 in man1test.py, the documented solution to that is to add man1.py to sys.path since Mans is outside the MansTest package. See The Module Search Path from the Python documentation. But if you don't want to modify sys.path directly, you can also modify PYTHONPATH:

sys.path is initialized from these locations:

  • The directory containing the input script (or the current directory when no file is specified).
  • PYTHONPATH (a list of directory names, with the same syntax as the shell variable PATH).
  • The installation-dependent default.

THIRD, for from ...MansTest.SoftLib import Soft which you said "was to facilitate the aforementioned import statement in man1.py", that's now how imports work. If you want to import Soft.SoftLib in man1.py, you have to setup man1.py to find Soft.SoftLib and import it there directly.

With that said, here's how I got it to work.

man1.py:

from Soft.SoftWork.manModules import *
# no change to import statement but need to add Soft to PYTHONPATH

def foo():
    print("called foo in man1.py")
    print("foo call module1 from manModules: " + module1())

man1test.py

# no need for "from ...MansTest.SoftLib import Soft" to facilitate importing..
from ...Mans import man1

man1.foo()

manModules.py

def module1():
    return "module1 in manModules"

Terminal output:

$ python3 -m man.MansTest.Unittests.man1test
Traceback (most recent call last):
  ...
    from ...Mans import man1
  File "/temp/man/Mans/man1.py", line 2, in <module>
    from Soft.SoftWork.manModules import *
ModuleNotFoundError: No module named 'Soft'

$ PYTHONPATH=$PYTHONPATH:/temp/man/MansTest/SoftLib
$ export PYTHONPATH
$ echo $PYTHONPATH
:/temp/man/MansTest/SoftLib
$ python3 -m man.MansTest.Unittests.man1test
called foo in man1.py
foo called module1 from manModules: module1 in manModules 

As a suggestion, maybe re-think the purpose of those SoftLib files. Is it some sort of "bridge" between man1.py and man1test.py? The way your files are setup right now, I don't think it's going to work as you expect it to be. Also, it's a bit confusing for the code-under-test (man1.py) to be importing stuff from under the test folder (MansTest).

How do I prevent Conda from activating the base environment by default?

To disable auto activation of conda base environment in terminal:

conda config --set auto_activate_base false

To activate conda base environment:

conda activate

JS file gets a net::ERR_ABORTED 404 (Not Found)

As mentionned in comments: you need a way to send your static files to the client. This can be achieved with a reverse proxy like Nginx, or simply using express.static().

Put all your "static" (css, js, images) files in a folder dedicated to it, different from where you put your "views" (html files in your case). I'll call it static for the example. Once it's done, add this line in your server code:

app.use("/static", express.static('./static/'));

This will effectively serve every file in your "static" folder via the /static route.

Querying your index.js file in the client thus becomes:

<script src="static/index.js"></script>

How to fix 'Unchecked runtime.lastError: The message port closed before a response was received' chrome issue?

For those coming here to debug this error in Chrome 73, one possibility is because Chrome 73 onwards disallows cross-origin requests in content scripts.

More reading:

  1. https://www.chromestatus.com/feature/5629709824032768
  2. https://www.chromium.org/Home/chromium-security/extension-content-script-fetches

This affects many Chrome extension authors, who now need to scramble to fix the extensions because Chrome thinks "Our data shows that most extensions will not be affected by this change."

(it has nothing to do with your app code)

UPDATE: I fixed the CORs issue but I still see this error. I suspect it is Chrome's fault here.

Git fatal: protocol 'https' is not supported

Just use double quotes with URL, like: git clone "https://yourRepoUrl"

(It somehow sees that you are using 2 quote marks on start, don't know why).

I was getting the same error => fatal: protocol ''https' is not supported (you can see 2 quote marks on https).

Can't perform a React state update on an unmounted component

If above solutions dont work, try this and it works for me:

componentWillUnmount() {
    // fix Warning: Can't perform a React state update on an unmounted component
    this.setState = (state,callback)=>{
        return;
    };
}

UnhandledPromiseRejectionWarning: This error originated either by throwing inside of an async function without a catch block

.catch(error => { throw error}) is a no-op. It results in unhandled rejection in route handler.

As explained in this answer, Express doesn't support promises, all rejections should be handled manually:

router.get("/emailfetch", authCheck, async (req, res, next) => {
  try {
  //listing messages in users mailbox 
    let emailFetch = await gmaiLHelper.getEmails(req.user._doc.profile_id , '/messages', req.user.accessToken)
    emailFetch = emailFetch.data
    res.send(emailFetch)
  } catch (err) {
    next(err);
  }
})

React hooks useState Array

To expand on Ryan's answer:

Whenever setStateValues is called, React re-renders your component, which means that the function body of the StateSelector component function gets re-executed.

React docs:

setState() will always lead to a re-render unless shouldComponentUpdate() returns false.

Essentially, you're setting state with:

setStateValues(allowedState);

causing a re-render, which then causes the function to execute, and so on. Hence, the loop issue.

To illustrate the point, if you set a timeout as like:

  setTimeout(
    () => setStateValues(allowedState),
    1000
  )

Which ends the 'too many re-renders' issue.

In your case, you're dealing with a side-effect, which is handled with UseEffectin your component functions. You can read more about it here.

HTTP Error 500.30 - ANCM In-Process Start Failure

HTTP Error 500.30 – ANCM In-Process Start Failure” is moreover a generic error. To know more information about the error

Go to Azure Portal > your App Service > under development tools open console. We can run the application through this console and thus visualize the real error that is causing our application not to load.

For that put, the name of our project followed by “.exe” and press the enter key.

Android Gradle 5.0 Update:Cause: org.jetbrains.plugins.gradle.tooling.util

The easiest way I've found is delete Android Studio from the applications folder, then download & install it again.

FlutterError: Unable to load asset

Flutter uses the pubspec.yaml file, located at the root of your project, to identify assets required by an app.

Here is an example:

flutter:
  assets:
    - assets/my_icon.png
    - assets/background.png

To include all assets under a directory, specify the directory name with the / character at the end:

flutter:
  assets:
    - directory/
    - directory/subdirectory/

For more info, see https://flutter.dev/docs/development/ui/assets-and-images

Pandas Merging 101

This post aims to give readers a primer on SQL-flavored merging with pandas, how to use it, and when not to use it.

In particular, here's what this post will go through:

  • The basics - types of joins (LEFT, RIGHT, OUTER, INNER)

    • merging with different column names
    • merging with multiple columns
    • avoiding duplicate merge key column in output

What this post (and other posts by me on this thread) will not go through:

  • Performance-related discussions and timings (for now). Mostly notable mentions of better alternatives, wherever appropriate.
  • Handling suffixes, removing extra columns, renaming outputs, and other specific use cases. There are other (read: better) posts that deal with that, so figure it out!

Note
Most examples default to INNER JOIN operations while demonstrating various features, unless otherwise specified.

Furthermore, all the DataFrames here can be copied and replicated so you can play with them. Also, see this post on how to read DataFrames from your clipboard.

Lastly, all visual representation of JOIN operations have been hand-drawn using Google Drawings. Inspiration from here.



Enough Talk, just show me how to use merge!

Setup & Basics

np.random.seed(0)
left = pd.DataFrame({'key': ['A', 'B', 'C', 'D'], 'value': np.random.randn(4)})    
right = pd.DataFrame({'key': ['B', 'D', 'E', 'F'], 'value': np.random.randn(4)})
  
left

  key     value
0   A  1.764052
1   B  0.400157
2   C  0.978738
3   D  2.240893

right

  key     value
0   B  1.867558
1   D -0.977278
2   E  0.950088
3   F -0.151357

For the sake of simplicity, the key column has the same name (for now).

An INNER JOIN is represented by

Note
This, along with the forthcoming figures all follow this convention:

  • blue indicates rows that are present in the merge result
  • red indicates rows that are excluded from the result (i.e., removed)
  • green indicates missing values that are replaced with NaNs in the result

To perform an INNER JOIN, call merge on the left DataFrame, specifying the right DataFrame and the join key (at the very least) as arguments.

left.merge(right, on='key')
# Or, if you want to be explicit
# left.merge(right, on='key', how='inner')

  key   value_x   value_y
0   B  0.400157  1.867558
1   D  2.240893 -0.977278

This returns only rows from left and right which share a common key (in this example, "B" and "D).

A LEFT OUTER JOIN, or LEFT JOIN is represented by

This can be performed by specifying how='left'.

left.merge(right, on='key', how='left')

  key   value_x   value_y
0   A  1.764052       NaN
1   B  0.400157  1.867558
2   C  0.978738       NaN
3   D  2.240893 -0.977278

Carefully note the placement of NaNs here. If you specify how='left', then only keys from left are used, and missing data from right is replaced by NaN.

And similarly, for a RIGHT OUTER JOIN, or RIGHT JOIN which is...

...specify how='right':

left.merge(right, on='key', how='right')

  key   value_x   value_y
0   B  0.400157  1.867558
1   D  2.240893 -0.977278
2   E       NaN  0.950088
3   F       NaN -0.151357

Here, keys from right are used, and missing data from left is replaced by NaN.

Finally, for the FULL OUTER JOIN, given by

specify how='outer'.

left.merge(right, on='key', how='outer')

  key   value_x   value_y
0   A  1.764052       NaN
1   B  0.400157  1.867558
2   C  0.978738       NaN
3   D  2.240893 -0.977278
4   E       NaN  0.950088
5   F       NaN -0.151357

This uses the keys from both frames, and NaNs are inserted for missing rows in both.

The documentation summarizes these various merges nicely:

enter image description here


Other JOINs - LEFT-Excluding, RIGHT-Excluding, and FULL-Excluding/ANTI JOINs

If you need LEFT-Excluding JOINs and RIGHT-Excluding JOINs in two steps.

For LEFT-Excluding JOIN, represented as

Start by performing a LEFT OUTER JOIN and then filtering (excluding!) rows coming from left only,

(left.merge(right, on='key', how='left', indicator=True)
     .query('_merge == "left_only"')
     .drop('_merge', 1))

  key   value_x  value_y
0   A  1.764052      NaN
2   C  0.978738      NaN

Where,

left.merge(right, on='key', how='left', indicator=True)

  key   value_x   value_y     _merge
0   A  1.764052       NaN  left_only
1   B  0.400157  1.867558       both
2   C  0.978738       NaN  left_only
3   D  2.240893 -0.977278       both

And similarly, for a RIGHT-Excluding JOIN,

(left.merge(right, on='key', how='right', indicator=True)
     .query('_merge == "right_only"')
     .drop('_merge', 1))

  key  value_x   value_y
2   E      NaN  0.950088
3   F      NaN -0.151357

Lastly, if you are required to do a merge that only retains keys from the left or right, but not both (IOW, performing an ANTI-JOIN),

You can do this in similar fashion—

(left.merge(right, on='key', how='outer', indicator=True)
     .query('_merge != "both"')
     .drop('_merge', 1))

  key   value_x   value_y
0   A  1.764052       NaN
2   C  0.978738       NaN
4   E       NaN  0.950088
5   F       NaN -0.151357

Different names for key columns

If the key columns are named differently—for example, left has keyLeft, and right has keyRight instead of key—then you will have to specify left_on and right_on as arguments instead of on:

left2 = left.rename({'key':'keyLeft'}, axis=1)
right2 = right.rename({'key':'keyRight'}, axis=1)

left2
 
  keyLeft     value
0       A  1.764052
1       B  0.400157
2       C  0.978738
3       D  2.240893

right2

  keyRight     value
0        B  1.867558
1        D -0.977278
2        E  0.950088
3        F -0.151357
left2.merge(right2, left_on='keyLeft', right_on='keyRight', how='inner')

  keyLeft   value_x keyRight   value_y
0       B  0.400157        B  1.867558
1       D  2.240893        D -0.977278

Avoiding duplicate key column in output

When merging on keyLeft from left and keyRight from right, if you only want either of the keyLeft or keyRight (but not both) in the output, you can start by setting the index as a preliminary step.

left3 = left2.set_index('keyLeft')
left3.merge(right2, left_index=True, right_on='keyRight')
    
    value_x keyRight   value_y
0  0.400157        B  1.867558
1  2.240893        D -0.977278

Contrast this with the output of the command just before (that is, the output of left2.merge(right2, left_on='keyLeft', right_on='keyRight', how='inner')), you'll notice keyLeft is missing. You can figure out what column to keep based on which frame's index is set as the key. This may matter when, say, performing some OUTER JOIN operation.


Merging only a single column from one of the DataFrames

For example, consider

right3 = right.assign(newcol=np.arange(len(right)))
right3
  key     value  newcol
0   B  1.867558       0
1   D -0.977278       1
2   E  0.950088       2
3   F -0.151357       3

If you are required to merge only "new_val" (without any of the other columns), you can usually just subset columns before merging:

left.merge(right3[['key', 'newcol']], on='key')

  key     value  newcol
0   B  0.400157       0
1   D  2.240893       1

If you're doing a LEFT OUTER JOIN, a more performant solution would involve map:

# left['newcol'] = left['key'].map(right3.set_index('key')['newcol']))
left.assign(newcol=left['key'].map(right3.set_index('key')['newcol']))

  key     value  newcol
0   A  1.764052     NaN
1   B  0.400157     0.0
2   C  0.978738     NaN
3   D  2.240893     1.0

As mentioned, this is similar to, but faster than

left.merge(right3[['key', 'newcol']], on='key', how='left')

  key     value  newcol
0   A  1.764052     NaN
1   B  0.400157     0.0
2   C  0.978738     NaN
3   D  2.240893     1.0

Merging on multiple columns

To join on more than one column, specify a list for on (or left_on and right_on, as appropriate).

left.merge(right, on=['key1', 'key2'] ...)

Or, in the event the names are different,

left.merge(right, left_on=['lkey1', 'lkey2'], right_on=['rkey1', 'rkey2'])

Other useful merge* operations and functions

This section only covers the very basics, and is designed to only whet your appetite. For more examples and cases, see the documentation on merge, join, and concat as well as the links to the function specs.



Continue Reading

Jump to other topics in Pandas Merging 101 to continue learning:

* you are here

Why is 2 * (i * i) faster than 2 * i * i in Java?

I got similar results:

2 * (i * i): 0.458765943 s, n=119860736
2 * i * i: 0.580255126 s, n=119860736

I got the SAME results if both loops were in the same program, or each was in a separate .java file/.class, executed on a separate run.

Finally, here is a javap -c -v <.java> decompile of each:

     3: ldc           #3                  // String 2 * (i * i):
     5: invokevirtual #4                  // Method java/io/PrintStream.print:(Ljava/lang/String;)V
     8: invokestatic  #5                  // Method java/lang/System.nanoTime:()J
     8: invokestatic  #5                  // Method java/lang/System.nanoTime:()J
    11: lstore_1
    12: iconst_0
    13: istore_3
    14: iconst_0
    15: istore        4
    17: iload         4
    19: ldc           #6                  // int 1000000000
    21: if_icmpge     40
    24: iload_3
    25: iconst_2
    26: iload         4
    28: iload         4
    30: imul
    31: imul
    32: iadd
    33: istore_3
    34: iinc          4, 1
    37: goto          17

vs.

     3: ldc           #3                  // String 2 * i * i:
     5: invokevirtual #4                  // Method java/io/PrintStream.print:(Ljava/lang/String;)V
     8: invokestatic  #5                  // Method java/lang/System.nanoTime:()J
    11: lstore_1
    12: iconst_0
    13: istore_3
    14: iconst_0
    15: istore        4
    17: iload         4
    19: ldc           #6                  // int 1000000000
    21: if_icmpge     40
    24: iload_3
    25: iconst_2
    26: iload         4
    28: imul
    29: iload         4
    31: imul
    32: iadd
    33: istore_3
    34: iinc          4, 1
    37: goto          17

FYI -

java -version
java version "1.8.0_121"
Java(TM) SE Runtime Environment (build 1.8.0_121-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.121-b13, mixed mode)

How to compare oldValues and newValues on React Hooks useEffect?

In your case(simple object):

useEffect(()=>{
  // your logic
}, [rate, sendAmount, receiveAmount])

In other case(complex object)

const {cityInfo} = props;
useEffect(()=>{
  // some logic
}, [cityInfo.cityId])

Has been blocked by CORS policy: Response to preflight request doesn’t pass access control check

This answer explains what's going on behind the scenes, and the basics of how to solve this problem in any language. For reference, see the MDN docs on this topic.

You are making a request for a URL from JavaScript running on one domain (say domain-a.com) to an API running on another domain (domain-b.com). When you do that, the browser has to ask domain-b.com if it's okay to allow requests from domain-a.com. It does that with an HTTP OPTIONS request. Then, in the response, the server on domain-b.com has to give (at least) the following HTTP headers that say "Yeah, that's okay":

HTTP/1.1 204 No Content                            // or 200 OK
Access-Control-Allow-Origin: https://domain-a.com  // or * for allowing anybody
Access-Control-Allow-Methods: POST, GET, OPTIONS   // What kind of methods are allowed
...                                                // other headers

If you're in Chrome, you can see what the response looks like by pressing F12 and going to the "Network" tab to see the response the server on domain-b.com is giving.

So, back to the bare minimum from @threeve's original answer:

header := w.Header()
header.Add("Access-Control-Allow-Origin", "*")

if r.Method == "OPTIONS" {
    w.WriteHeader(http.StatusOK)
    return
}

This will allow anybody from anywhere to access this data. The other headers he's included are necessary for other reasons, but these headers are the bare minimum to get past the CORS (Cross Origin Resource Sharing) requirements.

Xcode 10.2.1 Command PhaseScriptExecution failed with a nonzero exit code

Xcode 12.2 solution: Go to:

  1. Build settings -> Excluded Architectures
  2. Delete "arm64"

What is the meaning of "Failed building wheel for X" in pip install?

This may Help you ! ....

Uninstalling pycparser:

pip uninstall pycparser

Reinstall pycparser:

pip install pycparser

I got same error while installing termcolor and I fixed it by reinstalling it .

Set the space between Elements in Row Flutter

Just add "Container(width: 5, color: Colors.transparent)," between elements

new Container(
      alignment: FractionalOffset.center,
      child: new Row(
        mainAxisAlignment: MainAxisAlignment.spaceEvenly,
        children: <Widget>[
          new FlatButton(
            child: new Text('Don\'t have an account?', style: new TextStyle(color: Color(0xFF2E3233))),
          ),
            Container(width: 5, color: Colors.transparent),
          new FlatButton(
            child: new Text('Register.', style: new TextStyle(color: Color(0xFF84A2AF), fontWeight: FontWeight.bold),),
            onPressed: moveToRegister,
          )
        ],
      ),
    ),  

Selenium: WebDriverException:Chrome failed to start: crashed as google-chrome is no longer running so ChromeDriver is assuming that Chrome has crashed

Make sure that both the chromedriver and google-chrome executable have execute permissions

sudo chmod -x "/usr/bin/chromedriver"

sudo chmod -x "/usr/bin/google-chrome"

expected assignment or function call: no-unused-expressions ReactJS

In my case it is happened due to curly braces of function if you use jsx then you need to change curly braces to Parentheses, see below code

const [countries] = useState(["USA", "UK", "BD"])

I tried this but not work, don't know why

 {countries.map((country) => {
        <MenuItem value={country}>{country}</MenuItem>
  })}

But when I change Curly Braces to parentheses and Its working fine for me

  {countries.map((country) => ( //Changes is here instead of {
        <MenuItem value={country}>{country}</MenuItem>
  ))} //and here instead of }
             

Hopefully it will help you too...

Could not install packages due to an EnvironmentError: [Errno 13]

I already tried all suggestion posted in here, yet I'm still getting the errno 13,

I'm using Windows and my python version is 3.7.3

After 5 hours of trying to solve it, this step worked for me:

I try to open the command prompt by run as administrator

Flutter: RenderBox was not laid out

Wrap your ListView in an Expanded widget

 Expanded(child:MyListView())

WebView showing ERR_CLEARTEXT_NOT_PERMITTED although site is HTTPS

Solution:

Add the below line in your application tag:

android:usesCleartextTraffic="true"

As shown below:

<application
    ....
    android:usesCleartextTraffic="true"
    ....>

UPDATE: If you have network security config such as: android:networkSecurityConfig="@xml/network_security_config"

No Need to set clear text traffic to true as shown above, instead use the below code:

<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <domain-config cleartextTrafficPermitted="true">
        ....
        ....
    </domain-config>

    <base-config cleartextTrafficPermitted="false"/>
</network-security-config>  

Set the cleartextTrafficPermitted to true

Hope it helps.

OpenCV !_src.empty() in function 'cvtColor' error

I had the same problem and it turned out that my image names included special characters (e.g. château.jpg), which could not bet handled by cv2.imread. My solution was to make a temporary copy of the file, renaming it e.g. temp.jpg, which could be loaded by cv2.imread without any problems.

Note: I did not check the performance of shutil.copy2 vice versa other options. So probably there is a better/faster solution to make a temporary copy.

import shutil, sys, os, dlib, glob, cv2

for f in glob.glob(os.path.join(myfolder_path, "*.jpg")):
    shutil.copy2(f, myfolder_path + 'temp.jpg')
    img = cv2.imread(myfolder_path + 'temp.jpg')
    img = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)
    os.remove(myfolder_path + 'temp.jpg')

If there are only few files with special characters, renaming can also be done as an exeption, e.g.

for f in glob.glob(os.path.join(myfolder_path, "*.jpg")):
    try:
        img = cv2.imread(f)
        img = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)
    except:
        shutil.copy2(f, myfolder_path + 'temp.jpg')
        img = cv2.imread(myfolder_path + 'temp.jpg')
        img = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)
        os.remove(myfolder_path + 'temp.jpg')

pod has unbound PersistentVolumeClaims

You have to define a PersistentVolume providing disc space to be consumed by the PersistentVolumeClaim.

When using storageClass Kubernetes is going to enable "Dynamic Volume Provisioning" which is not working with the local file system.


To solve your issue:

  • Provide a PersistentVolume fulfilling the constraints of the claim (a size >= 100Mi)
  • Remove the storageClass-line from the PersistentVolumeClaim
  • Remove the StorageClass from your cluster

How do these pieces play together?

At creation of the deployment state-description it is usually known which kind (amount, speed, ...) of storage that application will need.
To make a deployment versatile you'd like to avoid a hard dependency on storage. Kubernetes' volume-abstraction allows you to provide and consume storage in a standardized way.

The PersistentVolumeClaim is used to provide a storage-constraint alongside the deployment of an application.

The PersistentVolume offers cluster-wide volume-instances ready to be consumed ("bound"). One PersistentVolume will be bound to one claim. But since multiple instances of that claim may be run on multiple nodes, that volume may be accessed by multiple nodes.

A PersistentVolume without StorageClass is considered to be static.

"Dynamic Volume Provisioning" alongside with a StorageClass allows the cluster to provision PersistentVolumes on demand. In order to make that work, the given storage provider must support provisioning - this allows the cluster to request the provisioning of a "new" PersistentVolume when an unsatisfied PersistentVolumeClaim pops up.


Example PersistentVolume

In order to find how to specify things you're best advised to take a look at the API for your Kubernetes version, so the following example is build from the API-Reference of K8S 1.17:

apiVersion: v1
kind: PersistentVolume
metadata:
  name: ckan-pv-home
  labels:
    type: local
spec:
  capacity:
    storage: 100Mi
  hostPath:
    path: "/mnt/data/ckan"

The PersistentVolumeSpec allows us to define multiple attributes. I chose a hostPath volume which maps a local directory as content for the volume. The capacity allows the resource scheduler to recognize this volume as applicable in terms of resource needs.


Additional Resources:

Post request in Laravel - Error - 419 Sorry, your session/ 419 your page has expired

It should work if you try all of these steps:

  1. Ensure that your session is well configured, the easiest way is to make it file and make sure storage folder has chmod 755 permission then in your .env you set it like below, file session driver is the easiest way to set.

    SESSION_DRIVER=file
    SESSION_DOMAIN=
    SESSION_SECURE_COOKIE=false
    
  2. Ensure Cache folder is cleared and writable, you can do this by running below artisan command.

    php artisan cache:clear
    
  3. Ensure folder permissions are well set, they should be configured like below:

    sudo chmod -R 755 storage
    sudo chmod -R 755 vendor
    sudo chmod -R 644 bootstrap/cache
    
  4. Ensure your form has @csrf token included.

Hope this will solve your problem.

How to install OpenJDK 11 on Windows?

Use the Chocolatey packet manager. It's a command-line tool similar to npm. Once you have installed it, use

choco install openjdk

in an elevated command prompt to install OpenJDK.

To update an installed version to the latest version, type

choco upgrade openjdk

Pretty simple to use and especially helpful to upgrade to the latest version. No manual fiddling with path environment variables.

Can't compile C program on a Mac after upgrade to Mojave

@JL Peyret is right!

if you macos 10.14.6 Mojave, Xcode 11.0+

then

cd /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs

sudo ln -s MacOSX.sdk/ MacOSX10.14.sdk

WARNING: API 'variant.getJavaCompile()' is obsolete and has been replaced with 'variant.getJavaCompileProvider()'

Go back from classpath 'com.android.tools.build:gradle:3.3.0-alpha13' to classpath 'com.android.tools.build:gradle:3.2.0'

this worked for me

Objects are not valid as a React child. If you meant to render a collection of children, use an array instead

Had the same error but with a different scenario. I had my state as

        this.state = {
        date: new Date()
    }

so when I was asking it in my Class Component I had

p>Date = {this.state.date}</p>

Instead of

p>Date = {this.state.date.toLocaleDateString()}</p>

Xcode 10, Command CodeSign failed with a nonzero exit code

My Problem was solved

  • Check Automatically manage signing on Target MyProject and Add Team.
  • Check Automatically manage signing on Target MyProjectTest and Add Team.
  • Product -> Clean Build Folder -> Build again or try to run on device.

The problem occurs when you have the wrong/different team on MyProject and MyProjectTest.

Reconnecting your phone prior to rebuilding may also assist with fixing this issue.

