Programs & Examples On #Vimclojure

Vim plugin for the Clojure programming language which adds syntax highlighting, indenting and code completion.

ImportError: cannot import name main when running pip --version command in windows7 32 bit

On Ubuntu Server 16, I have the same problem with python27. Try this:

Change

from pip import main
if __name__ == '__main__':
    sys.exit(main())

To

from pip._internal import main
if __name__ == '__main__':
    sys.exit(main())

Defining custom attrs

The traditional approach is full of boilerplate code and clumsy resource handling. That's why I made the Spyglass framework. To demonstrate how it works, here's an example showing how to make a custom view that displays a String title.

Step 1: Create a custom view class.

public class CustomView extends FrameLayout {
    private TextView titleView;

    public CustomView(Context context) {
        super(context);
        init(null, 0, 0);
    }

    public CustomView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(attrs, 0, 0);
    }

    public CustomView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(attrs, defStyleAttr, 0);
    }

    @RequiresApi(21)
    public CustomView(
            Context context, 
            AttributeSet attrs,
            int defStyleAttr,
            int defStyleRes) {

        super(context, attrs, defStyleAttr, defStyleRes);
        init(attrs, defStyleAttr, defStyleRes);
    }

    public void setTitle(String title) {
        titleView.setText(title);
    }

    private void init(AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        inflate(getContext(), R.layout.custom_view, this);

        titleView = findViewById(R.id.title_view);
    }
}

Step 2: Define a string attribute in the values/attrs.xml resource file:

<resources>
    <declare-styleable name="CustomView">
        <attr name="title" format="string"/>
    </declare-styleable>
</resources>

Step 3: Apply the @StringHandler annotation to the setTitle method to tell the Spyglass framework to route the attribute value to this method when the view is inflated.

@HandlesString(attributeId = R.styleable.CustomView_title)
public void setTitle(String title) {
    titleView.setText(title);
}

Now that your class has a Spyglass annotation, the Spyglass framework will detect it at compile-time and automatically generate the CustomView_SpyglassCompanion class.

Step 4: Use the generated class in the custom view's init method:

private void init(AttributeSet attrs, int defStyleAttr, int defStyleRes) {
    inflate(getContext(), R.layout.custom_view, this);

    titleView = findViewById(R.id.title_view);

    CustomView_SpyglassCompanion
            .builder()
            .withTarget(this)
            .withContext(getContext())
            .withAttributeSet(attrs)
            .withDefaultStyleAttribute(defStyleAttr)
            .withDefaultStyleResource(defStyleRes)
            .build()
            .callTargetMethodsNow();
}

That's it. Now when you instantiate the class from XML, the Spyglass companion interprets the attributes and makes the required method call. For example, if we inflate the following layout then setTitle will be called with "Hello, World!" as the argument.

<FrameLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:width="match_parent"
    android:height="match_parent">

    <com.example.CustomView
        android:width="match_parent"
        android:height="match_parent"
        app:title="Hello, World!"/>
</FrameLayout>

The framework isn't limited to string resources has lots of different annotations for handling other resource types. It also has annotations for defining default values and for passing in placeholder values if your methods have multiple parameters.

Have a look at the Github repo for more information and examples.

Forms authentication timeout vs sessionState timeout

The slidingExpiration=true value is basically saying that after every request made, the timer is reset and as long as the user makes a request within the timeout value, he will continue to be authenticated.

This is not correct. The authentication cookie timeout will only be reset if half the time of the timeout has passed.

See for example https://support.microsoft.com/de-ch/kb/910439/en-us or https://itworksonmymachine.wordpress.com/2008/07/17/forms-authentication-timeout-vs-session-timeout/

How to hide Soft Keyboard when activity starts

I hope this will work, I tried a lot of methods but this one worked for me in fragments. just put this line in onCreateview/init.

getActivity().getWindow().setSoftInputMode(
    WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);

The most efficient way to remove first N elements in a list?

Python lists were not made to operate on the beginning of the list and are very ineffective at this operation.

While you can write

mylist = [1, 2 ,3 ,4]
mylist.pop(0)

It's very inefficient.


If you only want to delete items from your list, you can do this with del:

del mylist[:n]

Which is also really fast:

In [34]: %%timeit
help=range(10000)
while help:
    del help[:1000]
   ....:
10000 loops, best of 3: 161 µs per loop

If you need to obtain elements from the beginning of the list, you should use collections.deque by Raymond Hettinger and its popleft() method.

from collections import deque

deque(['f', 'g', 'h', 'i', 'j'])

>>> d.pop()                          # return and remove the rightmost item
'j'
>>> d.popleft()                      # return and remove the leftmost item
'f'

A comparison:

list + pop(0)

In [30]: %%timeit
   ....: help=range(10000)
   ....: while help:
   ....:     help.pop(0)
   ....:
100 loops, best of 3: 17.9 ms per loop

deque + popleft()

In [33]: %%timeit
help=deque(range(10000))
while help:
    help.popleft()
   ....:
1000 loops, best of 3: 812 µs per loop

Using scanner.nextLine()

I think your problem is that

int selection = scanner.nextInt();

reads just the number, not the end of line or anything after the number. When you declare

String sentence = scanner.nextLine();

This reads the remainder of the line with the number on it (with nothing after the number I suspect)

Try placing a scanner.nextLine(); after each nextInt() if you intend to ignore the rest of the line.

How do I move a file from one location to another in Java?

You could execute an external tool for that task (like copy in windows environments) but, to keep the code portable, the general approach is to:

  1. read the source file into memory
  2. write the content to a file at the new location
  3. delete the source file

File#renameTo will work as long as source and target location are on the same volume. Personally I'd avoid using it to move files to different folders.

What's the easiest way to escape HTML in Python?

cgi.escape should be good to escape HTML in the limited sense of escaping the HTML tags and character entities.

But you might have to also consider encoding issues: if the HTML you want to quote has non-ASCII characters in a particular encoding, then you would also have to take care that you represent those sensibly when quoting. Perhaps you could convert them to entities. Otherwise you should ensure that the correct encoding translations are done between the "source" HTML and the page it's embedded in, to avoid corrupting the non-ASCII characters.

RegEx match open tags except XHTML self-contained tags

If you need this for PHP:

The PHP DOM functions won't work properly unless it is properly formatted XML. No matter how much better their use is for the rest of mankind.

simplehtmldom is good, but I found it a bit buggy, and it is is quite memory heavy [Will crash on large pages.]

I have never used querypath, so can't comment on its usefulness.

Another one to try is my DOMParser which is very light on resources and I've been using happily for a while. Simple to learn & powerful.

For Python and Java, similar links were posted.

For the downvoters - I only wrote my class when the XML parsers proved unable to withstand real use. Religious downvoting just prevents useful answers from being posted - keep things within perspective of the question, please.

How to use DISTINCT and ORDER BY in same SELECT statement?

Distinct will sort records in ascending order. If you want to sort in desc order use:

SELECT DISTINCT Category
FROM MonitoringJob
ORDER BY Category DESC

If you want to sort records based on CreationDate field then this field must be in the select statement:

SELECT DISTINCT Category, creationDate
FROM MonitoringJob
ORDER BY CreationDate DESC

Inverse of matrix in R

Note that if you care about speed and do not need to worry about singularities, solve() should be preferred to ginv() because it is much faster, as you can check:

require(MASS)
mat <- matrix(rnorm(1e6),nrow=1e3,ncol=1e3)

t0 <- proc.time()
inv0 <- ginv(mat)
proc.time() - t0 

t1 <- proc.time()
inv1 <- solve(mat)
proc.time() - t1 

Facebook database design?

This recent June 2013 post goes into some detail into explaining the transition from relationship databases to objects with associations for some data types.

https://www.facebook.com/notes/facebook-engineering/tao-the-power-of-the-graph/10151525983993920

There's a longer paper available at https://www.usenix.org/conference/atc13/tao-facebook’s-distributed-data-store-social-graph

git returns http error 407 from proxy after CONNECT

Maybe you are already using the system proxy setting - in this case unset all git proxies will work:

git config --global --unset http.proxy
git config --global --unset https.proxy

How can I select all children of an element except the last child?

When IE9 comes, it will be easier. A lot of the time though, you can switch the problem to one requiring :first-child and style the opposite side of the element (IE7+).

Download file through an ajax call php

You can't download the file directly via ajax.

You can put a link on the page with the URL to your file (returned from the ajax call) or another way is to use a hidden iframe and set the URL of the source of that iframe dynamically. This way you can download the file without refreshing the page.

