Programs & Examples On #Uplevel

Correct path for img on React.js

Adding file-loader npm to webpack.config.js per its official usage instruction like so:

config.module.rules.push(
    {
        test: /\.(png|jpg|gif)$/,
        use: [
            {
                loader: 'file-loader',
                options: {}
            }
        ]
    }
);

worked for me.

How to make a simple collection view with Swift

UICollectionView is same as UITableView but it gives us the additional functionality of simply creating a grid view, which is a bit problematic in UITableView. It will be a very long post I mention a link from where you will get everything in simple steps.

removing new line character from incoming stream using sed

To remove newlines, use tr:

tr -d '\n'

If you want to replace each newline with a single space:

tr '\n' ' '

The error ba: Event not found is coming from csh, and is due to csh trying to match !ba in your history list. You can escape the ! and write the command:

sed ':a;N;$\!ba;s/\n/ /g'  # Suitable for csh only!!

but sed is the wrong tool for this, and you would be better off using a shell that handles quoted strings more reasonably. That is, stop using csh and start using bash.

Single Line Nested For Loops

You might be interested in itertools.product, which returns an iterable yielding tuples of values from all the iterables you pass it. That is, itertools.product(A, B) yields all values of the form (a, b), where the a values come from A and the b values come from B. For example:

import itertools

A = [50, 60, 70]
B = [0.1, 0.2, 0.3, 0.4]

print [a + b for a, b in itertools.product(A, B)]

This prints:

[50.1, 50.2, 50.3, 50.4, 60.1, 60.2, 60.3, 60.4, 70.1, 70.2, 70.3, 70.4]

Notice how the final argument passed to itertools.product is the "inner" one. Generally, itertools.product(a0, a1, ... an) is equal to [(i0, i1, ... in) for in in an for in-1 in an-1 ... for i0 in a0]

Proper way to handle multiple forms on one page in Django

Based on this answer by @ybendana:

Again, we use is_bound to check if the form is capable of validation. See this section of the documentation:

Bound and unbound forms

A Form instance is either bound to a set of data, or unbound.

  • If it’s bound to a set of data, it’s capable of validating that data and rendering the form as HTML with the data displayed in the HTML.
  • If it’s unbound, it cannot do validation (because there’s no data to validate!), but it can still render the blank form as HTML.

We use a list of tuples for form objects and their details allowing for more extensibility and less repetition.

However, instead of overriding get(), we override get_context_data() to make inserting a new, blank instance of the form (with prefix) into the response the default action for any request. In the context of a POST request, we override the post() method to:

  1. Use the prefix to check if each form has been submitted
  2. Validate the forms that have been submitted
  3. Process the valid forms using the cleaned_data
  4. Return any invalid forms to the response by overwriting the context data
# views.py

class MultipleForms(TemplateResponseMixin, ContextMixin, View):

    form_list = [ # (context_key, formcls, prefix)
        ("form_a", FormA, "prefix_a"),
        ("form_b", FormB, "prefix_b"),
        ("form_c", FormC, "prefix_c"),
        ...
        ("form_x", FormX, "prefix_x"),
    ]

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        # Add blank forms to context with prefixes
        for context_key, formcls, prefix in self.form_list:
            context[context_key] = formcls(prefix=prefix)
        return context

    def post(self, request, *args, **kwargs):
        # Get object and context
        self.object = self.get_object()
        context = self.get_context_data(object=self.object)
        # Process forms
        for context_key, formcls, prefix in self.form_list:
            if prefix in request.POST:
                # Get the form object with prefix and pass it the POST data to \
                # validate and clean etc.
                form = formcls(request.POST, prefix=prefix)
                if form.is_bound:
                    # If the form is bound (i.e. it is capable of validation)  \
                    # check the validation
                    if form.is_valid():
                        # call the form's save() method or do whatever you     \
                        # want with form.cleaned_data
                        form.save()
                    else:
                        # overwrite context data for this form so that it is   \
                        # returned to the page with validation errors
                        context[context_key] = form
        # Pass context back to render_to_response() including any invalid forms
        return self.render_to_response(context)
        

This method allows repeated form entries on the same page, something I found did not work with @ybendana's answer.

I believe it wouldn't be masses more work to fold this method into a Mixin class, taking the form_list object as an attribute and hooking get_context_data() and post() as above.

Edit: This already exists. See this repository.

NB: This method required TemplateResponseMixin for render_to_response() and ContextMixin for get_context_data() to work. Either use these Mixins or a CBV that descends from them.

How to install a package inside virtualenv?

I had the same issue and the --no-site-packages did not work for me. I discovered on this older mailing list archive that you are able to force an installation in the virtualenv using the -U flag for pip, eg pip -U ipython. You may verify this works using the bash command which ipython while in the virtualenv.

source: https://mail.python.org/pipermail/python-list/2010-March/571663.html

How to add parameters to an external data query in Excel which can't be displayed graphically?

YES - solution is to save workbook in to XML file (eg. 'XML Spreadsheet 2003') and edit this file as text in notepad! use "SEARCH" function of notepad to find query text and change your data to "?".

save and open in excel, try refresh data and excel will be monit about parameters.

Checking if a string array contains a value, and if so, getting its position

You can try this, it looks up for the index containing this element, and it sets the index number as the int, then it checks if the int is greater then -1, so if it's 0 or more, then it means it found such an index - as arrays are 0 based.

string[] Selection = {"First", "Second", "Third", "Fourth"};
string Valid = "Third";    // You can change this to a Console.ReadLine() to 
    //use user input 
int temp = Array.IndexOf(Selection, Valid); // it gets the index of 'Valid', 
                // in our case it's "Third"
            if (temp > -1)
                Console.WriteLine("Valid selection");
            }
            else
            {
                Console.WriteLine("Not a valid selection");
            }

How do I associate file types with an iPhone application?

To deal with any type of files for my own APP, I use this configuration for CFBundleDocumentTypes:

    <key>CFBundleDocumentTypes</key>
    <array>
        <dict>
            <key>CFBundleTypeName</key>
            <string>IPA</string>
            <key>LSItemContentTypes</key>
            <array>
                <string>public.item</string>
                <string>public.content</string>
                <string>public.data</string>
                <string>public.database</string>
                <string>public.composite-content</string>
                <string>public.contact</string>
                <string>public.archive</string>
                <string>public.url-name</string>
                <string>public.text</string>
                <string>public.plain-text</string>
                <string>public.source-code</string>
                <string>public.executable</string>
                <string>public.script</string>
                <string>public.shell-script</string>
                <string>public.xml</string>
                <string>public.symlink</string>
                <string>org.gnu.gnu-zip-archve</string>
                <string>org.gnu.gnu-tar-archive</string>
                <string>public.image</string>
                <string>public.movie</string>
                <string>public.audiovisual-?content</string>
                <string>public.audio</string>
                <string>public.directory</string>
                <string>public.folder</string>
                <string>com.apple.bundle</string>
                <string>com.apple.package</string>
                <string>com.apple.plugin</string>
                <string>com.apple.application-?bundle</string>
                <string>com.pkware.zip-archive</string>
                <string>public.filename-extension</string>
                <string>public.mime-type</string>
                <string>com.apple.ostype</string>
                <string>com.apple.nspboard-typ</string>
                <string>com.adobe.pdf</string>
                <string>com.adobe.postscript</string>
                <string>com.adobe.encapsulated-?postscript</string>
                <string>com.adobe.photoshop-?image</string>
                <string>com.adobe.illustrator.ai-?image</string>
                <string>com.compuserve.gif</string>
                <string>com.microsoft.word.doc</string>
                <string>com.microsoft.excel.xls</string>
                <string>com.microsoft.powerpoint.?ppt</string>
                <string>com.microsoft.waveform-?audio</string>
                <string>com.microsoft.advanced-?systems-format</string>
                <string>com.microsoft.advanced-?stream-redirector</string>
                <string>com.microsoft.windows-?media-wmv</string>
                <string>com.microsoft.windows-?media-wmp</string>
                <string>com.microsoft.windows-?media-wma</string>
                <string>com.apple.keynote.key</string>
                <string>com.apple.keynote.kth</string>
                <string>com.truevision.tga-image</string>
            </array>
            <key>CFBundleTypeIconFiles</key>
            <array>
                <string>Icon-76@2x</string>
            </array>
        </dict>
    </array>

In Postgresql, force unique on combination of two columns

Seems like regular UNIQUE CONSTRAINT :)

CREATE TABLE example (
a integer,
b integer,
c integer,
UNIQUE (a, c));

More here

Use jQuery to hide a DIV when the user clicks outside of it

You might encounter some issues when using the accepted answer with pop-up windows. There might be a case where clicking on a random place might result in unwanted actions, i.e. clicking on a button by mistake might take you to a new page.

I am not sure if this is the most efficient solution but to prevent this I would suggest using a screenmask. Make sure the screenmask is right below the <body> tag so that it can cover all the screen by width:100%; height: 100%. Also note that it is above all elements by z-index: 99. If you want another item or div to be clickable when the screenmask is active, just assign a higher z-index to that item or div.

The screenmask is initially not-displayed (displayed:none) and it calls a hide function when clicked (onclick="hidemenu()").

<body>
<div class="screenmask" onclick="hidemenu()" style="position:fixed; width: 100%; height: 100%; top: 0px; right: 0px; display: none; z-index: 99;"></div>

The javascript functions to deal with "multiple distinct pop-up menus on the same page" might be like the ones below:

<script>
// an element with onclick="showmenu('id_here')" pops a menu in the screen
function showmenu(id) {  
  var popmenu = document.getElementById(id); // assume popmenu is of class .cardmenu
  $('.cardmenu').hide();   // clear the screen from other popmenus first
  $(menu).show();          // pop the desired specific menu
  $('.screenmask').show(); // activate screenmask
}
    
function hidemenu() {      // called when clicked on the screenmask
  $('.cardmenu').hide();   // clear the screen from all the popmenus
  $('.screenmask').hide(); // deactivate screenmask
}
</script>

Using a .php file to generate a MySQL dump

None of the above codes worked for me. I am using windows. Below Code worked for me...

$sql = "SELECT * FROM  $tableName WHERE yourclause";
$result = $conn->query($sql);


if($result){

        if ($result->num_rows > 0) {

            $myfile = fopen("daily_events_$district.sql", "w") or die("Unable to open file!");

            while($row = $result->fetch_assoc()) {  

                $rowToString = implode("','",$row);
                $writeToFile = "INSERT INTO $tableName VALUES('$rowToString');". PHP_EOL;
                fwrite($myfile,$writeToFile);
            }
            echo "File saved successfully";
        }
    } else {
        echo "No result found";
    }

This will save file in your project folder according to your query whatever data you want.

Ping site and return result in PHP

Another option (if you need/want to ping instead of send an HTTP request) is the Ping class for PHP. I wrote it for just this purpose, and it lets you use one of three supported methods to ping a server (some servers/environments only support one of the three methods).

Example usage:

require_once('Ping/Ping.php');
$host = 'www.example.com';
$ping = new Ping($host);
$latency = $ping->ping();
if ($latency) {
  print 'Latency is ' . $latency . ' ms';
}
else {
  print 'Host could not be reached.';
}

Python variables as keys to dict

for i in ('apple', 'banana', 'carrot'):
    fruitdict[i] = locals()[i]

How to activate JMX on my JVM for access with jconsole?

along with below command line parameters ,

-Dcom.sun.management.jmxremote.port=9999
-Dcom.sun.management.jmxremote.authenticate=false
-Dcom.sun.management.jmxremote.ssl=false

Sometimes in the linux servers , imx connection doesn't get succeeded. that is because , in cloud linux host, in /etc/hosts so that the hostname resolves to the host address.

the best way to fix it is, ping the particular linux server from other machine in network and use that host IP address in the

-Djava.rmi.server.hostname=IP address that obtained when you ping that linux server.

But never rely on the ipaddress that you get from linux server using ifconfig.me. the ip that you get there is masked one which is present in the host file.

How to get the first five character of a String

No one mentioned how to make proper checks when using Substring(), so I wanted to contribute about that.

If you don't want to use Linq and go with Substring(), you have to make sure that your string is bigger than the second parameter (length) of Substring() function.

Let's say you need the first 5 characters. You should get them with proper check, like this:

string title = "love" // 15 characters
var firstFiveChars = title.Length <= 5 ? title : title.Substring(0, 5);

// firstFiveChars: "love" (4 characters)

Without this check, Substring() function would throw an exception because it'd iterate through letters that aren't there.

I think you get the idea...

Failed to connect to mailserver at "localhost" port 25, verify your "SMTP" and "smtp_port" setting in php.ini or use ini_set()

If you are running your application just on localhost and it is not yet live, I believe it is very difficult to send mail using this.

Once you put your application online, I believe that this problem should be automatically solved. By the way,ini_set() helps you to change the values in php.ini during run time.

This is the same question as Failed to connect to mailserver at "localhost" port 25

also check this php mail function not working

How to set focus on a view when a layout is created and displayed?

You can try just hidding the keyboard. Something like this:

InputMethodManager inputManager = (InputMethodManager) getSystemService(INPUT_METHOD_SERVICE);
inputManager.hideSoftInputFromWindow(this.getCurrentFocus().getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);

"make_sock: could not bind to address [::]:443" when restarting apache (installing trac and mod_wsgi)

I'm adding another answer to this as I had the same problem and solved it the same way: I had installed SSL on apache2 using a2enmod ssl, which seems to have added an extra configuration in /etc/apache2/ports.conf:

NameVirtualHost *:80
Listen 80

NameVirtualHost *:443
Listen 443

<IfModule mod_ssl.c>
    Listen 443
</IfModule>

<IfModule mod_gnutls.c>
    Listen 443
</IfModule>

I had to comment out the first Listen 443 after the NameVirtualHost *:443 directive:

NameVirtualHost *:443
#Listen 443

But I'm thinking I can as well let it and comment the others. Anyway, thank you for the solution :)

Multiple linear regression in Python

Just to clarify, the example you gave is multiple linear regression, not multivariate linear regression refer. Difference:

The very simplest case of a single scalar predictor variable x and a single scalar response variable y is known as simple linear regression. The extension to multiple and/or vector-valued predictor variables (denoted with a capital X) is known as multiple linear regression, also known as multivariable linear regression. Nearly all real-world regression models involve multiple predictors, and basic descriptions of linear regression are often phrased in terms of the multiple regression model. Note, however, that in these cases the response variable y is still a scalar. Another term multivariate linear regression refers to cases where y is a vector, i.e., the same as general linear regression. The difference between multivariate linear regression and multivariable linear regression should be emphasized as it causes much confusion and misunderstanding in the literature.