Jenkins pipeline how to change to another folder

The dir wrapper can wrap, any other step, and it all works inside a steps block, for example:

steps {
    sh "pwd"
    dir('your-sub-directory') {
      sh "pwd"
    }
    sh "pwd"
} 

System has not been booted with systemd as init system (PID 1). Can't operate

Instead of using

sudo systemctl start redis

use:

sudo /etc/init.d/redis start

as of right now we do not have systemd in WSL

DeprecationWarning: Buffer() is deprecated due to security and usability issues when I move my script to another server

var userPasswordString = new Buffer(baseAuth, 'base64').toString('ascii');

Change this line from your code to this -

var userPasswordString = Buffer.from(baseAuth, 'base64').toString('ascii');

or in my case, I gave the encoding in reverse order

var userPasswordString = Buffer.from(baseAuth, 'utf-8').toString('base64');

Flutter - The method was called on null

The reason for this error occurs is that you are using the CryptoListPresenter _presenter without initializing.

I found that CryptoListPresenter _presenter would have to be initialized to fix because _presenter.loadCurrencies() is passing through a null variable at the time of instantiation;

there are two ways to initialize

  1. Can be initialized during an declaration, like this

    CryptoListPresenter _presenter = CryptoListPresenter();
    
  2. In the second, initializing(with assigning some value) it when initState is called, which the framework will call this method once for each state object.

    @override
    void initState() {
      _presenter = CryptoListPresenter(...);
    }
    

Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'

Changed my application.conf file as below. It solved the problem.

Before Change:

slick {
  dbs {
    default {
      profile = "slick.jdbc.MySQLProfile$"
      db {
        driver = "com.mysql.jdbc.Driver"
        url = "jdbc:mysql://localhost:3306/test"
        user = "root"
        password = "root"
      }
    }
  }
}

After Change:

slick {
  dbs {
    default {
      profile = "slick.jdbc.MySQLProfile$"
      db {
        driver = "com.mysql.cj.jdbc.Driver"
        url = "jdbc:mysql://localhost:3306/test"
        user = "root"
        password = "root"
      }
    }
  }
}

Could not install packages due to an EnvironmentError: [WinError 5] Access is denied:

To Install tensorflow use this command including --User.

pip install --ignore-installed --upgrade --user tensorflow==2.0.1

Here 2.0.1 is the version of tensorflow.

How do I install opencv using pip?

run the following command by creating a virtual enviroment using python 3 and run

pip3 install opencv-python

to check it has installed correctly run

python3 -c "import cv2"

Android Material and appcompat Manifest merger failed

This issue mainly happened for old dependencies.

There have 2 solution:

First one:

Update all old dependencies and ClassPaths from Project level gradle files.

classpath 'com.android.tools.build:gradle:3.3.1'
classpath 'com.google.gms:google-services:4.2.0'

Second one:

Your project Migrate to AndroidX

From Android Studio Menu -> Refanctor -> Migrate to AndroidX

Thanks, let me know if anyone help from this answer.

How to scroll page in flutter

You can try CustomScrollView. Put your CustomScrollView inside Column Widget.

Just for example -

class App extends StatelessWidget {

 App({Key key}): super(key: key);

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: AppBar(
          title: const Text('AppBar'),
      ),
      body: new Container(
          constraints: BoxConstraints.expand(),
          decoration: new BoxDecoration(
            image: new DecorationImage(
              alignment: Alignment.topLeft,
              image: new AssetImage('images/main-bg.png'),
              fit: BoxFit.cover,
            )
          ),
          child: new Column(
            children: <Widget>[               
              Expanded(
                child: new CustomScrollView(
                  scrollDirection: Axis.vertical,
                  shrinkWrap: false,
                  slivers: <Widget>[
                    new SliverPadding(
                      padding: const EdgeInsets.symmetric(vertical: 0.0),
                      sliver: new SliverList(
                        delegate: new SliverChildBuilderDelegate(
                          (context, index) => new YourRowWidget(),
                          childCount: 5,
                        ),
                      ),
                    ),
                  ],
                ),
              ),
            ],
          )),
    );
  }
}

In above code I am displaying a list of items ( total 5) in CustomScrollView. YourRowWidget widget gets rendered 5 times as list item. Generally you should render each row based on some data.

You can remove decoration property of Container widget, it is just for providing background image.

Waiting for another flutter command to release the startup lock

Nothing of ALL these answers didn't helped me.

The only one solution was to remove whole flutter stuff (and reinstall flutter from git):

<flutter directory>
<user>/.flutter_tool_state
<user>/.dart
<user>/.pub-cache
<user>/.dartServer
<user>/.flutter

Under which circumstances textAlign property works in Flutter?

textAlign property only works when there is a more space left for the Text's content. Below are 2 examples which shows when textAlign has impact and when not.


No impact

For instance, in this example, it won't have any impact because there is no extra space for the content of the Text.

Text(
  "Hello",
  textAlign: TextAlign.end, // no impact
),

enter image description here


Has impact

If you wrap it in a Container and provide extra width such that it has more extra space.

Container(
  width: 200,
  color: Colors.orange,
  child: Text(
    "Hello",
    textAlign: TextAlign.end, // has impact
  ),
)

enter image description here

Deprecated Gradle features were used in this build, making it incompatible with Gradle 5.0

The process below worked in my case- First check Gradle Version:

cd android
./gradlew -v

In my case it was 6.5

Go to https://developer.android.com/studio/releases/gradle-plugin and you'll get the plugin version for your gradle version. For gradle version 6.5, the plugin version is 4.1.0

Then go to app/build.gradle and change classpath 'com.android.tools.build:gradle:<plugin_version>

Confirm password validation in Angular 6

The simplest way imo:

(It can also be used with emails for example)

public static matchValues(
    matchTo: string // name of the control to match to
  ): (AbstractControl) => ValidationErrors | null {
    return (control: AbstractControl): ValidationErrors | null => {
      return !!control.parent &&
        !!control.parent.value &&
        control.value === control.parent.controls[matchTo].value
        ? null
        : { isMatching: false };
    };
}

In your Component:

this.SignUpForm = this.formBuilder.group({

password: [undefined, [Validators.required]],
passwordConfirm: [undefined, 
        [
          Validators.required,
          matchValues('password'),
        ],
      ],
});

Follow up:

As others pointed out in the comments, if you fix the error by fixing the password field the error won't go away, Because the validation triggers on passwordConfirm input. This can be fixed by a number of ways. I think the best is:

this.SignUpForm .controls.password.valueChanges.subscribe(() => {
  this.SignUpForm .controls.confirmPassword.updateValueAndValidity();
});

On password change, revliadte confirmPassword.

Angular 6: saving data to local storage

you can use localStorage for storing the json data:

the example is given below:-

let JSONDatas = [
    {"id": "Open"},
    {"id": "OpenNew", "label": "Open New"},
    {"id": "ZoomIn", "label": "Zoom In"},
    {"id": "ZoomOut", "label": "Zoom Out"},
    {"id": "Find", "label": "Find..."},
    {"id": "FindAgain", "label": "Find Again"},
    {"id": "Copy"},
    {"id": "CopyAgain", "label": "Copy Again"},
    {"id": "CopySVG", "label": "Copy SVG"},
    {"id": "ViewSVG", "label": "View SVG"}
]

localStorage.setItem("datas", JSON.stringify(JSONDatas));

let data = JSON.parse(localStorage.getItem("datas"));

console.log(data);

standard_init_linux.go:190: exec user process caused "no such file or directory" - Docker

in my case I had to change line ending from CRLF to LF for the run.sh file and the error was gone.

I hope this helps,
Kirsten

How to use mouseover and mouseout in Angular 6

In HTML:

<div (mouseover)="funcName1() (mouseout)="funcName2()">
   // Do what you want 
</div>

In TypeScript:

funcName1(){
 //Do Something
}
funcName2(){
//Do Something
}

git clone: Authentication failed for <URL>

The culprit was russian account password.

Accidentally set up it (wrong keyboard layout). Everything was working, so didnt bother changing it.

Out of despair changed it now and it worked.

If someone looked up this thread and its not a solution for you - check out comments under the question and steps i described in question, they might be useful to you.

How do I install the Nuget provider for PowerShell on a unconnected machine so I can install a nuget package from the PS command line?

Try this:

[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12

Install-PackageProvider NuGet -Force

Set-PSRepository PSGallery -InstallationPolicy Trusted

Xcode couldn't find any provisioning profiles matching

I opened XCode -> Preferences -> Accounts and clicked on Download certificate. That fixed my problem

Couldn't process file resx due to its being in the Internet or Restricted zone or having the mark of the web on the file

I had this issue on resx files in my solution. I'm using Onedrive. However none of the above solutions fixed it.

The problem was the icon I used was in the MyWindow.resx files for the windows.

I removed that then grabbed the icon from the App Local Resources resource folder.

 private ResourceManager rm = App_LocalResources.LocalResources.ResourceManager;
 
 ..
 
InitializeComponent();
this.Icon = (Icon)rm.GetObject("IconName");

This happened after an update to VS2019.

What is AndroidX?

Based on the documentation:

androidx is new package structure to make it clearer which packages are bundled with the Android operating system, and which are packaged with your app's APK. Going forward, the android.* package hierarchy will be reserved for Android packages that ship with the operating system; other packages will be issued in the new androidx.* package hierarchy.

The re-designed package structure is to encourage smaller and more focused libraries. You find details regarding the artifact mappings here.

There are support libraries (containing component and packages for backward compatibility) named "v7" when the minimal SDK level supported is 14, the new naming makes it clear to understand the division between APIs bundled with platform and the libraries for app developers which are used on different versions of Android. You can refer to official announcement for more details.

How to resolve TypeError: can only concatenate str (not "int") to str

Use f-strings to resolve the TypeError

# the following line causes a TypeError
# test = 'Here is a test that can be run' + 15 + 'times'

# same intent with a f-string
i = 15

test = f'Here is a test that can be run {i} times'

print(test)

# output
'Here is a test that can be run 15 times'
i = 15
# t = 'test' + i  # will cause a TypeError

# should be
t = f'test{i}'

print(t)

# output
'test15'
  • The issue may be attempting to evaluate an expression where a variable is the string of a numeric.
  • Convert the string to an int.
  • This scenario is specific to this question
  • When iterating, it's important to be aware of the dtype
i = '15'
# t = 15 + i  # will cause a TypeError

# convert the string to int
t = 15 + int(i)
print(t)

# output
30

Note

  • The preceding part of the answer addresses the TypeError shown in the question title, which is why people seem to be coming to this question.
  • However, this doesn't resolve the issue in relation to the example provided by the OP, which is addressed below.

Original Code Issues

  • TypeError is caused because message type is a str.
  • The code iterates each character and attempts to add char, a str type, to an int
  • That issue can be resolved by converting char to an int
  • As the code is presented, secret_string needs to be initialized with 0 instead of "".
  • The code also results in a ValueError: chr() arg not in range(0x110000) because 7429146 is out of range for chr().
  • Resolved by using a smaller number
  • The output is not a string, as was intended, which leads to the Updated Code in the question.
message = input("Enter a message you want to be revealed: ")

secret_string = 0

for char in message:
    char = int(char)
    value = char + 742146
    secret_string += ord(chr(value))
    
print(f'\nRevealed: {secret_string}')

# Output
Enter a message you want to be revealed:  999

Revealed: 2226465

Updated Code Issues

  • message is now an int type, so for char in message: causes TypeError: 'int' object is not iterable
  • message is converted to int to make sure the input is an int.
  • Set the type with str()
  • Only convert value to Unicode with chr
  • Don't use ord
while True:
    try:
        message = str(int(input("Enter a message you want to be decrypt: ")))
        break
    except ValueError:
        print("Error, it must be an integer")
        
secret_string = ""
for char in message:
    
    value = int(char) + 10000
    
    secret_string += chr(value)

print("Decrypted", secret_string)

# output
Enter a message you want to be decrypt:  999
Decrypted ???

Enter a message you want to be decrypt:  100
Decrypted ???

ADB.exe is obsolete and has serious performance problems

17-01-2019

This works for me. Just opened Android SDK Manager Then it showed 4 Updates Available. So I just Updated it and No more above warning.

enter image description here

FirebaseInstanceIdService is deprecated

And this:

FirebaseInstanceId.getInstance().getInstanceId().getResult().getToken()

suppose to be solution of deprecated:

FirebaseInstanceId.getInstance().getToken()

EDIT

FirebaseInstanceId.getInstance().getInstanceId().getResult().getToken() can produce exception if the task is not yet completed, so the method witch Nilesh Rathod described (with .addOnSuccessListener) is correct way to do it.

Kotlin:

FirebaseInstanceId.getInstance().instanceId.addOnSuccessListener(this) { instanceIdResult ->
        val newToken = instanceIdResult.token
        Log.e("newToken", newToken)
    }

Uncaught SyntaxError: Unexpected end of JSON input at JSON.parse (<anonymous>)

Remove this line from your code:

console.info(JSON.parse(scatterSeries));

Everytime I run gulp anything, I get a assertion error. - Task function must be specified

The problem is that you are using gulp 4 and the syntax in gulfile.js is of gulp 3. So either downgrade your gulp to 3.x.x or make use of gulp 4 syntaxes.

Syntax Gulp 3:

gulp.task('default', ['sass'], function() {....} );

Syntax Gulp 4:

gulp.task('default', gulp.series(sass), function() {....} );

You can read more about gulp and gulp tasks on: https://medium.com/@sudoanushil/how-to-write-gulp-tasks-ce1b1b7a7e81

installation app blocked by play protect

Not the solution, but you can use debug key for signing release builds to avoid blocking the installation from Google Play Protect. It looks like Play Protect doesn't warn for builds signed with automatically generated debug.keystore.

Note that your debug builds are not unsigned, they are just signed with a debug key.

Of course, you cannot use the build for production distribution (Google Play, Amazon, etc.), but it's still worth for pre-production internal testing which requires a high-frequency feedback loop.

You can add a task to build release with debug.keystore by adding the configuration in build.gradle, something like:

android {
  buildTypes {
    // add after the `release` definition
    releaseDebugKey { initWith release }
  }

  signingConfigs {
    // use debug.keystore for releaseDebugKey builds
    releaseDebugKey { initWith debug }
  }
}

then execute ./gradlew assembleReleaseDebugKey to build a release build with debug key.

Handling back button in Android Navigation Component

A little late to the party, but with the latest release of Navigation Component 1.0.0-alpha09, now we have an AppBarConfiguration.OnNavigateUpListener.

Refer to these links for more information: https://developer.android.com/reference/androidx/navigation/ui/AppBarConfiguration.OnNavigateUpListener https://developer.android.com/jetpack/docs/release-notes

Flask at first run: Do not use the development server in a production environment

If for some people (like me earlier) the above answers don't work, I think the following answer would work (for Mac users I think) Enter the following commands to do flask run

$ export FLASK_APP = hello.py
$ export FLASK_ENV = development
$ flask run

Alternatively you can do the following (I haven't tried this but one resource online talks about it)

$ export FLASK_APP = hello.py
$ python -m flask run

source: For more

Enable CORS in fetch api

Browser have cross domain security at client side which verify that server allowed to fetch data from your domain. If Access-Control-Allow-Origin not available in response header, browser disallow to use response in your JavaScript code and throw exception at network level. You need to configure cors at your server side.

You can fetch request using mode: 'cors'. In this situation browser will not throw execption for cross domain, but browser will not give response in your javascript function.

So in both condition you need to configure cors in your server or you need to use custom proxy server.

Google Maps shows "For development purposes only"

If you want a free simple location map showing a single marked location, for your website, Then

  • Go to AddMap.
  • Here you can fill details to fully customize your map like location details, sizing and formatting of map.
  • Finally to add google map api key, Generate it using this method.

Let me know If this would help..

Pytesseract : "TesseractNotFound Error: tesseract is not installed or it's not in your path", how do I fix this?

In windows:

pip install tesseract

pip install tesseract-ocr

and check the file which is stored in your system usr/appdata/local/programs/site-pakages/python/python36/lib/pytesseract/pytesseract.py file and compile the file

Axios having CORS issue

CORS issue can be simply resolved by following this:

Create a new shortcut of Google Chrome(update browser installation path accordingly) with following value:

"C:\Program Files (x86)\Google\Chrome\Application\chrome.exe" --disable-web-security --user-data-dir="D:\chrome\temp"

How to add image in Flutter

An alternative way to put images in your app (for me it just worked that way):

1 - Create an assets/images folder

2 - Add your image to the new folder

3 - Register the assets folder in pubspec.yaml

4 - Use this code:

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {

    var assetsImage = new AssetImage('assets/images/mountain.jpg'); //<- Creates an object that fetches an image.
    var image = new Image(image: assetsImage, fit: BoxFit.cover); //<- Creates a widget that displays an image.

    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text("Climb your mountain!"),
          backgroundColor: Colors.amber[600], //<- background color to combine with the picture :-)
        ),
        body: Container(child: image), //<- place where the image appears
      ),
    );
  }
}

Climb your mountain!

Cross-Origin Read Blocking (CORB)

There is an edge case worth mentioning in this context: Chrome (some versions, at least) checks CORS preflights using the algorithm set up for CORB. IMO, this is a bit silly because preflights don't seem to affect the CORB threat model, and CORB seems designed to be orthogonal to CORS. Also, the body of a CORS preflight is not accessible, so there is no negative consequence just an irritating warning.

Anyway, check that your CORS preflight responses (OPTIONS method responses) don't have a body (204). An empty 200 with content type application/octet-stream and length zero worked well here too.

You can confirm if this is the case you are hitting by counting CORB warnings vs. OPTIONS responses with a message body.

curl: (35) error:1408F10B:SSL routines:ssl3_get_record:wrong version number

More simply in one line:

proxy=192.168.2.1:8080;curl -v example.com

eg. $proxy=192.168.2.1:8080;curl -v example.com

xxxxxxxxx-ASUS:~$ proxy=192.168.2.1:8080;curl -v https://google.com|head -c 15 % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0

  • Trying 172.217.163.46:443...
  • TCP_NODELAY set
  • Connected to google.com (172.217.163.46) port 443 (#0)
  • ALPN, offering h2
  • ALPN, offering http/1.1
  • successfully set certificate verify locations:
  • CAfile: /etc/ssl/certs/ca-certificates.crt CApath: /etc/ssl/certs } [5 bytes data]
  • TLSv1.3 (OUT), TLS handshake, Client hello (1): } [512 bytes data]

Using Environment Variables with Vue.js

In vue-cli version 3:

There are the three options for .env files: Either you can use .env or:

  • .env.test
  • .env.development
  • .env.production

You can use custom .env variables by using the prefix regex as /^/ instead of /^VUE_APP_/ in /node_modules/@vue/cli-service/lib/util/resolveClientEnv.js:prefixRE

This is certainly not recommended for the sake of developing an open source app in different modes like test, development, and production of .env files. Because every time you npm install .. , it will be overridden.

Flutter position stack widget in center

The Problem is the Container that gets the smallest possible size.

Just give a width: to the Container (in red) and you are done.

width: MediaQuery.of(context).size.width

enter image description here

  new Positioned(
  bottom: 0.0,
  child: new Container(
    width: MediaQuery.of(context).size.width,
    color: Colors.red,
    margin: const EdgeInsets.all(0.0),
    child: new Column(
      mainAxisAlignment: MainAxisAlignment.center,
      children: <Widget>[
        new Align(
          alignment: Alignment.bottomCenter,
          child: new ButtonBar(
            alignment: MainAxisAlignment.center,
            children: <Widget>[
              new OutlineButton(
                onPressed: null,
                child: new Text(
                  "Login",
                  style: new TextStyle(color: Colors.white),
                ),
              ),
              new RaisedButton(
                color: Colors.white,
                onPressed: null,
                child: new Text(
                  "Register",
                  style: new TextStyle(color: Colors.black),
                ),
              )
            ],
          ),
        )
      ],
    ),
  ),
),

Angular 6: How to set response type as text while making http call

Have you tried not setting the responseType and just type casting the response?

This is what worked for me:

/**
 * Client for consuming recordings HTTP API endpoint.
 */
@Injectable({
  providedIn: 'root'
})
export class DownloadUrlClientService {
  private _log = Log.create('DownloadUrlClientService');


  constructor(
    private _http: HttpClient,
  ) {}

  private async _getUrl(url: string): Promise<string> {
    const httpOptions = {headers: new HttpHeaders({'auth': 'false'})};
    // const httpOptions = {headers: new HttpHeaders({'auth': 'false'}), responseType: 'text'};
    const res = await (this._http.get(url, httpOptions) as Observable<string>).toPromise();
    // const res = await (this._http.get(url, httpOptions)).toPromise();
    return res;
  }
}

Android design support library for API 28 (P) not working

Below code worked perfectly with me:

dependencies {
    api 'com.android.support:design:28.0.0-alpha3'

    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"

    testImplementation 'junit:junit:4.12'

    androidTestImplementation 'androidx.test:runner:1.1.0-alpha2'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.0-alpha2'
}

Xcode 10 Error: Multiple commands produce

If you are manually making your entity's CoreDataClass and CoreDataProperties, make sure you go to your xcdatamodel and set the Codegen in the inspector tab to "Manual/None". Xcode will automatically create a duplicate class for you if this is set as "Class Definition".

phpMyAdmin - Error > Incorrect format parameter?

Note: If you're using MAMP you MUST edit the file using the built-in editor.

Select PHP in the languages section (LH Menu Column) Next, in the main panel next to the default version drop-down click the small arrow pointing to the right. This will launch the php.ini file using the MAMP text editor. Any changes you make to this file will persist after you restart the servers.

Editing the file through Application->MAMP->bin->php->{choosen the version}->php.ini would not work. Since the application overwrites any changes you make.

Needless to say: "Here be dragons!" so please cut and paste a copy of the original and store it somewhere safe in case of disaster.enter image description here

How do I resolve a TesseractNotFoundError?

I tried adding to the path variable like others have mentioned, but still received the same error. what worked was adding this to my script:

pytesseract.pytesseract.tesseract_cmd = r"C:\Program Files (x86)\Tesseract-OCR\tesseract.exe"

Trying to merge 2 dataframes but get ValueError

@Arnon Rotem-Gal-Oz answer is right for the most part. But I would like to point out the difference between df['year']=df['year'].astype(int) and df.year.astype(int). df.year.astype(int) returns a view of the dataframe and doesn't not explicitly change the type, atleast in pandas 0.24.2. df['year']=df['year'].astype(int) explicitly change the type because it's an assignment. I would argue that this is the safest way to permanently change the dtype of a column.

Example:

df = pd.DataFrame({'Weed': ['green crack', 'northern lights', 'girl scout cookies'], 'Qty':[10,15,3]}) df.dtypes

Weed object, Qty int64

df['Qty'].astype(str) df.dtypes

Weed object, Qty int64

Even setting the inplace arg to True doesn't help at times. I don't know why this happens though. In most cases inplace=True equals an explicit assignment.

df['Qty'].astype(str, inplace = True) df.dtypes

Weed object, Qty int64

Now the assignment,

df['Qty'] = df['Qty'].astype(str) df.dtypes

Weed object, Qty object

On npm install: Unhandled rejection Error: EACCES: permission denied

This happens if the first time you run NPM it's with sudo, for example when trying to do an npm install -g.

The cache folders need to be owned by the current user, not root.

sudo chown -R $USER:$GROUP ~/.npm
sudo chown -R $USER:$GROUP ~/.config

This will give ownership to the above folders when running with normal user permissions (not as sudo).

It's also worth noting that you shouldn't be installing global packages using SUDO. If you do run into issues with permissions, it's worth changing your global directory. The docs recommend:

mkdir ~/.npm-global

npm config set prefix '~/.npm-global'

Then updating your PATH in wherever you define that (~/.profile etc.)

export PATH=~/.npm-global/bin:$PATH

You'll then need to make sure the PATH env variable is set (restarting terminal or using the source command)

https://docs.npmjs.com/resolving-eacces-permissions-errors-when-installing-packages-globally

Elasticsearch error: cluster_block_exception [FORBIDDEN/12/index read-only / allow delete (api)], flood stage disk watermark exceeded

By default, Elasticsearch installed goes into read-only mode when you have less than 5% of free disk space. If you see errors similar to this:

Elasticsearch::Transport::Transport::Errors::Forbidden: [403] {"error":{"root_cause":[{"type":"cluster_block_exception","reason":"blocked by: [FORBIDDEN/12/index read-only / allow delete (api)];"}],"type":"cluster_block_exception","reason":"blocked by: [FORBIDDEN/12/index read-only / allow delete (api)];"},"status":403}

Or in /usr/local/var/log/elasticsearch.log you can see logs similar to:

flood stage disk watermark [95%] exceeded on [nCxquc7PTxKvs6hLkfonvg][nCxquc7][/usr/local/var/lib/elasticsearch/nodes/0] free: 15.3gb[4.1%], all indices on this node will be marked read-only

Then you can fix it by running the following commands:

curl -XPUT -H "Content-Type: application/json" http://localhost:9200/_cluster/settings -d '{ "transient": { "cluster.routing.allocation.disk.threshold_enabled": false } }'
curl -XPUT -H "Content-Type: application/json" http://localhost:9200/_all/_settings -d '{"index.blocks.read_only_allow_delete": null}'

Failed to resolve: com.google.firebase:firebase-core:16.0.1

Go to

Settings -> Android SDK -> SDK Tools ->

and make sure you install Google Play Services

Python Pandas User Warning: Sorting because non-concatenation axis is not aligned

tl;dr:

concat and append currently sort the non-concatenation index (e.g. columns if you're adding rows) if the columns don't match. In pandas 0.23 this started generating a warning; pass the parameter sort=True to silence it. In the future the default will change to not sort, so it's best to specify either sort=True or False now, or better yet ensure that your non-concatenation indices match.


The warning is new in pandas 0.23.0:

In a future version of pandas pandas.concat() and DataFrame.append() will no longer sort the non-concatenation axis when it is not already aligned. The current behavior is the same as the previous (sorting), but now a warning is issued when sort is not specified and the non-concatenation axis is not aligned, link.