Here is the code

$.ajax({
    url : "yourURL.php",
    type : "GET",
    success : function(data) {
        $("#iframeID").attr('src', 'downloadFileURL');
    }
});

Render partial view with dynamic model in Razor view engine and ASP.NET MVC 3

Just found the answer, it appears that the view where I was placing the RenderPartial code had a dynamic model, and thus, MVC couldn't choose the correct method to use. Casting the model in the RenderPartial call to the correct type fixed the issue.

source: Using Html.RenderPartial() in ascx files

"X-UA-Compatible" content="IE=9; IE=8; IE=7; IE=EDGE"

In certain cases, it might be necessary to restrict the display of a webpage to a document mode supported by an earlier version of Internet Explorer. You can do this by serving the page with an x-ua-compatible header. For more info, see Specifying legacy document modes.
- https://msdn.microsoft.com/library/cc288325

Thus this tag is used to future proof the webpage, such that the older / compatible engine is used to render it the same way as intended by the creator.

Make sure that you have checked it to work properly with the IE version you specify.

MySQL timestamp select date range

I can see people giving lots of comments on this question. But I think, simple use of LIKE could be easier to get the data from the table.

SELECT * FROM table WHERE COLUMN LIKE '2013-05-11%'

Use LIKE and post data wild character search. Hopefully this will solve your problem.

Visual studio code terminal, how to run a command with administrator rights?

Option 1 - Easier & Persistent

Running Visual Studio Code as Administrator should do the trick.

If you're on Windows you can:

  1. Right click the shortcut or app/exe
  2. Go to properties
  3. Compatibility tab
  4. Check "Run this program as an administrator"
There is a caveat to it though

Make sure you have all other instances of VS Code closed and then try to run as Administrator. The electron framework likes to stall processes when closing them so it's best to check your task manager and kill the remaining processes.

Related Changes in Codebase

Option 2 - More like Sudo

If for some weird reason this is not running your commands as an Administrator you can try the runas command. Microsoft: runas command

Examples
  • runas /user:Administrator myCommand
  • runas "/user:First Last" "my command"
Notes
  • Just don't forget to put double quotes around anything that has a space in it.
  • Also it's quite possible that you have never set the password on the Administrator account, as it will ask you for the password when trying to run the command. You can always use an account without the username of Administrator if it has administrator access rights/permissions.

Difference between @Mock and @InjectMocks

In your test class, the tested class should be annotated with @InjectMocks. This tells Mockito which class to inject mocks into:

@InjectMocks
private SomeManager someManager;

From then on, we can specify which specific methods or objects inside the class, in this case, SomeManager, will be substituted with mocks:

@Mock
private SomeDependency someDependency;

In this example, SomeDependency inside the SomeManager class will be mocked.

How to sort by dates excel?

The hashes are just because your column width is not enough to display the "number".

About the sorting, you should review how you system region and language is configured. For the US region, Excel date input should be "5/17/2012" not "17/05/2012" (this 17-may-12).

Regards

Is there a way to pass jvm args via command line to maven?

I think MAVEN_OPTS would be most appropriate for you. See here: http://maven.apache.org/configure.html

In Unix:

Add the MAVEN_OPTS environment variable to specify JVM properties, e.g. export MAVEN_OPTS="-Xms256m -Xmx512m". This environment variable can be used to supply extra options to Maven.

In Win, you need to set environment variable via the dialogue box

Add ... environment variable by opening up the system properties (WinKey + Pause),... In the same dialog, add the MAVEN_OPTS environment variable in the user variables to specify JVM properties, e.g. the value -Xms256m -Xmx512m. This environment variable can be used to supply extra options to Maven.

batch file to check 64bit or 32bit OS

I really do not understand some of the answers given here (sorry for that). The top-voted answer for example does not return the Windows architecture, instead it will give you the processor architecture. While running a 32-bits Windows build on a 64-bits CPU you will get the wrong result (it's a query on hardware being used).

The safest option is to query the BuildLabEx value from the registry.

Determine x86 (intel) or x86-64 (amd)

reg query "HKLM\Software\Microsoft\Windows NT\CurrentVersion" /v "BuildLabEx" | >nul find /i ".x86fre."   && set "_ARCH_=x86" || set "_ARCH_=x86-64"

Determine x86 (intel), x86-64 (amd) or arm

set "_ARCH_=unknown"
reg query "HKLM\Software\Microsoft\Windows NT\CurrentVersion" /v "BuildLabEx" | >nul find /i ".x86fre."   && set "_ARCH_=x86" 
reg query "HKLM\Software\Microsoft\Windows NT\CurrentVersion" /v "BuildLabEx" | >nul find /i ".amd64fre." && set "_ARCH_=x86-64" 
reg query "HKLM\Software\Microsoft\Windows NT\CurrentVersion" /v "BuildLabEx" | >nul find /i ".armfre."   && set "_ARCH_=arm" 

An alternative option (mentioned before)

if defined ProgramFiles(x86) ( set "_ARCH_=x86-64" ) else ( set "_ARCH_=x86" )

The problem with the latter is when you mess up your variables, you are not able to use this method. Checking for the folder's existence will cause problems too when there are leftovers from a previous install (or some user purposely created the folder).

Jquery resizing image

So much code here, but I think this is the best answer

function resize() {
            var input = $("#picture");
            var maxWidth = 300;
            var maxHeight = 300;
            var width = input.width();
            var height = input.height();
            var ratioX = (maxWidth / width);
            var ratioY = (maxHeight / height);
            var ratio = Math.min(ratioX, ratioY);

            var newWidth  = (width * ratio);
            var newHeight = (height * ratio);
            input.css("width", newWidth);
            input.css("height", newHeight);
};

Is there any advantage of using map over unordered_map in case of trivial keys?

Summary

Assuming ordering is not important:

  • If you are going to build large table once and do lots of queries, use std::unordered_map
  • If you are going to build small table (may be under 100 elements) and do lots of queries, use std::map. This is because reads on it are O(log n).
  • If you are going to change table a lot then may be std::map is good option.
  • If you are in doubt, just use std::unordered_map.

Historical Context

In most languages, unordered map (aka hash based dictionaries) are the default map however in C++ you get ordered map as default map. How did that happen? Some people erroneously assume that C++ committee made this decision in their unique wisdom but the truth is unfortunately uglier than that.

It is widely believed that C++ ended up with ordered map as default because there are not too many parameters on how they can be implemented. On the other hand, hash based implementations has tons of things to talk about. So to avoid gridlocks in standardization they just got along with ordered map. Around 2005, many languages already had good implementations of hash based implementation and so it was more easier for the committee to accept new std::unordered_map. In a perfect world, std::map would have been unordered and we would have std::ordered_map as separate type.

Performance

Below two graphs should speak for themselves (source):

enter image description here

enter image description here

How to check for an empty struct?

Using reflect.deepEqual also works, especially when you have map inside the struct

package main

import "fmt"
import "time"
import "reflect"

type Session struct {
    playerId string
    beehive string
    timestamp time.Time
}

func (s Session) IsEmpty() bool {
  return reflect.DeepEqual(s,Session{})
}

func main() {
  x := Session{}
  if x.IsEmpty() {
    fmt.Print("is empty")
  } 
}

postgres default timezone

Note many third-party clients have own timezone settings overlapping any Postgres server and\or session settings.

E.g. if you're using 'IntelliJ IDEA 2017.3' (or DataGrips), you should define timezone as:

'DB source properties' -> 'Advanced' tab -> 'VM Options': -Duser.timezone=UTC+06:00

otherwise you will see 'UTC' despite of whatever you have set anywhere else.

Remove all special characters from a string in R?

Instead of using regex to remove those "crazy" characters, just convert them to ASCII, which will remove accents, but will keep the letters.

astr <- "Ábcdêãçoàúü"
iconv(astr, from = 'UTF-8', to = 'ASCII//TRANSLIT')

which results in

[1] "Abcdeacoauu"

Get difference between two dates in months using Java

You can use Joda time library for Java. It would be much easier to calculate time-diff between dates with it.

Sample snippet for time-diff:

Days d = Days.daysBetween(startDate, endDate);
int days = d.getDays();

Convert DateTime to TimeSpan

TimeSpan.FromTicks(DateTime.Now.Ticks)

AngularJS $location not changing the path

In my case, the problem was the optional parameter indicator('?') missing in my template configuration.

For example:

.when('/abc/:id?', {
    templateUrl: 'views/abc.html',
    controller: 'abcControl'
})


$location.path('/abc');

Without the interrogation character the route obviously would not change suppressing the route parameter.