In short:

  • multiple linear regression: the response y is a scalar.
  • multivariate linear regression: the response y is a vector.

(Another source.)

Using SELECT result in another SELECT

You are missing table NewScores, so it can't be found. Just join this table.

If you really want to avoid joining it directly you can replace NewScores.NetScore with SELECT NetScore FROM NewScores WHERE {conditions on which they should be matched}

YouTube: How to present embed video with sound muted

Just pass mute=1.

For example:

<iframe id="myVideo" src="https://www.youtube.com/embed/k0DN-BZrM4o?rel=0&amp;autoplay=1;mute=1" width="100%" height="600" frameborder="0" allowfullscreen></iframe>

Can I fade in a background image (CSS: background-image) with jQuery?

So.. I was also looking into this matter and saw that most of the answers here are asking to fade the container element, not the actual background-image. Then a hack crossed my mind. We can give multiple background right? what if we overlay other color and make it transparent, like code below-

 background: url("//unsplash.it/500/400") rgb(255, 255, 255, 0.5) no-repeat center;

This code actually works stand alone. Try it. We gave a bg image and asked other white color with transparency on top of the image and Voila. TIP- we can give different colors and transparencies to get different filter kind of effect.

How to get all count of mongoose model?

The code below works. Note the use of countDocuments.

 var mongoose = require('mongoose');
 var db = mongoose.connect('mongodb://localhost/myApp');
 var userSchema = new mongoose.Schema({name:String,password:String});
 var userModel =db.model('userlists',userSchema);
 var anand = new userModel({ name: 'anand', password: 'abcd'});
 anand.save(function (err, docs) {
   if (err) {
       console.log('Error');
   } else {
       userModel.countDocuments({name: 'anand'}, function(err, c) {
           console.log('Count is ' + c);
      });
   }
 }); 

How to take column-slices of dataframe in pandas

Also, Given a DataFrame

data

as in your example, if you would like to extract column a and d only (e.i. the 1st and the 4th column), iloc mothod from the pandas dataframe is what you need and could be used very effectively. All you need to know is the index of the columns you would like to extract. For example:

>>> data.iloc[:,[0,3]]

will give you

          a         d
0  0.883283  0.100975
1  0.614313  0.221731
2  0.438963  0.224361
3  0.466078  0.703347
4  0.955285  0.114033
5  0.268443  0.416996
6  0.613241  0.327548
7  0.370784  0.359159
8  0.692708  0.659410
9  0.806624  0.875476

Check if all checkboxes are selected

This is how I achieved it in my code:

if($('.citiescheckbox:checked').length == $('.citiescheckbox').length){
    $('.citycontainer').hide();
}else{
    $('.citycontainer').show();
}

How to call a method in MainActivity from another class?

I would suggest, one should not make object of an Activity type class.

MainActivity mActivity = new MainActivity();  // BIG NO TO THIS.

All Activities in Android must go through the Activity lifecycle so that they have a valid context attached to them.

By treating an Activity as a normal Java class, you end up with a null context. As most methods in an Activity are called on its Context, you will get a null pointer exception, which is why your app crashes.

Instead, move all such methods which need to be called from other classes into a Utility class which accepts a valid context in its constructor, and then use that context in the methods to do the work.

A formula to copy the values from a formula to another column

you can use those functions together with iferror as a work around.

try =IFERROR(VALUE(A4),(CONCATENATE(A4)))

how can I copy a conditional formatting in Excel 2010 to other cells, which is based on a other cells content?

condition: =K21+$F22

That is not a CONDITION. That is a VALUE. A CONDITION, evaluates as a BOOLEAN value (True/False) If True, then the format is applied.

This would be a CONDITION, for instance

condition: =K21+$F22>0

In general, when applying a CF to a range,

1) select the entire range that you want the Conditional FORMAT to be applied to.

2) enter the CONDITION, as it relates to the FIRST ROW of your selection.

The CF accordingly will be applied thru the range.

Yum fails with - There are no enabled repos.

ok, so my problem was that I tried to install the package with yum which is the primary tool for getting, installing, deleting, querying, and managing Red Hat Enterprise Linux RPM software packages from official Red Hat software repositories, as well as other third-party repositories.

But I'm using ubuntu and The usual way to install packages on the command line in Ubuntu is with apt-get. so the right command was:

sudo apt-get install libstdc++.i686

Finding the last index of an array

With C# 8:

int[] array = { 1, 3, 5 };
var lastItem = array[^1]; // 5

keytool error Keystore was tampered with, or password was incorrect

Check your home folder ~/.gradle/gradle.properties. Sometimes if you have gradle.properties in home directory it takes details from the there. Either you can change that or delete the files. Then it will take required details from your local folder.

How do I view the Explain Plan in Oracle Sql developer?

Explain only shows how the optimizer thinks the query will execute.

To show the real plan, you will need to run the sql once. Then use the same session run the following:

@yoursql 
select * from table(dbms_xplan.display_cursor()) 

This way can show the real plan used during execution. There are several other ways in showing plan using dbms_xplan. You can Google with term "dbms_xplan".

Laravel: Auth::user()->id trying to get a property of a non-object

Your question and code sample are a little vague, and I believe the other developers are focusing on the wrong thing. I am making an application in Laravel, have used online tutorials for creating a new user and authentication, and seemed to have noticed that when you create a new user in Laravel, no Auth object is created - which you use to get the (new) logged-in user's ID in the rest of the application. This is a problem, and I believe what you may be asking. I did this kind of cludgy hack in userController::store :

$user->save();

Session::flash('message','Successfully created user!');

//KLUDGE!! rest of site depends on user id in auth object - need to force/create it here
Auth::attempt(array('email' => Input::get('email'), 'password' => Input::get('password')), true);

Redirect::to('users/' . Auth::user()->id);

Shouldn't have to create and authenticate, but I didn't know what else to do.

MySQL default datetime through phpmyadmin

The best way for DateTime is use a Trigger:

/************ ROLE ************/
drop table if exists `role`;
create table `role` (
    `id_role` bigint(20) unsigned not null auto_increment,
    `date_created` datetime,
    `date_deleted` datetime,
    `name` varchar(35) not null,
    `description` text,
    primary key (`id_role`)
) comment='';

drop trigger if exists `role_date_created`;
create trigger `role_date_created` before insert
    on `role`
    for each row 
    set new.`date_created` = now();

How to use sha256 in php5.3.0

A way better solution is to just use the excelent compatibility script from Anthony Ferrara:

https://github.com/ircmaxell/password_compat

Please, and also, when checking the password, always add a way (preferibly async, so it doesn't impact the check process for timming attacks) to update the hash if needed.

Add 'x' number of hours to date

For a given DateTime, you can add days, hours, minutes, etc. Here's some examples:

$now = new \DateTime();

$now->add(new DateInterval('PT24H')); // adds 24 hours

$now->add(new DateInterval('P2D')); // adds 2 days

PHP: DateTime::add - Manual https://www.php.net/manual/fr/datetime.add.php

Is there way to use two PHP versions in XAMPP?

I know this is the old post but I want to share there is library for still running mysql_connect() in PHP 7. It works by overriding the real function (mysql_connect() is overridden by mysqli_connect() which work on this library).

I found from this video https://www.youtube.com/watch?v=Eqd-jJu4sQ4

hopefully it helps

How do you make an anchor link non-clickable or disabled?

Simply in SASS:

.some_class{
     // styles...

     &.active {
       pointer-events:none;
     }
}

How to add /usr/local/bin in $PATH on Mac

In MAC OS Catalina, this are the steps that worked for me, all the above solutions did help but didn't solve my problem.

  1. check node --version, still the old one in use.
  2. cd ~/
  3. atom .bash_profile
  4. Remove the $PATH pointing to old node version, in my case it was /usr/local/bin/node/@node8
  5. Add & save this to $PATH instead "export PATH=$PATH:/usr/local/git/bin:/usr/local/bin"
  6. Close all applications using node (terminal, simulator, browser expo etc)
  7. restart terminal and check node --version

HTML Input - already filled in text

<input type="text" value="Your value">

Use the value attribute for the pre filled in values.

Easily measure elapsed time

The values printed by your second program are seconds, and microseconds.

0 26339 = 0.026'339 s =   26339 µs
4 45025 = 4.045'025 s = 4045025 µs

Eclipse: "'Periodic workspace save.' has encountered a pro?blem."

I have the same problem since yesterday. Yesterday, I fixed it by creating a new workspace and reimporting the projects. It seemed to work well, but today it started again.

So, today I created the folder and the file manually and gave the full permissions -rwxrwxrwx.

Seems to work again...

Are dictionaries ordered in Python 3.6+?

Update: Guido van Rossum announced on the mailing list that as of Python 3.7 dicts in all Python implementations must preserve insertion order.

EOFError: end of file reached issue with Net::HTTP

After doing some research, this was happening in Ruby's XMLRPC::Client library - which uses NET::HTTP. The client uses the start() method in NET::HTTP which keeps the connection open for future requests.

This happened precisely at 30 seconds after the last requests - so my assumption here is that the server it's hitting is closing requests after that time. I'm not sure what the default is for NET::HTTP to keep the request open - but I'm about to test with 60 seconds to see if that solves the issue.

Symfony - generate url with parameter in controller

If you want absolute urls, you have the third parameter.

$product_url = $this->generateUrl('product_detail', 
    array(
        'slug' => 'slug'
    ),
    UrlGeneratorInterface::ABSOLUTE_URL
);

Remember to include UrlGeneratorInterface.

use Symfony\Component\Routing\Generator\UrlGeneratorInterface;

How to scroll to bottom in react?

In order to scroll down to the bottom of the page first we have to select an id which resides at the bottom of the page. Then we can use the document.getElementById to select the id and scroll down using scrollIntoView(). Please refer the below code.

   scrollToBottom= async ()=>{
      document.getElementById('bottomID').scrollIntoView();
    }

AttributeError: 'str' object has no attribute

The problem is in your playerMovement method. You are creating the string name of your room variables (ID1, ID2, ID3):

letsago = "ID" + str(self.dirDesc.values())

However, what you create is just a str. It is not the variable. Plus, I do not think it is doing what you think its doing:

>>>str({'a':1}.values())
'dict_values([1])'

If you REALLY needed to find the variable this way, you could use the eval function:

>>>foo = 'Hello World!'
>>>eval('foo')
'Hello World!'

or the globals function:

class Foo(object):
    def __init__(self):
        super(Foo, self).__init__()
    def test(self, name):
        print(globals()[name])

foo = Foo()
bar = 'Hello World!'
foo.text('bar')

However, instead I would strongly recommend you rethink you class(es). Your userInterface class is essentially a Room. It shouldn't handle player movement. This should be within another class, maybe GameManager or something like that.

Converting SVG to PNG using C#

When I had to rasterize svgs on the server, I ended up using P/Invoke to call librsvg functions (you can get the dlls from a windows version of the GIMP image editing program).

[DllImport("kernel32.dll", SetLastError = true)]
static extern bool SetDllDirectory(string pathname);

[DllImport("libgobject-2.0-0.dll", SetLastError = true)]
static extern void g_type_init(); 

[DllImport("librsvg-2-2.dll", SetLastError = true)]
static extern IntPtr rsvg_pixbuf_from_file_at_size(string file_name, int width, int height, out IntPtr error);

[DllImport("libgdk_pixbuf-2.0-0.dll", CallingConvention = CallingConvention.Cdecl, CharSet = CharSet.Ansi)]
static extern bool gdk_pixbuf_save(IntPtr pixbuf, string filename, string type, out IntPtr error, __arglist);

public static void RasterizeSvg(string inputFileName, string outputFileName)
{
    bool callSuccessful = SetDllDirectory("C:\\Program Files\\GIMP-2.0\\bin");
    if (!callSuccessful)
    {
        throw new Exception("Could not set DLL directory");
    }
    g_type_init();
    IntPtr error;
    IntPtr result = rsvg_pixbuf_from_file_at_size(inputFileName, -1, -1, out error);
    if (error != IntPtr.Zero)
    {
        throw new Exception(Marshal.ReadInt32(error).ToString());
    }
    callSuccessful = gdk_pixbuf_save(result, outputFileName, "png", out error, __arglist(null));
    if (!callSuccessful)
    {
        throw new Exception(error.ToInt32().ToString());
    }
}

When do we need curly braces around shell variables?

Curly braces are always needed for accessing array elements and carrying out brace expansion.

It's good to be not over-cautious and use {} for shell variable expansion even when there is no scope for ambiguity.

For example:

dir=log
prog=foo
path=/var/${dir}/${prog}      # excessive use of {}, not needed since / can't be a part of a shell variable name
logfile=${path}/${prog}.log   # same as above, . can't be a part of a shell variable name
path_copy=${path}             # {} is totally unnecessary
archive=${logfile}_arch       # {} is needed since _ can be a part of shell variable name

So, it is better to write the three lines as:

path=/var/$dir/$prog
logfile=$path/$prog.log
path_copy=$path

which is definitely more readable.