More information from linked very old github issue, comment by smcinerney :

When concat'ing DataFrames, the column names get alphanumerically sorted if there are any differences between them. If they're identical across DataFrames, they don't get sorted.

This sort is undocumented and unwanted. Certainly the default behavior should be no-sort.

After some time the parameter sort was implemented in pandas.concat and DataFrame.append:

sort : boolean, default None

Sort non-concatenation axis if it is not already aligned when join is 'outer'. The current default of sorting is deprecated and will change to not-sorting in a future version of pandas.

Explicitly pass sort=True to silence the warning and sort. Explicitly pass sort=False to silence the warning and not sort.

This has no effect when join='inner', which already preserves the order of the non-concatenation axis.

So if both DataFrames have the same columns in the same order, there is no warning and no sorting:

df1 = pd.DataFrame({"a": [1, 2], "b": [0, 8]}, columns=['a', 'b'])
df2 = pd.DataFrame({"a": [4, 5], "b": [7, 3]}, columns=['a', 'b'])

print (pd.concat([df1, df2]))
   a  b
0  1  0
1  2  8
0  4  7
1  5  3

df1 = pd.DataFrame({"a": [1, 2], "b": [0, 8]}, columns=['b', 'a'])
df2 = pd.DataFrame({"a": [4, 5], "b": [7, 3]}, columns=['b', 'a'])

print (pd.concat([df1, df2]))
   b  a
0  0  1
1  8  2
0  7  4
1  3  5

But if the DataFrames have different columns, or the same columns in a different order, pandas returns a warning if no parameter sort is explicitly set (sort=None is the default value):

df1 = pd.DataFrame({"a": [1, 2], "b": [0, 8]}, columns=['b', 'a'])
df2 = pd.DataFrame({"a": [4, 5], "b": [7, 3]}, columns=['a', 'b'])

print (pd.concat([df1, df2]))

FutureWarning: Sorting because non-concatenation axis is not aligned.

   a  b
0  1  0
1  2  8
0  4  7
1  5  3

print (pd.concat([df1, df2], sort=True))
   a  b
0  1  0
1  2  8
0  4  7
1  5  3

print (pd.concat([df1, df2], sort=False))
   b  a
0  0  1
1  8  2
0  7  4
1  3  5

If the DataFrames have different columns, but the first columns are aligned - they will be correctly assigned to each other (columns a and b from df1 with a and b from df2 in the example below) because they exist in both. For other columns that exist in one but not both DataFrames, missing values are created.

Lastly, if you pass sort=True, columns are sorted alphanumerically. If sort=False and the second DafaFrame has columns that are not in the first, they are appended to the end with no sorting:

df1 = pd.DataFrame({"a": [1, 2], "b": [0, 8], 'e':[5, 0]}, 
                    columns=['b', 'a','e'])
df2 = pd.DataFrame({"a": [4, 5], "b": [7, 3], 'c':[2, 8], 'd':[7, 0]}, 
                    columns=['c','b','a','d'])

print (pd.concat([df1, df2]))

FutureWarning: Sorting because non-concatenation axis is not aligned.

   a  b    c    d    e
0  1  0  NaN  NaN  5.0
1  2  8  NaN  NaN  0.0
0  4  7  2.0  7.0  NaN
1  5  3  8.0  0.0  NaN

print (pd.concat([df1, df2], sort=True))
   a  b    c    d    e
0  1  0  NaN  NaN  5.0
1  2  8  NaN  NaN  0.0
0  4  7  2.0  7.0  NaN
1  5  3  8.0  0.0  NaN

print (pd.concat([df1, df2], sort=False))

   b  a    e    c    d
0  0  1  5.0  NaN  NaN
1  8  2  0.0  NaN  NaN
0  7  4  NaN  2.0  7.0
1  3  5  NaN  8.0  0.0

In your code:

placement_by_video_summary = placement_by_video_summary.drop(placement_by_video_summary_new.index)
                                                       .append(placement_by_video_summary_new, sort=True)
                                                       .sort_index()

How to do a timer in Angular 5

This may be overkill for what you're looking for, but there is an npm package called marky that you can use to do this. It gives you a couple of extra features beyond just starting and stopping a timer. You just need to install it via npm and then import the dependency anywhere you'd like to use it. Here is a link to the npm package: https://www.npmjs.com/package/marky

An example of use after installing via npm would be as follows:

import * as _M from 'marky';

@Component({
 selector: 'app-test',
 templateUrl: './test.component.html',
 styleUrls: ['./test.component.scss']
})

export class TestComponent implements OnInit {
 Marky = _M;
}

constructor() {}

ngOnInit() {}

startTimer(key: string) {
 this.Marky.mark(key);
}

stopTimer(key: string) {
 this.Marky.stop(key);
}

key is simply a string which you are establishing to identify that particular measurement of time. You can have multiple measures which you can go back and reference your timer stats using the keys you create.

Iterating through a list to render multiple widgets in Flutter?

The Dart language has aspects of functional programming, so what you want can be written concisely as:

List<String> list = ['one', 'two', 'three', 'four'];
List<Widget> widgets = list.map((name) => new Text(name)).toList();

Read this as "take each name in list and map it to a Text and form them back into a List".

How to resolve Unable to load authentication plugin 'caching_sha2_password' issue

As Mentioned in above repilies:

Starting with MySQL 8.0.4, the MySQL team changed the default authentication plugin for MySQL server from mysql_native_password to caching_sha2_password.

So there are three ways to resolve this issue:

 1. drop USER 'user_name'@'localhost';
    flush privileges;
    CREATE USER 'user_name'@'localhost' IDENTIFIED BY 'user_name';
    GRANT ALL PRIVILEGES ON * . * TO 'user_name'@'localhost';
    ALTER USER 'user_name'@'localhost' IDENTIFIED WITH mysql_native_password BY 
    'user_name';

 2. drop USER 'user_name'@'localhost';
    flush privileges;
    CREATE USER 'user_name'@'localhost' IDENTIFIED WITH mysql_native_password BY 'user_name';
GRANT ALL PRIVILEGES ON * . * TO 'user_name'@'localhost'

 3. If the user is already created, the use the following command:

    ALTER USER 'user_name'@'localhost' IDENTIFIED WITH mysql_native_password BY 
        'user_name';

Connection Java-MySql : Public Key Retrieval is not allowed

The above error in my case was actually due to the wrong username and password. Solving the issue: 1. Go to the line DriverManager.getConnection("jdbc:mysql://localhost:3306/?useSSL=false", "username", "password"); The fields username and password might be wrong. Enter the username and password which you use to start your mysql client. The username is generally root and password is the string which you enter when a screen similar to this appears Startup screen of mysql

Note: The portname 3306 might be different in your case.

destination path already exists and is not an empty directory

Make a new-directory and then use the git clone url

How to set the width of a RaisedButton in Flutter?

Short and sweet solution for a full-width button:

Row(
  children: [
    Expanded(
      child: ElevatedButton(...),
    ),
  ],
)

HTTP POST with Json on Body - Flutter/Dart

This one is for using HTTPClient class

 request.headers.add("body", json.encode(map));

I attached the encoded json body data to the header and added to it. It works for me.

what is an illegal reflective access

Apart from an understanding of the accesses amongst modules and their respective packages. I believe the crux of it lies in the Module System#Relaxed-strong-encapsulation and I would just cherry-pick the relevant parts of it to try and answer the question.

What defines an illegal reflective access and what circumstances trigger the warning?

To aid in the migration to Java-9, the strong encapsulation of the modules could be relaxed.

  • An implementation may provide static access, i.e. by compiled bytecode.

  • May provide a means to invoke its run-time system with one or more packages of one or more of its modules open to code in all unnamed modules, i.e. to code on the classpath. If the run-time system is invoked in this way, and if by doing so some invocations of the reflection APIs succeed where otherwise they would have failed.

In such cases, you've actually ended up making a reflective access which is "illegal" since in a pure modular world you were not meant to do such accesses.

How it all hangs together and what triggers the warning in what scenario?

This relaxation of the encapsulation is controlled at runtime by a new launcher option --illegal-access which by default in Java9 equals permit. The permit mode ensures

The first reflective-access operation to any such package causes a warning to be issued, but no warnings are issued after that point. This single warning describes how to enable further warnings. This warning cannot be suppressed.

The modes are configurable with values debug(message as well as stacktrace for every such access), warn(message for each such access), and deny(disables such operations).


Few things to debug and fix on applications would be:-

  • Run it with --illegal-access=deny to get to know about and avoid opening packages from one module to another without a module declaration including such a directive(opens) or explicit use of --add-opens VM arg.
  • Static references from compiled code to JDK-internal APIs could be identified using the jdeps tool with the --jdk-internals option

The warning message issued when an illegal reflective-access operation is detected has the following form:

WARNING: Illegal reflective access by $PERPETRATOR to $VICTIM

where:

$PERPETRATOR is the fully-qualified name of the type containing the code that invoked the reflective operation in question plus the code source (i.e., JAR-file path), if available, and

$VICTIM is a string that describes the member being accessed, including the fully-qualified name of the enclosing type

Questions for such a sample warning: = JDK9: An illegal reflective access operation has occurred. org.python.core.PySystemState

Last and an important note, while trying to ensure that you do not face such warnings and are future safe, all you need to do is ensure your modules are not making those illegal reflective accesses. :)

How to set environment via `ng serve` in Angular 6

Angular no longer supports --env instead you have to use

ng serve -c dev

for development environment and,

ng serve -c prod 

for production.

NOTE: -c or --configuration

MongoNetworkError: failed to connect to server [localhost:27017] on first connect [MongoNetworkError: connect ECONNREFUSED 127.0.0.1:27017]

first create folder by command line mkdir C:\data\db (This is for database) then run command mongod --port 27018 by one command prompt(administration mode)- you can give name port number as your wish

Angular 5 Button Submit On Enter Key Press

try use keyup.enter or keydown.enter

  <button type="submit" (keyup.enter)="search(...)">Search</button>

Conflict with dependency 'com.android.support:support-annotations' in project ':app'. Resolved versions for app (26.1.0) and test app (27.1.1) differ.

If you use version 26 then inside dependencies version should be 1.0.1 and 3.0.1 i.e., as follows

  androidTestImplementation 'com.android.support.test:runner:1.0.1'
  androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'

If you use version 27 then inside dependencies version should be 1.0.2 and 3.0.2 i.e., as follows

  androidTestImplementation 'com.android.support.test:runner:1.0.2'
  androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'

Create a button with rounded border

So I did mine with the full styling and border colors like this:

new OutlineButton(
    shape: StadiumBorder(),
    textColor: Colors.blue,
    child: Text('Button Text'),
    borderSide: BorderSide(
        color: Colors.blue, style: BorderStyle.solid, 
        width: 1),
    onPressed: () {},
)

virtualbox Raw-mode is unavailable courtesy of Hyper-V windows 10

In my case, the problem was with the specific box I was trying to use ubuntu/xenial64, I just had to switch to centos/7 and all those errors disappeared.

Hope this helps someone.

Button Width Match Parent

This worked for me.

The simplest way to give match-parent width or height in the given code above.

...
width: double.infinity,
height: double.infinity,
...

Access IP Camera in Python OpenCV

Getting the correct URL for your camera seems to be the actual challenge! I'm putting my working URL here, it might help someone. The camera is EZVIZ C1C with exact model cs-c1c-d0-1d2wf. The working URL is

rtsp://admin:[email protected]/h264_stream

where SZGBZT is the verification code found at the bottom of the camera. admin is always admin regardless of any settings or users you have.

The final code will be

video_capture = cv2.VideoCapture('rtsp://admin:[email protected]/h264_stream')

Axios handling errors

I tried using the try{}catch{} method but it did not work for me. However, when I switched to using .then(...).catch(...), the AxiosError is caught correctly that I can play around with. When I try the former when putting a breakpoint, it does not allow me to see the AxiosError and instead, says to me that the caught error is undefined, which is also what eventually gets displayed in the UI.

Not sure why this happens I find it very trivial. Either way due to this, I suggest using the conventional .then(...).catch(...) method mentioned above to avoid throwing undefined errors to the user.

How to develop Android app completely using python?

There are two primary contenders for python apps on Android

Chaquopy

https://chaquo.com/chaquopy/

This integrates with the Android build system, it provides a Python API for all android features. To quote the site "The complete Android API and user interface toolkit are directly at your disposal."

Beeware (Toga widget toolkit)

https://pybee.org/

This provides a multi target transpiler, supports many targets such as Android and iOS. It uses a generic widget toolkit (toga) that maps to the host interface calls.

Which One?

Both are active projects and their github accounts shows a fair amount of recent activity.

Beeware Toga like all widget libraries is good for getting the basics out to multiple platforms. If you have basic designs, and a desire to expand to other platforms this should work out well for you.

On the other hand, Chaquopy is a much more precise in its mapping of the python API to Android. It also allows you to mix in Java, useful if you want to use existing code from other resources. If you have strict design targets, and predominantly want to target Android this is a much better resource.

phpMyAdmin on MySQL 8.0

I used ALTER USER root@localhost IDENTIFIED WITH mysql_native_password BY 'PASSWORD'; it worked

How to handle "Uncaught (in promise) DOMException: play() failed because the user didn't interact with the document first." on Desktop with Chrome 66?

You should have added muted attribute inside your videoElement for your code work as expected. Look bellow ..

<video id="IPcamerastream" muted="muted" autoplay src="videoplayback%20(1).mp4" width="960" height="540"></video>

Don' t forget to add a valid video link as source

You must add a reference to assembly 'netstandard, Version=2.0.0.0

I experienced this when upgrading .NET Core 1.1 to 2.1.

I followed the instructions outlined here.

Try to remove <RuntimeFrameworkVersion>1.1.1</RuntimeFrameworkVersion> or <NetStandardImplicitPackageVersion> section in the .csproj.

Uncaught (in promise): Error: StaticInjectorError(AppModule)[options]

In my case, the error was in using angular2-notifications 0.9.8 instead of 0.9.7

'pip install' fails for every package ("Could not find a version that satisfies the requirement")

Upgrade pip as follows:

curl https://bootstrap.pypa.io/get-pip.py | python

Note: You may need to use sudo python above if not in a virtual environment.

What's happening:

Python.org sites are stopping support for TLS versions 1.0 and 1.1. This means that Mac OS X version 10.12 (Sierra) or older will not be able to use pip unless they upgrade pip as above.

(Note that upgrading pip via pip install --upgrade pip will also not upgrade it correctly. It is a chicken-and-egg issue)

This thread explains it (thanks to this Twitter post):

Mac users who use pip and PyPI:

If you are running macOS/OS X version 10.12 or older, then you ought to upgrade to the latest pip (9.0.3) to connect to the Python Package Index securely:

curl https://bootstrap.pypa.io/get-pip.py | python

and we recommend you do that by April 8th.

Pip 9.0.3 supports TLSv1.2 when running under system Python on macOS < 10.13. Official release notes: https://pip.pypa.io/en/stable/news/

Also, the Python status page:

Completed - The rolling brownouts are finished, and TLSv1.0 and TLSv1.1 have been disabled. Apr 11, 15:37 UTC

Update - The rolling brownouts have been upgraded to a blackout, TLSv1.0 and TLSv1.1 will be rejected with a HTTP 403 at all times. Apr 8, 15:49 UTC

Lastly, to avoid other install errors, make sure you also upgrade setuptools after doing the above:

pip install --upgrade setuptools

How to make flutter app responsive according to different screen size?

create file name (app_config.dart) in folder name(responsive_screen) in lib folder:

import 'package:flutter/material.dart';

class AppConfig {
  BuildContext _context;
  double _height;
  double _width;
  double _heightPadding;
  double _widthPadding;

  AppConfig(this._context) {
    MediaQueryData _queryData = MediaQuery.of(_context);
    _height = _queryData.size.height / 100.0;
    _width = _queryData.size.width / 100.0;
    _heightPadding =
    _height - ((_queryData.padding.top + _queryData.padding.bottom) / 100.0);
    _widthPadding =
      _width - (_queryData.padding.left + _queryData.padding.right) / 100.0;
  }

  double rH(double v) {
   return _height * v;
  }

  double rW(double v) {
    return _width * v;
  }

  double rHP(double v) {
    return _heightPadding * v;
  }

 double rWP(double v) {
   return _widthPadding * v;
 }
}

then:

import 'responsive_screen/app_config.dart';
 ...
class RandomWordsState extends State<RandomWords> {
  AppConfig _ac;
  ...
  @override
  Widget build(BuildContext context) {
    _ac = AppConfig(context);
    ...
    return Scaffold(
      body: Container(
        height: _ac.rHP(50),
        width: _ac.rWP(50),
        color: Colors.red,
        child: Text('Test'),
      ),
    );
    ...
  }

Extract Google Drive zip from Google colab notebook

Try this:

!unpack file.zip

If its now working or file is 7z try below

!apt-get install p7zip-full
!p7zip -d file_name.tar.7z
!tar -xvf file_name.tar

Or

!pip install pyunpack
!pip install patool

from pyunpack import Archive
Archive(‘file_name.tar.7z’).extractall(‘path/to/’)
!tar -xvf file_name.tar

How to use lifecycle method getDerivedStateFromProps as opposed to componentWillReceiveProps

getDerivedStateFromProps is used whenever you want to update state before render and update with the condition of props

GetDerivedStateFromPropd updating the stats value with the help of props value

read https://www.w3schools.com/REACT/react_lifecycle.asp#:~:text=Lifecycle%20of%20Components,Mounting%2C%20Updating%2C%20and%20Unmounting.

Message "Async callback was not invoked within the 5000 ms timeout specified by jest.setTimeout"

The timeout problem occurs when either the network is slow or many network calls are made using await. These scenarios exceed the default timeout, i.e., 5000 ms. To avoid the timeout error, simply increase the timeout of globals that support a timeout. A list of globals and their signature can be found here.

For Jest 24.9

Adding an .env file to React Project

You have to install npm install env-cmd

Make .env in the root directory and update like this & REACT_APP_ is the compulsory prefix for the variable name.

REACT_APP_NODE_ENV="production"
REACT_APP_DB="http://localhost:5000"

Update package.json

  "scripts": {
    "start": "env-cmd react-scripts start",
    "build": "env-cmd react-scripts build",
    "test": "react-scripts test",
    "eject": "react-scripts eject"
  }

Error occurred during initialization of boot layer FindException: Module not found

I solved this issue by going into Properties -> Java Build Path and reordering my source folder so it was above the JRE System Library.

Default interface methods are only supported starting with Android N

As CommonsWare mentioned, for reference add this inside the android {...} closure in the build.gradle for your app module to resolve issue:

android {
...
  compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
...
}

Unable to compile simple Java 10 / Java 11 project with Maven

If you are using spring boot then add these tags in pom.xml.

<plugin>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-maven-plugin</artifactId>
</plugin>

and

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    `<maven.compiler.release>`10</maven.compiler.release>
</properties>

You can change java version to 11 or 13 as well in <maven.compiler.release> tag.

Just add below tags in pom.xml

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <maven.compiler.release>11</maven.compiler.release>
</properties>

You can change the 11 to 10, 13 as well to change java version. I am using java 13 which is latest. It works for me.

docker: Error response from daemon: Get https://registry-1.docker.io/v2/: Service Unavailable. IN DOCKER , MAC

NTML PROXY AND DOCKER 

If your company is behind MS Proxy Server that using the proprietary NTLM protocol.

You need to install **Cntlm** Authentication Proxy

After this SET the proxy in 
/etc/systemd/system/docker.service.d/http-proxy.conf) with the following format:

[Service]

Environment=“HTTP_PROXY=http://<<IP OF CNTLM Proxy Server>>:3182”

In addition you can set in the .DockerFile
export http_proxy=http://<<IP OF CNTLM Proxy Server>>:3182
export https_proxy=http://<IP OF CNTLM Proxy Server>>:3182
export no_proxy=localhost,127.0.0.1,10.0.2.*

Followed by:
systemctl daemon-reload

systemctl restart docker

This Worked for me

How do I disable a Button in Flutter?

I like to use flutter_mobx for this and work on the state.

Next I use an observer:

Container(child: Observer(builder: (_) {
  var method;
  if (!controller.isDisabledButton) method = controller.methodController;
  return RaiseButton(child: Text('Test') onPressed: method);
}));

On the Controller:

@observable
bool isDisabledButton = true;

Then inside the control you can manipulate this variable as you want.

Refs.: Flutter mobx

How to set bot's status

Use this:

client.user.setActivity("with depression", {
  type: "STREAMING",
  url: "https://www.twitch.tv/monstercat"
});

How to set up devices for VS Code for a Flutter emulator

You can connect an Android Phone via USB cable and then it will show the device in the bottom bar.(Please note ADB must be installed. Click here for more)

Or you can completely install Android Studio and setup emulator from there and run the emulator. Then VS Code will recogzine the emulator and show at the bottom bar.

How to clear Flutter's Build cache?

If in android studio Tools->Flutter->Clean

enter image description here

error: resource android:attr/fontVariationSettings not found

try to change the compileSdkVersion to:

compileSdkVersion 28

fontVariationSettings added in api level 28. Api doc here

Error - Android resource linking failed (AAPT2 27.0.3 Daemon #0)

In your layout (xml) files almost every element has a property i.e. "id" which, can be assigned in order to refer to it from the java/kotlin code or from the xml itself.

Now sometimes or in some versions of Android Studio errors in xml files is either not reported or some random error is thrown while compiling, of which, this thread is an example i.e. when assigning an id to an element or when refering to another element in the layout we use the ID but ids are not just written like any other word rather they are prefixed by these characters: @+id/, otherwise the above error is thrown.

Hence the solution below should be considered:-

I resolved it by adding @+id/ before all my IDs.

i.e. @+id/your_item_id

Error : Program type already present: android.support.design.widget.CoordinatorLayout$Behavior

This can happens when one library is loaded into gradle several times. Most often through other connected libraries.

Remove a implementation this library in build.gradle

Then Build -> Clear project

and you can run the assembly)

After Spring Boot 2.0 migration: jdbcUrl is required with driverClassName

This happened to me because I was using:

app.datasource.url=jdbc:mysql://localhost/test

When I replaced url by jdbc-url then it worked:

app.datasource.jdbc-url=jdbc:mysql://localhost/test

'ls' is not recognized as an internal or external command, operable program or batch file

I'm fairly certain that the ls command is for Linux, not Windows (I'm assuming you're using Windows as you referred to cmd, which is the command line for the Windows OS).

You should use dir instead, which is the Windows equivalent of ls.

Edit (since this post seems to be getting so many views :) ):

You can't use ls on cmd as it's not shipped with Windows, but you can use it on other terminal programs (such as GitBash). Note, ls might work on some FTP servers if the servers are linux based and the FTP is being used from cmd.

dir on Windows is similar to ls. To find out the various options available, just do dir/?.

If you really want to use ls, you could install 3rd party tools to allow you to run unix commands on Windows. Such a program is Microsoft Windows Subsystem for Linux (link to docs).

TypeScript and React - children type?

React components should have a single wrapper node or return an array of nodes.

Your <Aux>...</Aux> component has two nodes div and main.

Try to wrap your children in a div in Aux component.

import * as React from 'react';

export interface AuxProps  { 
  children: React.ReactNode
}

const aux = (props: AuxProps) => (<div>{props.children}</div>);

export default aux;

Check input value length

<input type='text' minlength=3 /><br />

if browser supports html5,

it will automatical be validate attributes(minlength) in tag

but Safari(iOS) doesn't working

Converting java.sql.Date to java.util.Date

If you really want the runtime type to be util.Date then just do this:

java.util.Date utilDate = new java.util.Date(sqlDate.getTime());

Brian.

When using .net MVC RadioButtonFor(), how do you group so only one selection can be made?

In my case, I had a collection of radio buttons that needed to be in a group. I just included a 'Selected' property in the model. Then, in the loop to output the radiobuttons just do...

@Html.RadioButtonFor(m => Model.Selected, Model.Categories[i].Title)

This way, the name is the same for all radio buttons. When the form is posted, the 'Selected' property is equal to the category title (or id or whatever) and this can be used to update the binding on the relevant radiobutton, like this...

model.Categories.Find(m => m.Title.Equals(model.Selected)).Selected = true;

May not be the best way, but it does work.

Is it possible to have empty RequestParam values use the defaultValue?

This was considered a bug in 2013: https://jira.spring.io/browse/SPR-10180

and was fixed with version 3.2.2. Problem shouldn't occur in any versions after that and your code should work just fine.

blur vs focusout -- any real differences?

The documentation for focusout says (emphasis mine):

The focusout event is sent to an element when it, or any element inside of it, loses focus. This is distinct from the blur event in that it supports detecting the loss of focus on descendant elements (in other words, it supports event bubbling).

The same distinction exists between the focusin and focus events.

Why does datetime.datetime.utcnow() not contain timezone information?

To add timezone information in Python 3.2+

import datetime

>>> d = datetime.datetime.now(tz=datetime.timezone.utc)
>>> print(d.tzinfo)
'UTC+00:00'

Getting PEAR to work on XAMPP (Apache/MySQL stack on Windows)

I tried all of the other answers first but none of them seemed to work so I set the pear path statically in the pear config file

C:\xampp\php\pear\Config.php

find this code:

if (!defined('PEAR_INSTALL_DIR') || !PEAR_INSTALL_DIR) {
    $PEAR_INSTALL_DIR = PHP_LIBDIR . DIRECTORY_SEPARATOR . 'pear';
} 
else {
    $PEAR_INSTALL_DIR = PEAR_INSTALL_DIR;
}

and just replace it with this:

$PEAR_INSTALL_DIR = "C:\\xampp\\php\\pear";

I restarted apache and used the command:

pear config-all 

make sure the all of the paths no longer start with C:\php\pear

Base64 Encoding Image

Check the following example:

// First get your image
$imgPath = 'path-to-your-picture/image.jpg';
$img = base64_encode(file_get_contents($imgPath));
echo '<img width="100" height="100" src="data:image/jpg;base64,'. $img .'" />'

Numpy ValueError: setting an array element with a sequence. This message may appear without the existing of a sequence?