Best tool for inspecting PDF files?

I've used PDFBox with good success. Here's a sample of what the code looks like (back from version 0.7.2), that likely came from one of the provided examples:

// load the document
System.out.println("Reading document: " + filename);
PDDocument doc = null;                                                                                                                                                                                                          
doc = PDDocument.load(filename);

// look at all the document information
PDDocumentInformation info = doc.getDocumentInformation();
COSDictionary dict = info.getDictionary();
List l = dict.keyList();
for (Object o : l) {
    //System.out.println(o.toString() + " " + dict.getString(o));
    System.out.println(o.toString());
}

// look at the document catalog
PDDocumentCatalog cat = doc.getDocumentCatalog();
System.out.println("Catalog:" + cat);

List<PDPage> lp = cat.getAllPages();
System.out.println("# Pages: " + lp.size());
PDPage page = lp.get(4);
System.out.println("Page: " + page);
System.out.println("\tCropBox: " + page.getCropBox());
System.out.println("\tMediaBox: " + page.getMediaBox());
System.out.println("\tResources: " + page.getResources());
System.out.println("\tRotation: " + page.getRotation());
System.out.println("\tArtBox: " + page.getArtBox());
System.out.println("\tBleedBox: " + page.getBleedBox());
System.out.println("\tContents: " + page.getContents());
System.out.println("\tTrimBox: " + page.getTrimBox());
List<PDAnnotation> la = page.getAnnotations();
System.out.println("\t# Annotations: " + la.size());

google chrome extension :: console.log() from background page?

You can open the background page's console if you click on the "background.html" link in the extensions list.

To access the background page that corresponds to your extensions open Settings / Extensions or open a new tab and enter chrome://extensions. You will see something like this screenshot.

Chrome extensions dialogue

Under your extension click on the link background page. This opens a new window. For the context menu sample the window has the title: _generated_background_page.html.

How to do an Integer.parseInt() for a decimal number?

Use Double.parseDouble(String a) what you are looking for is not an integer as it is not a whole number.

How to remove space from string?

You can also use echo to remove blank spaces, either at the beginning or at the end of the string, but also repeating spaces inside the string.

$ myVar="    kokor    iiij     ook      "
$ echo "$myVar"
    kokor    iiij     ook      
$ myVar=`echo $myVar`
$
$ # myVar is not set to "kokor iiij ook"
$ echo "$myVar"
kokor iiij ook

How to check if a directory containing a file exist?

EDIT: as of Java8 you'd better use Files class:

Path resultingPath = Files.createDirectories('A/B');

I don't know if this ultimately fixes your problem but class File has method mkdirs() which fully creates the path specified by the file.

File f = new File("/A/B/");
f.mkdirs();

TSQL PIVOT MULTIPLE COLUMNS

Since you want to pivot multiple columns of data, I would first suggest unpivoting the result, score and grade columns so you don't have multiple columns but you will have multiple rows.

Depending on your version of SQL Server you can use the UNPIVOT function or CROSS APPLY. The syntax to unpivot the data will be similar to:

select ratio, col, value
from GRAND_TOTALS
cross apply
(
  select 'result', cast(result as varchar(10)) union all
  select 'score', cast(score as varchar(10)) union all
  select 'grade', grade
) c(col, value)

See SQL Fiddle with Demo. Once the data has been unpivoted, then you can apply the PIVOT function:

select ratio = col,
  [current ratio], [gearing ratio], [performance ratio], total
from
(
  select ratio, col, value
  from GRAND_TOTALS
  cross apply
  (
    select 'result', cast(result as varchar(10)) union all
    select 'score', cast(score as varchar(10)) union all
    select 'grade', grade
  ) c(col, value)
) d
pivot
(
  max(value)
  for ratio in ([current ratio], [gearing ratio], [performance ratio], total)
) piv;

See SQL Fiddle with Demo. This will give you the result:

|  RATIO | CURRENT RATIO | GEARING RATIO | PERFORMANCE RATIO |     TOTAL |
|--------|---------------|---------------|-------------------|-----------|
|  grade |          Good |          Good |      Satisfactory |      Good |
| result |       1.29400 |       0.33840 |           0.04270 |    (null) |
|  score |      60.00000 |      70.00000 |          50.00000 | 180.00000 |

Hibernate openSession() vs getCurrentSession()

+----------------------+----------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------+
| Parameter            |                                openSession                                 |                                          getCurrentSession                                          |
+----------------------+----------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------+
| Session  creation    | Always open new session                                                    | It opens a new Session if not exists , else use same session which is in current hibernate context. |
+----------------------+----------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------+
| Session close        | Need to close the session object once all the database operations are done | No need to close the session. Once the session factory is closed, this session object is closed.    |
+----------------------+----------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------+
| Flush and close      | Need to explicity flush and close session objects                          | No need to flush and close sessions , since it is automatically taken by hibernate internally.      |
+----------------------+----------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------+
| Performance          | In single threaded environment , it is slower than getCurrentSession       | In single threaded environment , it is faster than openSession                                      |
+----------------------+----------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------+
| Configuration        | No need to configure any property to call this method                      | Need to configure additional property:                                                              |
|                      |                                                                            |  <property name=""hibernate.current_session_context_class"">thread</property>                       |
+----------------------+----------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------+

What is an .inc and why use it?

If you are concerned about the file's content being served rather than its output. You can use a double extension like: file.inc.php. It then serves the same purpose of helpfulness and maintainability.

I normally have 2 php files for each page on my site:

  1. One named welcome.php in the root folder, containing all of the HTML markup.
  2. And another named welcome.inc.php in the inc folder, containing all PHP functions specific to the welcome.php page.

EDIT: Another benefit of using the double extention .inc.php would be that any IDE can still recognise the file as PHP code.

rawQuery(query, selectionArgs)

if your SQL query is this

SELECT id,name,roll FROM student WHERE name='Amit' AND roll='7'

then rawQuery will be

String query="SELECT id, name, roll FROM student WHERE name = ? AND roll = ?";
String[] selectionArgs = {"Amit","7"} 
db.rawQuery(query, selectionArgs);

How do I (or can I) SELECT DISTINCT on multiple columns?

The problem with your query is that when using a GROUP BY clause (which you essentially do by using distinct) you can only use columns that you group by or aggregate functions. You cannot use the column id because there are potentially different values. In your case there is always only one value because of the HAVING clause, but most RDBMS are not smart enough to recognize that.

This should work however (and doesn't need a join):

UPDATE sales
SET status='ACTIVE'
WHERE id IN (
  SELECT MIN(id) FROM sales
  GROUP BY saleprice, saledate
  HAVING COUNT(id) = 1
)

You could also use MAX or AVG instead of MIN, it is only important to use a function that returns the value of the column if there is only one matching row.

Dropdownlist validation in Asp.net Using Required field validator

<asp:RequiredFieldValidator InitialValue="-1" ID="Req_ID" Display="Dynamic" 
    ValidationGroup="g1" runat="server" ControlToValidate="ControlID"
    Text="*" ErrorMessage="ErrorMessage"></asp:RequiredFieldValidator>

annotation to make a private method public only for test classes

The common way is to make the private method protected or package-private and to put the unit test for this method in the same package as the class under test.

Guava has a @VisibleForTesting annotation, but it's only for documentation purposes.

How to make button fill table cell

For starters:

<p align='center'>
<table width='100%'>
<tr>
<td align='center'><form><input type=submit value="click me" style="width:100%"></form></td>
</tr>
</table>
</p>

Note, if the width of the input button is 100%, you wont need the attribute "align='center'" anymore.

This would be the optimal solution:

<p align='center'>
<table width='100%'>
<tr>
<td><form><input type=submit value="click me" style="width:100%"></form></td>
</tr>
</table>
</p>

Running EXE with parameters

System.Diagnostics.Process.Start("PATH to exe", "Command Line Arguments");

UITableView, Separator color where to set?

Try + (instancetype)appearance of UITableView:

Objective-C:

[[UITableView appearance] setSeparatorColor:[UIColor blackColor]]; // set your desired colour in place of "[UIColor blackColor]"

Swift 3.0:

UITableView.appearance().separatorColor = UIColor.black // set your desired colour in place of "UIColor.black"

Note: Change will reflect to all tables used in application.

Proxy Error 502 : The proxy server received an invalid response from an upstream server

The HTTP 502 "Bad Gateway" response is generated when Apache web server does not receive a valid HTTP response from the upstream server, which in this case is your Tomcat web application.