Since a variable name can't start with a digit, shell doesn't need {} around numbered variables (like $1, $2 etc.) unless such expansion is followed by a digit. That's too subtle and it does make to explicitly use {} in such contexts:

set app      # set $1 to app
fruit=$1le   # sets fruit to apple, but confusing
fruit=${1}le # sets fruit to apple, makes the intention clear

See:

Which JDK version (Language Level) is required for Android Studio?

Try not to use JDK versions higher than the ones supported. I've actually ran into a very ambiguous problem a few months ago.

I had a jar library of my own that I compiled with JDK 8, and I was using it in my assignment. It was giving me some kind of preDexDebug error every time I tried running it. Eventually after hours of trying to decipher the error logs I finally had an idea of what was wrong. I checked the system requirements, changed compilers from 8 to 7, and it worked. Looks like putting my jar into a library cost me a few hours rather than save it...

How do you use window.postMessage across domains?

You should post a message from frame to parent, after loaded.

frame script:

$(document).ready(function() {
    window.parent.postMessage("I'm loaded", "*");
});

And listen it in parent:

function listenMessage(msg) {
    alert(msg);
}

if (window.addEventListener) {
    window.addEventListener("message", listenMessage, false);
} else {
    window.attachEvent("onmessage", listenMessage);
}

Use this link for more info: http://en.wikipedia.org/wiki/Web_Messaging

Android saving file to external storage

since android 4.4 file saving has been changed. there is

ContextCompat.getExternalFilesDirs(context, name);

it retuns an array.

when name is null

the first value is like /storage/emulated/0/Android/com.my.package/files

the second value is like /storage/extSdCard/Android/com.my.package/files

android 4.3 and less it retuns a single item array

parts of little messy code but it demonstrates how it works:

    /** Create a File for saving an image or video 
     * @throws Exception */
    private File getOutputMediaFile(int type) throws Exception{

        // Check that the SDCard is mounted
        File mediaStorageDir;
        if(internalstorage.isChecked())
        {
            mediaStorageDir = new File(getFilesDir().getAbsolutePath() );
        }
        else
        {
            File[] dirs=ContextCompat.getExternalFilesDirs(this, null);
            mediaStorageDir = new File(dirs[dirs.length>1?1:0].getAbsolutePath() );
        }


        // Create the storage directory(MyCameraVideo) if it does not exist
        if (! mediaStorageDir.exists()){

            if (! mediaStorageDir.mkdirs()){

                output.setText("Failed to create directory.");

                Toast.makeText(this, "Failed to create directory.", Toast.LENGTH_LONG).show();

                Log.d("myapp", "Failed to create directory");
                return null;
            }
        }


        // Create a media file name

        // For unique file name appending current timeStamp with file name
        java.util.Date date= new java.util.Date();
        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss",Locale.ENGLISH)  .format(date.getTime());

        File mediaFile;

        if(type == MEDIA_TYPE_VIDEO) {

            // For unique video file name appending current timeStamp with file name
            mediaFile = new File(mediaStorageDir.getPath() + File.separator + slpid + "_" + pwsid + "_" + timeStamp + ".mp4");

        }
        else if(type == MEDIA_TYPE_AUDIO) {

            // For unique video file name appending current timeStamp with file name
            mediaFile = new File(mediaStorageDir.getPath() + File.separator + slpid + "_" + pwsid + "_" + timeStamp + ".3gp");

        } else {
            return null;
        }

        return mediaFile;
    }



    /** Create a file Uri for saving an image or video 
     * @throws Exception */
    private  Uri getOutputMediaFileUri(int type) throws Exception{

          return Uri.fromFile(getOutputMediaFile(type));
    }

//usage:
        try {
            file=getOutputMediaFileUri(MEDIA_TYPE_AUDIO).getPath();
        } catch (Exception e1) {
            e1.printStackTrace();
            return;
        }

How to calculate date difference in JavaScript?

function DateDiff(b, e)
{
    let
        endYear = e.getFullYear(),
        endMonth = e.getMonth(),
        years = endYear - b.getFullYear(),
        months = endMonth - b.getMonth(),
        days = e.getDate() - b.getDate();
    if (months < 0)
    {
        years--;
        months += 12;
    }
    if (days < 0)
    {
        months--;
        days += new Date(endYear, endMonth, 0).getDate();
    }
    return [years, months, days];
}

[years, months, days] = DateDiff(
    new Date("October 21, 1980"),
    new Date("July 11, 2017")); // 36 8 20

Why does ENOENT mean "No such file or directory"?

It's an abbreviation of Error NO ENTry (or Error NO ENTity), and can actually be used for more than files/directories.

It's abbreviated because C compilers at the dawn of time didn't support more than 8 characters in symbols.

How do I ignore files in a directory in Git?

If you want to put a .gitignore file at the top level and make it work for any folder below it use /**/.

E.g. to ignore all *.map files in a /src/main/ folder and sub-folders use:

/src/main/**/*.map

Python extract pattern matches

You can also use a capture group (?P<user>pattern) and access the group like a dictionary match['user'].

string = '''someline abc\n
            someother line\n
            name my_user_name is valid\n
            some more lines\n'''

pattern = r'name (?P<user>.*) is valid'
matches = re.search(pattern, str(string), re.DOTALL)
print(matches['user'])

# my_user_name

Invalid length parameter passed to the LEFT or SUBSTRING function

CHARINDEX will return 0 if no spaces are in the string and then you look for a substring of -1 length.

You can tack a trailing space on to the end of the string to ensure there is always at least one space and avoid this problem.

SELECT SUBSTRING(PostCode, 1 , CHARINDEX(' ', PostCode + ' ' ) -1)

Rails.env vs RAILS_ENV

According to the docs, #Rails.env wraps RAILS_ENV:

    # File vendor/rails/railties/lib/initializer.rb, line 55
     def env
       @_env ||= ActiveSupport::StringInquirer.new(RAILS_ENV)
     end

But, look at specifically how it's wrapped, using ActiveSupport::StringInquirer:

Wrapping a string in this class gives you a prettier way to test for equality. The value returned by Rails.env is wrapped in a StringInquirer object so instead of calling this:

Rails.env == "production"

you can call this:

Rails.env.production?

So they aren't exactly equivalent, but they're fairly close. I haven't used Rails much yet, but I'd say #Rails.env is certainly the more visually attractive option due to using StringInquirer.

Phone mask with jQuery and Masked Input Plugin

I was developed simple and easy masks on input field to US phone format jquery-input-mask-phone-number

Simple Add jquery-input-mask-phone-number plugin in to your HTML file and call usPhoneFormat method.

$(document).ready(function () {
    $('#yourphone').usPhoneFormat({
        format: '(xxx) xxx-xxxx',
    });   
});

Working JSFiddle Link https://jsfiddle.net/1kbat1nb/

NPM Reference URL https://www.npmjs.com/package/jquery-input-mask-phone-number

GitHub Reference URL https://github.com/rajaramtt/jquery-input-mask-phone-number

Convert Int to String in Swift

iam using this simple approach

String to Int:

 var a = Int()
var string1 = String("1")
a = string1.toInt()

and from Int to String:

var a = Int()
a = 1
var string1 = String()
 string1= "\(a)"

How do I define a method in Razor?

You can also just use the @{ } block to create functions:

@{
    async Task<string> MyAsyncString(string input)
    {
        return Task.FromResult(input);
    }
}

Then later in your razor page:

   <div>@(await MyAsyncString("weee").ConfigureAwait(false))</div>

Failed to install *.apk on device 'emulator-5554': EOF

When it shows the red writing - the error , don't close the emulator - leave it as is and run the application again.

How to obtain the last index of a list?

the best and fast way to obtain last index of a list is using -1 for number of index , for example:

my_list = [0, 1, 'test', 2, 'hi']
print(my_list[-1])

out put is : 'hi'. index -1 in show you last index or first index of the end.

How to skip a iteration/loop in while-loop

While you could use a continue, why not just inverse the logic in your if?

while(rs.next())
{
    if(!f.exists() || f.isDirectory()){
    //proceed
    }
}

You don't even need an else {continue;} as it will continue anyway if the if conditions are not satisfied.

How do I serialize an object and save it to a file in Android?

Complete code with error handling and added file stream closes. Add it to your class that you want to be able to serialize and deserialize. In my case the class name is CreateResumeForm. You should change it to your own class name. Android interface Serializable is not sufficient to save your objects to the file, it only creates streams.

// Constant with a file name
public static String fileName = "createResumeForm.ser";

// Serializes an object and saves it to a file
public void saveToFile(Context context) {
    try {
        FileOutputStream fileOutputStream = context.openFileOutput(fileName, Context.MODE_PRIVATE);
        ObjectOutputStream objectOutputStream = new ObjectOutputStream(fileOutputStream);
        objectOutputStream.writeObject(this);
        objectOutputStream.close();
        fileOutputStream.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}


// Creates an object by reading it from a file
public static CreateResumeForm readFromFile(Context context) {
    CreateResumeForm createResumeForm = null;
    try {
        FileInputStream fileInputStream = context.openFileInput(fileName);
        ObjectInputStream objectInputStream = new ObjectInputStream(fileInputStream);
        createResumeForm = (CreateResumeForm) objectInputStream.readObject();
        objectInputStream.close();
        fileInputStream.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
    catch (ClassNotFoundException e) {
        e.printStackTrace();
    }
    return createResumeForm;
}

Use it like this in your Activity:

form = CreateResumeForm.readFromFile(this);

Date in mmm yyyy format in postgresql

I think in Postgres you can play with formats for example if you want dd/mm/yyyy

TO_CHAR(submit_time, 'DD/MM/YYYY') as submit_date

git: fatal unable to auto-detect email address

If git config --global user.email "[email protected]" git config --global user.name "github_username"

Dont work like in my case, you can use:

git config --replace-all user.email "[email protected]"
git config --replace-all user.name "github_username"

Typescript: How to extend two classes?

If you don't like using multi-inheritance, use extends and implements together to stay safe.

class C extends B implements A {
  // implements A here
}

How to check identical array in most efficient way?

You could compare String representations so:

array1.toString() == array2.toString()
array1.toString() !== array3.toString()

but that would also make

array4 = ['1',2,3,4,5]

equal to array1 if that matters to you

Creating multiline strings in JavaScript

I program this way:

sys = {
    layout: null,
    makeLayout: function (obCLS) {
        this.layout = $('<div />').addClass('editor').appendTo($(obCLS)).append(

            /* Cargador */
            /* @this.layout.find('> div:nth-of-child(1)'); */
            '<div>' +
            '   <p>Seleccione la imagen que desea procesar.</p>' +
            '   <input type="button" value="Seleccionar" class="btn btn-xlarge btn-success" />' +
            '   <span></span>' +
            '</div>' +

            /* Cargador - Progreso */
            /* @this.layout.find('> div:nth-of-child(2)'); */
            '<div>' +
            '   <div>' +
            '       <div></div>' +
            '       <div>' +
            '           <div></div>' +
            '       </div>' +
            '   </div>' +
            '</div>' +

            /* Editor */
            /* @this.layout.find('> div:nth-of-child(3)');
             * @sidebar = this.layout.find('> div:nth-of-child(3) > div > div > div:nth-of-type(1)');
             * @body    = this.layout.find('> div:nth-of-child(3) > div > div > div:nth-of-type(2) > div'); */
            '<div>' +
            '   <div>' +
            '       <div>' +
            '           <div></div>' +
            '           <div>' +
            '               <div></div>' +
            '           </div>' +
            '       </div>' +
            '   </div>' +
            '</div>'
        );
    }
}

sys.makeLayout('#div');

What is the purpose of "&&" in a shell command?

It's to execute a second statement if the first statement ends succesfully. Like an if statement:

 if (1 == 1 && 2 == 2)
  echo "test;"

Its first tries if 1==1, if that is true it checks if 2==2

get everything between <tag> and </tag> with php

you can use /<code>([\s\S]*)<\/code>/msU this catch NEWLINES too!

grep --ignore-case --only

This is a known bug on the initial 2.5.1, and has been fixed in early 2007 (Redhat 2.5.1-5) according to the bug reports. Unfortunately Apple is still using 2.5.1 even on Mac OS X 10.7.2.

You could get a newer version via Homebrew (3.0) or MacPorts (2.26) or fink (3.0-1).


Edit: Apparently it has been fixed on OS X 10.11 (or maybe earlier), even though the grep version reported is still 2.5.1.

The identity used to sign the executable is no longer valid

If you are using jailcoder, make sure you jailbreak your iphone successfully. Don't forget install AppSync for IOS in Cydia.

How do I get a substring of a string in Python?

Well, I got a situation where I needed to translate a PHP script to Python, and it had many usages of substr(string, beginning, LENGTH).
If I chose Python's string[beginning:end] I'd have to calculate a lot of end indexes, so the easier way was to use string[beginning:][:length], it saved me a lot of trouble.

Saving lists to txt file

@Jon's answer is great and will get you where you need to go. So why is your code printing out what it is. The answer: You're not writing out the contents of your list, but the String representation of your list itself, by an implicit call to Lists.verbList.ToString(). Object.ToString() defines the default behavior you're seeing here.

How to trigger event in JavaScript?

Just to suggest an alternative that does not involve the need to manually invoke a listener event:

Whatever your event listener does, move it into a function and call that function from the event listener.

Then, you can also call that function anywhere else that you need to accomplish the same thing that the event does when it fires.

I find this less "code intensive" and easier to read.

C# using Sendkey function to send a key to another application

If notepad is already started, you should write:

// import the function in your class
[DllImport ("User32.dll")]
static extern int SetForegroundWindow(IntPtr point);

//...

Process p = Process.GetProcessesByName("notepad").FirstOrDefault();
if (p != null)
{
    IntPtr h = p.MainWindowHandle;
    SetForegroundWindow(h);
    SendKeys.SendWait("k");
}

GetProcessesByName returns an array of processes, so you should get the first one (or find the one you want).