You're getting the error message

ValueError: setting an array element with a sequence.

because you're trying to set an array element with a sequence. I'm not trying to be cute, there -- the error message is trying to tell you exactly what the problem is. Don't think of it as a cryptic error, it's simply a phrase. What line is giving the problem?

kOUT[i]=func(TempLake[i],Z)

This line tries to set the ith element of kOUT to whatever func(TempLAke[i], Z) returns. Looking at the i=0 case:

In [39]: kOUT[0]
Out[39]: 0.0

In [40]: func(TempLake[0], Z)
Out[40]: array([ 0.,  0.,  0.,  0.])

You're trying to load a 4-element array into kOUT[0] which only has a float. Hence, you're trying to set an array element (the left hand side, kOUT[i]) with a sequence (the right hand side, func(TempLake[i], Z)).

Probably func isn't doing what you want, but I'm not sure what you really wanted it to do (and don't forget you can usually use vectorized operations like A*B rather than looping in numpy.) That should explain the problem, anyway.

Get the current first responder without using a private API

In one of my applications I often want the first responder to resign if the user taps on the background. For this purpose I wrote a category on UIView, which I call on the UIWindow.

The following is based on that and should return the first responder.

@implementation UIView (FindFirstResponder)
- (id)findFirstResponder
{
    if (self.isFirstResponder) {
        return self;        
    }
    for (UIView *subView in self.subviews) {
        id responder = [subView findFirstResponder];
        if (responder) return responder;
    }
    return nil;
}
@end

iOS 7+

- (id)findFirstResponder
{
    if (self.isFirstResponder) {
        return self;
    }
    for (UIView *subView in self.view.subviews) {
        if ([subView isFirstResponder]) {
            return subView;
        }
    }
    return nil;
}

Swift:

extension UIView {
    var firstResponder: UIView? {
        guard !isFirstResponder else { return self }

        for subview in subviews {
            if let firstResponder = subview.firstResponder {
                return firstResponder
            }
        }

        return nil
    }
}

Usage example in Swift:

if let firstResponder = view.window?.firstResponder {
    // do something with `firstResponder`
}

Format output string, right alignment

To do it by using f-string and with control of the number of trailing digits:

print(f'A number -> {my_number:>20.5f}')

SQL Server Pivot Table with multiple column aggregates

I would do this slightly different by applying both the UNPIVOT and the PIVOT functions to get the final result. The unpivot takes the values from both the totalcount and totalamount columns and places them into one column with multiple rows. You can then pivot on those results.:

select chardate,
  Australia_totalcount as [Australia # of Transactions], 
  Australia_totalamount as [Australia Total $ Amount],
  Austria_totalcount as [Austria # of Transactions], 
  Austria_totalamount as [Austria Total $ Amount]
from
(
  select 
    numericmonth, 
    chardate,
    country +'_'+col col, 
    value
  from
  (
    select numericmonth, 
      country, 
      chardate,
      cast(totalcount as numeric(10, 2)) totalcount,
      cast(totalamount as numeric(10, 2)) totalamount
    from mytransactions
  ) src
  unpivot
  (
    value
    for col in (totalcount, totalamount)
  ) unpiv
) s
pivot
(
  sum(value)
  for col in (Australia_totalcount, Australia_totalamount,
              Austria_totalcount, Austria_totalamount)
) piv
order by numericmonth

See SQL Fiddle with Demo.

If you have an unknown number of country names, then you can use dynamic SQL:

DECLARE @cols AS NVARCHAR(MAX),
    @colsName AS NVARCHAR(MAX),
    @query  AS NVARCHAR(MAX)

select @cols = STUFF((SELECT distinct ',' + QUOTENAME(country +'_'+c.col) 
                      from mytransactions
                      cross apply 
                      (
                        select 'TotalCount' col
                        union all
                        select 'TotalAmount'
                      ) c
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,'')

select @colsName 
    = STUFF((SELECT distinct ', ' + QUOTENAME(country +'_'+c.col) 
               +' as ['
               + country + case when c.col = 'TotalCount' then ' # of Transactions]' else 'Total $ Amount]' end
             from mytransactions
             cross apply 
             (
                select 'TotalCount' col
                union all
                select 'TotalAmount'
             ) c
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,'')

set @query 
  = 'SELECT chardate, ' + @colsName + ' 
     from 
     (
      select 
        numericmonth, 
        chardate,
        country +''_''+col col, 
        value
      from
      (
        select numericmonth, 
          country, 
          chardate,
          cast(totalcount as numeric(10, 2)) totalcount,
          cast(totalamount as numeric(10, 2)) totalamount
        from mytransactions
      ) src
      unpivot
      (
        value
        for col in (totalcount, totalamount)
      ) unpiv
     ) s
     pivot 
     (
       sum(value)
       for col in (' + @cols + ')
     ) p 
     order by numericmonth'

execute(@query)

See SQL Fiddle with Demo

Both give the result:

|             CHARDATE | AUSTRALIA # OF TRANSACTIONS | AUSTRALIA TOTAL $ AMOUNT | AUSTRIA # OF TRANSACTIONS | AUSTRIA TOTAL $ AMOUNT |
--------------------------------------------------------------------------------------------------------------------------------------
| Jul-12               |                          36 |                   699.96 |                        11 |                 257.82 |
| Aug-12               |                          44 |                  1368.71 |                         5 |                 126.55 |
| Sep-12               |                          52 |                  1161.33 |                         7 |                  92.11 |
| Oct-12               |                          50 |                  1099.84 |                        12 |                 103.56 |
| Nov-12               |                          38 |                  1078.94 |                        21 |                 377.68 |
| Dec-12               |                          63 |                  1668.23 |                         3 |                  14.35 |

How to test enum types?

If you use all of the months in your code, your IDE won't let you compile, so I think you don't need unit testing.

But if you are using them with reflection, even if you delete one month, it will compile, so it's valid to put a unit test.

Aborting a stash pop in Git

I could reproduce clean git stash pop on "dirty" directory, with uncommitted changes, but not yet pop that generates a merge conflict.

If on merge conflict the stash you tried to apply didn't disappear, you can try to examine git show stash@{0} (optionally with --ours or --theirs) and compare with git statis and git diff HEAD. You should be able to see which changes came from applying a stash.

php return 500 error but no error log

In the past, I had no error logs in two cases:

  1. The user under which Apache was running had no permissions to modify php_error_log file.
  2. Error 500 occurred because of bad configuration of .htaccess, for example wrong rewrite module settings. In this situation errors are logged to Apache error_log file.

Unable to copy ~/.ssh/id_rsa.pub

The following is also working for me:

ssh <user>@<host>  "cat <filepath>"|pbcopy 

How to get ALL child controls of a Windows Forms form of a specific type (Button/Textbox)?

I'd like to amend PsychoCoders answer: as the user wants to get all controls of a certain type we could use generics in the following way:

    public IEnumerable<T> FindControls<T>(Control control) where T : Control
    {
        // we can't cast here because some controls in here will most likely not be <T>
        var controls = control.Controls.Cast<Control>();

        return controls.SelectMany(ctrl => FindControls<T>(ctrl))
                                  .Concat(controls)
                                  .Where(c => c.GetType() == typeof(T)).Cast<T>();
    }

This way, we can call the function as follows:

private void Form1_Load(object sender, EventArgs e)
{
    var c = FindControls<TextBox>(this);
    MessageBox.Show("Total Controls: " + c.Count());
}

Java best way for string find and replace?

Simply include the Apache Commons Lang JAR and use the org.apache.commons.lang.StringUtils class. You'll notice lots of methods for replacing Strings safely and efficiently.

You can view the StringUtils API at the previously linked website.

"Don't reinvent the wheel"

How can I enable "URL Rewrite" Module in IIS 8.5 in Server 2012?

Download it from here:

http://www.iis.net/downloads/microsoft/url-rewrite

or if you already have Web Platform Installer on your machine you can install it from there.

How to list only files and not directories of a directory Bash?

You can also use ls with grep or egrep and put it in your profile as an alias:

ls -l | egrep -v '^d'
ls -l | grep -v '^d'

How to read the content of a file to a string in C?

Note: This is a modification of the accepted answer above.

Here's a way to do it, complete with error checking.

I've added a size checker to quit when file was bigger than 1 GiB. I did this because the program puts the whole file into a string which may use too much ram and crash a computer. However, if you don't care about that you could just remove it from the code.

#include <stdio.h>
#include <stdlib.h>

#define FILE_OK 0
#define FILE_NOT_EXIST 1
#define FILE_TO_LARGE 2
#define FILE_READ_ERROR 3

char * c_read_file(const char * f_name, int * err, size_t * f_size) {
    char * buffer;
    size_t length;
    FILE * f = fopen(f_name, "rb");
    size_t read_length;
    
    if (f) {
        fseek(f, 0, SEEK_END);
        length = ftell(f);
        fseek(f, 0, SEEK_SET);
        
        // 1 GiB; best not to load a whole large file in one string
        if (length > 1073741824) {
            *err = FILE_TO_LARGE;
            
            return NULL;
        }
        
        buffer = (char *)malloc(length + 1);
        
        if (length) {
            read_length = fread(buffer, 1, length, f);
            
            if (length != read_length) {
                 free(buffer);
                 *err = FILE_READ_ERROR;

                 return NULL;
            }
        }
        
        fclose(f);
        
        *err = FILE_OK;
        buffer[length] = '\0';
        *f_size = length;
    }
    else {
        *err = FILE_NOT_EXIST;
        
        return NULL;
    }
    
    return buffer;
}

And to check for errors:

int err;
size_t f_size;
char * f_data;

f_data = c_read_file("test.txt", &err, &f_size);

if (err) {
    // process error
}
else {
    // process data
    free(f_data);
}

How to convert image into byte array and byte array to base64 String in android?

They have wrapped most stuff need to solve your problem, one of the tests looks like this:

String filename = CSSURLEmbedderTest.class.getResource("folder.png").getPath().replace("%20", " ");
String code = "background: url(folder.png);";

StringWriter writer = new StringWriter();
embedder = new CSSURLEmbedder(new StringReader(code), true);
embedder.embedImages(writer, filename.substring(0, filename.lastIndexOf("/")+1));

String result = writer.toString();
assertEquals("background: url(" + folderDataURI + ");", result);

jQuery CSS Opacity

try using .animate instead of .css or even just on the opacity one and leave .css on the display?? may b

jQuery(document).ready(function(){
if (jQuery('#nav .drop').animate('display') === 'block') {
    jQuery('#main').animate('opacity') = '0.6';

How do I grab an INI value within a shell script?

The answer of "Karen Gabrielyan" among another answers was the best but in some environments we dont have awk, like typical busybox, i changed the answer by below code.

trim()
{
    local trimmed="$1"

    # Strip leading space.
    trimmed="${trimmed## }"
    # Strip trailing space.
    trimmed="${trimmed%% }"

    echo "$trimmed"
}


  function parseIniFile() { #accepts the name of the file to parse as argument ($1)
        #declare syntax below (-gA) only works with bash 4.2 and higher
        unset g_iniProperties
        declare -gA g_iniProperties
        currentSection=""
        while read -r line
        do
            if [[ $line = [*  ]] ; then
                if [[ $line = [* ]] ; then 
                    currentSection=$(echo $line | sed -e 's/\r//g' | tr -d "[]")  
                fi
            else
                if [[ $line = *=*  ]] ; then
                    cleanLine=$(echo $line | sed -e 's/\r//g')
                    key=$(trim $currentSection.$(echo $cleanLine | cut -d'=' -f1'))
                    value=$(trim $(echo $cleanLine | cut -d'=' -f2))
                    g_iniProperties[$key]=$value
                fi
            fi;
        done < $1
    }

"starting Tomcat server 7 at localhost has encountered a prob"

Go to web.xml add <element> before <web-app> and close </element> after </web-app>

should be somethings like this

<?xml version="1.0" encoding="UTF-8"?>

<element>

<web-app>

....
</web-app>

</element>

How does the "this" keyword work?

Daniel, awesome explanation! A couple of words on this and good list of this execution context pointer in case of event handlers.

In two words, this in JavaScript points the object from whom (or from whose execution context) the current function was run and it's always read-only, you can't set it anyway (such an attempt will end up with 'Invalid left-hand side in assignment' message.

For event handlers: inline event handlers, such as <element onclick="foo">, override any other handlers attached earlier and before, so be careful and it's better to stay off of inline event delegation at all. And thanks to Zara Alaverdyan who inspired me to this list of examples through a dissenting debate :)

  • el.onclick = foo; // in the foo - obj
  • el.onclick = function () {this.style.color = '#fff';} // obj
  • el.onclick = function() {doSomething();} // In the doSomething - Window
  • el.addEventListener('click',foo,false) // in the foo - obj
  • el.attachEvent('onclick, function () { // this }') // window, all the compliance to IE :)
  • <button onclick="this.style.color = '#fff';"> // obj
  • <button onclick="foo"> // In the foo - window, but you can <button onclick="foo(this)">

Need to combine lots of files in a directory

In windows I use a simple command in a batch file and I use a Scheduled Task to keep all the info in only one file. Be sure to choose another path to the result file, or You will have duplicate data.

type PathToOriginalFiles\*.Extension > AnotherPathToResultFile\NameOfTheResultFile.Extension

If you need to join lots of csv files, a good thing to do is to have the header in only one file with a name like 0header.csv, or other name, so that it will allways be the first file in list, and be sure to program all the other csv files to not contain an header.

Using onBlur with JSX and React

There are a few problems here.

1: onBlur expects a callback, and you are calling renderPasswordConfirmError and using the return value, which is null.

2: you need a place to render the error.

3: you need a flag to track "and I validating", which you would set to true on blur. You can set this to false on focus if you want, depending on your desired behavior.

handleBlur: function () {
  this.setState({validating: true});
},
render: function () {
  return <div>
    ...
    <input
        type="password"
        placeholder="Password (confirm)"
        valueLink={this.linkState('password2')}
        onBlur={this.handleBlur}
     />
    ...
    {this.renderPasswordConfirmError()}
  </div>
},
renderPasswordConfirmError: function() {
  if (this.state.validating && this.state.password !== this.state.password2) {
    return (
      <div>
        <label className="error">Please enter the same password again.</label>
      </div>
    );
  }  
  return null;
},

Is List<Dog> a subclass of List<Animal>? Why are Java generics not implicitly polymorphic?

Further to the answer by Jon Skeet, which uses this example code:

// Illegal code - because otherwise life would be Bad
List<Dog> dogs = new ArrayList<Dog>(); // ArrayList implements List
List<Animal> animals = dogs; // Awooga awooga
animals.add(new Cat());
Dog dog = dogs.get(0); // This should be safe, right?

At the deepest level, the problem here is that dogs and animals share a reference. That means that one way to make this work would be to copy the entire list, which would break reference equality:

// This code is fine
List<Dog> dogs = new ArrayList<Dog>();
dogs.add(new Dog());
List<Animal> animals = new ArrayList<>(dogs); // Copy list
animals.add(new Cat());
Dog dog = dogs.get(0);   // This is fine now, because it does not return the Cat

After calling List<Animal> animals = new ArrayList<>(dogs);, you cannot subsequently directly assign animals to either dogs or cats:

// These are both illegal
dogs = animals;
cats = animals;

therefore you can't put the wrong subtype of Animal into the list, because there is no wrong subtype -- any object of subtype ? extends Animal can be added to animals.

Obviously, this changes the semantics, since the lists animals and dogs are no longer shared, so adding to one list does not add to the other (which is exactly what you want, to avoid the problem that a Cat could be added to a list that is only supposed to contain Dog objects). Also, copying the entire list can be inefficient. However, this does solve the type equivalence problem, by breaking reference equality.

How to get a complete list of ticker symbols from Yahoo Finance?

I managed to do something similar by using this URL:

http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20yahoo.finance.industry%20where%20id%20in%20(select%20industry.id%20from%20yahoo.finance.sectors)&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys

It downloads a complete list of stock symbols using the Yahoo YQL API, including the stock name, stock symbol, and industry ID. What it doesn't seem to have is any sort of stock symbol modifiers. E.g. for Rogers Communications Inc, it only downloads RCI, not RCI-A.TO, RCI-B.TO, etc. I haven't found a source for that information yet - if anyone knows of a way to automate downloading that, I'd like to hear it. Also, it'd be nice to find a way to download some sort of relation between the stock symbol and the exchange it's traded on, since some are traded on multiple exchanges, or maybe I only want to look at stuff on the TSX or something.

How to get time (hour, minute, second) in Swift 3 using NSDate?

Swift 4.2 & 5

// *** Create date ***
let date = Date()

// *** create calendar object ***
var calendar = Calendar.current

// *** Get components using current Local & Timezone ***
print(calendar.dateComponents([.year, .month, .day, .hour, .minute], from: date))

// *** define calendar components to use as well Timezone to UTC ***
calendar.timeZone = TimeZone(identifier: "UTC")!

// *** Get All components from date ***
let components = calendar.dateComponents([.hour, .year, .minute], from: date)
print("All Components : \(components)")

// *** Get Individual components from date ***
let hour = calendar.component(.hour, from: date)
let minutes = calendar.component(.minute, from: date)
let seconds = calendar.component(.second, from: date)
print("\(hour):\(minutes):\(seconds)")

Swift 3.0

// *** Create date ***
let date = Date()

// *** create calendar object ***
var calendar = NSCalendar.current

// *** Get components using current Local & Timezone ***    
print(calendar.dateComponents([.year, .month, .day, .hour, .minute], from: date as Date))

// *** define calendar components to use as well Timezone to UTC ***
let unitFlags = Set<Calendar.Component>([.hour, .year, .minute])
calendar.timeZone = TimeZone(identifier: "UTC")!

// *** Get All components from date ***
let components = calendar.dateComponents(unitFlags, from: date)
print("All Components : \(components)")

// *** Get Individual components from date ***
let hour = calendar.component(.hour, from: date)
let minutes = calendar.component(.minute, from: date)
let seconds = calendar.component(.second, from: date)
print("\(hour):\(minutes):\(seconds)")

Web scraping with Python

I use a combination of Scrapemark (finding urls - py2) and httlib2 (downloading images - py2+3). The scrapemark.py has 500 lines of code, but uses regular expressions, so it may be not so fast, did not test.

Example for scraping your website:

import sys
from pprint import pprint
from scrapemark import scrape

pprint(scrape("""
    <table class="spad">
        <tbody>
            {*
                <tr>
                    <td>{{[].day}}</td>
                    <td>{{[].sunrise}}</td>
                    <td>{{[].sunset}}</td>
                    {# ... #}
                </tr>
            *}
        </tbody>
    </table>
""", url=sys.argv[1] ))

Usage:

python2 sunscraper.py http://www.example.com/

Result:

[{'day': u'1. Dez 2012', 'sunrise': u'08:18', 'sunset': u'16:10'},
 {'day': u'2. Dez 2012', 'sunrise': u'08:19', 'sunset': u'16:10'},
 {'day': u'3. Dez 2012', 'sunrise': u'08:21', 'sunset': u'16:09'},
 {'day': u'4. Dez 2012', 'sunrise': u'08:22', 'sunset': u'16:09'},
 {'day': u'5. Dez 2012', 'sunrise': u'08:23', 'sunset': u'16:08'},
 {'day': u'6. Dez 2012', 'sunrise': u'08:25', 'sunset': u'16:08'},
 {'day': u'7. Dez 2012', 'sunrise': u'08:26', 'sunset': u'16:07'}]

How to create web service (server & Client) in Visual Studio 2012?

--- create a ws server vs2012 upd 3

  1. new project

  2. choose .net framework 3.5

  3. asp.net web service application

  4. right click on the project root

  5. choose add service reference

  6. choose wsdl

--- how can I create a ws client from a wsdl file?

I´ve a ws server Axis2 under tomcat 7 and I want to test the compatibility

How to select all records from one table that do not exist in another table?

This is pure set theory which you can achieve with the minus operation.

select id, name from table1
minus
select id, name from table2

Correct way to focus an element in Selenium WebDriver using Java

The following code -

element.sendKeys("");

tries to find an input tag box to enter some information, while

new Actions(driver).moveToElement(element).perform();

is more appropriate as it will work for image elements, link elements, dropdown boxes etc.

Therefore using moveToElement() method makes more sense to focus on any generic WebElement on the web page.

For an input box you will have to click() on the element to focus.

new Actions(driver).moveToElement(element).click().perform();

while for links and images the mouse will be over that particular element,you can decide to click() on it depending on what you want to do.

If the click() on an input tag does not work -

Since you want this function to be generic, you first check if the webElement is an input tag or not by -

if("input".equals(element.getTagName()){
   element.sendKeys("");
} 
else{
   new Actions(driver).moveToElement(element).perform();

}

You can make similar changes based on your preferences.

Error #2032: Stream Error

From a quick google search it seems that the problem is a file or url couldn't be found be the HTTPservice.

Here are the links where I found this information:

http://www.judahfrangipane.com/blog/2007/02/15/error-2032-stream-error/

http://curtismorley.com/2008/02/08/actionscript-error-2032/

Set line height in Html <p> to make the html looks like a office word when <p> has different font sizes

You can set the line-height in pixels instead of percentage. Is that what you mean?

CSS white space at bottom of page despite having both min-height and height tag

This will remove the margin and padding from your page elements, since there is a paragraph with a script inside that is causing an added margin. this way you should reset it and then you can style the other elements of your page, or you could give that paragraph an id and set margin to zero only for it.

<style>
* {
   margin: 0;
   padding: 0;
}
</style>

Try to put this as the first style.

How do I execute a Shell built-in command with a C function?

If you just want to execute the shell command in your c program, you could use,

   #include <stdlib.h>

   int system(const char *command);

In your case,

system("pwd");

The issue is that there isn't an executable file called "pwd" and I'm unable to execute "echo $PWD", since echo is also a built-in command with no executable to be found.

What do you mean by this? You should be able to find the mentioned packages in /bin/

sudo find / -executable -name pwd
sudo find / -executable -name echo

Convert hours:minutes:seconds into total minutes in excel

Just use the formula

120 = (HOUR(A8)*3600+MINUTE(A8)*60+SECOND(A8))/60

How to install latest version of git on CentOS 7.x/6.x

To build and install modern Git on CentOS 6:

yum install -y curl-devel expat-devel gettext-devel openssl-devel zlib-devel gcc perl-ExtUtils-MakeMaker
export GIT_VERSION=2.6.4
mkdir /root/git
cd /root/git
wget "https://www.kernel.org/pub/software/scm/git/git-${GIT_VERSION}.tar.gz"
tar xvzf "git-${GIT_VERSION}.tar.gz"
cd git-${GIT_VERSION}
make prefix=/usr/local all
make prefix=/usr/local install
yum remove -y git
git --version # should be GIT_VERSION

Python/Json:Expecting property name enclosed in double quotes

as JSON only allows enclosing strings with double quotes you can manipulate the string like this:

str = str.replace("\'", "\"")

if your JSON holds escaped single-quotes (\') then you should use the more precise following code:

import re
p = re.compile('(?<!\\\\)\'')
str = p.sub('\"', str)

This will replace all occurrences of single quote with double quote in the JSON string str and in the latter case will not replace escaped single-quotes.

You can also use js-beautify which is less strict:

$ pip install jsbeautifier
$ js-beautify file.js

Reading and writing value from a textfile by using vbscript code

Dim obj : Set obj = CreateObject("Scripting.FileSystemObject")
Dim outFile : Set outFile = obj.CreateTextFile("listfile.txt")
Dim inFile: Set inFile = obj.OpenTextFile("listfile.txt")

' read file
data = inFile.ReadAll
inFile.Close

' write file
outFile.write (data)
outFile.Close

How do I style appcompat-v7 Toolbar like Theme.AppCompat.Light.DarkActionBar?

Yout can try this below.

<style name="MyToolbar" parent="Widget.AppCompat.Toolbar">
    <!-- your code here -->
</style>

And the detail elements you can find them in https://developer.android.com/reference/android/support/v7/appcompat/R.styleable.html#Toolbar

Here are some more:TextAppearance.Widget.AppCompat.Toolbar.Title, TextAppearance.Widget.AppCompat.Toolbar.Subtitle, Widget.AppCompat.Toolbar.Button.Navigation.

Hope this can help you.

How to display hexadecimal numbers in C?

You can use the following snippet code:

#include<stdio.h>
int main(int argc, char *argv[]){
    unsigned int i;
    printf("decimal  hexadecimal\n");
    for (i = 0; i <= 256; i+=16)
        printf("%04d     0x%04X\n", i, i);
    return 0;
}

It prints both decimal and hexadecimal numbers in 4 places with zero padding.

Defining a variable with or without export

Just to show the difference between an exported variable being in the environment (env) and a non-exported variable not being in the environment:

If I do this:

$ MYNAME=Fred
$ export OURNAME=Jim

then only $OURNAME appears in the env. The variable $MYNAME is not in the env.

$ env | grep NAME
OURNAME=Jim

but the variable $MYNAME does exist in the shell

$ echo $MYNAME
Fred

How do I get the n-th level parent of an element in jQuery?

It's simple. Just use

$(selector).parents().eq(0); 

where 0 is the parent level (0 is parent, 1 is parent's parent etc)

splitting a string based on tab in the file

Python has support for CSV files in the eponymous csv module. It is relatively misnamed since it support much more that just comma separated values.

If you need to go beyond basic word splitting you should take a look. Say, for example, because you are in need to deal with quoted values...

How to get the squared symbol (²) to display in a string

Not sure what kind of text box you are refering to. However, I'm not sure if you can do this in a text box on a user form.

A text box on a sheet you can though.

Sheets("Sheet1").Shapes("TextBox 1").TextFrame2.TextRange.Text = "R2=" & variable
Sheets("Sheet1").Shapes("TextBox 1").TextFrame2.TextRange.Characters(2, 1).Font.Superscript = msoTrue

And same thing for an excel cell

Sheets("Sheet1").Range("A1").Characters(2, 1).Font.Superscript = True

If this isn't what you're after you will need to provide more information in your question.