Some reasons why this might happen:

  • Tomcat may have crashed
  • The web application did not respond in time and the request from Apache timed out
  • The Tomcat threads are timing out
  • A network device is blocking the request, perhaps as some sort of connection timeout or DoS attack prevention system

If the problem is related to timeout settings, you may be able to resolve it by investigating the following:

  • ProxyTimeout directive of Apache's mod_proxy
  • Connector config of Apache Tomcat
  • Your network device's manual

Where IN clause in LINQ

The "IN" clause is built into linq via the .Contains() method.

For example, to get all People whose .States's are "NY" or "FL":

using (DataContext dc = new DataContext("connectionstring"))
{
    List<string> states = new List<string>(){"NY", "FL"};
    List<Person> list = (from p in dc.GetTable<Person>() where states.Contains(p.State) select p).ToList();
}

C++ - unable to start correctly (0xc0150002)

I agree with Brandrew, the problem is most likely caused by some missing dlls that can't be found neither on the system path nor in the folder where the executable is. Try putting the following DLLs nearby the executable:

  • the Visual Studio C++ runtime (in VS2008, they could be found at places like C:\Program Files\Microsoft Visual Studio 9.0\VC\redist\x86.) Include all 3 of the DLL files as well as the manifest file.
  • the four OpenCV dlls (cv210.dll, cvaux210.dll, cxcore210.dll and highgui210.dll, or the ones your OpenCV version has)
  • if that still doesn't work, try the debug VS runtime (executables compiled for "Debug" use a different set of dlls, named something like msvcrt9d.dll, important part is the "d")

Alternatively, try loading the executable into Dependency Walker ( http://www.dependencywalker.com/ ), it should point out the missing dlls for you.

What is the difference between XML and XSD?

XML has a much wider application than f.ex. HTML. It doesn't have an intrinsic, or default "application". So, while you might not really care that web pages are also governed by what's allowed, from the author's side, you'll probably want to precisely define what an XML document may and may not contain.

It's like designing a database.

The thing about XML technologies is that they are textual in nature. With XSD, it means you have a data structure definition framework that can be "plugged in" to text processing tools like PHP. So not only can you manipulate the data itself, but also very easily change and document the structure, and even auto-generate front-ends.

Viewed like this, XSD is the "glue" or "middleware" between data (XML) and data-processing tools.

How to define a List bean in Spring?

Use the util namespace, you will be able to register the list as a bean in your application context. You can then reuse the list to inject it in other bean definitions.

PHP Error: Cannot use object of type stdClass as array (array and object issues)

If you're iterating over an object instead of an array, you'll need to access the properties using:

$id = $blog->id;
$title = $blog->title;
$content = $blog->content;

That, or change your object to an array.

Python: For each list element apply a function across the list

If working with Python =2.6 (including 3.x), you can:

from __future__ import division
import operator, itertools

def getmin(alist):
    return min(
        (operator.div(*pair), pair)
        for pair in itertools.product(alist, repeat=2)
    )[1]

getmin([1, 2, 3, 4, 5])

EDIT: Now that I think of it and if I remember my mathematics correctly, this should also give the answer assuming that all numbers are non-negative:

def getmin(alist):
    return min(alist), max(alist)

comparing strings in vb

If String.Compare(string1,string2,True) Then

    'perform operation

EndIf

External resource not being loaded by AngularJs

The best and easy solution for solving this issue is pass your data from this function in controller.

$scope.trustSrcurl = function(data) 
{
    return $sce.trustAsResourceUrl(data);
}

In html page

<iframe class="youtube-player" type="text/html" width="640" height="385" ng-src="{{trustSrcurl(video.src)}}" allowfullscreen frameborder="0"></iframe>

Check if character is number?

Similar to one of the answers above, I used

 var sum = 0; //some value
 let num = parseInt(val); //or just Number.parseInt
 if(!isNaN(num)) {
     sum += num;
 }

This blogpost sheds some more light on this check if a string is numeric in Javascript | Typescript & ES6

Simulate string split function in Excel formula

AFAIK the best you can do to emulate Split() is to use FILTERXML which is available from Excel 2013 onwards (not Excel Online or Mac).

The syntax more or less always is:

=FILTERXML("<t><s>"&SUBSTITUTE(A1,"|","</s><s>")&"</s></t>","//s")

This would return an array to be used in other functions and would even hold up if no delimiter is found. If you want to read more about it, maybe you are interested in this post.

Does functional programming replace GoF design patterns?

I would say that when you have a language like Lisp with its support for macros, then you can build you own domain-specific abstractions, abstractions which often are much better than the general idiom solutions.

Why there is no ConcurrentHashSet against ConcurrentHashMap

There's no built in type for ConcurrentHashSet because you can always derive a set from a map. Since there are many types of maps, you use a method to produce a set from a given map (or map class).

Prior to Java 8, you produce a concurrent hash set backed by a concurrent hash map, by using Collections.newSetFromMap(map)

In Java 8 (pointed out by @Matt), you can get a concurrent hash set view via ConcurrentHashMap.newKeySet(). This is a bit simpler than the old newSetFromMap which required you to pass in an empty map object. But it is specific to ConcurrentHashMap.

Anyway, the Java designers could have created a new set interface every time a new map interface was created, but that pattern would be impossible to enforce when third parties create their own maps. It is better to have the static methods that derive new sets; that approach always works, even when you create your own map implementations.

How to generate XML from an Excel VBA macro?

This one more version - this will help in generic

Public strSubTag As String
Public iStartCol As Integer
Public iEndCol As Integer
Public strSubTag2 As String
Public iStartCol2 As Integer
Public iEndCol2 As Integer

Sub Create()
Dim strFilePath As String
Dim strFileName As String

'ThisWorkbook.Sheets("Sheet1").Range("C3").Activate
'strTag = ActiveCell.Offset(0, 1).Value
strFilePath = ThisWorkbook.Sheets("Sheet1").Range("B4").Value
strFileName = ThisWorkbook.Sheets("Sheet1").Range("B5").Value
strSubTag = ThisWorkbook.Sheets("Sheet1").Range("F3").Value
iStartCol = ThisWorkbook.Sheets("Sheet1").Range("F4").Value
iEndCol = ThisWorkbook.Sheets("Sheet1").Range("F5").Value

strSubTag2 = ThisWorkbook.Sheets("Sheet1").Range("G3").Value
iStartCol2 = ThisWorkbook.Sheets("Sheet1").Range("G4").Value
iEndCol2 = ThisWorkbook.Sheets("Sheet1").Range("G5").Value

Dim iCaptionRow As Integer
iCaptionRow = ThisWorkbook.Sheets("Sheet1").Range("B3").Value
'strFileName = ThisWorkbook.Sheets("Sheet1").Range("B4").Value
MakeXML iCaptionRow, iCaptionRow + 1, strFilePath, strFileName

End Sub


Sub MakeXML(iCaptionRow As Integer, iDataStartRow As Integer, sOutputFilePath As String, sOutputFileName As String)
    Dim Q As String
    Dim sOutputFileNamewithPath As String
    Q = Chr$(34)

    Dim sXML As String


    'sXML = sXML & "<rows>"

'    ''--determine count of columns
    Dim iColCount As Integer
    iColCount = 1

    While Trim$(Cells(iCaptionRow, iColCount)) > ""
        iColCount = iColCount + 1
    Wend


    Dim iRow As Integer
    Dim iCount  As Integer
    iRow = iDataStartRow
    iCount = 1
    While Cells(iRow, 1) > ""
        'sXML = sXML & "<row id=" & Q & iRow & Q & ">"
        sXML = "<?xml version=" & Q & "1.0" & Q & " encoding=" & Q & "UTF-8" & Q & "?>"
        For iCOl = 1 To iColCount - 1
          If (iStartCol = iCOl) Then
               sXML = sXML & "<" & strSubTag & ">"
          End If
          If (iEndCol = iCOl) Then
               sXML = sXML & "</" & strSubTag & ">"
          End If
         If (iStartCol2 = iCOl) Then
               sXML = sXML & "<" & strSubTag2 & ">"
          End If
          If (iEndCol2 = iCOl) Then
               sXML = sXML & "</" & strSubTag2 & ">"
          End If
           sXML = sXML & "<" & Trim$(Cells(iCaptionRow, iCOl)) & ">"
           sXML = sXML & Trim$(Cells(iRow, iCOl))
           sXML = sXML & "</" & Trim$(Cells(iCaptionRow, iCOl)) & ">"
        Next

        'sXML = sXML & "</row>"
        Dim nDestFile As Integer, sText As String

    ''Close any open text files
        Close

    ''Get the number of the next free text file
        nDestFile = FreeFile
        sOutputFileNamewithPath = sOutputFilePath & sOutputFileName & iCount & ".XML"
    ''Write the entire file to sText
        Open sOutputFileNamewithPath For Output As #nDestFile
        Print #nDestFile, sXML

        iRow = iRow + 1
        sXML = ""
        iCount = iCount + 1
    Wend
    'sXML = sXML & "</rows>"

    Close
End Sub

How to run a class from Jar which is not the Main-Class in its Manifest file

You can execute any class which has a public final static main method from a JAR file, even if the jar file has a Main-Class defined.