If you want to start notepad and send the key, you should write:

Process p = Process.Start("notepad.exe");
p.WaitForInputIdle();
IntPtr h = p.MainWindowHandle;
SetForegroundWindow(h);
SendKeys.SendWait("k");

The only situation in which the code may not work is when notepad is started as Administrator and your application is not.

Excel VBA Run-time error '13' Type mismatch

Sub HighlightSpecificValue()

'PURPOSE: Highlight all cells containing a specified values


Dim fnd As String, FirstFound As String
Dim FoundCell As Range, rng As Range
Dim myRange As Range, LastCell As Range

'What value do you want to find?
  fnd = InputBox("I want to hightlight cells containing...", "Highlight")

    'End Macro if Cancel Button is Clicked or no Text is Entered
      If fnd = vbNullString Then Exit Sub

Set myRange = ActiveSheet.UsedRange
Set LastCell = myRange.Cells(myRange.Cells.Count)

enter code here
Set FoundCell = myRange.Find(what:=fnd, after:=LastCell)

'Test to see if anything was found
  If Not FoundCell Is Nothing Then
    FirstFound = FoundCell.Address

  Else
    GoTo NothingFound
  End If

Set rng = FoundCell

'Loop until cycled through all unique finds
  Do Until FoundCell Is Nothing
    'Find next cell with fnd value
      Set FoundCell = myRange.FindNext(after:=FoundCell)







    'Add found cell to rng range variable
      Set rng = Union(rng, FoundCell)

    'Test to see if cycled through to first found cell
      If FoundCell.Address = FirstFound Then Exit Do


  Loop

'Highlight Found cells yellow

  rng.Interior.Color = RGB(255, 255, 0)

  Dim fnd1 As String
  fnd1 = "Rah"
  'Condition highlighting

  Set FoundCell = myRange.FindNext(after:=FoundCell)



  If FoundCell.Value("rah") Then
      rng.Interior.Color = RGB(255, 0, 0)

  ElseIf FoundCell.Value("Nav") Then

    rng.Interior.Color = RGB(0, 0, 255)



    End If





'Report Out Message
  MsgBox rng.Cells.Count & " cell(s) were found containing: " & fnd

Exit Sub

'Error Handler
NothingFound:
  MsgBox "No cells containing: " & fnd & " were found in this worksheet"

End Sub

Creating and Update Laravel Eloquent

Save function:

$shopOwner->save()

already do what you want...

Laravel code:

    // If the model already exists in the database we can just update our record
    // that is already in this database using the current IDs in this "where"
    // clause to only update this model. Otherwise, we'll just insert them.
    if ($this->exists)
    {
        $saved = $this->performUpdate($query);
    }

    // If the model is brand new, we'll insert it into our database and set the
    // ID attribute on the model to the value of the newly inserted row's ID
    // which is typically an auto-increment value managed by the database.
    else
    {
        $saved = $this->performInsert($query);
    }

Converting array to list in Java

One-liner:

List<Integer> list = Arrays.asList(new Integer[] {1, 2, 3, 4});

How to check if a character in a string is a digit or letter

You could use the existing methods from the Character class. Take a look at the docs:

http://download.java.net/jdk7/archive/b123/docs/api/java/lang/Character.html#isDigit(char)

So, you could do something like this...

String character = in.next();
char c = character.charAt(0);
...
if (Character.isDigit(c)) { 
    ... 
} else if (Character.isLetter(c)) {
    ...
}
...

If you ever want to know exactly how this is implemented, you could always look at the Java source code.

Best way to test exceptions with Assert to ensure they will be thrown

Unfortunately MSTest STILL only really has the ExpectedException attribute (just shows how much MS cares about MSTest) which IMO is pretty awful because it breaks the Arrange/Act/Assert pattern and it doesnt allow you to specify exactly which line of code you expect the exception to occur on.

When I'm using (/forced by a client) to use MSTest I always use this helper class:

public static class AssertException
{
    public static void Throws<TException>(Action action) where TException : Exception
    {
        try
        {
            action();
        }
        catch (Exception ex)
        {
            Assert.IsTrue(ex.GetType() == typeof(TException), "Expected exception of type " + typeof(TException) + " but type of " + ex.GetType() + " was thrown instead.");
            return;
        }
        Assert.Fail("Expected exception of type " + typeof(TException) + " but no exception was thrown.");
    }

    public static void Throws<TException>(Action action, string expectedMessage) where TException : Exception
    {
        try
        {
            action();
        }
        catch (Exception ex)
        {
            Assert.IsTrue(ex.GetType() == typeof(TException), "Expected exception of type " + typeof(TException) + " but type of " + ex.GetType() + " was thrown instead.");
            Assert.AreEqual(expectedMessage, ex.Message, "Expected exception with a message of '" + expectedMessage + "' but exception with message of '" + ex.Message + "' was thrown instead.");
            return;
        }
        Assert.Fail("Expected exception of type " + typeof(TException) + " but no exception was thrown.");
    }
}

Example of usage:

AssertException.Throws<ArgumentNullException>(() => classUnderTest.GetCustomer(null));

Extract the first word of a string in a SQL Server query

Enhancement of Ben Brandt's answer to compensate even if the string starts with space by applying LTRIM(). Tried to edit his answer but rejected, so I am now posting it here separately.

DECLARE @test NVARCHAR(255)
SET @test = 'First Second'

SELECT SUBSTRING(LTRIM(@test),1,(CHARINDEX(' ',LTRIM(@test) + ' ')-1))

Body of Http.DELETE request in Angular2

Since the deprecation of RequestOptions, sending data as body in a DELETE request is not supported.

If you look at the definition of DELETE, it looks like this:

    delete<T>(url: string, options?: {
      headers?: HttpHeaders | {
         [header: string]: string | string[];
        };
      observe?: 'body';
      params?: HttpParams | {
          [param: string]: string | string[];
         };
      reportProgress?: boolean;
      responseType?: 'json';
      withCredentials?: boolean;
     }): Observable<T>;

You can send payload along with the DELETE request as part of the params in the options object as follows:

this.http.delete('http://testAPI:3000/stuff', { params: {
    data: yourData
     }).subscribe((data)=>. 
        {console.log(data)});

However, note that params only accept data as string or string[] so you will not be able to send your own interface data unless you stringify it.

What is the JavaScript equivalent of var_dump or print_r in PHP?

Most common way:

console.log(object);

However I must mention JSON.stringify which is useful to dump variables in non-browser scripts:

console.log( JSON.stringify(object) );

The JSON.stringify function also supports built-in prettification as pointed out by Simon Zyx.

Example:

var obj = {x: 1, y: 2, z: 3};

console.log( JSON.stringify(obj, null, 2) ); // spacing level = 2

The above snippet will print:

{
  "x": 1,
  "y": 2,
  "z": 3
}

On caniuse.com you can view the browsers that support natively the JSON.stringify function: http://caniuse.com/json

You can also use the Douglas Crockford library to add JSON.stringify support on old browsers: https://github.com/douglascrockford/JSON-js

Docs for JSON.stringify: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify

I hope this helps :-)

Response Buffer Limit Exceeded

Thank you so much! <%Response.Buffer = False%> worked like a charm! My asp/HTML table that was returning a blank page at about 2700 records. The following debugging lines helped expose the buffering problem: I replace the Do While loop as follows and played with my limit numbers to see what was happening:

Replace

Do While not rs.EOF

'etc .... your block of code that writes the table rows

rs.moveNext

Loop

with

Do While reccount < 2500

if rs.EOF then recount = 2501

'etc .... your block of code that writes the table rows

rs.moveNext

Loop

response.write "recount = " & recount

raise or lower the 2500 and 2501 to see if it is a buffer problem. for my record set, I could see that the blank page return, blank table, was happening at about 2700 records, good luck to all and thank you again for solving this problem! Such a simple great solution!

how to reset <input type = "file">

I use for vuejs

   <input
          type="file"
          ref="fileref"
          @change="onChange"/>

this.$refs.fileref.value = ''

Warning comparison between pointer and integer

This: "\0" is a string, not a character. A character uses single quotes, like '\0'.

Group query results by month and year in postgresql

Take a look at example E of this tutorial -> https://www.postgresqltutorial.com/postgresql-group-by/

You need to call the function on your GROUP BY instead of calling the name of the virtual attribute you created on select. I was doing what all the answers above recommended and I was getting a column 'year_month' does not exist error.

What worked for me was:

SELECT 
    date_trunc('month', created_at), 'MM/YYYY' AS month
FROM 
    "orders"  
GROUP BY 
    date_trunc('month', created_at)

How to ping an IP address

On linux with oracle-jdk the code the OP submitted uses port 7 when not root and ICMP when root. It does do a real ICMP echo request when run as root as the documentation specifies.

If you running this on a MS machine you may have to run the app as administrator to get the ICMP behaviour.

Javascript isnull

Why not try .test() ? ... Try its and best boolean (true or false):

$.urlParam = function(name){
    var results = new RegExp('[\\?&]' + name + '=([^&#]*)');
    return results.test(window.location.href);
}

Tutorial: http://www.w3schools.com/jsref/jsref_regexp_test.asp

Datatable select with multiple conditions

Dim dr As DataRow()


dr = dt.Select("A="& a & "and B="& b & "and C=" & c,"A",DataViewRowState.CurrentRows)

Where A,B,C are the column names where second parameter is for sort expression

C# Copy a file to another location with a different name

The easiest method you can use is this:

System.IO.File.Replace(string sourceFileName, string destinationFileName, string destinationBackupFileName);

This will take care of everything you requested.

How can I play sound in Java?

For playing sound in java, you can refer to the following code.

import java.io.*;
import java.net.URL;
import javax.sound.sampled.*;
import javax.swing.*;

// To play sound using Clip, the process need to be alive.
// Hence, we use a Swing application.
public class SoundClipTest extends JFrame {

   public SoundClipTest() {
      this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      this.setTitle("Test Sound Clip");
      this.setSize(300, 200);
      this.setVisible(true);

      try {
         // Open an audio input stream.
         URL url = this.getClass().getClassLoader().getResource("gameover.wav");
         AudioInputStream audioIn = AudioSystem.getAudioInputStream(url);
         // Get a sound clip resource.
         Clip clip = AudioSystem.getClip();
         // Open audio clip and load samples from the audio input stream.
         clip.open(audioIn);
         clip.start();
      } catch (UnsupportedAudioFileException e) {
         e.printStackTrace();
      } catch (IOException e) {
         e.printStackTrace();
      } catch (LineUnavailableException e) {
         e.printStackTrace();
      }
   }

   public static void main(String[] args) {
      new SoundClipTest();
   }
}

Load local JSON file into variable

The built-in node.js module fs will do it either asynchronously or synchronously depending on your needs.

You can load it using var fs = require('fs');

Asynchronous

fs.readFile('./content.json', (err, data) => {
    if (err)
      console.log(err);
    else {
      var json = JSON.parse(data);
    //your code using json object
    }
})

Synchronous

var json = JSON.parse(fs.readFileSync('./content.json').toString());

Make XAMPP / Apache serve file outside of htdocs folder

A VirtualHost would also work for this and may work better for you as you can host several projects without the need for subdirectories. Here's how you do it:

httpd.conf (or extra\httpd-vhosts.conf relative to httpd.conf. Trailing slashes "\" might cause it not to work):

NameVirtualHost *:80
# ...
<VirtualHost *:80>  
    DocumentRoot C:\projects\transitCalculator\trunk\
    ServerName transitcalculator.localhost
    <Directory C:\projects\transitCalculator\trunk\>  
        Order allow,deny  
        Allow from all  
    </Directory>
</VirtualHost> 

HOSTS file (c:\windows\system32\drivers\etc\hosts usually):

# localhost entries
127.0.0.1 localhost transitcalculator.localhost

Now restart XAMPP and you should be able to access http://transitcalculator.localhost/ and it will map straight to that directory.

This can be helpful if you're trying to replicate a production environment where you're developing a site that will sit on the root of a domain name. You can, for example, point to files with absolute paths that will carry over to the server:

<img src="/images/logo.png" alt="My Logo" />

whereas in an environment using aliases or subdirectories, you'd need keep track of exactly where the "images" directory was relative to the current file.

Comparing Arrays of Objects in JavaScript

I know this is an old question and the answers provided work fine ... but this is a bit shorter and doesn't require any additional libraries ( i.e. JSON ):

function arraysAreEqual(ary1,ary2){
  return (ary1.join('') == ary2.join(''));
}

Byte Array in Python

An alternative that also has the added benefit of easily logging its output:

hexs = "13 00 00 00 08 00"
logging.debug(hexs)
key = bytearray.fromhex(hexs)

allows you to do easy substitutions like so:

hexs = "13 00 00 00 08 {:02X}".format(someByte)
logging.debug(hexs)
key = bytearray.fromhex(hexs)

setting the id attribute of an input element dynamically in IE: alternative for setAttribute method

I wasn't aware of a problem with setAttribute in IE ? However you could directly set the expando property on the node itself:

hiddenInput.id = "uniqueIdentifier";

Jquery post, response in new window

Use the write()-Method of the Popup's document to put your markup there:

$.post(url, function (data) {
    var w = window.open('about:blank');
    w.document.open();
    w.document.write(data);
    w.document.close();
});

How to identify which columns are not "NA" per row in a matrix?

Try:

which( !is.na(p), arr.ind=TRUE)

Which I think is just as informative and probably more useful than the output you specified, But if you really wanted the list version, then this could be used:

> apply(p, 1, function(x) which(!is.na(x)) )
[[1]]
[1] 2 3

[[2]]
[1] 4 7

[[3]]
integer(0)

[[4]]
[1] 5

[[5]]
integer(0)

Or even with smushing together with paste:

lapply(apply(p, 1, function(x) which(!is.na(x)) ) , paste, collapse=", ")

The output from which function the suggested method delivers the row and column of non-zero (TRUE) locations of logical tests:

> which( !is.na(p), arr.ind=TRUE)
     row col
[1,]   1   2
[2,]   1   3
[3,]   2   4
[4,]   4   5
[5,]   2   7

Without the arr.ind parameter set to non-default TRUE, you only get the "vector location" determined using the column major ordering the R has as its convention. R-matrices are just "folded vectors".