EDIT: posted this after the comment sorry

Select rows from a data frame based on values in a vector

Another option would be to use a keyed data.table:

library(data.table)
setDT(dt, key = 'fct')[J(vc)]  # or: setDT(dt, key = 'fct')[.(vc)]

which results in:

   fct X
1:   a 2
2:   a 7
3:   a 1
4:   c 3
5:   c 5
6:   c 9
7:   c 2
8:   c 4

What this does:

  • setDT(dt, key = 'fct') transforms the data.frame to a data.table (which is an enhanced form of a data.frame) with the fct column set as key.
  • Next you can just subset with the vc vector with [J(vc)].

NOTE: when the key is a factor/character variable, you can also use setDT(dt, key = 'fct')[vc] but that won't work when vc is a numeric vector. When vc is a numeric vector and is not wrapped in J() or .(), vc will work as a rowindex.

A more detailed explanation of the concept of keys and subsetting can be found in the vignette Keys and fast binary search based subset.

An alternative as suggested by @Frank in the comments:

setDT(dt)[J(vc), on=.(fct)]

When vc contains values that are not present in dt, you'll need to add nomatch = 0:

setDT(dt, key = 'fct')[J(vc), nomatch = 0]

or:

setDT(dt)[J(vc), on=.(fct), nomatch = 0]

prevent refresh of page when button inside form clicked

This one is the best solution:

<form  method="post"> 
    <button  type="button" name="data" onclick="getData()">Click Me</button>
</form>

Note: My code is very simple.

Angular2 Routing with Hashtag to page anchor

Adding on to Kalyoyan's answer, this subscription is tied to the router and will live until the page is fully refreshed. When subscribing to router events in a component, be sure to unsubscribe in ngOnDestroy:

import { OnDestroy } from '@angular/core';
import { Router, NavigationEnd } from '@angular/router';
import { Subscription } from "rxjs/Rx";

class MyAppComponent implements OnDestroy {

  private subscription: Subscription;

  constructor(router: Router) {
    this.subscription = router.events.subscribe(s => {
      if (s instanceof NavigationEnd) {
        const tree = router.parseUrl(router.url);
        if (tree.fragment) {
          const element = document.querySelector("#" + tree.fragment);
          if (element) { element.scrollIntoView(element); }
        }
      }
    });
  }

  public ngOnDestroy() {
    this.subscription.unsubscribe();
  }
}

How do I bottom-align grid elements in bootstrap fluid layout

You need to add some style for span6, smthg like that:

.row-fluid .span6 {
  display: table-cell;
  vertical-align: bottom;
  float: none;
}

and this is your fiddle: http://jsfiddle.net/sgB3T/

Test for existence of nested JavaScript object key

Slight edit to this answer to allow nested arrays in the path

_x000D_
_x000D_
var has = function (obj, key) {_x000D_
    return key.split(".").every(function (x) {_x000D_
        if (typeof obj != "object" || obj === null || !x in obj)_x000D_
            return false;_x000D_
        if (obj.constructor === Array) _x000D_
            obj = obj[0];_x000D_
        obj = obj[x];_x000D_
        return true;_x000D_
    });_x000D_
}
_x000D_
_x000D_
_x000D_

Check linked answer for usages :)

Spring Maven clean error - The requested profile "pom.xml" could not be activated because it does not exist

I was getting this same warning everytime I was doing 'maven clean'. I found the solution :

Step - 1 Right click on your project in Eclipse

Step - 2 Click Properties

Step - 3 Select Maven in the left hand side list.

Step - 4 You will notice "pom.xml" in the Active Maven Profiles text box on the right hand side. Clear it and click Apply.

Below is the screen shot :

Properties dialog box

Hope this helps. :)

How to create Android Facebook Key Hash?

Here is complete details (For Windows)

1. Download OpenSSl either 3rd or 4th (with e will work better) based on your system 32bit or 64bit .

2. Extract the downloaded zip inside C directory

3. Open the extracted folder up to bin and copy the path ,it should be some thing like C:\openssl-0.9.8k_X64\bin\openssl (add \openssl at end)

4. (Get the path to the bin folder of Jdk ,if you know how,ignore this ) .

Open android studio ~file~Project Structure(ctrl+alt+shift+s) , select SDK location in left side panel ,copy the JDK location and add /bin to it

So final JDK Location will be like C:\Program Files\Android\Android Studio\jre\bin

we are following this method to get Jdk location because you might use embedded jdk like me

enter image description here

now you have OpenSSl location & JDK location

5. now we need debug keystore location , for that open C~>Users~>YourUserName~>.android there should be a file name debug.keystore ,now copy the path location ,it should be some thing like

C:\Users\Redman\.android\debug.keystore

6. now open command prompt and type command

cd YourJDKLocationFromStep4  

in my case

 cd "C:\Program Files\Android\Android Studio\jre\bin"

7. now construct the following command

keytool -exportcert -alias androiddebugkey -keystore YOURKEYSTORELOCATION | YOUROPENSSLLOCATION sha1 -binary | YOUROPENSSLLOCATION base64

in my case the command will look like

keytool -exportcert -alias androiddebugkey -keystore "C:\Users\Redman\.android\debug.keystore" | "C:\openssl-0.9.8k_X64\bin\openssl" sha1 -binary | "C:\openssl-0.9.8k_X64\bin\openssl" base64

now enter this command in command prompt , if you did ever thing right you will be asked for password (password is android)

Enter keystore password:  android

thats it ,you will be given the Key Hash , just copy it and use it

For Signed KeyHash construct the following Command

keytool -exportcert -alias YOUR_ALIAS_FOR_JKS -keystore YOUR_JKS_LOCATION | YOUROPENSSLLOCATION sha1 -binary | YOUROPENSSLLOCATION base64

enter your keystore password , If you enter wrong password it will give wrong KeyHash

NOTE

If for some reason if it gives error at some path then wrap that path in double quotes .Also Windows power shell was not working well for me, I used git bash (or use command prompt) .

example

keytool -exportcert -alias androiddebugkey -keystore "C:\Users\Redman\.android\debug.keystore" | "C:\openssl-0.9.8k_X64\bin\openssl" sha1 -binary | "C:\openssl-0.9.8k_X64\bin\openssl" base64

How to list files using dos commands?

If you just want to get the file names and not directory names then use :

dir /b /a-d > file.txt

Scale Image to fill ImageView width and keep aspect ratio

FOR IMAGE VIEW (set these parameters)

android:layout_width     = "match_parent"
android:layout_height    = "wrap_content"
android:scaleType        = "fitCenter"
android:adjustViewBounds = "true"

Now whatever the size of the image is there, it's width will match the parent and height will be according to match the ratio. I have tested this and I am 100% sure.

we want this --> adjustViewBound = true

not this --> adjustViewBound = false

// Results will be: 
Image width -> stretched as match parent
Image height -> according to image width (maximum to aspect ratio)

// like the first one

How to modify values of JsonObject / JsonArray directly?

This works for modifying childkey value using JSONObject. import used is

import org.json.JSONObject;

ex json:(convert json file to string while giving as input)

{
    "parentkey1": "name",
    "parentkey2": {
     "childkey": "test"
    },
}

Code

JSONObject jObject  = new JSONObject(String jsoninputfileasstring);
jObject.getJSONObject("parentkey2").put("childkey","data1");
System.out.println(jObject);

output:

{
    "parentkey1": "name",
    "parentkey2": {
     "childkey": "data1"
    },
}

Please help me convert this script to a simple image slider

Problems only surface when I am I trying to give the first loaded content an active state

Does this mean that you want to add a class to the first button?

$('.o-links').click(function(e) {   // ... }).first().addClass('O_Nav_Current'); 

instead of using IDs for the slider's items and resetting html contents you can use classes and indexes:

CSS:

.image-area {     width: 100%;     height: auto;     display: none; }  .image-area:first-of-type {     display: block; } 

JavaScript:

var $slides = $('.image-area'),     $btns = $('a.o-links');  $btns.on('click', function (e) {     var i = $btns.removeClass('O_Nav_Current').index(this);     $(this).addClass('O_Nav_Current');      $slides.filter(':visible').fadeOut(1000, function () {         $slides.eq(i).fadeIn(1000);     });      e.preventDefault();  }).first().addClass('O_Nav_Current'); 

http://jsfiddle.net/RmF57/

How to downgrade the installed version of 'pip' on windows?

well the only thing that will work is

python -m pip install pip==

you can and should run it under IDE terminal (mine was pycharm)

Convert string to boolean in C#

I know this is not an ideal question to answer but as the OP seems to be a beginner, I'd love to share some basic knowledge with him... Hope everybody understands

OP, you can convert a string to type Boolean by using any of the methods stated below:

 string sample = "True";
 bool myBool = bool.Parse(sample);

 ///or

 bool myBool = Convert.ToBoolean(sample);

bool.Parse expects one parameter which in this case is sample, .ToBoolean also expects one parameter.

You can use TryParse which is the same as Parse but it doesn't throw any exception :)

  string sample = "false";
  Boolean myBool;

  if (Boolean.TryParse(sample , out myBool))
  {
  }

Please note that you cannot convert any type of string to type Boolean because the value of a Boolean can only be True or False

Hope you understand :)

How to check if a radiobutton is checked in a radiogroup in Android?

Try to use the method isChecked();

Like,

selectedRadioButton.isChecked() -> returns boolean.

Refere here for more details on Radio Button

On postback, how can I check which control cause postback in Page_Init event

Assuming it's a server control, you can use Request["ButtonName"]

To see if a specific button was clicked: if (Request["ButtonName"] != null)

Numpy: find index of the elements within range

You can use np.where to get indices and np.logical_and to set two conditions:

import numpy as np
a = np.array([1, 3, 5, 6, 9, 10, 14, 15, 56])

np.where(np.logical_and(a>=6, a<=10))
# returns (array([3, 4, 5]),)

What are C++ functors and their uses?

Like others have mentioned, a functor is an object that acts like a function, i.e. it overloads the function call operator.

Functors are commonly used in STL algorithms. They are useful because they can hold state before and between function calls, like a closure in functional languages. For example, you could define a MultiplyBy functor that multiplies its argument by a specified amount:

class MultiplyBy {
private:
    int factor;

public:
    MultiplyBy(int x) : factor(x) {
    }

    int operator () (int other) const {
        return factor * other;
    }
};

Then you could pass a MultiplyBy object to an algorithm like std::transform:

int array[5] = {1, 2, 3, 4, 5};
std::transform(array, array + 5, array, MultiplyBy(3));
// Now, array is {3, 6, 9, 12, 15}

Another advantage of a functor over a pointer to a function is that the call can be inlined in more cases. If you passed a function pointer to transform, unless that call got inlined and the compiler knows that you always pass the same function to it, it can't inline the call through the pointer.

Prevent textbox autofill with previously entered values

For firefox

Either:

<asp:TextBox id="Textbox1" runat="server" autocomplete="off"></asp:TextBox>

Or from the CodeBehind:

Textbox1.Attributes.Add("autocomplete", "off");

How do I make background-size work in IE?

In IE11 Windows 7 this worked for me,

background-size: 100% 100%;

How to display hidden characters by default (ZERO WIDTH SPACE ie. &#8203)

A very simple solution is to search your file(s) for non-ascii characters using a regular expression. This will nicely highlight all the spots where they are found with a border.

Search for [^\x00-\x7F] and check the box for Regex.

The result will look like this (in dark mode):

zero width space made visible

How to use Global Variables in C#?

A useful feature for this is using static

As others have said, you have to create a class for your globals:

public static class Globals {
    public const float PI = 3.14;
}

But you can import it like this in order to no longer write the class name in front of its static properties:

using static Globals;
[...]
Console.WriteLine("Pi is " + PI);

How to request Administrator access inside a batch file

@echo off 
Net session >nul 2>&1 || (PowerShell start -verb runas '%~0' &exit /b)
Echo Administrative privileges have been got. & pause

The above works on my Windows 10 Version 1903

How to move a file?

This is what I'm using at the moment:

import os, shutil
path = "/volume1/Users/Transfer/"
moveto = "/volume1/Users/Drive_Transfer/"
files = os.listdir(path)
files.sort()
for f in files:
    src = path+f
    dst = moveto+f
    shutil.move(src,dst)

Now fully functional. Hope this helps you.

Edit:

I've turned this into a function, that accepts a source and destination directory, making the destination folder if it doesn't exist, and moves the files. Also allows for filtering of the src files, for example if you only want to move images, then you use the pattern '*.jpg', by default, it moves everything in the directory

import os, shutil, pathlib, fnmatch

def move_dir(src: str, dst: str, pattern: str = '*'):
    if not os.path.isdir(dst):
        pathlib.Path(dst).mkdir(parents=True, exist_ok=True)
    for f in fnmatch.filter(os.listdir(src), pattern):
        shutil.move(os.path.join(src, f), os.path.join(dst, f))

How to prevent a browser from storing passwords

This worked for me:

<form action='/login' class='login-form' autocomplete='off'>
  User:
  <input type='user' name='user-entry'>
  <input type='hidden' name='user'>

  Password:
  <input type='password' name='password-entry'>
  <input type='hidden' name='password'>
</form>

Preloading images with JavaScript

I recommend you use a try/catch to prevent some possible issues:

OOP:

    var preloadImage = function (url) {
        try {
            var _img = new Image();
            _img.src = url;
        } catch (e) { }
    }

Standard:

    function preloadImage (url) {
        try {
            var _img = new Image();
            _img.src = url;
        } catch (e) { }
    }

Also, while I love DOM, old stupid browsers may have problems with you using DOM, so avoid it altogether IMHO contrary to freedev's contribution. Image() has better support in old trash browsers.

What is the difference among col-lg-*, col-md-* and col-sm-* in Bootstrap?

enter image description here

I think this image is pretty good to understand the concept better!

for more detail understanding please go though below link:

https://getbootstrap.com/docs/3.4/css/

Ignore cells on Excel line graph

There are many cases in which gaps are desired in a chart.

I am currently trying to make a plot of flow rate in a heating system vs. the time of day. I have data for two months. I want to plot only vs. the time of day from 00:00 to 23:59, which causes lines to be drawn between 23:59 and 00:01 of the next day which extend across the chart and disturb the otherwise regular daily variation.

Using the NA() formula (in German NV()) causes Excel to ignore the cells, but instead the previous and following points are simply connected, which has the same problem with lines across the chart.

The only solution I have been able to find is to delete the formulas from the cells which should create the gaps.

Using an IF formula with "" as its value for the gaps makes Excel interpret the X-values as string labels (shudder) for the chart instead of numbers (and makes me swear about the people who wrote that requirement).

How do you set the title color for the new Toolbar?

Option 1) The quick and easy way (Toolbar only)

Since appcompat-v7-r23 you can use the following attributes directly on your Toolbar or its style:

app:titleTextColor="@color/primary_text"
app:subtitleTextColor="@color/secondary_text"

If your minimum SDK is 23 and you use native Toolbar just change the namespace prefix to android.

In Java you can use the following methods:

toolbar.setTitleTextColor(Color.WHITE);
toolbar.setSubtitleTextColor(Color.WHITE);

These methods take a color int not a color resource ID!

Option 2) Override Toolbar style and theme attributes

layout/xxx.xml

<android.support.v7.widget.Toolbar
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:minHeight="?attr/actionBarSize"
    android:theme="@style/ThemeOverlay.MyApp.ActionBar"
    app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
    style="@style/Widget.MyApp.Toolbar.Solid"/>

values/styles.xml

<style name="Widget.MyApp.Toolbar.Solid" parent="Widget.AppCompat.ActionBar">
    <item name="android:background">@color/actionbar_color</item>
    <item name="android:elevation" tools:ignore="NewApi">4dp</item>
    <item name="titleTextAppearance">...</item>
</style>

<style name="ThemeOverlay.MyApp.ActionBar" parent="ThemeOverlay.AppCompat.ActionBar">
    <!-- Parent theme sets colorControlNormal to textColorPrimary. -->
    <item name="android:textColorPrimary">@color/actionbar_title_text</item>
</style>

Help! My icons changed color too!

@PeterKnut reported this affects the color of overflow button, navigation drawer button and back button. It also changes text color of SearchView.

Concerning the icon colors: The colorControlNormal inherits from

  • android:textColorPrimary for dark themes (white on black)
  • android:textColorSecondary for light themes (black on white)

If you apply this to the action bar's theme, you can customize the icon color.

<item name="colorControlNormal">#de000000</item>

There was a bug in appcompat-v7 up to r23 which required you to also override the native counterpart like so:

<item name="android:colorControlNormal" tools:ignore="NewApi">?colorControlNormal</item>

Help! My SearchView is a mess!

Note: This section is possibly obsolete.

Since you use the search widget which for some reason uses different back arrow (not visually, technically) than the one included with appcompat-v7, you have to set it manually in the app's theme. Support library's drawables get tinted correctly. Otherwise it would be always white.

<item name="homeAsUpIndicator">@drawable/abc_ic_ab_back_mtrl_am_alpha</item>

As for the search view text...there's no easy way. After digging through its source I found a way to get to the text view. I haven't tested this so please let me know in the comments if this didn't work.

SearchView sv = ...; // get your search view instance in onCreateOptionsMenu
// prefix identifier with "android:" if you're using native SearchView
TextView tv = sv.findViewById(getResources().getIdentifier("id/search_src_text", null, null));
tv.setTextColor(Color.GREEN); // and of course specify your own color

Bonus: Override ActionBar style and theme attributes

Appropriate styling for a default action appcompat-v7 action bar would look like this:

<!-- ActionBar vs Toolbar. -->
<style name="Widget.MyApp.ActionBar.Solid" parent="Widget.AppCompat.ActionBar.Solid">
    <item name="background">@color/actionbar_color</item> <!-- No prefix. -->
    <item name="elevation">4dp</item> <!-- No prefix. -->
    <item name="titleTextStyle">...</item> <!-- Style vs appearance. -->
</style>

<style name="Theme.MyApp" parent="Theme.AppCompat">
    <item name="actionBarStyle">@style/Widget.MyApp.ActionBar.Solid</item>
    <item name="actionBarTheme">@style/ThemeOverlay.MyApp.ActionBar</item>
    <item name="actionBarPopupTheme">@style/ThemeOverlay.AppCompat.Light</item>
</style>

Matplotlib discrete colorbar

This topic is well covered already but I wanted to add something more specific : I wanted to be sure that a certain value would be mapped to that color (not to any color).

It is not complicated but as it took me some time, it might help others not lossing as much time as I did :)

import matplotlib
from matplotlib.colors import ListedColormap

# Let's design a dummy land use field
A = np.reshape([7,2,13,7,2,2], (2,3))
vals = np.unique(A)

# Let's also design our color mapping: 1s should be plotted in blue, 2s in red, etc...
col_dict={1:"blue",
          2:"red",
          13:"orange",
          7:"green"}

# We create a colormar from our list of colors
cm = ListedColormap([col_dict[x] for x in col_dict.keys()])

# Let's also define the description of each category : 1 (blue) is Sea; 2 (red) is burnt, etc... Order should be respected here ! Or using another dict maybe could help.
labels = np.array(["Sea","City","Sand","Forest"])
len_lab = len(labels)

# prepare normalizer
## Prepare bins for the normalizer
norm_bins = np.sort([*col_dict.keys()]) + 0.5
norm_bins = np.insert(norm_bins, 0, np.min(norm_bins) - 1.0)
print(norm_bins)
## Make normalizer and formatter
norm = matplotlib.colors.BoundaryNorm(norm_bins, len_lab, clip=True)
fmt = matplotlib.ticker.FuncFormatter(lambda x, pos: labels[norm(x)])

# Plot our figure
fig,ax = plt.subplots()
im = ax.imshow(A, cmap=cm, norm=norm)

diff = norm_bins[1:] - norm_bins[:-1]
tickz = norm_bins[:-1] + diff / 2
cb = fig.colorbar(im, format=fmt, ticks=tickz)
fig.savefig("example_landuse.png")
plt.show()

enter image description here

Oracle: If Table Exists

The best and most efficient way is to catch the "table not found" exception: this avoids the overhead of checking if the table exists twice; and doesn't suffer from the problem that if the DROP fails for some other reason (that might be important) the exception is still raised to the caller:

BEGIN
   EXECUTE IMMEDIATE 'DROP TABLE ' || table_name;
EXCEPTION
   WHEN OTHERS THEN
      IF SQLCODE != -942 THEN
         RAISE;
      END IF;
END;

ADDENDUM For reference, here are the equivalent blocks for other object types:

Sequence

BEGIN
  EXECUTE IMMEDIATE 'DROP SEQUENCE ' || sequence_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -2289 THEN
      RAISE;
    END IF;
END;

View

BEGIN
  EXECUTE IMMEDIATE 'DROP VIEW ' || view_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -942 THEN
      RAISE;
    END IF;
END;

Trigger

BEGIN
  EXECUTE IMMEDIATE 'DROP TRIGGER ' || trigger_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -4080 THEN
      RAISE;
    END IF;
END;

Index

BEGIN
  EXECUTE IMMEDIATE 'DROP INDEX ' || index_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -1418 THEN
      RAISE;
    END IF;
END;

Column

BEGIN
  EXECUTE IMMEDIATE 'ALTER TABLE ' || table_name
                || ' DROP COLUMN ' || column_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -904 AND SQLCODE != -942 THEN
      RAISE;
    END IF;
END;

Database Link

BEGIN
  EXECUTE IMMEDIATE 'DROP DATABASE LINK ' || dblink_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -2024 THEN
      RAISE;
    END IF;
END;

Materialized View

BEGIN
  EXECUTE IMMEDIATE 'DROP MATERIALIZED VIEW ' || mview_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -12003 THEN
      RAISE;
    END IF;
END;

Type

BEGIN
  EXECUTE IMMEDIATE 'DROP TYPE ' || type_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -4043 THEN
      RAISE;
    END IF;
END;

Constraint

BEGIN
  EXECUTE IMMEDIATE 'ALTER TABLE ' || table_name
            || ' DROP CONSTRAINT ' || constraint_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -2443 AND SQLCODE != -942 THEN
      RAISE;
    END IF;
END;

Scheduler Job

BEGIN
  DBMS_SCHEDULER.drop_job(job_name);
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -27475 THEN
      RAISE;
    END IF;
END;

User / Schema

BEGIN
  EXECUTE IMMEDIATE 'DROP USER ' || user_name;
  /* you may or may not want to add CASCADE */
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -1918 THEN
      RAISE;
    END IF;
END;

Package

BEGIN
  EXECUTE IMMEDIATE 'DROP PACKAGE ' || package_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -4043 THEN
      RAISE;
    END IF;
END;

Procedure

BEGIN
  EXECUTE IMMEDIATE 'DROP PROCEDURE ' || procedure_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -4043 THEN
      RAISE;
    END IF;
END;

Function

BEGIN
  EXECUTE IMMEDIATE 'DROP FUNCTION ' || function_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -4043 THEN
      RAISE;
    END IF;
END;

Tablespace

BEGIN
  EXECUTE IMMEDIATE 'DROP TABLESPACE' || tablespace_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -959 THEN
      RAISE;
    END IF;
END;

Synonym

BEGIN
  EXECUTE IMMEDIATE 'DROP SYNONYM ' || synonym_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -1434 THEN
      RAISE;
    END IF;
END;

Referring to a table in LaTeX

You must place the label after a caption in order to for label to store the table's number, not the chapter's number.

\begin{table}
\begin{tabular}{| p{5cm} | p{5cm} | p{5cm} |}
  -- cut --
\end{tabular}
\caption{My table}
\label{table:kysymys}
\end{table}

Table \ref{table:kysymys} on page \pageref{table:kysymys} refers to the ...

Create comma separated strings C#?

You can use the string.Join method to do something like string.Join(",", o.Number, o.Id, o.whatever, ...).

edit: As digEmAll said, string.Join is faster than StringBuilder. They use an external implementation for the string.Join.

Profiling code (of course run in release without debug symbols):

class Program
{
    static void Main(string[] args)
    {
        Stopwatch sw = new Stopwatch();
        string r;
        int iter = 10000;

        string[] values = { "a", "b", "c", "d", "a little bit longer please", "one more time" };

        sw.Restart();
        for (int i = 0; i < iter; i++)
            r = Program.StringJoin(",", values);
        sw.Stop();
        Console.WriteLine("string.Join ({0} times): {1}ms", iter, sw.ElapsedMilliseconds);

        sw.Restart();
        for (int i = 0; i < iter; i++)
            r = Program.StringBuilderAppend(",", values);
        sw.Stop();
        Console.WriteLine("StringBuilder.Append ({0} times): {1}ms", iter, sw.ElapsedMilliseconds);
        Console.ReadLine();
    }

    static string StringJoin(string seperator, params string[] values)
    {
        return string.Join(seperator, values);
    }

    static string StringBuilderAppend(string seperator, params string[] values)
    {
        StringBuilder builder = new StringBuilder();
        builder.Append(values[0]);
        for (int i = 1; i < values.Length; i++)
        {
            builder.Append(seperator);
            builder.Append(values[i]);
        }
        return builder.ToString();
    }
}

string.Join took 2ms on my machine and StringBuilder.Append 5ms. So there is noteworthy difference. Thanks to digAmAll for the hint.

Resolving tree conflict

What you can do to resolve your conflict is

svn resolve --accept working -R <path>

where <path> is where you have your conflict (can be the root of your repo).

Explanations:

  • resolve asks svn to resolve the conflict
  • accept working specifies to keep your working files
  • -R stands for recursive

Hope this helps.

EDIT:

To sum up what was said in the comments below:

  • <path> should be the directory in conflict (C:\DevBranch\ in the case of the OP)
  • it's likely that the origin of the conflict is
    • either the use of the svn switch command
    • or having checked the Switch working copy to new branch/tag option at branch creation
  • more information about conflicts can be found in the dedicated section of Tortoise's documentation.
  • to be able to run the command, you should have the CLI tools installed together with Tortoise:

Command line client tools

Regular expression - starting and ending with a character string

^wp.*\.php$ Should do the trick.