Execute Main-Class:

java -jar MyJar.jar  // will execute the Main-Class

Execute another class with a public static void main method:

java -cp MyJar.jar com.mycomp.myproj.AnotherClassWithMainMethod

Note: the first uses -jar, the second uses -cp.

creating charts with angularjs

The ZingChart library has an AngularJS directive that was built in-house. Features include:

  • Full access to the entire ZingChart library (all charts, maps, and features)
  • Takes advantage of Angular's 2-way data binding, making data and chart elements easy to update
  • Support from the development team

    ...
    $scope.myJson = {
    type : 'line',
       series : [
          { values : [54,23,34,23,43] },{ values : [10,15,16,20,40] }
       ]
    };
    ...
    
    <zingchart id="myChart" zc-json="myJson" zc-height=500 zc-width=600></zingchart>
    

There is a full demo with code examples available.

Best Practices: working with long, multiline strings in PHP?

Sure, you could use HEREDOC, but as far as code readability goes it's not really any better than the first example, wrapping the string across multiple lines.

If you really want your multi-line string to look good and flow well with your code, I'd recommend concatenating strings together as such:

$text = "Hello, {$vars->name},\r\n\r\n"
    . "The second line starts two lines below.\r\n"
    . ".. Third line... etc";

This might be slightly slower than HEREDOC or a multi-line string, but it will flow well with your code's indentation and make it easier to read.

Getting a list of files in a directory with a glob

You need to roll your own method to eliminate the files you don't want.

This isn't easy with the built in tools, but you could use RegExKit Lite to assist with finding the elements in the returned array you are interested in. According to the release notes this should work in both Cocoa and Cocoa-Touch applications.

Here's the demo code I wrote up in about 10 minutes. I changed the < and > to " because they weren't showing up inside the pre block, but it still works with the quotes. Maybe somebody who knows more about formatting code here on StackOverflow will correct this (Chris?).

This is a "Foundation Tool" Command Line Utility template project. If I get my git daemon up and running on my home server I'll edit this post to add the URL for the project.

#import "Foundation/Foundation.h"
#import "RegexKit/RegexKit.h"

@interface MTFileMatcher : NSObject 
{
}
- (void)getFilesMatchingRegEx:(NSString*)inRegex forPath:(NSString*)inPath;
@end

int main (int argc, const char * argv[])
{
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

    // insert code here...
    MTFileMatcher* matcher = [[[MTFileMatcher alloc] init] autorelease];
    [matcher getFilesMatchingRegEx:@"^.+\\.[Jj][Pp][Ee]?[Gg]$" forPath:[@"~/Pictures" stringByExpandingTildeInPath]];

    [pool drain];
    return 0;
}

@implementation MTFileMatcher
- (void)getFilesMatchingRegEx:(NSString*)inRegex forPath:(NSString*)inPath;
{
    NSArray* filesAtPath = [[[NSFileManager defaultManager] directoryContentsAtPath:inPath] arrayByMatchingObjectsWithRegex:inRegex];
    NSEnumerator* itr = [filesAtPath objectEnumerator];
    NSString* obj;
    while (obj = [itr nextObject])
    {
        NSLog(obj);
    }
}
@end

How to run functions in parallel?

In 2021 the easiest way is to use asyncio:

import asyncio, time

async def say_after(delay, what):
    await asyncio.sleep(delay)
    print(what)

async def main():

    task1 = asyncio.create_task(
        say_after(4, 'hello'))

    task2 = asyncio.create_task(
        say_after(3, 'world'))

    print(f"started at {time.strftime('%X')}")

    # Wait until both tasks are completed (should take
    # around 2 seconds.)
    await task1
    await task2

    print(f"finished at {time.strftime('%X')}")


asyncio.run(main())

References:

[1] https://docs.python.org/3/library/asyncio-task.html

What's wrong with using == to compare floats in Java?

Just to give the reason behind what everyone else is saying.

The binary representation of a float is kind of annoying.

In binary, most programmers know the correlation between 1b=1d, 10b=2d, 100b=4d, 1000b=8d

Well it works the other way too.

.1b=.5d, .01b=.25d, .001b=.125, ...

The problem is that there is no exact way to represent most decimal numbers like .1, .2, .3, etc. All you can do is approximate in binary. The system does a little fudge-rounding when the numbers print so that it displays .1 instead of .10000000000001 or .999999999999 (which are probably just as close to the stored representation as .1 is)

Edit from comment: The reason this is a problem is our expectations. We fully expect 2/3 to be fudged at some point when we convert it to decimal, either .7 or .67 or .666667.. But we don't automatically expect .1 to be rounded in the same way as 2/3--and that's exactly what's happening.

By the way, if you are curious the number it stores internally is a pure binary representation using a binary "Scientific Notation". So if you told it to store the decimal number 10.75d, it would store 1010b for the 10, and .11b for the decimal. So it would store .101011 then it saves a few bits at the end to say: Move the decimal point four places right.

(Although technically it's no longer a decimal point, it's now a binary point, but that terminology wouldn't have made things more understandable for most people who would find this answer of any use.)

How to combine class and ID in CSS selector?

In your stylesheet:

div#content.myClass

Edit: These might help, too:

div#content.myClass.aSecondClass.aThirdClass /* Won't work in IE6, but valid */
div.firstClass.secondClass /* ditto */

and, per your example:

div#content.sectionA

Edit, 4 years later: Since this is super old and people keep finding it: don't use the tagNames in your selectors. #content.myClass is faster than div#content.myClass because the tagName adds a filtering step that you don't need. Use tagNames in selectors only where you must!

setting JAVA_HOME & CLASSPATH in CentOS 6

Instructions:

  1. Click on the Terminal icon in the desktop panel to open a terminal window and access the command prompt.
  2. Type the command which java to find the path to the Java executable file.
  3. Type the command su - to become the root user.
  4. Type the command vi /root/.bash_profile to open the system bash_profile file in the Vi text editor. You can replace vi with your preferred text editor.
  5. Type export JAVA_HOME=/usr/local/java/ at the bottom of the file. Replace /usr/local/java with the location found in step two.
  6. Save and close the bash_profile file.
  7. Type the command exit to close the root session.
  8. Log out of the system and log back in.
  9. Type the command echo $JAVA_HOME to ensure that the path was set correctly.

set java_home in centos

How can I compare two ordered lists in python?

If you want to just check if they are identical or not, a == b should give you true / false with ordering taken into account.

In case you want to compare elements, you can use numpy for comparison

c = (numpy.array(a) == numpy.array(b))

Here, c will contain an array with 3 elements all of which are true (for your example). In the event elements of a and b don't match, then the corresponding elements in c will be false.

Bootstrap css hides portion of container below navbar navbar-fixed-top

Just define an empty navbar prior to the fixed one, it will create the space needed.

<nav class="navbar navbar-default ">
</nav>
<nav class="navbar  navbar-default navbar-fixed-top ">
     <div class="container-fluid">
// Your menu code 
     </div>
</nav>

Python and pip, list all versions of a package that's available?