> which( !is.na(p) )
[1]  6 11 17 24 32

Android ImageView Zoom-in and Zoom-Out

I think Chirag Ravals' answer is great!

The only thing it could be improved is moving all this code inside some class like:

PinchZoomImageView extends ImageView {...

and adding there initial Image Matrix initialization to prevent zooming after the first tap:

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    matrix = new Matrix(this.getImageMatrix());
}

BTW, this will fix a bug mentioned by Muhammad Umar and Baz

P.S. Having Max and Min zoom limits could be also useful. E.g Max zoom is 2X and min zoom is the original scale when the image is fitted to screen:

static final int MAX_SCALE_FACTOR = 2;

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);

    // Getting initial Image matrix
    mViewMatrix = new Matrix(this.getImageMatrix());
    mMinScaleMatrix = new Matrix(mViewMatrix);
    float initialScale = getMatrixScale(mViewMatrix);


    if (initialScale < 1.0f) // Image is bigger than screen
        mMaxScale = MAX_SCALE_FACTOR;
    else
        mMaxScale = MAX_SCALE_FACTOR * initialScale;

    mMinScale = getMatrixScale(mMinScaleMatrix);
}


@Override
public boolean onTouch(View v, MotionEvent event) {
    ImageView view = (ImageView) v;
    // We set scale only after onMeasure was called and automatically fit image to screen
    if(!mWasScaleTypeSet) {
        view.setScaleType(ImageView.ScaleType.MATRIX);
        mWasScaleTypeSet = true;
    }

    float scale;

    dumpEvent(event);

    switch (event.getAction() & MotionEvent.ACTION_MASK) {
    case MotionEvent.ACTION_DOWN: // first finger down only
        mCurSavedMatrix.set(mViewMatrix);
        start.set(event.getX(), event.getY());
        mCurrentMode = DRAG;
        break;

    case MotionEvent.ACTION_UP: // first finger lifted
    case MotionEvent.ACTION_POINTER_UP: // second finger lifted
        mCurrentMode = NONE;

        float resScale = getMatrixScale(mViewMatrix);

        if (resScale > mMaxScale) {
            downscaleMatrix(resScale, mViewMatrix);
        } else if (resScale < mMinScale)
            mViewMatrix = new Matrix(mMinScaleMatrix);
        else if ((resScale - mMinScale) < 0.1f) // Don't allow user to drag picture outside in case of FIT TO WINDOW zoom
            mViewMatrix = new Matrix(mMinScaleMatrix);
        else
            break;

        break;

    case MotionEvent.ACTION_POINTER_DOWN: // first and second finger down
        mOldDist = spacing(event);
        Helper.LOGD(TAG, "oldDist=" + mOldDist);
        if (mOldDist > 5f) {
            mCurSavedMatrix.set(mViewMatrix);
            midPoint(mCurMidPoint, event);
            mCurrentMode = ZOOM;
            Helper.LOGD(TAG, "mode=ZOOM");
        }
        break;

    case MotionEvent.ACTION_MOVE:
        if (mCurrentMode == DRAG) {
            mViewMatrix.set(mCurSavedMatrix);
            mViewMatrix.postTranslate(event.getX() - start.x, event.getY() - start.y); // create the transformation in the matrix  of points
        } else if (mCurrentMode == ZOOM) {
            // pinch zooming
            float newDist = spacing(event);
            Helper.LOGD(TAG, "newDist=" + newDist);
            if (newDist > 1.f) {
                mViewMatrix.set(mCurSavedMatrix);
                scale = newDist / mOldDist; // setting the scaling of the
                                            // matrix...if scale > 1 means
                                            // zoom in...if scale < 1 means
                                            // zoom out
                mViewMatrix.postScale(scale, scale, mCurMidPoint.x, mCurMidPoint.y);
            }
        }
        break;
    }

    view.setImageMatrix(mViewMatrix); // display the transformation on screen

    return true; // indicate event was handled
}


////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////// PRIVATE SECTION ///////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// These matrices will be used to scale points of the image
private Matrix mViewMatrix = new Matrix();
private Matrix mCurSavedMatrix = new Matrix();
// These PointF objects are used to record the point(s) the user is touching
private PointF start = new PointF();
private PointF mCurMidPoint = new PointF();
private float mOldDist = 1f;

private Matrix mMinScaleMatrix;
private float mMinScale;
private float mMaxScale;
float[] mTmpValues = new float[9];
private boolean mWasScaleTypeSet;


/**
 * Returns scale factor of the Matrix
 * @param matrix
 * @return
 */
private float getMatrixScale(Matrix matrix) {
    matrix.getValues(mTmpValues);
    return mTmpValues[Matrix.MSCALE_X];
}

/**
 * Downscales matrix with the scale to maximum allowed scale factor, but the same translations
 * @param scale
 * @param dist
 */
private void downscaleMatrix(float scale, Matrix dist) {
    float resScale = mMaxScale / scale;
    dist.postScale(resScale, resScale, mCurMidPoint.x, mCurMidPoint.y);
}

Difference between \n and \r?

In windows, the \n moves to the beginning of the next line. The \r moves to the beginning of the current line, without moving to the next line. I have used \r in my own console apps where I am testing out some code and I don't want to see text scrolling up my screen, so rather than use \n after printing out some text, of say, a frame rate (FPS), I will printf("%-10d\r", fps); This will return the cursor to the beginning of the line without moving down to the next line and allow me to have other information on the screen that doesn't get scrolled off while the framerate constantly updates on the same line (the %-10 makes certain the output is at least 10 characters, left justified so it ends up padded by spaces, overwriting any old values for that line). It's quite handy for stuff like this, usually when I have debugging stuff output to my console screen.

A little history

The /r stands for "return" or "carriage return" which owes it's history to the typewriter. A carriage return moved your carriage all the way to the right so you were typing at the start of the line.

The /n stands for "new line", again, from typewriter days you moved down to a new line. Not nessecarily to the start of it though, which is why some OSes adopted the need for both a /r return followed by a /n newline, as that was the order a typewriter did it in. It also explains the old 8bit computers that used to have "Return" rather than "Enter", from "carriage return", which was familiar.

HTML Table cell background image alignment

This works in IE9 (Compatibility View and Normal Mode), Firefox 17, and Chrome 23:

<table>
    <tr>
        <td style="background-image:url(untitled.png); background-position:right 0px; background-repeat:no-repeat;">
            Hello World
        </td>
    </tr>
</table>

select data up to a space?

You can use a combiation of LEFT and CHARINDEX to find the index of the first space, and then grab everything to the left of that.

 SELECT LEFT(YourColumn, charindex(' ', YourColumn) - 1) 

And in case any of your columns don't have a space in them:

SELECT LEFT(YourColumn, CASE WHEN charindex(' ', YourColumn) = 0 THEN 
    LEN(YourColumn) ELSE charindex(' ', YourColumn) - 1 END)

When is layoutSubviews called?

I had a similar question, but wasn't satisfied with the answer (or any I could find on the net), so I tried it in practice and here is what I got:

  • init does not cause layoutSubviews to be called (duh)
  • addSubview: causes layoutSubviews to be called on the view being added, the view it’s being added to (target view), and all the subviews of the target
  • view setFrame intelligently calls layoutSubviews on the view having its frame set only if the size parameter of the frame is different
  • scrolling a UIScrollView causes layoutSubviews to be called on the scrollView, and its superview
  • rotating a device only calls layoutSubview on the parent view (the responding viewControllers primary view)
  • Resizing a view will call layoutSubviews on its superview

My results - http://blog.logichigh.com/2011/03/16/when-does-layoutsubviews-get-called/

How do I check if an object's type is a particular subclass in C++?

 

class Base
{
  public: virtual ~Base() {}
};

class D1: public Base {};

class D2: public Base {};

int main(int argc,char* argv[]);
{
  D1   d1;
  D2   d2;

  Base*  x = (argc > 2)?&d1:&d2;

  if (dynamic_cast<D2*>(x) == nullptr)
  {
    std::cout << "NOT A D2" << std::endl;
  }
  if (dynamic_cast<D1*>(x) == nullptr)
  {
    std::cout << "NOT A D1" << std::endl;
  }
}

X-Frame-Options: ALLOW-FROM in firefox and chrome

For Chrome, instead of

response.AppendHeader("X-Frame-Options", "ALLOW-FROM " + host);

you need to add Content-Security-Policy

string selfAuth = System.Web.HttpContext.Current.Request.Url.Authority;
string refAuth = System.Web.HttpContext.Current.Request.UrlReferrer.Authority;
response.AppendHeader("Content-Security-Policy", "default-src 'self' 'unsafe-inline' 'unsafe-eval' data: *.msecnd.net vortex.data.microsoft.com " + selfAuth + " " + refAuth);

to the HTTP-response-headers.
Note that this assumes you checked on the server whether or not refAuth is allowed.
And also, note that you need to do browser-detection in order to avoid adding the allow-from header for Chrome (outputs error on console).

For details, see my answer here.

How do I render a shadow?

I am using React-Native 0.40 and below code works for me both on IOS and Android.

(Android-only) Sets the elevation of a view, using Android's underlying elevation API. This adds a drop shadow to the item and affects z-order for overlapping views. Only supported on Android 5.0+, has no effect on earlier versions.

 class MainApp extends Component {
  render() {
    return (
      <View style={styles.container}>

        <View elevation={5} style={styles.buttonContainer}>
          <Text style={styles.textStyle}>Shadow Applied</Text>
        </View>
      </View>
    );
  }
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
    backgroundColor: '#FFFFFF'
  },
  textStyle: {
    color: '#FFFFFF'
  },
  buttonContainer: {
    backgroundColor: '#2E9298',
    borderRadius: 10,
    padding: 10,
    shadowColor: '#000000',
    shadowOffset: {
      width: 0,
      height: 3
    },
    shadowRadius: 5,
    shadowOpacity: 1.0
  }
})

Tested on iPhone.

enter image description here

Edit

Comment from @ James. Thanks.

Note: For those on android, the backgroundColor is critical. I was using View as a container for another element and couldn't get a shadow until I specified a background color.

Clear dropdownlist with JQuery

How about storing the new options in a variable, and then using .html(variable) to replace the data in the container?

How Do I Make Glyphicons Bigger? (Change Size?)

Fontawesome has a perfect solution to this.

I implemented the same. just on your main .css file add this

.gi-2x{font-size: 2em;}
.gi-3x{font-size: 3em;}
.gi-4x{font-size: 4em;}
.gi-5x{font-size: 5em;}

In your example you just have to do this.

<div class = "jumbotron">
    <span class="glyphicon glyphicon-globe gi-5x"></span>
</div>  

Selecting option by text content with jQuery

Replace this:

var cat = $.jqURL.get('category');
var $dd = $('#cbCategory');
var $options = $('option', $dd);
$options.each(function() {
if ($(this).text() == cat)
    $(this).select(); // This is where my problem is
});

With this:

$('#cbCategory').val(cat);

Calling val() on a select list will automatically select the option with that value, if any.

How to tar certain file types in all subdirectories?

tar -cf my_archive `find ./ | grep '.php\|.html'`

Use "find" and "grep" to get all path of .php and .html files in all directory and its sub-directories. Then pass those path information to tar to compress.

Please be careful with those symbol ` and '. Note also that this will hit the limit of how many characters your shell will allow on the command line, unlike some of the other answers.

Combining a class selector and an attribute selector with jQuery

I think you just need to remove the space. i.e.

$(".myclass[reference=12345]").css('border', '#000 solid 1px');

There is a fiddle here http://jsfiddle.net/xXEHY/

How to completely uninstall python 2.7.13 on Ubuntu 16.04

sudo apt-get update   
sudo apt purge python2.7-minimal

Remove all HTMLtags in a string (with the jquery text() function)

Another option:

 $("<p>").html(myContent).text();

JavaScript replace \n with <br />

Handles either type of line break

str.replace(new RegExp('\r?\n','g'), '<br />');

Change drawable color programmatically

You can try this for svg vector drawable

DrawableCompat.setTint(
    DrawableCompat.wrap(myImageView.getDrawable()),
    ContextCompat.getColor(context, R.color.another_nice_color)
);

Django return redirect() with parameters

Firstly, your URL definition does not accept any parameters at all. If you want parameters to be passed from the URL into the view, you need to define them in the urlconf.

Secondly, it's not at all clear what you are expecting to happen to the cleaned_data dictionary. Don't forget you can't redirect to a POST - this is a limitation of HTTP, not Django - so your cleaned_data either needs to be a URL parameter (horrible) or, slightly better, a series of GET parameters - so the URL would be in the form:

/link/mybackend/?field1=value1&field2=value2&field3=value3

and so on. In this case, field1, field2 and field3 are not included in the URLconf definition - they are available in the view via request.GET.

So your urlconf would be:

url(r'^link/(?P<backend>\w+?)/$', my_function)

and the view would look like:

def my_function(request, backend):
   data = request.GET

and the reverse would be (after importing urllib):

return "%s?%s" % (redirect('my_function', args=(backend,)),
                  urllib.urlencode(form.cleaned_data))

Edited after comment

The whole point of using redirect and reverse, as you have been doing, is that you go to the URL - it returns an Http code that causes the browser to redirect to the new URL, and call that.

If you simply want to call the view from within your code, just do it directly - no need to use reverse at all.

That said, if all you want to do is store the data, then just put it in the session:

request.session['temp_data'] = form.cleaned_data

How to fix homebrew permissions?