The .* means "any character, repeated 0 or more times". The next . is escaped because it's a special character, and you want a literal period (".php"). Don't forget that if you're typing this in as a literal string in something like C#, Java, etc., you need to escape the backslash because it's a special character in many literal strings.

Use ASP.NET MVC validation with jquery ajax?

Client Side

Using the jQuery.validate library should be pretty simple to set up.

Specify the following settings in your Web.config file:

<appSettings>
    <add key="ClientValidationEnabled" value="true"/> 
    <add key="UnobtrusiveJavaScriptEnabled" value="true"/> 
</appSettings>

When you build up your view, you would define things like this:

@Html.LabelFor(Model => Model.EditPostViewModel.Title, true)
@Html.TextBoxFor(Model => Model.EditPostViewModel.Title, 
                                new { @class = "tb1", @Style = "width:400px;" })
@Html.ValidationMessageFor(Model => Model.EditPostViewModel.Title)

NOTE: These need to be defined within a form element

Then you would need to include the following libraries:

<script src='@Url.Content("~/Scripts/jquery.validate.js")' type='text/javascript'></script>
<script src='@Url.Content("~/Scripts/jquery.validate.unobtrusive.js")' type='text/javascript'></script>

This should be able to set you up for client side validation

Resources

Server Side

NOTE: This is only for additional server side validation on top of jQuery.validation library

Perhaps something like this could help:

[ValidateAjax]
public JsonResult Edit(EditPostViewModel data)
{
    //Save data
    return Json(new { Success = true } );
}

Where ValidateAjax is an attribute defined as:

public class ValidateAjaxAttribute : ActionFilterAttribute
{
    public override void OnActionExecuting(ActionExecutingContext filterContext)
    {
        if (!filterContext.HttpContext.Request.IsAjaxRequest())
            return;

        var modelState = filterContext.Controller.ViewData.ModelState;
        if (!modelState.IsValid)
        {
            var errorModel = 
                    from x in modelState.Keys
                    where modelState[x].Errors.Count > 0
                    select new
                           {
                               key = x,
                               errors = modelState[x].Errors.
                                                      Select(y => y.ErrorMessage).
                                                      ToArray()
                           };
            filterContext.Result = new JsonResult()
                                       {
                                           Data = errorModel
                                       };
            filterContext.HttpContext.Response.StatusCode = 
                                                  (int) HttpStatusCode.BadRequest;
        }
    }
}

What this does is return a JSON object specifying all of your model errors.

Example response would be

[{
    "key":"Name",
    "errors":["The Name field is required."]
},
{
    "key":"Description",
    "errors":["The Description field is required."]
}]

This would be returned to your error handling callback of the $.ajax call

You can loop through the returned data to set the error messages as needed based on the Keys returned (I think something like $('input[name="' + err.key + '"]') would find your input element

How do I force detach Screen from another SSH session?

Short answer

  1. Reattach without ejecting others: screen -x
  2. Get list of displays: ^A *, select the one to disconnect, press d


Explained answer

Background: When I was looking for the solution with same problem description, I have always landed on this answer. I would like to provide more sensible solution. (For example: the other attached screen has a different size and a I cannot force resize it in my terminal.)

Note: PREFIX is usually ^A = ctrl+a

Note: the display may also be called:

  • "user front-end" (in at command manual in screen)
  • "client" (tmux vocabulary where this functionality is detach-client)
  • "terminal" (as we call the window in our user interface) /depending on

1. Reattach a session: screen -x

-x attach to a not detached screen session without detaching it

2. List displays of this session: PREFIX *

It is the default key binding for: PREFIX :displays. Performing it within the screen, identify the other display we want to disconnect (e.g. smaller size). (Your current display is displayed in brighter color/bold when not selected).

term-type   size         user interface           window       Perms
---------- ------- ---------- ----------------- ----------     -----
 screen     240x60         you@/dev/pts/2      nb  0(zsh)        rwx
 screen      78x40         you@/dev/pts/0      nb  0(zsh)        rwx

Using arrows ? ?, select the targeted display, press d If nothing happens, you tried to detach your own display and screen will not detach it. If it was another one, within a second or two, the entry will disappear.

Press ENTER to quit the listing.

Optionally: in order to make the content fit your screen, reflow: PREFIX F (uppercase F)

Excerpt from man page of screen:

displays

Shows a tabular listing of all currently connected user front-ends (displays). This is most useful for multiuser sessions. The following keys can be used in displays list:

  • mouseclick Move to the selected line. Available when "mousetrack" is set to on.
  • space Refresh the list
  • d Detach that display
  • D Power detach that display
  • C-g, enter, or escape Exit the list

How to change indentation mode in Atom?

When Atom auto-indent-detection got it hopelessly wrong and refused to let me type a literal Tab character, I eventually found the 'Force-Tab' extension - which gave me back control. I wanted to keep shift-tab for outdenting, so set ctrl-tab to insert a hard tab. In my keymap I added:

'atom-text-editor': 'ctrl-tab': 'force-tab:insert-actual-tab'

Using command line arguments in VBscript

If you need direct access:

WScript.Arguments.Item(0)
WScript.Arguments.Item(1)
...

Can I set an opacity only to the background image of a div?

Hello to everybody I did this and it worked well

_x000D_
_x000D_
 var canvas, ctx;_x000D_
_x000D_
  function init() {_x000D_
   canvas = document.getElementById('color');_x000D_
   ctx = canvas.getContext('2d');_x000D_
_x000D_
   ctx.save();_x000D_
   ctx.fillStyle = '#bfbfbf'; //  #00843D   // 118846_x000D_
   ctx.fillRect(0, 0, 490, 490);_x000D_
   ctx.restore();_x000D_
  }
_x000D_
section{_x000D_
  height: 400px;_x000D_
  background: url(https://images.pexels.com/photos/265087/pexels-photo-265087.jpeg?w=1260&h=750&auto=compress&cs=tinysrgb);_x000D_
  background-repeat: no-repeat;_x000D_
  background-position: center;_x000D_
  background-size: cover;_x000D_
  position: relative;_x000D_
 _x000D_
}_x000D_
_x000D_
canvas {_x000D_
 width: 100%;_x000D_
 height: 400px;_x000D_
 opacity: 0.9;_x000D_
_x000D_
}_x000D_
_x000D_
#text {_x000D_
 position: absolute;_x000D_
 top: 10%;_x000D_
 left: 0;_x000D_
 width: 100%;_x000D_
 text-align: center;_x000D_
}_x000D_
_x000D_
_x000D_
.middle{_x000D_
 text-align: center;_x000D_
 _x000D_
}_x000D_
_x000D_
section small{_x000D_
 background-color: #262626;_x000D_
 padding: 12px;_x000D_
 color: whitesmoke;_x000D_
  letter-spacing: 1.5px;_x000D_
_x000D_
}_x000D_
_x000D_
section i{_x000D_
  color: white;_x000D_
  background-color: grey;_x000D_
}_x000D_
_x000D_
section h1{_x000D_
  opacity: 0.8;_x000D_
}
_x000D_
<html lang="en">_x000D_
<head>_x000D_
 <meta charset="UTF-8">_x000D_
 <title>Metrics</title>_x000D_
 <meta name="viewport" content="width=device-width, initial-scale=1">_x000D_
<link rel="stylesheet" href="https://fonts.googleapis.com/icon?family=Material+Icons">  _x000D_
</head>  _x000D_
  _x000D_
<body onload="init();">_x000D_
<section>_x000D_
<canvas id="color"></canvas>_x000D_
_x000D_
<div class="w3-container middle" id="text">_x000D_
<i class="material-icons w3-highway-blue" style="font-size:60px;">assessment</i>_x000D_
<h1>Medimos las acciones de tus ventas y disenamos en la WEB tu Marca.</h1>_x000D_
<small>Metrics &amp; WEB</small>_x000D_
</div>_x000D_
</section> 
_x000D_
_x000D_
_x000D_

How can I delay a :hover effect in CSS?

div {
     background: #dbdbdb;
    -webkit-transition: .5s all;   
    -webkit-transition-delay: 5s; 
    -moz-transition: .5s all;   
    -moz-transition-delay: 5s; 
    -ms-transition: .5s all;   
    -ms-transition-delay: 5s; 
    -o-transition: .5s all;   
    -o-transition-delay: 5s; 
    transition: .5s all;   
    transition-delay: 5s; 
}

div:hover {
    background:#5AC900;
    -webkit-transition-delay: 0s;
    -moz-transition-delay: 0s;
    -ms-transition-delay: 0s;
    -o-transition-delay: 0s;
    transition-delay: 0s;
}

This will add a transition delay, which will be applicable to almost every browser..

How to do a redirect to another route with react-router?

Easiest solution for web!

Up to date 2020
confirmed working with:

"react-router-dom": "^5.1.2"
"react": "^16.10.2"

Use the useHistory() hook!

import React from 'react';
import { useHistory } from "react-router-dom";


export function HomeSection() {
  const history = useHistory();
  const goLogin = () => history.push('login');

  return (
    <Grid>
      <Row className="text-center">          
        <Col md={12} xs={12}>
          <div className="input-group">
            <span className="input-group-btn">
              <button onClick={goLogin} type="button" />
            </span>
          </div>
        </Col>
      </Row>
    </Grid>
  );
}

I want my android application to be only run in portrait mode?

In the manifest, set this for all your activities:

<activity android:name=".YourActivity"
    android:configChanges="orientation"
    android:screenOrientation="portrait"/>

Let me explain:

  • With android:configChanges="orientation" you tell Android that you will be responsible of the changes of orientation.
  • android:screenOrientation="portrait" you set the default orientation mode.

Download file and automatically save it to folder

Well, your solution almost works. There are a few things to take into account to keep it simple:

  • Cancel the default navigation only for specific URLs you know a download will occur, or the user won't be able to navigate anywhere. This means you musn't change your website download URLs.

  • DownloadFileAsync doesn't know the name reported by the server in the Content-Disposition header so you have to specify one, or compute one from the original URL if that's possible. You cannot just specify the folder and expect the file name to be retrieved automatically.

  • You have to handle download server errors from the DownloadCompleted callback because the web browser control won't do it for you anymore.

Sample piece of code, that will download into the directory specified in textBox1, but with a random file name, and without any additional error handling:

private void webBrowser1_Navigating(object sender, WebBrowserNavigatingEventArgs e) {
    /* change this to match your URL. For example, if the URL always is something like "getfile.php?file=xxx", try e.Url.ToString().Contains("getfile.php?") */
    if (e.Url.ToString().EndsWith(".zip")) {
        e.Cancel = true;
        string filePath = Path.Combine(textBox1.Text, Path.GetRandomFileName());
        var client = new WebClient();
        client.DownloadFileCompleted += client_DownloadFileCompleted;
        client.DownloadFileAsync(e.Url, filePath);
    }
}

private void client_DownloadFileCompleted(object sender, AsyncCompletedEventArgs e) {
    MessageBox.Show("File downloaded");
}

This solution should work but can be broken very easily. Try to consider some web service listing the available files for download and make a custom UI for it. It'll be simpler and you will control the whole process.

How can I select all options of multi-select select box on click?

Try this:

$('#select_all').click(function() {
    $('#countries option').prop('selected', true);
});

And here's a live demo.

How to prettyprint a JSON file?

It's far from perfect, but it does the job.

data = data.replace(',"',',\n"')

you can improve it, add indenting and so on, but if you just want to be able to read a cleaner json, this is the way to go.

Passing an array of parameters to a stored procedure

If you are using Sql Server 2008 or better, you can use something called a Table-Valued Parameter (TVP) instead of serializing & deserializing your list data every time you want to pass it to a stored procedure.

Let's start by creating a simple schema to serve as our playground:

CREATE DATABASE [TestbedDb]
GO


USE [TestbedDb]
GO

    /* First, setup the sample program's account & credentials*/
CREATE LOGIN [testbedUser] WITH PASSWORD=N'µ×?
?S[°¿Q­¥½q?_Ĭ¼Ð)3õļ%dv', DEFAULT_DATABASE=[master], DEFAULT_LANGUAGE=[us_english], CHECK_EXPIRATION=OFF, CHECK_POLICY=ON
GO

CREATE USER [testbedUser] FOR LOGIN [testbedUser] WITH DEFAULT_SCHEMA=[dbo]
GO

EXEC sp_addrolemember N'db_owner', N'testbedUser'
GO


    /* Now setup the schema */
CREATE TABLE dbo.Table1 ( t1Id INT NOT NULL PRIMARY KEY );
GO

INSERT INTO dbo.Table1 (t1Id)
VALUES
    (1),
    (2),
    (3),
    (4),
    (5),
    (6),
    (7),
    (8),
    (9),
    (10);
GO

With our schema and sample data in place, we are now ready to create our TVP stored procedure:

CREATE TYPE T1Ids AS Table (
        t1Id INT
);
GO


CREATE PROCEDURE dbo.FindMatchingRowsInTable1( @Table1Ids AS T1Ids READONLY )
AS
BEGIN
        SET NOCOUNT ON;

        SELECT Table1.t1Id FROM dbo.Table1 AS Table1
        JOIN @Table1Ids AS paramTable1Ids ON Table1.t1Id = paramTable1Ids.t1Id;
END
GO

With both our schema and API in place, we can call the TVP stored procedure from our program like so:

        // Curry the TVP data
        DataTable t1Ids = new DataTable( );
        t1Ids.Columns.Add( "t1Id",
                           typeof( int ) );

        int[] listOfIdsToFind = new[] {1, 5, 9};
        foreach ( int id in listOfIdsToFind )
        {
            t1Ids.Rows.Add( id );
        }
        // Prepare the connection details
        SqlConnection testbedConnection =
                new SqlConnection(
                        @"Data Source=.\SQLExpress;Initial Catalog=TestbedDb;Persist Security Info=True;User ID=testbedUser;Password=letmein12;Connect Timeout=5" );

        try
        {
            testbedConnection.Open( );

            // Prepare a call to the stored procedure
            SqlCommand findMatchingRowsInTable1 = new SqlCommand( "dbo.FindMatchingRowsInTable1",
                                                                  testbedConnection );
            findMatchingRowsInTable1.CommandType = CommandType.StoredProcedure;

            // Curry up the TVP parameter
            SqlParameter sqlParameter = new SqlParameter( "Table1Ids",
                                                          t1Ids );
            findMatchingRowsInTable1.Parameters.Add( sqlParameter );

            // Execute the stored procedure
            SqlDataReader sqlDataReader = findMatchingRowsInTable1.ExecuteReader( );

            while ( sqlDataReader.Read( ) )
            {
                Console.WriteLine( "Matching t1ID: {0}",
                                   sqlDataReader[ "t1Id" ] );
            }
        }
        catch ( Exception e )
        {
            Console.WriteLine( e.ToString( ) );
        }
  /* Output:
   * Matching t1ID: 1
   * Matching t1ID: 5
   * Matching t1ID: 9
   */

There is probably a less painful way to do this using a more abstract API, such as Entity Framework. However, I do not have the time to see for myself at this time.

IIS7 Cache-Control

That's not true Jeff.

You simply have to select a folder within your IIS 7 Manager UI (e.g. Images or event the Default Web Application folder) and then click on "HTTP Response Headers". Then you have to click on "Set Common Header.." in the right pane and select the "Expire Web content". There you can easily configure a max-age of 24 hours by choosing "After:", entering "24" in the Textbox and choose "Hours" in the combobox.

Your first paragraph regarding the web.config entry is right. I'd add the cacheControlCustom-attribute to set the cache control header to "public" or whatever is needed in that case.

You can, of course, achieve the same by providing web.config entries (or files) as needed.

Edit: removed a confusing sentence :)

Regex AND operator

Example of a Boolean (AND) plus Wildcard search, which I'm using inside a javascript Autocomplete plugin:

String to match: "my word"

String to search: "I'm searching for my funny words inside this text"

You need the following regex: /^(?=.*my)(?=.*word).*$/im

Explaining:

^ assert position at start of a line

?= Positive Lookahead

.* matches any character (except newline)

() Groups

$ assert position at end of a line

i modifier: insensitive. Case insensitive match (ignores case of [a-zA-Z])

m modifier: multi-line. Causes ^ and $ to match the begin/end of each line (not only begin/end of string)

Test the Regex here: https://regex101.com/r/iS5jJ3/1

So, you can create a javascript function that:

  1. Replace regex reserved characters to avoid errors
  2. Split your string at spaces
  3. Encapsulate your words inside regex groups
  4. Create a regex pattern
  5. Execute the regex match

Example:

_x000D_
_x000D_
function fullTextCompare(myWords, toMatch){_x000D_
    //Replace regex reserved characters_x000D_
    myWords=myWords.replace(/[-\/\\^$*+?.()|[\]{}]/g, '\\$&');_x000D_
    //Split your string at spaces_x000D_
    arrWords = myWords.split(" ");_x000D_
    //Encapsulate your words inside regex groups_x000D_
    arrWords = arrWords.map(function( n ) {_x000D_
        return ["(?=.*"+n+")"];_x000D_
    });_x000D_
    //Create a regex pattern_x000D_
    sRegex = new RegExp("^"+arrWords.join("")+".*$","im");_x000D_
    //Execute the regex match_x000D_
    return(toMatch.match(sRegex)===null?false:true);_x000D_
}_x000D_
_x000D_
//Using it:_x000D_
console.log(_x000D_
    fullTextCompare("my word","I'm searching for my funny words inside this text")_x000D_
);_x000D_
_x000D_
//Wildcards:_x000D_
console.log(_x000D_
    fullTextCompare("y wo","I'm searching for my funny words inside this text")_x000D_
);
_x000D_
_x000D_
_x000D_

How to concat a string to xsl:value-of select="...?

Use:

<a href="wantedText{/*/properties/property[@name='report']/@value)}"></a>

grant remote access of MySQL database from any IP address

GRANT ALL PRIVILEGES ON *.* TO 'user'@'ipadress'

What primitive data type is time_t?

You can use the function difftime. It returns the difference between two given time_t values, the output value is double (see difftime documentation).

time_t actual_time;
double actual_time_sec;
actual_time = time(0);
actual_time_sec = difftime(actual_time,0); 
printf("%g",actual_time_sec);

How to read a .xlsx file using the pandas Library in iPython?

I usually create a dictionary containing a DataFrame for every sheet:

xl_file = pd.ExcelFile(file_name)

dfs = {sheet_name: xl_file.parse(sheet_name) 
          for sheet_name in xl_file.sheet_names}

Update: In pandas version 0.21.0+ you will get this behavior more cleanly by passing sheet_name=None to read_excel:

dfs = pd.read_excel(file_name, sheet_name=None)

In 0.20 and prior, this was sheetname rather than sheet_name (this is now deprecated in favor of the above):

dfs = pd.read_excel(file_name, sheetname=None)

Best way to remove an event handler in jQuery?

This wasn't available when this question was answered, but you can also use the live() method to enable/disable events.

$('#myimage:not(.disabled)').live('click', myclickevent);

$('#mydisablebutton').click( function () { $('#myimage').addClass('disabled'); });

What will happen with this code is that when you click #mydisablebutton, it will add the class disabled to the #myimage element. This will make it so that the selector no longer matches the element and the event will not be fired until the 'disabled' class is removed making the .live() selector valid again.

This has other benefits by adding styling based on that class as well.

Java - No enclosing instance of type Foo is accessible

Well... so many good answers but i wanna to add more on it. A brief look on Inner class in Java- Java allows us to define a class within another class and Being able to nest classes in this way has certain advantages:

  1. It can hide(It increases encapsulation) the class from other classes - especially relevant if the class is only being used by the class it is contained within. In this case there is no need for the outside world to know about it.

  2. It can make code more maintainable as the classes are logically grouped together around where they are needed.

  3. The inner class has access to the instance variables and methods of its containing class.

We have mainly three types of Inner Classes

  1. Local inner
  2. Static Inner Class
  3. Anonymous Inner Class

Some of the important points to be remember

  • We need class object to access the Local Inner Class in which it exist.
  • Static Inner Class get directly accessed same as like any other static method of the same class in which it is exists.
  • Anonymous Inner Class are not visible to out side world as well as to the other methods or classes of the same class(in which it is exist) and it is used on the point where it is declared.

Let`s try to see the above concepts practically_

public class MyInnerClass {

public static void main(String args[]) throws InterruptedException {
    // direct access to inner class method
    new MyInnerClass.StaticInnerClass().staticInnerClassMethod();

    // static inner class reference object
    StaticInnerClass staticInnerclass = new StaticInnerClass();
    staticInnerclass.staticInnerClassMethod();

    // access local inner class
    LocalInnerClass localInnerClass = new MyInnerClass().new LocalInnerClass();
    localInnerClass.localInnerClassMethod();

    /*
     * Pay attention to the opening curly braces and the fact that there's a
     * semicolon at the very end, once the anonymous class is created:
     */
    /*
     AnonymousClass anonymousClass = new AnonymousClass() {
         // your code goes here...

     };*/
 }

// static inner class
static class StaticInnerClass {
    public void staticInnerClassMethod() {
        System.out.println("Hay... from Static Inner class!");
    }
}

// local inner class
class LocalInnerClass {
    public void localInnerClassMethod() {
        System.out.println("Hay... from local Inner class!");
    }
 }

}

I hope this will helps to everyone. Please refer for more

How do you underline a text in Android XML?

<resource>
    <string name="your_string_here">This is an <u>underline</u>.</string>
</resources>

If it does not work then

<resource>
<string name="your_string_here">This is an &lt;u>underline&lt;/u>.</string>

Because "<" could be a keyword at some time.

And for Displaying

TextView textView = (TextView) view.findViewById(R.id.textview);
textView.setText(Html.fromHtml(getString(R.string.your_string_here)));

Is there a Social Security Number reserved for testing/examples?

There are multiple number groups and some particular numbers that will never be allocated:

Consider using one of these (the obviously invalid 000-00-0000 would be a good one IMO).

(Answer has been updated to provide source information beyond Wikipedia and remove information that is no longer accurate after the SSA made its randomization change in mid 2011.)

Calculating Pearson correlation and significance in Python

You can do this with pandas.DataFrame.corr, too:

import pandas as pd
a = [[1, 2, 3],
     [5, 6, 9],
     [5, 6, 11],
     [5, 6, 13],
     [5, 3, 13]]
df = pd.DataFrame(data=a)
df.corr()

This gives

          0         1         2
0  1.000000  0.745601  0.916579
1  0.745601  1.000000  0.544248
2  0.916579  0.544248  1.000000

Multi column forms with fieldsets

There are a couple of things that need to be adjusted in your layout:

  1. You are nesting col elements within form-group elements. This should be the other way around (the form-group should be within the col-sm-xx element).

  2. You should always use a row div for each new "row" in your design. In your case, you would need at least 5 rows (Username, Password and co, Title/First/Last name, email, Language). Otherwise, your problematic .col-sm-12 is still on the same row with the above 3 .col-sm-4 resulting in a total of columns greater than 12, and causing the overlap problem.

Here is a fixed demo.

And an excerpt of what the problematic section HTML should become:

<fieldset>
    <legend>Personal Information</legend>
    <div class='row'>
        <div class='col-sm-4'>    
            <div class='form-group'>
                <label for="user_title">Title</label>
                <input class="form-control" id="user_title" name="user[title]" size="30" type="text" />
            </div>
        </div>
        <div class='col-sm-4'>
            <div class='form-group'>
                <label for="user_firstname">First name</label>
                <input class="form-control" id="user_firstname" name="user[firstname]" required="true" size="30" type="text" />
            </div>
        </div>
        <div class='col-sm-4'>
            <div class='form-group'>
                <label for="user_lastname">Last name</label>
                <input class="form-control" id="user_lastname" name="user[lastname]" required="true" size="30" type="text" />
            </div>
        </div>
    </div>
    <div class='row'>
        <div class='col-sm-12'>
            <div class='form-group'>

                <label for="user_email">Email</label>
                <input class="form-control required email" id="user_email" name="user[email]" required="true" size="30" type="text" />
            </div>
        </div>
    </div>
</fieldset>

How to convert milliseconds to seconds with precision

I had this problem too, somehow my code did not present the exact values but rounded the number in seconds to 0.0 (if milliseconds was under 1 second). What helped me out is adding the decimal to the division value.

double time_seconds = time_milliseconds / 1000.0;   // add the decimal
System.out.println(time_milliseconds);              // Now this should give you the right value.

Create a GUID in Java

This answer contains 2 generators for random-based and name-based UUIDs, compliant with RFC-4122. Feel free to use and share.