Update:
As of Sep 2017 this method no longer works: --no-install was removed in pip 7

Use pip install -v, you can see all versions that available

root@node7:~# pip install web.py -v
Downloading/unpacking web.py
  Using version 0.37 (newest of versions: 0.37, 0.36, 0.35, 0.34, 0.33, 0.33, 0.32, 0.31, 0.22, 0.2)
  Downloading web.py-0.37.tar.gz (90Kb): 90Kb downloaded
  Running setup.py egg_info for package web.py
    running egg_info
    creating pip-egg-info/web.py.egg-info

To not install any package, use one of following solution:

root@node7:~# pip install --no-deps --no-install flask -v                                                                                                      
Downloading/unpacking flask
  Using version 0.10.1 (newest of versions: 0.10.1, 0.10, 0.9, 0.8.1, 0.8, 0.7.2, 0.7.1, 0.7, 0.6.1, 0.6, 0.5.2, 0.5.1, 0.5, 0.4, 0.3.1, 0.3, 0.2, 0.1)
  Downloading Flask-0.10.1.tar.gz (544Kb): 544Kb downloaded

or

root@node7:~# cd $(mktemp -d)
root@node7:/tmp/tmp.c6H99cWD0g# pip install flask -d . -v
Downloading/unpacking flask
  Using version 0.10.1 (newest of versions: 0.10.1, 0.10, 0.9, 0.8.1, 0.8, 0.7.2, 0.7.1, 0.7, 0.6.1, 0.6, 0.5.2, 0.5.1, 0.5, 0.4, 0.3.1, 0.3, 0.2, 0.1)
  Downloading Flask-0.10.1.tar.gz (544Kb): 4.1Kb downloaded

Tested with pip 1.0

root@node7:~# pip --version
pip 1.0 from /usr/lib/python2.7/dist-packages (python 2.7)

Check if a class `active` exist on element with jquery

    if($('selector').hasClass('active')){ }

i think this will check if the selector hasClass active ...

TypeError: unsupported operand type(s) for /: 'str' and 'str'

The first thing you should do is learn to read error messages. What does it tell you -- that you can't use two strings with the divide operator.

So, ask yourself why they are strings and how do you make them not-strings. They are strings because all input is done via strings. And the way to make then not-strings is to convert them.

One way to convert a string to an integer is to use the int function. For example:

percent = (int(pyc) / int(tpy)) * 100

Can an html element have multiple ids?

No. While the definition from w3c for HTML 4 doesn't seem to explicitly cover your question, the definition of the name and id attribute says no spaces in the identifier:

ID and NAME tokens must begin with a letter ([A-Za-z]) and may be followed by any number of letters, digits ([0-9]), hyphens ("-"), underscores ("_"), colons (":"), and periods (".").

LINQ Join with Multiple Conditions in On Clause

You just need to name the anonymous property the same on both sides

on new { t1.ProjectID, SecondProperty = true } equals 
   new { t2.ProjectID, SecondProperty = t2.Completed } into j1

Based on the comments of @svick, here is another implementation that might make more sense:

from t1 in Projects
from t2 in Tasks.Where(x => t1.ProjectID == x.ProjectID && x.Completed == true)
                .DefaultIfEmpty()
select new { t1.ProjectName, t2.TaskName }

In Python, what is the difference between ".append()" and "+= []"?

For your case the only difference is performance: append is twice as fast.

Python 3.0 (r30:67507, Dec  3 2008, 20:14:27) [MSC v.1500 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import timeit
>>> timeit.Timer('s.append("something")', 's = []').timeit()
0.20177424499999999
>>> timeit.Timer('s += ["something"]', 's = []').timeit()
0.41192320500000079

Python 2.5.1 (r251:54863, Apr 18 2007, 08:51:08) [MSC v.1310 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import timeit
>>> timeit.Timer('s.append("something")', 's = []').timeit()
0.23079359499999999
>>> timeit.Timer('s += ["something"]', 's = []').timeit()
0.44208112500000141

In general case append will add one item to the list, while += will copy all elements of right-hand-side list into the left-hand-side list.

Update: perf analysis

Comparing bytecodes we can assume that append version wastes cycles in LOAD_ATTR + CALL_FUNCTION, and += version -- in BUILD_LIST. Apparently BUILD_LIST outweighs LOAD_ATTR + CALL_FUNCTION.

>>> import dis
>>> dis.dis(compile("s = []; s.append('spam')", '', 'exec'))
  1           0 BUILD_LIST               0
              3 STORE_NAME               0 (s)
              6 LOAD_NAME                0 (s)
              9 LOAD_ATTR                1 (append)
             12 LOAD_CONST               0 ('spam')
             15 CALL_FUNCTION            1
             18 POP_TOP
             19 LOAD_CONST               1 (None)
             22 RETURN_VALUE
>>> dis.dis(compile("s = []; s += ['spam']", '', 'exec'))
  1           0 BUILD_LIST               0
              3 STORE_NAME               0 (s)
              6 LOAD_NAME                0 (s)
              9 LOAD_CONST               0 ('spam')
             12 BUILD_LIST               1
             15 INPLACE_ADD
             16 STORE_NAME               0 (s)
             19 LOAD_CONST               1 (None)
             22 RETURN_VALUE

We can improve performance even more by removing LOAD_ATTR overhead:

>>> timeit.Timer('a("something")', 's = []; a = s.append').timeit()
0.15924410999923566

Plot multiple columns on the same graph in R

The easiest is to convert your data to a "tall" format.

s <- 
"A       B        C       G       Xax
0.451   0.333   0.034   0.173   0.22        
0.491   0.270   0.033   0.207   0.34    
0.389   0.249   0.084   0.271   0.54    
0.425   0.819   0.077   0.281   0.34
0.457   0.429   0.053   0.386   0.53    
0.436   0.524   0.049   0.249   0.12    
0.423   0.270   0.093   0.279   0.61    
0.463   0.315   0.019   0.204   0.23
"
d <- read.delim(textConnection(s), sep="")

library(ggplot2)
library(reshape2)
d <- melt(d, id.vars="Xax")

# Everything on the same plot
ggplot(d, aes(Xax,value, col=variable)) + 
  geom_point() + 
  stat_smooth() 

# Separate plots
ggplot(d, aes(Xax,value)) + 
  geom_point() + 
  stat_smooth() +
  facet_wrap(~variable)

Difference between matches() and find() in Java Regex

matches() will only return true if the full string is matched. find() will try to find the next occurrence within the substring that matches the regex. Note the emphasis on "the next". That means, the result of calling find() multiple times might not be the same. In addition, by using find() you can call start() to return the position the substring was matched.

final Matcher subMatcher = Pattern.compile("\\d+").matcher("skrf35kesruytfkwu4ty7sdfs");
System.out.println("Found: " + subMatcher.matches());
System.out.println("Found: " + subMatcher.find() + " - position " + subMatcher.start());
System.out.println("Found: " + subMatcher.find() + " - position " + subMatcher.start());
System.out.println("Found: " + subMatcher.find() + " - position " + subMatcher.start());
System.out.println("Found: " + subMatcher.find());
System.out.println("Found: " + subMatcher.find());
System.out.println("Matched: " + subMatcher.matches());

System.out.println("-----------");
final Matcher fullMatcher = Pattern.compile("^\\w+$").matcher("skrf35kesruytfkwu4ty7sdfs");
System.out.println("Found: " + fullMatcher.find() + " - position " + fullMatcher.start());
System.out.println("Found: " + fullMatcher.find());
System.out.println("Found: " + fullMatcher.find());
System.out.println("Matched: " + fullMatcher.matches());
System.out.println("Matched: " + fullMatcher.matches());
System.out.println("Matched: " + fullMatcher.matches());
System.out.println("Matched: " + fullMatcher.matches());

Will output:

Found: false
Found: true - position 4
Found: true - position 17
Found: true - position 20
Found: false
Found: false
Matched: false
-----------
Found: true - position 0
Found: false
Found: false
Matched: true
Matched: true
Matched: true
Matched: true

So, be careful when calling find() multiple times if the Matcher object was not reset, even when the regex is surrounded with ^ and $ to match the full string.

pip or pip3 to install packages for Python 3?

In my system, I use the update alternatives.

sudo update-alternatives --install /usr/bin/pip pip /usr/bin/pip3 1
sudo update-alternatives --install /usr/bin/pip pip /usr/bin/pip2 2

If I want to switch between them I use the following command.

sudo update-alternatives --config pip

Note: The 1st line is enough if you have only pip3 installed and not pip2.

Undo git update-index --assume-unchanged <file>

git update-index function has several option you can find typing as below:

git update-index --help

Here you will find various option - how to handle with the function update-index.

[if you don't know the file name]

git update-index --really-refresh 

[if you know the file name ]

git update-index --no-assume-unchanged <file>

will revert all the files those have been added in ignore list through.

git update-index --assume-unchanged <file>

Get started with Latex on Linux

If you use Ubuntu or Debian, I made a tutorial easy to follow: Install LaTeX on Ubuntu or Debian. This tutorial explains how to install LaTeX and how to create your first PDF.

How to get the result of OnPostExecute() to main activity because AsyncTask is a separate class?

You can do it in a few lines, just override onPostExecute when you call your AsyncTask. Here is an example for you:

new AasyncTask()
{
    @Override public void onPostExecute(String result)
    {
       // do whatever you want with result 
    }
}.execute(a.targetServer);

I hope it helped you, happy codding :)

Check if EditText is empty.