If you're on OSX High Sierra, /usr/local can no longer be chown'd. You can use:

sudo chown -R $(whoami) $(brew --prefix)/*

NPM vs. Bower vs. Browserify vs. Gulp vs. Grunt vs. Webpack

Webpack is a bundler. Like Browserfy it looks in the codebase for module requests (require or import) and resolves them recursively. What is more, you can configure Webpack to resolve not just JavaScript-like modules, but CSS, images, HTML, literally everything. What especially makes me excited about Webpack, you can combine both compiled and dynamically loaded modules in the same app. Thus one get a real performance boost, especially over HTTP/1.x. How exactly you you do it I described with examples here http://dsheiko.com/weblog/state-of-javascript-modules-2017/ As an alternative for bundler one can think of Rollup.js (https://rollupjs.org/), which optimizes the code during compilation, but stripping all the found unused chunks.

For AMD, instead of RequireJS one can go with native ES2016 module system, but loaded with System.js (https://github.com/systemjs/systemjs)

Besides, I would point that npm is often used as an automating tool like grunt or gulp. Check out https://docs.npmjs.com/misc/scripts. I personally go now with npm scripts only avoiding other automation tools, though in past I was very much into grunt. With other tools you have to rely on countless plugins for packages, that often are not good written and not being actively maintained. npm knows its packages, so you call to any of locally installed packages by name like:

{
  "scripts": {
    "start": "npm http-server"
  },
  "devDependencies": {
    "http-server": "^0.10.0"
  }
}

Actually you as a rule do not need any plugin if the package supports CLI.

Java: String - add character n-times

for(int i = 0; i < n; i++) {
    existing_string += 'c';
}

but you should use StringBuilder instead, and save memory

int n = 3;
String existing_string = "string";
StringBuilder builder = new StringBuilder(existing_string);
for (int i = 0; i < n; i++) {
    builder.append(" append ");
}

System.out.println(builder.toString());

What is the difference between JOIN and UNION?

Joins and Unions can be used to combine data from one or more tables. The difference lies in how the data is combined.

In simple terms, joins combine data into new columns. If two tables are joined together, then the data from the first table is shown in one set of column alongside the second table’s column in the same row.

Unions combine data into new rows. If two tables are “unioned” together, then the data from the first table is in one set of rows, and the data from the second table in another set. The rows are in the same result.

Here is a visual depiction of a join. Table A and B’s columns are combined into a single result.

enter image description here

Each row in the result contains columns from BOTH table A and B. Rows are created when columns from one table match columns from another. This match is called the join condition.

This makes joins really great for looking up values and including them in results. This is usually the result of denormalizing (reversing normalization) and involves using the foreign key in one table to look up column values by using the primary key in another.

Now compare the above depiction with that of a union. In a union each row within the result is from one table OR the other. In a union, columns aren’t combined to create results, rows are combined.

enter image description here

Both joins and unions can be used to combine data from one or more tables into a single results. They both go about this is different ways. Whereas a join is used to combine columns from different tables, the union is used to combine rows.

Source

JavaScript implementation of Gzip

I had another problem, I did not want to encode data in gzip but to decode gzipped data. I am running javascript code outside of the browser so I need to decode it using pure javascript.

It took me some time but i found that in the JSXGraph library there is a way to read gzipped data.

Here is where I found the library: http://jsxgraph.uni-bayreuth.de/wp/2009/09/29/jsxcompressor-zlib-compressed-javascript-code/ There is even a standalone utility that can do that, JSXCompressor, and the code is LGPL licencied.

Just include the jsxcompressor.js file in your project and then you will be able to read a base 64 encoded gzipped data:

<!doctype html>
</head>
<title>Test gzip decompression page</title>
<script src="jsxcompressor.js"></script>
</head>
<body>
<script>
    document.write(JXG.decompress('<?php 
        echo base64_encode(gzencode("Try not. Do, or do not. There is no try.")); 
    ?>'));
</script>
</html>

I understand it is not what you wanted but I still reply here because I suspect it will help some people.

How can I view the Git history in Visual Studio Code?

It is evident to me that GitLens is the most popular extension for Git history.

enter image description here

What I like the most it can provide you side annotations when some line has been changed the last time and by whom.

Enter image description here

Drop data frame columns by name

If you have a large data.frame and are low on memory use [ . . . . or rm and within to remove columns of a data.frame, as subset is currently (R 3.6.2) using more memory - beside the hint of the manual to use subset interactively.

getData <- function() {
  n <- 1e7
  set.seed(7)
  data.frame(a = runif(n), b = runif(n), c = runif(n), d = runif(n))
}

DF <- getData()
tt <- sum(.Internal(gc(FALSE, TRUE, TRUE))[13:14])
DF <- DF[setdiff(names(DF), c("a", "c"))] ##
#DF <- DF[!(names(DF) %in% c("a", "c"))] #Alternative
#DF <- DF[-match(c("a","c"),names(DF))]  #Alternative
sum(.Internal(gc(FALSE, FALSE, TRUE))[13:14]) - tt
#0.1 MB are used

DF <- getData()
tt <- sum(.Internal(gc(FALSE, TRUE, TRUE))[13:14])
DF <- subset(DF, select = -c(a, c)) ##
sum(.Internal(gc(FALSE, FALSE, TRUE))[13:14]) - tt
#357 MB are used

DF <- getData()
tt <- sum(.Internal(gc(FALSE, TRUE, TRUE))[13:14])
DF <- within(DF, rm(a, c)) ##
sum(.Internal(gc(FALSE, FALSE, TRUE))[13:14]) - tt
#0.1 MB are used

DF <- getData()
tt <- sum(.Internal(gc(FALSE, TRUE, TRUE))[13:14])
DF[c("a", "c")]  <- NULL ##
sum(.Internal(gc(FALSE, FALSE, TRUE))[13:14]) - tt
#0.1 MB are used

How can I easily convert DataReader to List<T>?

I would suggest writing an extension method for this:

public static IEnumerable<T> Select<T>(this IDataReader reader,
                                       Func<IDataReader, T> projection)
{
    while (reader.Read())
    {
        yield return projection(reader);
    }
}

You can then use LINQ's ToList() method to convert that into a List<T> if you want, like this:

using (IDataReader reader = ...)
{
    List<Customer> customers = reader.Select(r => new Customer {
        CustomerId = r["id"] is DBNull ? null : r["id"].ToString(),
        CustomerName = r["name"] is DBNull ? null : r["name"].ToString() 
    }).ToList();
}

I would actually suggest putting a FromDataReader method in Customer (or somewhere else):

public static Customer FromDataReader(IDataReader reader) { ... }

That would leave:

using (IDataReader reader = ...)
{
    List<Customer> customers = reader.Select<Customer>(Customer.FromDataReader)
                                     .ToList();
}

(I don't think type inference would work in this case, but I could be wrong...)

Best practices for API versioning?

There are a few places you can do versioning in a REST API:

  1. As noted, in the URI. This can be tractable and even esthetically pleasing if redirects and the like are used well.

  2. In the Accepts: header, so the version is in the filetype. Like 'mp3' vs 'mp4'. This will also work, though IMO it works a bit less nicely than...

  3. In the resource itself. Many file formats have their version numbers embedded in them, typically in the header; this allows newer software to 'just work' by understanding all existing versions of the filetype while older software can punt if an unsupported (newer) version is specified. In the context of a REST API, it means that your URIs never have to change, just your response to the particular version of data you were handed.

I can see reasons to use all three approaches:

  1. if you like doing 'clean sweep' new APIs, or for major version changes where you want such an approach.
  2. if you want the client to know before it does a PUT/POST whether it's going to work or not.
  3. if it's okay if the client has to do its PUT/POST to find out if it's going to work.

LEFT INNER JOIN vs. LEFT OUTER JOIN - Why does the OUTER take longer?

The fact that the same number of rows is returned is an after fact, the query optimizer cannot know in advance that every row in Accepts has a matching row in Marker, can it?

If you join two tables A and B, say A has 1 million rows and B has 1 row. If you say A LEFT INNER JOIN B it means only rows that match both A and B can result, so the query plan is free to scan B first, then use an index to do a range scan in A, and perhaps return 10 rows. But if you say A LEFT OUTER JOIN B then at least all rows in A have to be returned, so the plan must scan everything in A no matter what it finds in B. By using an OUTER join you are eliminating one possible optimization.

If you do know that every row in Accepts will have a match in Marker, then why not declare a foreign key to enforce this? The optimizer will see the constraint, and if is trusted, will take it into account in the plan.

How can I show figures separately in matplotlib?

With Matplotlib prior to version 1.0.1, show() should only be called once per program, even if it seems to work within certain environments (some backends, on some platforms, etc.).

The relevant drawing function is actually draw():

import matplotlib.pyplot as plt

plt.plot(range(10))  # Creates the plot.  No need to save the current figure.
plt.draw()  # Draws, but does not block
raw_input()  # This shows the first figure "separately" (by waiting for "enter").

plt.figure()  # New window, if needed.  No need to save it, as pyplot uses the concept of current figure
plt.plot(range(10, 20))
plt.draw()
# raw_input()  # If you need to wait here too...

# (...)

# Only at the end of your program:
plt.show()  # blocks

It is important to recognize that show() is an infinite loop, designed to handle events in the various figures (resize, etc.). Note that in principle, the calls to draw() are optional if you call matplotlib.ion() at the beginning of your script (I have seen this fail on some platforms and backends, though).

I don't think that Matplotlib offers a mechanism for creating a figure and optionally displaying it; this means that all figures created with figure() will be displayed. If you only need to sequentially display separate figures (either in the same window or not), you can do like in the above code.

Now, the above solution might be sufficient in simple cases, and for some Matplotlib backends. Some backends are nice enough to let you interact with the first figure even though you have not called show(). But, as far as I understand, they do not have to be nice. The most robust approach would be to launch each figure drawing in a separate thread, with a final show() in each thread. I believe that this is essentially what IPython does.

The above code should be sufficient most of the time.

PS: now, with Matplotlib version 1.0.1+, show() can be called multiple times (with most backends).

How can I find script's directory?

Use os.path.abspath('')

EditText non editable

android:editable="false" should work, but it is deprecated, you should be using android:inputType="none" instead.

Alternatively, if you want to do it in the code you could do this :

EditText mEdit = (EditText) findViewById(R.id.yourid);
mEdit.setEnabled(false);

This is also a viable alternative :

EditText mEdit = (EditText) findViewById(R.id.yourid);
mEdit.setKeyListener(null);

If you're going to make your EditText non-editable, may I suggest using the TextView widget instead of the EditText, since using a EditText seems kind of pointless in that case.

EDIT: Altered some information since I've found that android:editable is deprecated, and you should use android:inputType="none", but there is a bug about it on android code; So please check this.

scp with port number specified

I'm using different ports then standard and copy files between files like this:

scp -P 1234 user@[ip address or host name]:/var/www/mywebsite/dumps/* /var/www/myNewPathOnCurrentLocalMachine

This is only for occasional use, if it repeats itself based on a schedule you should use rsync and cron job to do it.

Visual Studio Community 2015 expiration date

There is and there isn't an expiration date. If you register Visual Studio 2015 Community Edition by successfully signing into Visual Studio then the product is fully unlocked with no set expiry date. If you don't sign in (or haven't entered a purchased licence key), you only have 30 day evaluation license.

You can check whether your copy of Visual Studio has is registered or not by selecting Help -> About Microsoft Studio and clicking on the "License Status" link in the upper right of the About dialog. If your product isn't registered you'll see something like this:

Visual Studio 2015 License Status Window

How to replace case-insensitive literal substrings in Java

String newstring  = "";
String target2 = "fooBar";
newstring = target2.substring("foo".length()).trim();   
logger.debug("target2: {}",newstring); 
// output: target2: Bar
    
String target3 = "FooBar";
newstring = target3.substring("foo".length()).trim();
logger.debug("target3: {}",newstring); 
// output: target3: Bar

Create table in SQLite only if it doesn't exist already

From http://www.sqlite.org/lang_createtable.html:

CREATE TABLE IF NOT EXISTS some_table (id INTEGER PRIMARY KEY AUTOINCREMENT, ...);

MySQL show status - active or total connections?

As per doc http://dev.mysql.com/doc/refman/5.0/en/server-status-variables.html#statvar_Connections

Connections

The number of connection attempts (successful or not) to the MySQL server.

What is the &#xA; character?

&#xA; is the HTML representation in hex of a line feed character. It represents a new line on Unix and Unix-like (for example) operating systems.

You can find a list of such characters at (for example) http://la.remifa.so/unicode/latin1.html

Test if element is present using Selenium WebDriver?

I had the same issue. For me, depending on a user's permission level, some links, buttons and other elements will not show on the page. Part of my suite was testing that the elements that SHOULD be missing, are missing. I spent hours trying to figure this out. I finally found the perfect solution.

What this does, is tells the browser to look for any and all elements based specified. If it results in 0, that means no elements based on the specification was found. Then i have the code execute an if statement to let me know it was not found.

This is in C#, so translations would need to be done to Java. But shouldnt be too hard.

public void verifyPermission(string link)
{
    IList<IWebElement> adminPermissions = driver.FindElements(By.CssSelector(link));
    if (adminPermissions.Count == 0)
    {
        Console.WriteLine("User's permission properly hidden");
    }
}

There's also another path you can take depending on what you need for your test.

The following snippet is checking to see if a very specific element exists on the page. Depending on the element's existence I have the test execute an if else.

If the element exists and is displayed on the page, I have console.write let me know and move on. If the element in question exists, I cannot execute the test I needed, which is the main reasoning behind needing to set this up.

If the element Does Not exists, and is not displayed on the page. I have the else in the if else execute the test.

IList<IWebElement> deviceNotFound = driver.FindElements(By.CssSelector("CSS LINK GOES HERE"));
//if the element specified above results in more than 0 elements and is displayed on page execute the following, otherwise execute whats in the else statement
if (deviceNotFound.Count > 0 && deviceNotFound[0].Displayed){
    //script to execute if element is found
} else {
    //Test script goes here.
}

I know I'm a little late on the response to the OP. Hopefully this helps someone!