RANDOM-BASED (v4)

This utility class that generates random-based UUIDs:

package your.package.name;

import java.security.SecureRandom;
import java.util.Random;
import java.util.UUID;

/**
 * Utility class that creates random-based UUIDs.
 * 
 */
public abstract class RandomUuidCreator {

    private static final int RANDOM_VERSION = 4;

    /**
     * Returns a random-based UUID.
     * 
     * It uses a thread local {@link SecureRandom}.
     * 
     * @return a random-based UUID
     */
    public static UUID getRandomUuid() {
        return getRandomUuid(SecureRandomLazyHolder.THREAD_LOCAL_RANDOM.get());
    }

    /**
     * Returns a random-based UUID.
     * 
     * It uses any instance of {@link Random}.
     * 
     * @return a random-based UUID
     */
    public static UUID getRandomUuid(Random random) {

        long msb = 0;
        long lsb = 0;

        // (3) set all bit randomly
        if (random instanceof SecureRandom) {
            // Faster for instances of SecureRandom
            final byte[] bytes = new byte[16];
            random.nextBytes(bytes);
            msb = toNumber(bytes, 0, 8); // first 8 bytes for MSB
            lsb = toNumber(bytes, 8, 16); // last 8 bytes for LSB
        } else {
            msb = random.nextLong(); // first 8 bytes for MSB
            lsb = random.nextLong(); // last 8 bytes for LSB
        }

        // Apply version and variant bits (required for RFC-4122 compliance)
        msb = (msb & 0xffffffffffff0fffL) | (RANDOM_VERSION & 0x0f) << 12; // apply version bits
        lsb = (lsb & 0x3fffffffffffffffL) | 0x8000000000000000L; // apply variant bits

        // Return the UUID
        return new UUID(msb, lsb);
    }

    private static long toNumber(final byte[] bytes, final int start, final int length) {
        long result = 0;
        for (int i = start; i < length; i++) {
            result = (result << 8) | (bytes[i] & 0xff);
        }
        return result;
    }

    // Holds thread local secure random
    private static class SecureRandomLazyHolder {
        static final ThreadLocal<Random> THREAD_LOCAL_RANDOM = ThreadLocal.withInitial(SecureRandom::new);
    }

    /**
     * For tests!
     */
    public static void main(String[] args) {

        System.out.println("// Using thread local `java.security.SecureRandom` (DEFAULT)");
        System.out.println("RandomUuidCreator.getRandomUuid()");
        System.out.println();
        for (int i = 0; i < 5; i++) {
            System.out.println(RandomUuidCreator.getRandomUuid());
        }

        System.out.println();
        System.out.println("// Using `java.util.Random` (FASTER)");
        System.out.println("RandomUuidCreator.getRandomUuid(new Random())");
        System.out.println();
        Random random = new Random();
        for (int i = 0; i < 5; i++) {
            System.out.println(RandomUuidCreator.getRandomUuid(random));
        }
    }
}

This is the output:

// Using thread local `java.security.SecureRandom` (DEFAULT)
RandomUuidCreator.getRandomUuid()

'ef4f5ad2-8147-46cb-8389-c2b8c3ef6b10'
'adc0305a-df29-4f08-9d73-800fde2048f0'
'4b794b59-bff8-4013-b656-5d34c33f4ce3'
'22517093-ee24-4120-96a5-ecee943992d1'
'899fb1fb-3e3d-4026-85a8-8a2d274a10cb'

// Using `java.util.Random` (FASTER)
RandomUuidCreator.getRandomUuid(new Random())

'4dabbbc2-fcb2-4074-a91c-5e2977a5bbf8'
'078ec231-88bc-4d74-9774-96c0b820ceda'
'726638fa-69a6-4a18-b09f-5fd2a708059b'
'15616ebe-1dfd-4f5c-b2ed-cea0ac1ad823'
'affa31ad-5e55-4cde-8232-cddd4931923a'

NAME-BASED (v3 and v5)

This utility class that generates name-based UUIDs (MD5 and SHA1):

package your.package.name;

import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.UUID;

/**
 * Utility class that creates UUIDv3 (MD5) and UUIDv5 (SHA1).
 *
 */
public class HashUuidCreator {

    // Domain Name System
    public static final UUID NAMESPACE_DNS = new UUID(0x6ba7b8109dad11d1L, 0x80b400c04fd430c8L);
    // Uniform Resource Locator
    public static final UUID NAMESPACE_URL = new UUID(0x6ba7b8119dad11d1L, 0x80b400c04fd430c8L);
    // ISO Object ID
    public static final UUID NAMESPACE_ISO_OID = new UUID(0x6ba7b8129dad11d1L, 0x80b400c04fd430c8L);
    // X.500 Distinguished Name
    public static final UUID NAMESPACE_X500_DN = new UUID(0x6ba7b8149dad11d1L, 0x80b400c04fd430c8L);

    private static final int VERSION_3 = 3; // UUIDv3 MD5
    private static final int VERSION_5 = 5; // UUIDv5 SHA1

    private static final String MESSAGE_DIGEST_MD5 = "MD5"; // UUIDv3
    private static final String MESSAGE_DIGEST_SHA1 = "SHA-1"; // UUIDv5

    private static UUID getHashUuid(UUID namespace, String name, String algorithm, int version) {

        final byte[] hash;
        final MessageDigest hasher;

        try {
            // Instantiate a message digest for the chosen algorithm
            hasher = MessageDigest.getInstance(algorithm);

            // Insert name space if NOT NULL
            if (namespace != null) {
                hasher.update(toBytes(namespace.getMostSignificantBits()));
                hasher.update(toBytes(namespace.getLeastSignificantBits()));
            }

            // Generate the hash
            hash = hasher.digest(name.getBytes(StandardCharsets.UTF_8));

            // Split the hash into two parts: MSB and LSB
            long msb = toNumber(hash, 0, 8); // first 8 bytes for MSB
            long lsb = toNumber(hash, 8, 16); // last 8 bytes for LSB

            // Apply version and variant bits (required for RFC-4122 compliance)
            msb = (msb & 0xffffffffffff0fffL) | (version & 0x0f) << 12; // apply version bits
            lsb = (lsb & 0x3fffffffffffffffL) | 0x8000000000000000L; // apply variant bits

            // Return the UUID
            return new UUID(msb, lsb);

        } catch (NoSuchAlgorithmException e) {
            throw new RuntimeException("Message digest algorithm not supported.");
        }
    }

    public static UUID getMd5Uuid(String string) {
        return getHashUuid(null, string, MESSAGE_DIGEST_MD5, VERSION_3);
    }

    public static UUID getSha1Uuid(String string) {
        return getHashUuid(null, string, MESSAGE_DIGEST_SHA1, VERSION_5);
    }

    public static UUID getMd5Uuid(UUID namespace, String string) {
        return getHashUuid(namespace, string, MESSAGE_DIGEST_MD5, VERSION_3);
    }

    public static UUID getSha1Uuid(UUID namespace, String string) {
        return getHashUuid(namespace, string, MESSAGE_DIGEST_SHA1, VERSION_5);
    }

    private static byte[] toBytes(final long number) {
        return new byte[] { (byte) (number >>> 56), (byte) (number >>> 48), (byte) (number >>> 40),
                (byte) (number >>> 32), (byte) (number >>> 24), (byte) (number >>> 16), (byte) (number >>> 8),
                (byte) (number) };
    }

    private static long toNumber(final byte[] bytes, final int start, final int length) {
        long result = 0;
        for (int i = start; i < length; i++) {
            result = (result << 8) | (bytes[i] & 0xff);
        }
        return result;
    }

    /**
     * For tests!
     */
    public static void main(String[] args) {

        String string = "JUST_A_TEST_STRING";
        UUID namespace = UUID.randomUUID(); // A custom name space

        System.out.println("Java's generator");
        System.out.println("UUID.nameUUIDFromBytes():      '" + UUID.nameUUIDFromBytes(string.getBytes()) + "'");
        System.out.println();
        System.out.println("This generator");
        System.out.println("HashUuidCreator.getMd5Uuid():  '" + HashUuidCreator.getMd5Uuid(string) + "'");
        System.out.println("HashUuidCreator.getSha1Uuid(): '" + HashUuidCreator.getSha1Uuid(string) + "'");
        System.out.println();
        System.out.println("This generator WITH name space");
        System.out.println("HashUuidCreator.getMd5Uuid():  '" + HashUuidCreator.getMd5Uuid(namespace, string) + "'");
        System.out.println("HashUuidCreator.getSha1Uuid(): '" + HashUuidCreator.getSha1Uuid(namespace, string) + "'");
    }
}

This is the output:

// Java's generator
UUID.nameUUIDFromBytes():      '9e120341-627f-32be-8393-58b5d655b751'

// This generator
HashUuidCreator.getMd5Uuid():  '9e120341-627f-32be-8393-58b5d655b751'
HashUuidCreator.getSha1Uuid(): 'e4586bed-032a-5ae6-9883-331cd94c4ffa'

// This generator WITH name space
HashUuidCreator.getMd5Uuid():  '2b098683-03c9-3ed8-9426-cf5c81ab1f9f'
HashUuidCreator.getSha1Uuid(): '1ef568c7-726b-58cc-a72a-7df173463bbb'

ALTERNATE GENERATOR

You can also use the uuid-creator library. See these examples:

// Create a random-based UUID
UUID uuid = UuidCreator.getRandomBased();
// Create a name based UUID (SHA1)
String name = "JUST_A_TEST_STRING";
UUID uuid = UuidCreator.getNameBasedSha1(name);

Project page: https://github.com/f4b6a3/uuid-creator

SQL Error with Order By in Subquery

This is the error you get (emphasis mine):

The ORDER BY clause is invalid in views, inline functions, derived tables, subqueries, and common table expressions, unless TOP or FOR XML is also specified.

So, how can you avoid the error? By specifying TOP, would be one possibility, I guess.

SELECT (
  SELECT TOP 100 PERCENT
  COUNT(1) FROM Seanslar WHERE MONTH(tarihi) = 4
  GROUP BY refKlinik_id
  ORDER BY refKlinik_id
) as dorduncuay

Format a Go string without printing?

1. Simple strings

For "simple" strings (typically what fits into a line) the simplest solution is using fmt.Sprintf() and friends (fmt.Sprint(), fmt.Sprintln()). These are analogous to the functions without the starter S letter, but these Sxxx() variants return the result as a string instead of printing them to the standard output.

For example:

s := fmt.Sprintf("Hi, my name is %s and I'm %d years old.", "Bob", 23)

The variable s will be initialized with the value:

Hi, my name is Bob and I'm 23 years old.

Tip: If you just want to concatenate values of different types, you may not automatically need to use Sprintf() (which requires a format string) as Sprint() does exactly this. See this example:

i := 23
s := fmt.Sprint("[age:", i, "]") // s will be "[age:23]"

For concatenating only strings, you may also use strings.Join() where you can specify a custom separator string (to be placed between the strings to join).

Try these on the Go Playground.

2. Complex strings (documents)

If the string you're trying to create is more complex (e.g. a multi-line email message), fmt.Sprintf() becomes less readable and less efficient (especially if you have to do this many times).

For this the standard library provides the packages text/template and html/template. These packages implement data-driven templates for generating textual output. html/template is for generating HTML output safe against code injection. It provides the same interface as package text/template and should be used instead of text/template whenever the output is HTML.

Using the template packages basically requires you to provide a static template in the form of a string value (which may be originating from a file in which case you only provide the file name) which may contain static text, and actions which are processed and executed when the engine processes the template and generates the output.

You may provide parameters which are included/substituted in the static template and which may control the output generation process. Typical form of such parameters are structs and map values which may be nested.

Example:

For example let's say you want to generate email messages that look like this:

Hi [name]!

Your account is ready, your user name is: [user-name]

You have the following roles assigned:
[role#1], [role#2], ... [role#n]

To generate email message bodies like this, you could use the following static template:

const emailTmpl = `Hi {{.Name}}!

Your account is ready, your user name is: {{.UserName}}

You have the following roles assigned:
{{range $i, $r := .Roles}}{{if $i}}, {{end}}{{.}}{{end}}
`

And provide data like this for executing it:

data := map[string]interface{}{
    "Name":     "Bob",
    "UserName": "bob92",
    "Roles":    []string{"dbteam", "uiteam", "tester"},
}

Normally output of templates are written to an io.Writer, so if you want the result as a string, create and write to a bytes.Buffer (which implements io.Writer). Executing the template and getting the result as string:

t := template.Must(template.New("email").Parse(emailTmpl))
buf := &bytes.Buffer{}
if err := t.Execute(buf, data); err != nil {
    panic(err)
}
s := buf.String()

This will result in the expected output:

Hi Bob!

Your account is ready, your user name is: bob92

You have the following roles assigned:
dbteam, uiteam, tester

Try it on the Go Playground.

Also note that since Go 1.10, a newer, faster, more specialized alternative is available to bytes.Buffer which is: strings.Builder. Usage is very similar:

builder := &strings.Builder{}
if err := t.Execute(builder, data); err != nil {
    panic(err)
}
s := builder.String()

Try this one on the Go Playground.

Note: you may also display the result of a template execution if you provide os.Stdout as the target (which also implements io.Writer):

t := template.Must(template.New("email").Parse(emailTmpl))
if err := t.Execute(os.Stdout, data); err != nil {
    panic(err)
}

This will write the result directly to os.Stdout. Try this on the Go Playground.

C-like structures in Python

How about a dictionary?

Something like this:

myStruct = {'field1': 'some val', 'field2': 'some val'}

Then you can use this to manipulate values:

print myStruct['field1']
myStruct['field2'] = 'some other values'

And the values don't have to be strings. They can be pretty much any other object.

Difference between null and empty string

Null means nothing. Its just a literal. Null is the value of reference variable. But empty string is blank.It gives the length=0. Empty string is a blank value,means the string does not have any thing.

How to include Javascript file in Asp.Net page

Probably the file is not in the path specified. '../../../' will move 3 step up to the directory in which the page is located and look for the js file in a folder named JS.

Also the language attribute is Deprecated.

See Scripts:

18.2.1 The SCRIPT element

language = cdata [CI]

Deprecated. This attribute specifies the scripting language of the contents of this element. Its value is an identifier for the language, but since these identifiers are not standard, this attribute has been deprecated in favor of type.

Edit

Try changing

<script src="../../../JS/Registration.js" language="javascript" type="text/javascript" /> 

to

<script src="../../../JS/Registration.js" language="javascript" type="text/javascript"></script>

Streaming via RTSP or RTP in HTML5

With VLC i'm able to transcode a live RTSP stream (mpeg4) to an HTTP stream in a OGG format (Vorbis/Theora). The quality is poor but the video work in Chrome 9. I have also tested with a trancoding in WEBM (VP8) but it's don't seem to work (VLC have the option but i don't know if it's really implemented for now..)

The first to have a doc on this should notify us ;)

How to open spss data files in excel?

You can use online converter, developed by me at N'counter.

This is the easiest way to open SPSS file in Excel.

1) You just have to upload your file to SPSS coN'verter at https://secure.ncounter.de/SpssConverter

2) Select some options

3) And your converted Excel file will be downloaded

No information about your file contents is retained on our server. The file travels to our server, is converted in-memory, and is immediately discarded: We don't peer into your data at any time!

R: "Unary operator error" from multiline ggplot2 command

It's the '+' operator at the beginning of the line that trips things up (not just that you are using two '+' operators consecutively). The '+' operator can be used at the end of lines, but not at the beginning.

This works:

ggplot(combined.data, aes(x = region, y = expression, fill = species)) +
geom_boxplot() 

The does not:

ggplot(combined.data, aes(x = region, y = expression, fill = species))
+ geom_boxplot() 

*Error in + geom_boxplot():
invalid argument to unary operator*

You also can't use two '+' operators, which in this case you've done. But to fix this, you'll have to selectively remove those at the beginning of lines.

Web Service vs WCF Service

This answer is based on an article that no longer exists:

Summary of article:

"Basically, WCF is a service layer that allows you to build applications that can communicate using a variety of communication mechanisms. With it, you can communicate using Peer to Peer, Named Pipes, Web Services and so on.

You can’t compare them because WCF is a framework for building interoperable applications. If you like, you can think of it as a SOA enabler. What does this mean?

Well, WCF conforms to something known as ABC, where A is the address of the service that you want to communicate with, B stands for the binding and C stands for the contract. This is important because it is possible to change the binding without necessarily changing the code. The contract is much more powerful because it forces the separation of the contract from the implementation. This means that the contract is defined in an interface, and there is a concrete implementation which is bound to by the consumer using the same idea of the contract. The datamodel is abstracted out."

... later ...

"should use WCF when we need to communicate with other communication technologies (e,.g. Peer to Peer, Named Pipes) rather than Web Service"

How can I print literal curly-brace characters in a string and also use .format on it?

If you are going to be doing this a lot, it might be good to define a utility function that will let you use arbitrary brace substitutes instead, like

def custom_format(string, brackets, *args, **kwargs):
    if len(brackets) != 2:
        raise ValueError('Expected two brackets. Got {}.'.format(len(brackets)))
    padded = string.replace('{', '{{').replace('}', '}}')
    substituted = padded.replace(brackets[0], '{').replace(brackets[1], '}')
    formatted = substituted.format(*args, **kwargs)
    return formatted

>>> custom_format('{{[cmd]} process 1}', brackets='[]', cmd='firefox.exe')
'{{firefox.exe} process 1}'

Note that this will work either with brackets being a string of length 2 or an iterable of two strings (for multi-character delimiters).

Difference between "\n" and Environment.NewLine

From the docs ...

A string containing "\r\n" for non-Unix platforms, or a string containing "\n" for Unix platforms.

How to access a mobile's camera from a web app?

I don't think you can - there is a W3C draft API to get audio or video, but there is no implementation yet on any of the major mobile OSs.

Second best The only option is to go with Dennis' suggestion to use PhoneGap. This will mean you need to create a native app and add it to the mobile app store/marketplace.

get current date and time in groovy?

Date has the time part, so we only need to extract it from Date

I personally prefer the default format parameter of the Date when date and time needs to be separated instead of using the extra SimpleDateFormat

Date date = new Date()
String datePart = date.format("dd/MM/yyyy")
String timePart = date.format("HH:mm:ss")

println "datePart : " + datePart + "\ttimePart : " + timePart

Add st, nd, rd and th (ordinal) suffix to a number

I wrote this function for higher numbers and all test cases

function numberToOrdinal(num) {
    if (num === 0) {
        return '0'
    };
    let i = num.toString(), j = i.slice(i.length - 2), k = i.slice(i.length - 1);
    if (j >= 10 && j <= 20) {
        return (i + 'th')
    } else if (j > 20 && j < 100) {
        if (k == 1) {
            return (i + 'st')
        } else if (k == 2) {
            return (i + 'nd')
        } else if (k == 3) {
            return (i + 'rd')
        } else {
            return (i + 'th')
        }
    } else if (j == 1) {
        return (i + 'st')
    } else if (j == 2) {
        return (i + 'nd')
    } else if (j == 3) {
        return (i + 'rd')
    } else {
        return (i + 'th')
    }
}

Nullable type as a generic parameter possible?

This may be a dead thread, but I tend to use the following:

public static T? GetValueOrNull<T>(this DbDataRecord reader, string columnName)
where T : struct 
{
    return reader[columnName] as T?;
}

Node.js: socket.io close client connection

Did you try:

socket.disconnect() 

on client?

How to solve Object reference not set to an instance of an object.?

You need to initialize the list first:

protected List<string> list = new List<string>();

Is there a Google Sheets formula to put the name of the sheet into a cell?

I have a sheet that is made to used by others and I have quite a few indirect() references around, so I need to formulaically handle a changed sheet tab name.

I used the formula from JohnP2 (below) but was having trouble because it didn't update automatically when a sheet name was changed. You need to go to the actual formula, make an arbitrary change and refresh to run it again.

=REGEXREPLACE(CELL("address",'SHEET NAME'!A1),"'?([^']+)'?!.*","$1")

I solved this by using info found in this solution on how to force a function to refresh. It may not be the most elegant solution, but it forced Sheets to pay attention to this cell and update it regularly, so that it catches an updated sheet title.

=IF(TODAY()=TODAY(), REGEXREPLACE(CELL("address",'SHEET NAME'!A1),"'?([^']+)'?!.*","$1"), "")

Using this, Sheets know to refresh this cell every time you make a change, which results in the address being updated whenever it gets renamed by a user.

How to sort a Pandas DataFrame by index?

Slightly more compact:

df = pd.DataFrame([1, 2, 3, 4, 5], index=[100, 29, 234, 1, 150], columns=['A'])
df = df.sort_index()
print(df)

Note:

Selecting multiple items in ListView

In listView you can use it by Adapter

ArrayAdapter<String> adapterChannels = new ArrayAdapter<>(this, android.R.layout.simple_list_item_multiple_choice);

Deploy a project using Git push

As complementary answer I would like to offer an alternative. I'm using git-ftp and it works fine.

https://github.com/git-ftp/git-ftp

Easy to use, only type:

git ftp push

and git will automatically upload project files.

Regards

Import JavaScript file and call functions using webpack, ES6, ReactJS

import * as utils from './utils.js'; 

If you do the above, you will be able to use functions in utils.js as

utils.someFunction()

How do you add an action to a button programmatically in xcode

 CGRect buttonFrame = CGRectMake( x-pos, y-pos, width, height );   //
 CGRectMake(10,5,10,10) 

 UIButton *button = [[UIButton alloc] initWithFrame: buttonFrame];

 button setTitle: @"My Button" forState: UIControlStateNormal];

 [button addTarget:self action:@selector(btnClicked:) 
 forControlEvents:UIControlEventTouchUpInside];

 [button setTitleColor: [UIColor BlueVolor] forState:
 UIControlStateNormal];

 [view addSubview:button];




 -(void)btnClicked {
    // your code }

How can I add a hint text to WPF textbox?

For WPF, there isn't a way. You have to mimic it. See this example. A secondary (flaky solution) is to host a WinForms user control that inherits from TextBox and send the EM_SETCUEBANNER message to the edit control. ie.

[DllImport("user32.dll", CharSet = CharSet.Auto)]
private static extern IntPtr SendMessage(IntPtr hWnd, Int32 msg, IntPtr wParam, IntPtr lParam);

private const Int32 ECM_FIRST = 0x1500;
private const Int32 EM_SETCUEBANNER = ECM_FIRST + 1;

private void SetCueText(IntPtr handle, string cueText) {
    SendMessage(handle, EM_SETCUEBANNER, IntPtr.Zero, Marshal.StringToBSTR(cueText));
}

public string CueText {
    get {
        return m_CueText;
    } 
    set {
        m_CueText = value;
        SetCueText(this.Handle, m_CueText);
}

Also, if you want to host a WinForm control approach, I have a framework that already includes this implementation called BitFlex Framework, which you can download for free here.

Here is an article about BitFlex if you want more information. You will start to find that if you are looking to have Windows Explorer style controls that this generally never comes out of the box, and because WPF does not work with handles generally you cannot write an easy wrapper around Win32 or an existing control like you can with WinForms.

Screenshot: enter image description here

Multiple inputs with same name through POST in php

It can be:

echo "Welcome".$_POST['firstname'].$_POST['lastname'];

How do I center an anchor element in CSS?

Just put it between center tags:

<center>><Your text here>></center>

Inserting a string into a list without getting split into characters

I suggest to add the '+' operator as follows:

list = list + ['foo']

Hope it helps!

Error when testing on iOS simulator: Couldn't register with the bootstrap server

  1. Close simulator
  2. Stop the app from running in xCode.
  3. Open Activity Monitor and search for a process running with your App NAME.
  4. Kill this process in Activity Monitor
  5. Rebuild your project and you should be all set

Model backing a DB Context has changed; Consider Code First Migrations

Easiest and Safest Method If you know that you really want to change/update your data structure so that the database can sync with your DBContext, The safest way is to:

  1. Open up your Package Manager Console
  2. Type: update-database -verbose -force

This tells EF to make changes to your database so that it matches your DBContext data structure

Google Chrome "window.open" workaround?

menubar must no, or 0, for Google Chrome to open in new window instead of tab.

What is useState() in React?

useState is a hook that lets you add state to a functional component. It accepts an argument which is the initial value of the state property and returns the current value of state property and a method which is capable of updating that state property.
Following is a simple example:

import React, {useState} from react    

function HookCounter {    
  const [count, stateCount]= useState(0)    
    return(    
      <div>     
        <button onClick{( ) => setCount(count+1)}> count{count}</button>    
      </div>    
    )   
 }

useState accepts the initial value of the state variable which is zero in this case and returns a pair of values. The current value of the state has been called count and a method that can update the state variable has been called as setCount.

Counting repeated elements in an integer array

package jaa.stu.com.wordgame;

/**
 * Created by AnandG on 3/14/2016.
 */
public final class NumberMath {
    public static boolean isContainDistinct(int[] arr) {

        boolean isDistinct = true;
        for (int i = 0; i < arr.length; i++)

        {

            for (int j = 0; j < arr.length; j++) {
                if (arr[i] == arr[j] && i!=j) {
                    isDistinct = false;
                    break;
                }
            }

        }
        return isDistinct;
    }
    public static boolean isContainDistinct(float[] arr) {

        boolean isDistinct = true;
        for (int i = 0; i < arr.length; i++)

        {

            for (int j = 0; j < arr.length; j++) {
                if (arr[i] == arr[j] && i!=j) {
                    isDistinct = false;
                    break;
                }
            }

        }
        return isDistinct;
    }
    public static boolean isContainDistinct(char[] arr) {

        boolean isDistinct = true;
        for (int i = 0; i < arr.length; i++)

        {

            for (int j = 0; j < arr.length; j++) {
                if (arr[i] == arr[j] && i!=j) {
                    isDistinct = false;
                    break;
                }
            }

        }
        return isDistinct;
    }
    public static boolean isContainDistinct(String[] arr) {

        boolean isDistinct = true;
        for (int i = 0; i < arr.length; i++)

        {

            for (int j = 0; j < arr.length; j++) {
                if (arr[i] == arr[j] && i!=j) {
                    isDistinct = false;
                    break;
                }
            }

        }
        return isDistinct;
    }
    public static int[] NumberofRepeat(int[] arr) {

        int[] repCount= new int[arr.length];
        for (int i = 0; i < arr.length; i++)

        {

            for (int j = 0; j < arr.length; j++) {
                if (arr[i] == arr[j] ) {
                    repCount[i]+=1;
                }
            }

        }
        return repCount;
    }
}


call  by NumberMath.isContainDistinct(array) for find is it contains repeat or not

call by int[] repeat=NumberMath.NumberofRepeat(array) for find repeat count. Each location contains how many repeat corresponding value of array...

Best way to work with dates in Android SQLite

"SELECT  "+_ID+" ,  "+_DESCRIPTION +","+_CREATED_DATE +","+_DATE_TIME+" FROM "+TBL_NOTIFICATION+" ORDER BY "+"strftime(%s,"+_DATE_TIME+") DESC";

What is the purpose of the "role" attribute in HTML?

Role attribute mainly improve accessibility for people using screen readers. For several cases we use it such as accessibility, device adaptation,server-side processing, and complex data description. Know more click: https://www.w3.org/WAI/PF/HTML/wiki/RoleAttribute.

How to handle windows file upload using Selenium WebDriver?