Why not just disable the button if EditText is empty? IMHO This looks more professional:

        final EditText txtFrecuencia = (EditText) findViewById(R.id.txtFrecuencia);  
        final ToggleButton toggle = (ToggleButton) findViewById(R.id.toggleStartStop);
        txtFrecuencia.addTextChangedListener(new TextWatcher() {
        @Override
        public void afterTextChanged(Editable s) {
            toggle.setEnabled(txtFrecuencia.length() > 0);
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count,
                int after) {
        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before,
                int count) {

        }
       });

How to select date from datetime column?

Using WHERE DATE(datetime) = '2009-10-20' has performance issues. As stated here:

  • it will calculate DATE() for all rows, including those that don't match.
  • it will make it impossible to use an index for the query.

Use BETWEEN or >, <, = operators which allow to use an index:

SELECT * FROM data 
WHERE datetime BETWEEN '2009-10-20 00:00:00' AND '2009-10-20 23:59:59'

Update: the impact on using LIKE instead of operators in an indexed column is high. These are some test results on a table with 1,176,000 rows:

  • using datetime LIKE '2009-10-20%' => 2931ms
  • using datetime >= '2009-10-20 00:00:00' AND datetime <= '2009-10-20 23:59:59' => 168ms

When doing a second call over the same query the difference is even higher: 2984ms vs 7ms (yes, just 7 milliseconds!). I found this while rewriting some old code on a project using Hibernate.

SVN upgrade working copy

You can upgrade to Subversion 1.7. In order to update to Subversion 1.7 you have to launch existing project in Xcode 5 or above. This will prompt an warning ‘The working copy ProjectName should be upgraded to Subversion 1.7’ (shown in below screenshot).

Screenshot for warning

You should select ‘Upgrade’ button to upgrade to Subversion 1.7. This will take a bit of time.

If you are using terminal then you can upgrade to Subversion 1.7 by running below command in your project directory: svn upgrade

Note that once you have upgraded to Subversion 1.7 you cannot go back to Subversion 1.6.

Refer Apple docs for more details.

How to disable all <input > inside a form with jQuery?

You can do it like this:

//HTML BUTTON
<button type="button" onclick="disableAll()">Disable</button>

//Jquery function
function disableAll() {
    //DISABLE ALL FIELDS THAT ARE NOT DISABLED
    $('form').find(':input:not(:disabled)').prop('disabled', true);

    //ENABLE ALL FIELDS THAT DISABLED
    //$('form').find(':input(:disabled)').prop('disabled', false);
}

How to iterate through a DataTable

The above examples are quite helpful. But, if we want to check if a particular row is having a particular value or not. If yes then delete and break and in case of no value found straight throw error. Below code works:

foreach (DataRow row in dtData.Rows)
        {
            if (row["Column_name"].ToString() == txtBox.Text)
            {
                // Getting the sequence number from the textbox.
                string strName1 = txtRowDeletion.Text;

                // Creating the SqlCommand object to access the stored procedure
                // used to get the data for the grid.
                string strDeleteData = "Sp_name";
                SqlCommand cmdDeleteData = new SqlCommand(strDeleteData, conn);
                cmdDeleteData.CommandType = System.Data.CommandType.StoredProcedure;

                // Running the query.
                conn.Open();
                cmdDeleteData.ExecuteNonQuery();
                conn.Close();

                GetData();

                dtData = (DataTable)Session["GetData"];
                BindGrid(dtData);

                lblMsgForDeletion.Text = "The row successfully deleted !!" + txtRowDeletion.Text;
                txtRowDeletion.Text = "";
                break;
            }
            else
            {
                lblMsgForDeletion.Text = "The row is not present ";
            }
        }

iOS9 Untrusted Enterprise Developer with no option to trust

On iOS 9.2 Profiles renamed to Device Management.
Now navigation looks like that:
Settings -> General -> Device Management -> Tap on necessary profile in list -> Trust.

How to properly validate input values with React.JS?

I have written This library which allows you to wrap your form element components, and lets you define your validators in the format :-

<Validation group="myGroup1"
    validators={[
            {
             validator: (val) => !validator.isEmpty(val),
             errorMessage: "Cannot be left empty"
            },...
        }]}>
            <TextField value={this.state.value}
                       className={styles.inputStyles}
                       onChange={
                        (evt)=>{
                          console.log("you have typed: ", evt.target.value);
                        }
                       }/>
</Validation>

How do I install PIL/Pillow for Python 3.6?

Pillow is released with installation wheels on Windows:

We provide Pillow binaries for Windows compiled for the matrix of supported Pythons in both 32 and 64-bit versions in wheel, egg, and executable installers. These binaries have all of the optional libraries included

https://pillow.readthedocs.io/en/3.3.x/installation.html#basic-installation

Update: Python 3.6 is now supported by Pillow. Install with pip install pillow and check https://pillow.readthedocs.io/en/latest/installation.html for more information.


However, Python 3.6 is still in alpha and not officially supported yet, although the tests do all pass for the nightly Python builds (currently 3.6a4).

https://travis-ci.org/python-pillow/Pillow/jobs/155605577

If it's somehow possible to install the 3.5 wheel for 3.6, that's your best bet. Otherwise, zlib notwithstanding, you'll need to build from source, requiring an MS Visual C++ compiler, and which isn't straightforward. For tips see:

https://pillow.readthedocs.io/en/3.3.x/installation.html#building-from-source

And also see how it's built for Windows on AppVeyor CI (but not yet 3.5 or 3.6):

https://github.com/python-pillow/Pillow/tree/master/winbuild

Failing that, downgrade to Python 3.5 or wait until 3.6 is supported by Pillow, probably closer to the 3.6's official release.

int array to string

If this is long array you could use

var sb = arr.Aggregate(new StringBuilder(), ( s, i ) => s.Append( i ), s.ToString());

Clone contents of a GitHub repository (without the folder itself)

If the current directory is empty, you can do that with:

git clone git@github:me/name.git .

(Note the . at the end to specify the current directory.) Of course, this also creates the .git directory in your current folder, not just the source code from your project.

This optional [directory] parameter is documented in the git clone manual page, which points out that cloning into an existing directory is only allowed if that directory is empty.

How to preview an image before and after upload?

_x000D_
_x000D_
function readURL(input) {_x000D_
  if (input.files && input.files[0]) {_x000D_
    var reader = new FileReader();_x000D_
_x000D_
    reader.onload = function(e) {_x000D_
      $('#ImdID').attr('src', e.target.result);_x000D_
    };_x000D_
_x000D_
    reader.readAsDataURL(input.files[0]);_x000D_
  }_x000D_
}
_x000D_
img {_x000D_
  max-width: 180px;_x000D_
}
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>_x000D_
<input type='file' onchange="readURL(this);" />_x000D_
<img id="ImdID" src="" alt="Image" />
_x000D_
_x000D_
_x000D_

How to open a new form from another form

private void Button1_Click(object sender, EventArgs e)
{
    NewForm newForm = new NewForm();    //Create the New Form Object
    this.Hide();    //Hide the Old Form
    newForm.ShowDialog();    //Show the New Form
    this.Close();    //Close the Old Form
}

SQL alias for SELECT statement

Yes, but you can select only one column in your subselect

SELECT (SELECT id FROM bla) AS my_select FROM bla2

JPA: how do I persist a String into a database field, type MYSQL Text

Since you're using JPA, use the Lob annotation (and optionally the Column annotation). Here is what the JPA specification says about it:

9.1.19 Lob Annotation

A Lob annotation specifies that a persistent property or field should be persisted as a large object to a database-supported large object type. Portable applications should use the Lob annotation when mapping to a database Lob type. The Lob annotation may be used in conjunction with the Basic annotation. A Lob may be either a binary or character type. The Lob type is inferred from the type of the persistent field or property, and except for string and character-based types defaults to Blob.

So declare something like this:

@Lob 
@Column(name="CONTENT", length=512)
private String content;

References

  • JPA 1.0 specification:
    • Section 9.1.19 "Lob Annotation"

#pragma mark in Swift?

Pragma mark - [SOME TEXT HERE] was used in Objective-C to group several function together by line separating.

In Swift you can achieve this using MARK, TODO OR FIXME

i. MARK : //MARK: viewDidLoad

This will create a horizontal line with functions grouped under viewDidLoad(shown in screenshot 1)

Screenshot 1

ii. TODO : //TODO: - viewDidLoad

This will group function under TODO: - viewDidLoad category (shown in screenshot 2)

Screenshot 2

iii. FIXME : //FIXME - viewDidLoad

This will group function under FIXME: - viewDidLoad category (shown in screenshot 3)

Screenshot 3

Check this apple documentation for details.