Reusing a PreparedStatement multiple times

The loop in your code is only an over-simplified example, right?

It would be better to create the PreparedStatement only once, and re-use it over and over again in the loop.

In situations where that is not possible (because it complicated the program flow too much), it is still beneficial to use a PreparedStatement, even if you use it only once, because the server-side of the work (parsing the SQL and caching the execution plan), will still be reduced.

To address the situation that you want to re-use the Java-side PreparedStatement, some JDBC drivers (such as Oracle) have a caching feature: If you create a PreparedStatement for the same SQL on the same connection, it will give you the same (cached) instance.

About multi-threading: I do not think JDBC connections can be shared across multiple threads (i.e. used concurrently by multiple threads) anyway. Every thread should get his own connection from the pool, use it, and return it to the pool again.

How can I divide two integers stored in variables in Python?

Use this line to get the division behavior you want:

from __future__ import division

Alternatively, you could use modulus:

if (a % b) == 0: #do something

Where is Java Installed on Mac OS X?

Java package structure of Mac OS is a bit different from Windows. Don't be upset for this as a developer just needs to set PATH and JAVA_HOME.

So in .bash_profile set JAVA_HOME and PATH as below. This example is for Java 6:

export JAVA_HOME=/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home
export PATH=/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/bin:$PATH

What integer hash function are good that accepts an integer hash key?

Depends on how your data is distributed. For a simple counter, the simplest function

f(i) = i

will be good (I suspect optimal, but I can't prove it).

java.lang.NoClassDefFoundError: com/fasterxml/jackson/core/JsonFactory

The requested jar is probably not jackson-annotations-x.y.z.jar but jackson-core-x.y.z.jar which could be found here: http://www.java2s.com/Code/Jar/j/Downloadjacksoncore220rc1jar.htm

How do I define the name of image built with docker-compose

Option 1: Hinting default image name

The name of the image generated by docker-compose depends on the folder name by default but you can override it by using --project-name argument:

$ docker-compose --project-name foo build bar
$ docker images foo_bar

Option 2: Specifying image name

Once docker-compose 1.6.0 is out, you may specify build: and image: to have an explicit image name (see arulraj.net's answer).

Option 3: Create image from container

A third is to create an image from the container:

$ docker-compose up -d bar
$ docker commit $(docker-compose ps -q bar) foo_bar
$ docker-compose rm -f bar

How to get the text of the selected value of a dropdown list?

The easiest way is through css3 $("select option:selected") and then use the .text() or .html() function. depending on what you want to have.

How do I rename a MySQL schema?

If you're on the Model Overview page you get a tab with the schema. If you rightclick on that tab you get an option to "edit schema". From there you can rename the schema by adding a new name, then click outside the field. This goes for MySQL Workbench 5.2.30 CE

Edit: On the model overview it's under Physical Schemata

Screenshot:

enter image description here

Why does JSON.parse fail with the empty string?

As an empty string is not valid JSON it would be incorrect for JSON.parse('') to return null because "null" is valid JSON. e.g.

JSON.parse("null");

returns null. It would be a mistake for invalid JSON to also be parsed to null.

While an empty string is not valid JSON two quotes is valid JSON. This is an important distinction.

Which is to say a string that contains two quotes is not the same thing as an empty string.

JSON.parse('""');

will parse correctly, (returning an empty string). But

JSON.parse('');

will not.

Valid minimal JSON strings are

The empty object '{}'

The empty array '[]'

The string that is empty '""'

A number e.g. '123.4'

The boolean value true 'true'

The boolean value false 'false'

The null value 'null'

How to check if a URL exists or returns 404 with Java?

There is nothing wrong with your code. It's the NBC.com doing tricks on you. When NBC.com decides that your browser is not capable of displaying PDF, it simply sends back a webpage regardless what you are requesting, even if it doesn't exist.

You need to trick it back by telling it your browser is capable, something like,

conn.setRequestProperty("User-Agent",
    "Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.0.13) Gecko/2009073021 Firefox/3.0.13");

Strange PostgreSQL "value too long for type character varying(500)"

Character varying is different than text. Try running

ALTER TABLE product_product ALTER COLUMN code TYPE text;

That will change the column type to text, which is limited to some very large amount of data (you would probably never actually hit it.)

How to get longitude and latitude of any address?

<?php
$address = 'BTM 2nd Stage, Bengaluru, Karnataka 560076'; // Address
$apiKey = 'api-key'; // Google maps now requires an API key.
// Get JSON results from this request
$geo = file_get_contents('https://maps.googleapis.com/maps/api/geocode/json?address='.urlencode($address).'&sensor=false&key='.$apiKey);
$geo = json_decode($geo, true); // Convert the JSON to an array

if (isset($geo['status']) && ($geo['status'] == 'OK')) {
  $latitude = $geo['results'][0]['geometry']['location']['lat']; // Latitude
  $longitude = $geo['results'][0]['geometry']['location']['lng']; // Longitude
}
?>

How to install package from github repo in Yarn

I use this short format for github repositories:

yarn add github_user/repository_name#commit_hash

pandas dataframe convert column type to string or categorical

Prior answers focused on nominal data (e.g. unordered). If there is a reason to impose order for an ordinal variable, then one would use:

# Transform to category
df['zipcode_category'] = df['zipcode_category'].astype('category')

# Add ordered category
df['zipcode_ordered'] = df['zipcode_category']

# Setup the ordering
df.zipcode_ordered.cat.set_categories(
    new_categories = [90211, 90210], ordered = True, inplace = True
)

# Output IDs
df['zipcode_ordered_id'] = df.zipcode_ordered.cat.codes
print(df)
#  zipcode_category zipcode_ordered  zipcode_ordered_id
#            90210           90210                   1
#            90211           90211                   0

More details on setting ordered categories can be found at the pandas website:

https://pandas.pydata.org/pandas-docs/stable/user_guide/categorical.html#sorting-and-order

Split / Explode a column of dictionaries into separate columns with pandas

df = pd.concat([df['a'], df.b.apply(pd.Series)], axis=1)

Alert handling in Selenium WebDriver (selenium 2) with Java

Alert alert = driver.switchTo().alert();

alert.accept();

You can also decline the alert box:


Alert alert = driver.switchTo().alert();

alert().dismiss();

Redirect to a page/URL after alert button is pressed

<head>
<script>
    function myFunction() {
        var x;
        var r = confirm("Do you want to clear data?");
        if (r == true) {
            x = "Your Data is Cleared";
            window.location.href = "firstpage.php";
        }
        else {
            x = "You pressed Cancel!";
        }
        document.getElementById("demo").innerHTML = x;
    }
</script>
</head>
<body>
<button onclick="myFunction()">Retest</button>

<p id="demo"></p>
</body>
</html>

This will redirect to new php page.

How do I get the path and name of the file that is currently executing?

import os

import wx


# return the full path of this file
print(os.getcwd())

icon = wx.Icon(os.getcwd() + '/img/image.png', wx.BITMAP_TYPE_PNG, 16, 16)

# put the icon on the frame
self.SetIcon(icon)

Asynchronously wait for Task<T> to complete with timeout

Definitely don't do this, but it is an option if ... I can't think of a valid reason.

((CancellationTokenSource)cancellationToken.GetType().GetField("m_source",
    System.Reflection.BindingFlags.NonPublic |
    System.Reflection.BindingFlags.Instance
).GetValue(cancellationToken)).Cancel();

parseInt with jQuery

var test = parseInt($("#testid").val(), 10);

You have to tell it you want the value of the input you are targeting.

And also, always provide the second argument (radix) to parseInt. It tries to be too clever and autodetect it if not provided and can lead to unexpected results.

Providing 10 assumes you are wanting a base 10 number.

How to calculate percentage with a SQL statement

In any sql server version you could use a variable for the total of all grades like this:

declare @countOfAll decimal(18, 4)
select @countOfAll = COUNT(*) from Grades

select
Grade,  COUNT(*) / @countOfAll * 100
from Grades
group by Grade

How to install and use "make" in Windows?

The accepted answer is a bad idea in general because the manually created make.exe will stick around and can potentially cause unexpected problems. It actually breaks RubyInstaller: https://github.com/oneclick/rubyinstaller2/issues/105

An alternative is installing make via Chocolatey (as pointed out by @Vasantha Ganesh K)

Another alternative is installing MSYS2 from Chocolatey and using make from C:\tools\msys64\usr\bin. If make isn't installed automatically with MSYS2 you need to install it manually via pacman -S make (as pointed out by @Thad Guidry and @Luke).

What does the DOCKER_HOST variable do?

Upon investigation, it's also worth noting that when you want to start using docker in a new terminal window, the correct command is:

$(boot2docker shellinit)

I had tested these commands:

>>  docker info
Get http:///var/run/docker.sock/v1.15/info: dial unix /var/run/docker.sock: no such file or directory
>>  boot2docker shellinit
Writing /Users/ddavison/.boot2docker/certs/boot2docker-vm/ca.pem
Writing /Users/ddavison/.boot2docker/certs/boot2docker-vm/cert.pem
Writing /Users/ddavison/.boot2docker/certs/boot2docker-vm/key.pem
    export DOCKER_HOST=tcp://192.168.59.103:2376
    export DOCKER_CERT_PATH=/Users/ddavison/.boot2docker/certs/boot2docker-vm
    export DOCKER_TLS_VERIFY=1
>> docker info
Get http:///var/run/docker.sock/v1.15/info: dial unix /var/run/docker.sock: no such file or directory

Notice that docker info returned that same error. however.. when using $(boot2docker shellinit)...

>>  $(boot2docker init)
Writing /Users/ddavison/.boot2docker/certs/boot2docker-vm/ca.pem
Writing /Users/ddavison/.boot2docker/certs/boot2docker-vm/cert.pem
Writing /Users/ddavison/.boot2docker/certs/boot2docker-vm/key.pem
>>  docker info
Containers: 3
...

How to print the current Stack Trace in .NET without any exception?

Console.WriteLine(
    new System.Diagnostics.StackTrace().ToString()
    );

The output will be similar to:

at YourNamespace.Program.executeMethod(String msg)

at YourNamespace.Program.Main(String[] args)

Replace Console.WriteLine with your Log method. Actually, there is no need for .ToString() for the Console.WriteLine case as it accepts object. But you may need that for your Log(string msg) method.

Using jQuery to center a DIV on the screen

you're getting that poor transition because you're adjusting the position of the element every time the document is scrolled. What you want is to use fixed positioning. I tried that fixed center plugin listed above and that seems to do solve the problem nicely. Fixed positioning allows you to center an element once, and the CSS property will take care of maintaining that position for you every time you scroll.

Apply multiple functions to multiple groupby columns

Ted's answer is amazing. I ended up using a smaller version of that in case anyone is interested. Useful when you are looking for one aggregation that depends on values from multiple columns:

create a dataframe

df=pd.DataFrame({'a': [1,2,3,4,5,6], 'b': [1,1,0,1,1,0], 'c': ['x','x','y','y','z','z']})


   a  b  c
0  1  1  x
1  2  1  x
2  3  0  y
3  4  1  y
4  5  1  z
5  6  0  z

grouping and aggregating with apply (using multiple columns)

df.groupby('c').apply(lambda x: x['a'][(x['a']>1) & (x['b']==1)].mean())

c
x    2.0
y    4.0
z    5.0

grouping and aggregating with aggregate (using multiple columns)

I like this approach since I can still use aggregate. Perhaps people will let me know why apply is needed for getting at multiple columns when doing aggregations on groups.

It seems obvious now, but as long as you don't select the column of interest directly after the groupby, you will have access to all the columns of the dataframe from within your aggregation function.

only access to the selected column

df.groupby('c')['a'].aggregate(lambda x: x[x>1].mean())

access to all columns since selection is after all the magic

df.groupby('c').aggregate(lambda x: x[(x['a']>1) & (x['b']==1)].mean())['a']

or similarly

df.groupby('c').aggregate(lambda x: x['a'][(x['a']>1) & (x['b']==1)].mean())

I hope this helps.

Multiple rows to one comma-separated value in Sql Server

Test Data

DECLARE @Table1 TABLE(ID INT, Value INT)
INSERT INTO @Table1 VALUES (1,100),(1,200),(1,300),(1,400)

Query

SELECT  ID
       ,STUFF((SELECT ', ' + CAST(Value AS VARCHAR(10)) [text()]
         FROM @Table1 
         WHERE ID = t.ID
         FOR XML PATH(''), TYPE)
        .value('.','NVARCHAR(MAX)'),1,2,' ') List_Output
FROM @Table1 t
GROUP BY ID

Result Set

+--------------------------+
¦ ID ¦     List_Output     ¦
¦----+---------------------¦
¦  1 ¦  100, 200, 300, 400 ¦
+--------------------------+

SQL Server 2017 and Later Versions

If you are working on SQL Server 2017 or later versions, you can use built-in SQL Server Function STRING_AGG to create the comma delimited list:

DECLARE @Table1 TABLE(ID INT, Value INT);
INSERT INTO @Table1 VALUES (1,100),(1,200),(1,300),(1,400);


SELECT ID , STRING_AGG([Value], ', ') AS List_Output
FROM @Table1
GROUP BY ID;

Result Set

+--------------------------+
¦ ID ¦     List_Output     ¦
¦----+---------------------¦
¦  1 ¦  100, 200, 300, 400 ¦
+--------------------------+

Using :: in C++

The :: are used to dereference scopes.

const int x = 5;

namespace foo {
  const int x = 0;
}

int bar() {
  int x = 1;
  return x;
}

struct Meh {
  static const int x = 2;
}

int main() {
  std::cout << x; // => 5
  {
    int x = 4;
    std::cout << x; // => 4
    std::cout << ::x; // => 5, this one looks for x outside the current scope
  }
  std::cout << Meh::x; // => 2, use the definition of x inside the scope of Meh
  std::cout << foo::x; // => 0, use the definition of x inside foo
  std::cout << bar(); // => 1, use the definition of x inside bar (returned by bar)
}

unrelated: cout and cin are not functions, but instances of stream objects.