Import System.Windows.Forms binary to the test solution and call the following two LOC on clicking the Upload button on the UI.

        // Send the file path and enter file path and wait.
        System.Windows.Forms.SendKeys.SendWait("complete path of the file");
        System.Windows.Forms.SendKeys.SendWait("{ENTER}");

Checking if jquery is loaded using Javascript

You can just type window.jQuery in Console . If it return a function(e,n) ... Then it is confirmed that the jquery is loaded and working successfully.

How do you convert a DataTable into a generic list?

If you're using .NET 3.5, you can use DataTableExtensions.AsEnumerable (an extension method) and then if you really need a List<DataRow> instead of just IEnumerable<DataRow> you can call Enumerable.ToList:

IEnumerable<DataRow> sequence = dt.AsEnumerable();

or

using System.Linq;
...
List<DataRow> list = dt.AsEnumerable().ToList();

Is it safe to store a JWT in localStorage with ReactJS?

I know this is an old question but according what @mikejones1477 said, modern front end libraries and frameworks escape the text giving you protection against XSS. The reason why cookies are not a secure method using credentials is that cookies doesn't prevent CSRF when localStorage does (also remember that cookies are accessible by javascript too, so XSS isn't the big problem here), this answer resume why.

The reason storing an authentication token in local storage and manually adding it to each request protects against CSRF is that key word: manual. Since the browser is not automatically sending that auth token, if I visit evil.com and it manages to send a POST http://example.com/delete-my-account, it will not be able to send my authn token, so the request is ignored.

Of course httpOnly is the holy grail but you can't access from reactjs or any js framework beside you still have CSRF vulnerability. My recommendation would be localstorage or if you want to use cookies make sure implemeting some solution to your CSRF problem like django does.

Regarding with the CDN's make sure you're not using some weird CDN, for example CDN like google or bootstrap provide, are maintained by the community and doesn't contain malicious code, if you are not sure, you're free to review.

How to make a cross-module variable?

I could achieve cross-module modifiable (or mutable) variables by using a dictionary:

# in myapp.__init__
Timeouts = {} # cross-modules global mutable variables for testing purpose
Timeouts['WAIT_APP_UP_IN_SECONDS'] = 60

# in myapp.mod1
from myapp import Timeouts

def wait_app_up(project_name, port):
    # wait for app until Timeouts['WAIT_APP_UP_IN_SECONDS']
    # ...

# in myapp.test.test_mod1
from myapp import Timeouts

def test_wait_app_up_fail(self):
    timeout_bak = Timeouts['WAIT_APP_UP_IN_SECONDS']
    Timeouts['WAIT_APP_UP_IN_SECONDS'] = 3
    with self.assertRaises(hlp.TimeoutException) as cm:
        wait_app_up(PROJECT_NAME, PROJECT_PORT)
    self.assertEqual("Timeout while waiting for App to start", str(cm.exception))
    Timeouts['WAIT_JENKINS_UP_TIMEOUT_IN_SECONDS'] = timeout_bak

When launching test_wait_app_up_fail, the actual timeout duration is 3 seconds.

The source was not found, but some or all event logs could not be searched. Inaccessible logs: Security

Use NetworkService as Identity value in the application pool advanced settings when you are debugging in Visual Studio. ApplicationPoolIdentity is working if you open the site directly from the browser (or go to virtual directory in IIS and use Browse option at right).

Environment Specific application.properties file in Spring Boot application

Yes you can. Since you are using spring, check out @PropertySource anotation.

Anotate your configuration with

@PropertySource("application-${spring.profiles.active}.properties")

You can call it what ever you like, and add inn multiple property files if you like too. Can be nice if you have more sets and/or defaults that belongs to all environments (can be written with @PropertySource{...,...,...} as well).

@PropertySources({
  @PropertySource("application-${spring.profiles.active}.properties"),
  @PropertySource("my-special-${spring.profiles.active}.properties"),
  @PropertySource("overridden.properties")})

Then you can start the application with environment

-Dspring.active.profiles=test

In this example, name will be replaced with application-test-properties and so on.

What is __stdcall?

It has to do with how the function is called- basically the order in which things are put on the the stack and who is responsible for cleanup.

Here's the documentation, but it doesn't mean much unless you understand the first part:
http://msdn.microsoft.com/en-us/library/zxk0tw93.aspx

Get random boolean in Java

you could get your clock() value and check if it is odd or even. I dont know if it is %50 of true

And you can custom-create your random function:

static double  s=System.nanoTime();//in the instantiating of main applet
public static double randoom()
{

s=(double)(((555555555* s+ 444444)%100000)/(double)100000);


    return s;
}

numbers 55555.. and 444.. are the big numbers to get a wide range function please ignore that skype icon :D

What is the regular expression to allow uppercase/lowercase (alphabetical characters), periods, spaces and dashes only?

The regex you're looking for is ^[A-Za-z.\s_-]+$

  • ^ asserts that the regular expression must match at the beginning of the subject
  • [] is a character class - any character that matches inside this expression is allowed
  • A-Z allows a range of uppercase characters
  • a-z allows a range of lowercase characters
  • . matches a period rather than a range of characters
  • \s matches whitespace (spaces and tabs)
  • _ matches an underscore
  • - matches a dash (hyphen); we have it as the last character in the character class so it doesn't get interpreted as being part of a character range. We could also escape it (\-) instead and put it anywhere in the character class, but that's less clear
  • + asserts that the preceding expression (in our case, the character class) must match one or more times
  • $ Finally, this asserts that we're now at the end of the subject

When you're testing regular expressions, you'll likely find a tool like regexpal helpful. This allows you to see your regular expression match (or fail to match) your sample data in real time as you write it.

How to create a foreign key in phpmyadmin

To be able to create a relation, the table Storage Engine must be InnoDB. You can edit in Operations tab. Storage Engine Configuration

Then, you need to be sure that the id column in your main table has been indexed. It should appear at Index section in Structure tab.

Index list

Finally, you could see the option Relations View in Structure tab. When edditing, you will be able to select the parent column in foreign table to create the relation.

enter image description here

See attachments. I hope this could be useful for anyone.

TypeScript and field initializers

I wanted a solution that would have the following:

  • All the data objects are required and must be filled by the constructor.
  • No need to provide defaults.
  • Can use functions inside the class.

Here is the way that I do it:

export class Person {
  id!: number;
  firstName!: string;
  lastName!: string;

  getFullName() {
    return `${this.firstName} ${this.lastName}`;
  }

  constructor(data: OnlyData<Person>) {
    Object.assign(this, data);
  }
}

const person = new Person({ id: 5, firstName: "John", lastName: "Doe" });
person.getFullName();

All the properties in the constructor are mandatory and may not be omitted without a compiler error.

It is dependant on the OnlyData that filters out getFullName() out of the required properties and it is defined like so:

// based on : https://medium.com/dailyjs/typescript-create-a-condition-based-subset-types-9d902cea5b8c
type FilterFlags<Base, Condition> = { [Key in keyof Base]: Base[Key] extends Condition ? never : Key };
type AllowedNames<Base, Condition> = FilterFlags<Base, Condition>[keyof Base];
type SubType<Base, Condition> = Pick<Base, AllowedNames<Base, Condition>>;
type OnlyData<T> = SubType<T, (_: any) => any>;

Current limitations of this way:

  • Requires TypeScript 2.8
  • Classes with getters/setters

Parse usable Street Address, City, State, Zip from a string

If it's human entered data, then you'll spend too much time trying to code around the exceptions.

Try:

  1. Regular expression to extract the zip code

  2. Zip code lookup (via appropriate government DB) to get the correct address

  3. Get an intern to manually verify the new data matches the old

How to get first two characters of a string in oracle query?

Try select substr(orderno, 1,2) from shipment;

Superscript in markdown (Github flavored)?

Comments about previous answers

The universal solution is using the HTML tag <sup>, as suggested in the main answer.
However, the idea behind Markdown is precisely to avoid the use of such tags:
The document should look nice as plain text, not only when rendered.

Another answer proposes using Unicode characters, which makes the document look nice as a plain text document but could reduce compatibility.

Finally, I would like to remember the simplest solution for some documents: the character ^.
Some Markdown implementation (e.g. MacDown in macOS) interprets the caret as an instruction for superscript.

Ex.
Sin^2 + Cos^2 = 1
Clearly, Stack Overflow does not interpret the caret as a superscript instruction. However, the text is comprehensible, and this is what really matters when using Markdown.

Disabling right click on images using jquery

what is your purpose of disabling the right click. problem with any technique is that there is always a way to go around them. the console for firefox (firebug) and chrome allow for unbinding of that event. or if you want the image to be protected one could always just take a look at their temporary cache for the images.

If you want to create your own contextual menu the preventDefault is fine. Just pick your battles here. not even a big JavaScript library like tnyMCE works on all browsers... and that is not because it's not possible ;-).

$(document).bind("contextmenu",function(e){
  e.preventDefault()
});

Personally I'm more in for an open internet. Native browser behavior should not be hindered by the pages interactions. I am sure that other ways can be found to interact that are not the right click.

How to print the current Stack Trace in .NET without any exception?

   private void ExceptionTest()
    {
        try
        {
            int j = 0;
            int i = 5;
            i = 1 / j;
        }
        catch (Exception ex)
        {
            Console.WriteLine("Error: " + ex.Message);
            var stList = ex.StackTrace.ToString().Split('\\');
            Console.WriteLine("Exception occurred at " + stList[stList.Count() - 1]);
        }
    }

Seems to work for me

How can I make Bootstrap 4 columns all the same height?

You can use the new Bootstrap cards:

_x000D_
_x000D_
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/css/bootstrap.min.css" integrity="sha384-rwoIResjU2yc3z8GV/NPeZWAv56rSmLldC3R/AZzGRnGxQQKnKkoFVhFQhNUwEyJ" crossorigin="anonymous">_x000D_
<script src="https://code.jquery.com/jquery-3.1.1.slim.min.js" integrity="sha384-A7FZj7v+d/sdmMqp/nOQwliLvUsJfDHW+k9Omg/a/EheAdgtzNs3hpfag6Ed950n" crossorigin="anonymous"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/tether/1.4.0/js/tether.min.js" integrity="sha384-DztdAPBWPRXSA/3eYEEUWrWCy7G5KFbe8fFjk5JAIxUYHKkDx6Qin1DkWx51bBrb" crossorigin="anonymous"></script>_x000D_
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/js/bootstrap.min.js" integrity="sha384-vBWWzlZJ8ea9aCX4pEW3rVHjgjt7zpkNpZk+02D9phzyeVkE+jo0ieGizqPLForn" crossorigin="anonymous"></script>_x000D_
_x000D_
<div class="card-group">_x000D_
  <div class="card">_x000D_
    <img class="card-img-top" src="..." alt="Card image cap">_x000D_
    <div class="card-block">_x000D_
      <h4 class="card-title">Card title</h4>_x000D_
      <p class="card-text">This is a wider card with supporting text below as a natural lead-in to additional content. This content is a little bit longer.</p>_x000D_
    </div>_x000D_
    <div class="card-footer">_x000D_
      <small class="text-muted">Last updated 3 mins ago</small>_x000D_
    </div>_x000D_
  </div>_x000D_
  <div class="card">_x000D_
    <img class="card-img-top" src="..." alt="Card image cap">_x000D_
    <div class="card-block">_x000D_
      <h4 class="card-title">Card title</h4>_x000D_
      <p class="card-text">This card has supporting text below as a natural lead-in to additional content.</p>_x000D_
    </div>_x000D_
    <div class="card-footer">_x000D_
      <small class="text-muted">Last updated 3 mins ago</small>_x000D_
    </div>_x000D_
  </div>_x000D_
  <div class="card">_x000D_
    <img class="card-img-top" src="..." alt="Card image cap">_x000D_
    <div class="card-block">_x000D_
      <h4 class="card-title">Card title</h4>_x000D_
      <p class="card-text">This is a wider card with supporting text below as a natural lead-in to additional content. This card has even longer content than the first to show that equal height action.</p>_x000D_
    </div>_x000D_
    <div class="card-footer">_x000D_
      <small class="text-muted">Last updated 3 mins ago</small>_x000D_
    </div>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Link: Click here

regards,

How to generate Javadoc HTML files in Eclipse?

To quickly add a Javadoc use following shortcut:

Windows: alt + shift + J

Mac: ? + Alt + J

Depending on selected context, a Javadoc will be printed. To create Javadoc written by OP, select corresponding method and hit the shotcut keys.

Send POST data using XMLHttpRequest

The code below demonstrates on how to do this.

var http = new XMLHttpRequest();
var url = 'get_data.php';
var params = 'orem=ipsum&name=binny';
http.open('POST', url, true);

//Send the proper header information along with the request
http.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');

http.onreadystatechange = function() {//Call a function when the state changes.
    if(http.readyState == 4 && http.status == 200) {
        alert(http.responseText);
    }
}
http.send(params);

In case you have/create an object you can turn it into params using the following code, i.e:

var params = new Object();
params.myparam1 = myval1;
params.myparam2 = myval2;

// Turn the data object into an array of URL-encoded key/value pairs.
let urlEncodedData = "", urlEncodedDataPairs = [], name;
for( name in params ) {
 urlEncodedDataPairs.push(encodeURIComponent(name)+'='+encodeURIComponent(params[name]));
}

org.hibernate.MappingException: Could not determine type for: java.util.List, at table: College, for columns: [org.hibernate.mapping.Column(students)]

You are using field access strategy (determined by @Id annotation). Put any JPA related annotation right above each field instead of getter property

@OneToMany(targetEntity=Student.class, mappedBy="college", fetch=FetchType.EAGER)
private List<Student> students;

Access item in a list of lists

You can use itertools.cycle:

>>> from itertools import cycle
>>> lis = [[10,13,17],[3,5,1],[13,11,12]]
>>> cyc = cycle((-1, 1))
>>> 50 + sum(x*next(cyc) for x in lis[0])   # lis[0] is [10,13,17]
36

Here the generator expression inside sum would return something like this:

>>> cyc = cycle((-1, 1))
>>> [x*next(cyc) for x in lis[0]]
[-10, 13, -17]

You can also use zip here:

>>> cyc = cycle((-1, 1))
>>> [x*y for x, y  in zip(lis[0], cyc)]
[-10, 13, -17]

md-table - How to update the column width

I found a combination of jymdman's and Rahul Patil's answers is working best for me:

.mat-column-userId {
  flex: 0 0 75px;
}

Also, if you have one "leading" column which you want to always occupy a certain amount of space across different devices, I found the following quite handy to adopt to the available container width in a more responsive kind (this forces the remaining columns to use the remaining space evenly):

.mat-column-userName {
  flex: 0 0 60%;
}

HTML Table cell background image alignment

use like this your inline css

<td width="178" rowspan="3" valign="top" 
align="right" background="images/left.jpg" 
style="background-repeat:background-position: right top;">
</td>

HTML Table width in percentage, table rows separated equally

Yes, you will need to specify the width for each cell, otherwise they will try to be "intelligent" about it and divide the 100% between whichever cells think they need it most. Cells with more content will take up more width than those with less.

To make sure you get equal width for each cell you need to make it clear. Either do it as you already have, or use CSS.

table.className td { width: 25%; }

How can I do string interpolation in JavaScript?

Since ES6, you can use template literals:

_x000D_
_x000D_
const age = 3_x000D_
console.log(`I'm ${age} years old!`)
_x000D_
_x000D_
_x000D_

P.S. Note the use of backticks: ``.

What is the difference between static_cast<> and C style casting?

struct A {};
struct B : A {};
struct C {}; 

int main()
{
    A* a = new A;    

    int i = 10;

    a = (A*) (&i); // NO ERROR! FAIL!

    //a = static_cast<A*>(&i); ERROR! SMART!

    A* b = new B;

    B* b2 = static_cast<B*>(b); // NO ERROR! SMART!

    C* c = (C*)(b); // NO ERROR! FAIL!

    //C* c = static_cast<C*>(b); ERROR! SMART!
}

How to reduce the image size without losing quality in PHP

I'd go for jpeg. Read this post regarding image size reduction and after deciding on the technique, use ImageMagick

Hope this helps

XML Parser for C

Two of the most widely used parsers are Expat and libxml.

If you are okay with using C++, there's Xerces-C++ too.

How to read numbers separated by space using scanf

int main()
{
char string[200];
int g,a,i,G[20],A[20],met;

gets(string);
g=convert_input(G,string);

for(i=0;i<=g;i++)
    printf("\n%d>>%d",i,G[i]);
return 0;
}

int convert_input(int K[],char string[200])
{
int j=0,i=0,temp=0;
while(string[i]!='\0')
{
    temp=0;
    while(string[i]!=' ' && string[i]!='\0')
        temp=temp*10 + (string[i++]-'0') ;
    if(string[i]==' ')
        i++;
    K[j++]=temp;
}
return j-1;
}

How to delete parent element using jQuery

Use parents() instead of parent():

$("a").click(function(event) {
  event.preventDefault();
  $(this).parents('.li').remove();
});

Subclipse svn:ignore

This is quite frustrating, but it's a containment issue (the .svn folders keep track also of ignored files). Any item that needs to be ignored is to be added to the ignore list of the immediate parent folder.

So, I had a new sub-folder with a new file in it and wanted to ignore that file but I couldn't do it because the option was grayed out. I solved it by committing the new folder first, which I wanted to (it was a cache folder), and then adding that file to the ignore list (of the newly added folder ;-), having the chance to add a pattern instead of a single file.

Use a list of values to select rows from a pandas dataframe

You can use isin method:

In [1]: df = pd.DataFrame({'A': [5,6,3,4], 'B': [1,2,3,5]})

In [2]: df
Out[2]:
   A  B
0  5  1
1  6  2
2  3  3
3  4  5

In [3]: df[df['A'].isin([3, 6])]
Out[3]:
   A  B
1  6  2
2  3  3

And to get the opposite use ~:

In [4]: df[~df['A'].isin([3, 6])]
Out[4]:
   A  B
0  5  1
3  4  5

Code coverage with Mocha

Blanket.js works perfect too.

npm install --save-dev blanket

in front of your test/tests.js

require('blanket')({
    pattern: function (filename) {
        return !/node_modules/.test(filename);
    }
});

run mocha -R html-cov > coverage.html

When is a CDATA section necessary within a script tag?

When browsers treat the markup as XML:

<script>
<![CDATA[
    ...code...
]]>
</script>

When browsers treat the markup as HTML:

<script>
    ...code...
</script>

When browsers treat the markup as HTML and you want your XHTML 1.0 markup (for example) to validate.

<script>
//<![CDATA[
    ...code...
//]]>
</script>

How do I get a Date without time in Java?

The most straigthforward way that makes full use of the huge TimeZone Database of Java and is correct:

long currentTime = new Date().getTime();
long dateOnly = currentTime + TimeZone.getDefault().getOffset(currentTime);

How can I disable selected attribute from select2() dropdown Jquery?

The below code also works fine for Select2 3.x

For Enable Select Box:

$('#foo').select2('enable');

For Disable Select Box:

$('#foo').select2('disable');

jsfiddle: http://jsfiddle.net/DcunN/

How can I extract a number from a string in JavaScript?

For this specific example,

 var thenum = thestring.replace( /^\D+/g, ''); // replace all leading non-digits with nothing

in the general case:

 thenum = "foo3bar5".match(/\d+/)[0] // "3"

Since this answer gained popularity for some reason, here's a bonus: regex generator.

_x000D_
_x000D_
function getre(str, num) {_x000D_
  if(str === num) return 'nice try';_x000D_
  var res = [/^\D+/g,/\D+$/g,/^\D+|\D+$/g,/\D+/g,/\D.*/g, /.*\D/g,/^\D+|\D.*$/g,/.*\D(?=\d)|\D+$/g];_x000D_
  for(var i = 0; i < res.length; i++)_x000D_
    if(str.replace(res[i], '') === num) _x000D_
      return 'num = str.replace(/' + res[i].source + '/g, "")';_x000D_
  return 'no idea';_x000D_
};_x000D_
function update() {_x000D_
  $ = function(x) { return document.getElementById(x) };_x000D_
  var re = getre($('str').value, $('num').value);_x000D_
  $('re').innerHTML = 'Numex speaks: <code>' + re + '</code>';_x000D_
}
_x000D_
<p>Hi, I'm Numex, the Number Extractor Oracle._x000D_
<p>What is your string? <input id="str" value="42abc"></p>_x000D_
<p>What number do you want to extract? <input id="num" value="42"></p>_x000D_
<p><button onclick="update()">Insert Coin</button></p>_x000D_
<p id="re"></p>
_x000D_
_x000D_
_x000D_

Reverse a string in Python

This class uses python magic functions to reverse a string:

class Reverse(object):
    """ Builds a reverse method using magic methods """

    def __init__(self, data):
        self.data = data
        self.index = len(data)


    def __iter__(self):
        return self

    def __next__(self):
        if self.index == 0:
            raise StopIteration

        self.index = self.index - 1
        return self.data[self.index]


REV_INSTANCE = Reverse('hello world')

iter(REV_INSTANCE)

rev_str = ''
for char in REV_INSTANCE:
    rev_str += char

print(rev_str)  

Output

dlrow olleh

Reference

How to prevent a click on a '#' link from jumping to top of page?

you can even write it just like this:

<a href="javascript:void(0);"></a>

im not sure its a better way but it is a way :)

Laravel: Error [PDOException]: Could not Find Driver in PostgreSQL

You should remove the comment before extension on your driver.

The driver came disactivated by default you should active by yourself. after that it will work well.

I hope this do.

Catch KeyError in Python

If you don't want to handle error just NoneType and use get() e.g.:

manager.connect.get("")

.attr("disabled", "disabled") issue

Try this updated code :

$(bla).click(function(){        
  if (something) {
     console.log($target.prev("input")) // gives out the right object
     $target.toggleClass("open").prev("input").attr("disabled", "true");
  }else{
     $target.toggleClass("open").prev("input").removeAttr("disabled"); //this works
  }
})

Disable ONLY_FULL_GROUP_BY

This worked for me:

SET SESSION sql_mode=(SELECT REPLACE(@@sql_mode,'ONLY_FULL_GROUP_BY',''));

Pretty-print an entire Pandas Series / DataFrame

datascroller was created in part to solve this problem.

pip install datascroller

It loads the dataframe into a terminal view you can "scroll" with your mouse or arrow keys, kind of like an Excel workbook at the terminal that supports querying, highlighting, etc.

import pandas as pd
from datascroller import scroll

# Call `scroll` with a Pandas DataFrame as the sole argument:
my_df = pd.read_csv('<path to your csv>')
scroll(my_df)

How to install JQ on Mac by command-line?

For CentOS, RHEL, Amazon Linux: sudo yum install jq

JMS Topic vs Queues

Queues

Pros

  • Simple messaging pattern with a transparent communication flow
  • Messages can be recovered by putting them back on the queue

Cons

  • Only one consumer can get the message
  • Implies a coupling between producer and consumer as it’s an one-to-one relation

Topics

Pros

  • Multiple consumers can get a message
  • Decoupling between producer and consumers (publish-and-subscribe pattern)

Cons

  • More complicated communication flow
  • A message cannot be recovered for a single listener

What's the difference between "super()" and "super(props)" in React when using es6 classes?

There is only one reason when one needs to pass props to super():

When you want to access this.props in constructor.

Passing:

class MyComponent extends React.Component {    
    constructor(props) {
        super(props)

        console.log(this.props)
        // -> { icon: 'home', … }
    }
}

Not passing:

class MyComponent extends React.Component {    
    constructor(props) {
        super()

        console.log(this.props)
        // -> undefined

        // Props parameter is still available
        console.log(props)
        // -> { icon: 'home', … }
    }

    render() {
        // No difference outside constructor
        console.log(this.props)
        // -> { icon: 'home', … }
    }
}

Note that passing or not passing props to super has no effect on later uses of this.props outside constructor. That is render, shouldComponentUpdate, or event handlers always have access to it.

This is explicitly said in one Sophie Alpert's answer to a similar question.


The documentation—State and Lifecycle, Adding Local State to a Class, point 2—recommends:

Class components should always call the base constructor with props.

However, no reason is provided. We can speculate it is either because of subclassing or for future compatibility.

(Thanks @MattBrowne for the link)

Responsive Images with CSS

Use max-width on the images too. Change:

.erb-image-wrapper img{
    width:100% !important;
    height:100% !important;
    display:block;
}

to...

.erb-image-wrapper img{
    max-width:100% !important;
    max-height:100% !important;
    display:block;
}

JUnit Testing Exceptions

An adventage of use ExpectedException Rule (version 4.7) is that you can test exception message and not only the expected exception.

And using Matchers, you can test the part of message you are interested:

exception.expectMessage(containsString("income: -1000.0"));

Error: "an object reference is required for the non-static field, method or property..."

Simply add static in the declaration of these two methods and the compile time error will disappear!

By default in C# methods are instance methods, and they receive the implicit "self" argument. By making them static, no such argument is needed (nor available), and the method must then of course refrain from accessing any instance (non-static) objects or methods of the class.

More info on static methods
Provided the class and the method's access modifiers (public vs. private) are ok, a static method can then be called from anywhere without having to previously instantiate a instance of the class. In other words static methods are used with the following syntax:

    className.classMethod(arguments)
rather than
    someInstanceVariable.classMethod(arguments)

A classical example of static methods are found in the System.Math class, whereby we can call a bunch of these methods like

   Math.Sqrt(2)
   Math.Cos(Math.PI)

without ever instantiating a "Math" class (in fact I don't even know if such an instance is possible)

Test if a property is available on a dynamic variable

Denis's answer made me think to another solution using JsonObjects,

a header property checker:

Predicate<object> hasHeader = jsonObject =>
                                 ((JObject)jsonObject).OfType<JProperty>()
                                     .Any(prop => prop.Name == "header");

or maybe better:

Predicate<object> hasHeader = jsonObject =>
                                 ((JObject)jsonObject).Property("header") != null;

for example:

dynamic json = JsonConvert.DeserializeObject(data);
string header = hasHeader(json) ? json.header : null;