EDIT fixed as Keine Lust suggested

How to use patterns in a case statement?

if and grep -Eq

arg='abc'
if echo "$arg" | grep -Eq 'a.c|d.*'; then
  echo 'first'
elif echo "$arg" | grep -Eq 'a{2,3}'; then
  echo 'second'
fi

where:

  • -q prevents grep from producing output, it just produces the exit status
  • -E enables extended regular expressions

I like this because:

One downside is that this is likely slower than case since it calls an external grep program, but I tend to consider performance last when using Bash.

case is POSIX 7

Bash appears to follow POSIX by default without shopt as mentioned by https://stackoverflow.com/a/4555979/895245

Here is the quote: http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_01 section "Case Conditional Construct":

The conditional construct case shall execute the compound-list corresponding to the first one of several patterns (see Pattern Matching Notation) [...] Multiple patterns with the same compound-list shall be delimited by the '|' symbol. [...]

The format for the case construct is as follows:

case word in
     [(] pattern1 ) compound-list ;;
     [[(] pattern[ | pattern] ... ) compound-list ;;] ...
     [[(] pattern[ | pattern] ... ) compound-list]
  esac

and then http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_13 section "2.13. Pattern Matching Notation" only mentions ?, * and [].

How to make a gap between two DIV within the same column

you can use $nbsp; for a single space, if you like just using single allows you single space instead of using creating own class

    <div id="bulkOptionContainer" class="col-xs-4">
        <select class="form-control" name="" id="">
            <option value="">Select Options</option>
            <option value="">Published</option>
            <option value="">Draft</option>
            <option value="">Delete</option>
        </select>
    </div>

    <div class="col-xs-4">

        <input type="submit" name="submit" class="btn btn-success " value="Apply">
         &nbsp;
        <a class="btn btn-primary" href="add_posts.php">Add post</a>

    </div>


</form>

CLICK ON IMAGE

On Selenium WebDriver how to get Text from Span Tag

Pythonic way to get text from Span tags:

driver.find_element_by_xpath("//*[@id='customSelect_3']/.//span[contains(@class,'selectLabel clear')]").text

How to Validate Google reCaptcha on Form Submit

You can first verify in the frontend side that the checkbox is marked:

    var recaptchaRes = grecaptcha.getResponse();
    var message = "";

    if(recaptchaRes.length == 0) {
        // You can return the message to user
        message = "Please complete the reCAPTCHA challenge!";
        return false;
    } else {
       // Add reCAPTCHA response to the POST
       form.recaptchaRes = recaptchaRes;
    }

And then in the server side verify the received response using Google reCAPTCHA API:

    $receivedRecaptcha = $_POST['recaptchaRes'];
    $verifiedRecaptcha = file_get_contents('https://www.google.com/recaptcha/api/siteverify?secret='.$google_secret.'&response='.$receivedRecaptcha);

    $verResponseData = json_decode($verifiedRecaptcha);

    if(!$verResponseData->success)
    {
        return "reCAPTCHA is not valid; Please try again!";
    }

For more info you can visit Google docs.

Get the current fragment object

If you are extending from AbstractActivity, you could use the getFragments() method:

for (Fragment f : getFragments()) {
    if (f instanceof YourClass) {
        // do stuff here
    }
}

How to split large text file in windows?

you can split using a third party software http://www.hjsplit.org/, for example give yours input that could be upto 9GB and then split, in my case I split 10 MB each enter image description here

How to open a specific port such as 9090 in Google Compute Engine

This question is old and Carlos Rojas's answer is good, but I think I should post few things which should be kept in mind while trying to open the ports.

The first thing to remember is that Networking section is renamed to VPC Networking. So if you're trying to find out where Firewall Rules option is available, go look at VPC Networking.

The second thing is, if you're trying to open ports on a Linux VM, make sure under no circumstances should you try to open port using ufw command. I tried using that and lost ssh access to the VM. So don't repeat my mistake.

The third thing is, if you're trying to open ports on a Windows VM, you'll need to create Firewall rules inside the VM also in Windows Firewall along with VPC Networking -> Firewall Rules. The port needs to be opened in both firewall rules, unlike Linux VM. So if you're not getting access to the port from outside the VM, check if you've opened the port in both GCP console and Windows Firewall.

The last (obvious) thing is, do not open ports unnecessarily. Close the ports, as soon as you no longer need it.

I hope this answer is useful.

Converting HTML files to PDF

You can use a headless firefox with an extension. It's pretty annoying to get running but it does produce good results.

Check out this answer for more info.

What is the difference between 'typedef' and 'using' in C++11?

Both keywords are equivalent, but there are a few caveats. One is that declaring a function pointer with using T = int (*)(int, int); is clearer than with typedef int (*T)(int, int);. Second is that template alias form is not possible with typedef. Third is that exposing C API would require typedef in public headers.

how to install tensorflow on anaconda python 3.6

Uninstall Python 3.7 for Windows, and only install Python 3.6.0 then you will have no problem or receive the error message:

import tensorflow as tf ModuleNotFoundError: No module named 'tensorflow'

Python: How to get stdout after running os.system?

If all you need is the stdout output, then take a look at subprocess.check_output():

import subprocess

batcmd="dir"
result = subprocess.check_output(batcmd, shell=True)

Because you were using os.system(), you'd have to set shell=True to get the same behaviour. You do want to heed the security concerns about passing untrusted arguments to your shell.

If you need to capture stderr as well, simply add stderr=subprocess.STDOUT to the call:

result = subprocess.check_output([batcmd], stderr=subprocess.STDOUT)

to redirect the error output to the default output stream.

If you know that the output is text, add text=True to decode the returned bytes value with the platform default encoding; use encoding="..." instead if that codec is not correct for the data you receive.

How to split one text file into multiple *.txt files?

You can use the linux bash core utility split

split -b 1M -d  file.txt file 

Note that M or MB both are OK but size is different. MB is 1000 * 1000, M is 1024^2

If you want to separate by lines you can use -l parameter.

UPDATE

a=(`wc -l yourfile`) ; lines=`echo $(($a/12)) | bc -l` ; split -l $lines -d  file.txt file

Another solution as suggested by Kirill, you can do something like the following

split -n l/12 file.txt

Note that is l not one, split -n has a few options, like N, k/N, l/k/N, r/N, r/k/N.

Android get current Locale, not default

The default Locale is constructed statically at runtime for your application process from the system property settings, so it will represent the Locale selected on that device when the application was launched. Typically, this is fine, but it does mean that if the user changes their Locale in settings after your application process is running, the value of getDefaultLocale() probably will not be immediately updated.

If you need to trap events like this for some reason in your application, you might instead try obtaining the Locale available from the resource Configuration object, i.e.

Locale current = getResources().getConfiguration().locale;

You may find that this value is updated more quickly after a settings change if that is necessary for your application.

C++ Compare char array with string

In this code you are not comparing string values, you are comparing pointer values. If you want to compare string values you need to use a string comparison function such as strcmp.

if ( 0 == strcmp(var1, "dev")) {
  ..
}

How can I add a hint or tooltip to a label in C# Winforms?

just another way to do it.

Label lbl = new Label();
new ToolTip().SetToolTip(lbl, "tooltip text here");

Change keystore password from no password to a non blank password

this way worked better for me:

echo y | keytool -storepasswd -storepass 123456 -keystore /tmp/IT-Root-CA.keystore -import -alias IT-Root-CA -file /etc/pki/ca-trust/source/anchors/IT-Root-CA.crt

machine running:

[root@rhel80-68]# cat /etc/redhat-release 
Red Hat Enterprise Linux release 8.1 (Ootpa)

How to make a edittext box in a dialog

Simplest of all would be.

  • Create xml layout file for dialog . Add whatever view you want like EditText , ListView , Spinner etc.

    Inflate this view and set this to AlertDialog

Lets start with Layout file first.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center_horizontal"
    android:orientation="vertical">


    <EditText
        android:id="@+id/etComments"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:gravity="top"
        android:hint="Enter comments(Optional)"
        android:inputType="textMultiLine"
        android:lines="8"
        android:maxLines="3"
        android:minLines="6"
        android:scrollbars="vertical" />

</LinearLayout>

final View view = layoutInflater.inflate(R.layout.xml_file_created_above, null);
AlertDialog alertDialog = new AlertDialog.Builder(ct).create();
alertDialog.setTitle("Your Title Here");
alertDialog.setIcon("Icon id here");
alertDialog.setCancelable(false);
Constant.alertDialog.setMessage("Your Message Here");


final EditText etComments = (EditText) view.findViewById(R.id.etComments);

alertDialog.setButton(AlertDialog.BUTTON_POSITIVE, "OK", new OnClickListener() {
    @Override
    public void onClick(DialogInterface dialog, int which) {

    }
});


alertDialog.setButton(AlertDialog.BUTTON_NEGATIVE, "Cancel", new OnClickListener() {
    @Override
    public void onClick(DialogInterface dialog, int which) {
        alertDialog.dismiss()
    }
});


alertDialog.setView(view);
alertDialog.show();

Fastest way to check a string contain another substring in JavaScript?

You have three possibilites:

  1. Regular expression:

     (new RegExp('word')).test(str)
     // or
     /word/.test(str)
    
  2. indexOf:

     str.indexOf('word') !== -1
    
  3. includes:

     str.includes('word')
    

Regular expressions seem to be faster (at least in Chrome 10).

Performance test - short haystack
Performance test - long haystack


**Update 2011:**

It cannot be said with certainty which method is faster. The differences between the browsers is enormous. While in Chrome 10 indexOf seems to be faster, in Safari 5, indexOf is clearly slower than any other method.

You have to see and try for your self. It depends on your needs. For example a case-insensitive search is way faster with regular expressions.


Update 2018:

Just to save people from running the tests themselves, here are the current results for most common browsers, the percentages indicate performance increase over the next fastest result (which varies between browsers):

Chrome: indexOf (~98% faster) <-- wow
Firefox: cached RegExp (~18% faster)
IE11: cached RegExp(~10% faster)
Edge: indexOf (~18% faster)
Safari: cached RegExp(~0.4% faster)

Note that cached RegExp is: var r = new RegExp('simple'); var c = r.test(str); as opposed to: /simple/.test(str)

Change the encoding of a file in Visual Studio Code

Apart from the settings explained in the answer by @DarkNeuron:

"files.encoding": "any encoding"

you can also specify settings for a specific language like so:

"[language id]": {
  "files.encoding": "any encoding"
}

For example, I use this when I need to edit PowerShell files previously created with ISE (which are created in ANSI format):

"[powershell]": {
    "files.encoding": "windows1252"
}

You can get a list of identifiers of well-known languages here.

Format y axis as percent

For those who are looking for the quick one-liner:

plt.gca().set_yticklabels(['{:.0f}%'.format(x*100) for x in plt.gca().get_yticks()]) 

Or if you are using Latex as the axis text formatter, you have to add one backslash '\'

plt.gca().set_yticklabels(['{:.0f}\%'.format(x*100) for x in plt.gca().get_yticks()]) 

How do I copy a string to the clipboard?

The snippet I share here take advantage of the ability to format text files: what if you want to copy a complex output to the clipboard ? (Say a numpy array in column or a list of something)

import subprocess
import os

def cp2clip(clist):

    #create a temporary file
    fi=open("thisTextfileShouldNotExist.txt","w")

    #write in the text file the way you want your data to be
    for m in clist:
        fi.write(m+"\n")

    #close the file
    fi.close()

    #send "clip < file" to the shell
    cmd="clip < thisTextfileShouldNotExist.txt"
    w = subprocess.check_call(cmd,shell=True)

    #delete the temporary text file
    os.remove("thisTextfileShouldNotExist.txt")

    return w

works only for windows, can be adapted for linux or mac I guess. Maybe a bit complicated...

example:

>>>cp2clip(["ET","phone","home"])
>>>0

Ctrl+V in any text editor :

ET
phone
home

Reading tab-delimited file with Pandas - works on Windows, but not on Mac

Another option would be to add engine='python' to the command pandas.read_csv(filename, sep='\t', engine='python')

Sorting a Dictionary in place with respect to keys

The correct answer is already stated (just use SortedDictionary).

However, if by chance you have some need to retain your collection as Dictionary, it is possible to access the Dictionary keys in an ordered way, by, for example, ordering the keys in a List, then using this list to access the Dictionary. An example...

Dictionary<string, int> dupcheck = new Dictionary<string, int>();

...some code that fills in "dupcheck", then...

if (dupcheck.Count > 0) {
  Console.WriteLine("\ndupcheck (count: {0})\n----", dupcheck.Count);
  var keys_sorted = dupcheck.Keys.ToList();
    keys_sorted.Sort();
  foreach (var k in keys_sorted) {
    Console.WriteLine("{0} = {1}", k, dupcheck[k]);
  }
}

Don't forget using System.Linq; for this.

Comparison of DES, Triple DES, AES, blowfish encryption for data

All of these schemes, except AES and Blowfish, have known vulnerabilities and should not be used.
However, Blowfish has been replaced by Twofish.

How do you discover model attributes in Rails?

some_instance.attributes

Source: blog

Uploading Images to Server android

use below code it helps you....

        BitmapFactory.Options options = new BitmapFactory.Options();

        options.inSampleSize = 4;
        options.inPurgeable = true;
        Bitmap bm = BitmapFactory.decodeFile("your path of image",options);

        ByteArrayOutputStream baos = new ByteArrayOutputStream();

        bm.compress(Bitmap.CompressFormat.JPEG,40,baos); 


        // bitmap object

        byteImage_photo = baos.toByteArray();

                    //generate base64 string of image

                   String encodedImage =Base64.encodeToString(byteImage_photo,Base64.DEFAULT);

  //send this encoded string to server