How to add onload event to a div element

onload event it only supports with few tags like listed below.

<body>, <frame>, <iframe>, <img>, <input type="image">, <link>, <script>, <style>

Here the reference for onload event

How to add months to a date in JavaScript?

Corrected as of 25.06.2019:

var newDate = new Date(date.setMonth(date.getMonth()+8));

Old From here:

var jan312009 = new Date(2009, 0, 31);
var eightMonthsFromJan312009  = jan312009.setMonth(jan312009.getMonth()+8);

How can I scroll up more (increase the scroll buffer) in iTerm2?

macOS default termianl

macOS 10.15.7

  1. open Terminal
  2. click Prefrences...
  3. select Window tab
  4. just change Scrollback to Limit number of rows to: what your wanted.

my screenshots

enter image description here

enter image description here

enter image description here

How do I convert a factor into date format?

You were close. format= needs to be added to the as.Date call:

mydate <- factor("1/15/2006 0:00:00")
as.Date(mydate, format = "%m/%d/%Y")
## [1] "2006-01-15"

Get all non-unique values (i.e.: duplicate/more than one occurrence) in an array

I have just figured out a simple way to achieve this using an Array filter

_x000D_
_x000D_
    var list = [9, 9, 111, 2, 3, 4, 4, 5, 7];_x000D_
    _x000D_
    // Filter 1: to find all duplicates elements_x000D_
    var duplicates = list.filter(function(value,index,self) {_x000D_
       return self.indexOf(value) !== self.lastIndexOf(value) && self.indexOf(value) === index;_x000D_
    });_x000D_
    _x000D_
    console.log(duplicates);
_x000D_
_x000D_
_x000D_

SQL Server - inner join when updating

UPDATE R 
SET R.status = '0' 
FROM dbo.ProductReviews AS R
INNER JOIN dbo.products AS P 
       ON R.pid = P.id 
WHERE R.id = '17190' 
  AND P.shopkeeper = '89137';

How many threads can a Java VM support?

Additional information for modern (systemd) linux systems.

There are many resources about this of values that may need tweaking (such as How to increase maximum number of JVM threads (Linux 64bit)); however a new limit is imposed by way of the systemd "TasksMax" limit which sets pids.max on the cgroup.

For login sessions the UserTasksMax default is 33% of the kernel limit pids_max (usually 12,288) and can be override in /etc/systemd/logind.conf.

For services the DefaultTasksMax default is 15% of the kernel limit pids_max (usually 4,915). You can override it for the service by setting TasksMax in "systemctl edit" or update DefaultTasksMax in /etc/systemd/system.conf

Add a thousands separator to a total with Javascript or jQuery?

This will add thousand separators while retaining the decimal part of a given number:

function format(n, sep, decimals) {
    sep = sep || "."; // Default to period as decimal separator
    decimals = decimals || 2; // Default to 2 decimals

    return n.toLocaleString().split(sep)[0]
        + sep
        + n.toFixed(decimals).split(sep)[1];
}

format(4567354.677623); // 4,567,354.68

You could also probe for the locale's decimal separator with:

var sep = (0).toFixed(1)[1];

MySQL Error 1093 - Can't specify target table for update in FROM clause

If something does not work, when coming thru the front-door, then take the back-door:

drop table if exists apples;
create table if not exists apples(variety char(10) primary key, price int);

insert into apples values('fuji', 5), ('gala', 6);

drop table if exists apples_new;
create table if not exists apples_new like apples;
insert into apples_new select * from apples;

update apples_new
    set price = (select price from apples where variety = 'gala')
    where variety = 'fuji';
rename table apples to apples_orig;
rename table apples_new to apples;
drop table apples_orig;

It's fast. The bigger the data, the better.

get the value of DisplayName attribute

Please try below code, I think this will solve your problem.

var classObj = new Class1();
classObj.Name => "StackOverflow";

var property = new Class1().GetType().GetProperty(nameof(classObj.Name));
var displayNameAttributeValue = (property ?? throw new InvalidOperationException())
    .GetCustomAttributes(typeof(DisplayNameAttribute)) as DisplayNameAttribute; 

if (displayNameAttributeValue != null)
{
   Console.WriteLine("{0} = {1}", displayNameAttributeValue, classObj.Name);
}

How can I center an image in Bootstrap?

Since the img is an inline element, Just use text-center on it's container. Using mx-auto will center the container (column) too.

<div class="row">
    <div class="col-4 mx-auto text-center">
        <img src="..">
    </div>
</div>

By default, images are display:inline. If you only want the center the image (and not the other column content), make the image display:block using the d-block class, and then mx-auto will work.

<div class="row">
  <div class="col-4">
    <img class="mx-auto d-block" src="..">
  </div>
</div>

Demo: http://codeply.com/go/iakGGLdB8s

C++ multiline string literal

Option 1. Using boost library, you can declare the string as below

const boost::string_view helpText = "This is very long help text.\n"
      "Also more text is here\n"
      "And here\n"

// Pass help text here
setHelpText(helpText);

Option 2. If boost is not available in your project, you can use std::string_view() in modern C++.

Adding placeholder attribute using Jquery

Try something like the following if you want to use pure JavaScript:

document.getElementsByName('link')[0].placeholder='Type here to search';

Get class name of object as string in Swift

To get the type name as a string in Swift 4 (I haven't checked the earlier versions), just use string interpolation:

"\(type(of: myViewController))"

You can use .self on a type itself, and the type(of:_) function on an instance:

// Both constants will have "UIViewController" as their value
let stringFromType = "\(UIViewController.self)"
let stringFromInstance = "\(type(of: UIViewController()))"

Creating new table with SELECT INTO in SQL

The syntax for creating a new table is

CREATE TABLE new_table
AS
SELECT *
  FROM old_table

This will create a new table named new_table with whatever columns are in old_table and copy the data over. It will not replicate the constraints on the table, it won't replicate the storage attributes, and it won't replicate any triggers defined on the table.

SELECT INTO is used in PL/SQL when you want to fetch data from a table into a local variable in your PL/SQL block.

MongoDB Aggregation: How to get total records count?

Use this to find total count in resulting collection.

db.collection.aggregate( [
{ $match : { score : { $gt : 70, $lte : 90 } } },
{ $group: { _id: null, count: { $sum: 1 } } }
] );

Check if an HTML input element is empty or has no value entered by user

The getElementById method returns an Element object that you can use to interact with the element. If the element is not found, null is returned. In case of an input element, the value property of the object contains the string in the value attribute.

By using the fact that the && operator short circuits, and that both null and the empty string are considered "falsey" in a boolean context, we can combine the checks for element existence and presence of value data as follows:

var myInput = document.getElementById("customx");
if (myInput && myInput.value) {
  alert("My input has a value!");
}

Get everything after and before certain character in SQL Server

 declare @T table
  (
  Col varchar(20)
  )



  insert into @T 
  Select 'images/test1.jpg'
  union all
  Select 'images/test2.png'
  union all
  Select 'images/test3.jpg'
  union all
  Select 'images/test4.jpeg'
  union all
  Select 'images/test5.jpeg'

 Select substring( LEFT(Col,charindex('.',Col)-1),charindex('/',Col)+1,len(LEFT(Col,charindex('.',Col)-1))-1 )
from @T

How to simulate POST request?

Postman is the best application to test your APIs !

You can import or export your routes and let him remember all your body requests ! :)

EDIT : This comment is 5 yea's old and deprecated :D

Here's the new Postman App : https://www.postman.com/

Check if boolean is true?

i personally would prefer

if(true == foo)
{
}

there is no chance for the ==/= mistype and i find it more expressive in terms of foo's type. But it is a very subjective question.

select into in mysql

Use the CREATE TABLE SELECT syntax.

http://dev.mysql.com/doc/refman/5.0/en/create-table-select.html

CREATE TABLE new_tbl SELECT * FROM orig_tbl;

How to upgrade docker container after its image changed

After evaluating the answers and studying the topic I'd like to summarize.

The Docker way to upgrade containers seems to be the following:

Application containers should not store application data. This way you can replace app container with its newer version at any time by executing something like this:

docker pull mysql
docker stop my-mysql-container
docker rm my-mysql-container
docker run --name=my-mysql-container --restart=always \
  -e MYSQL_ROOT_PASSWORD=mypwd -v /my/data/dir:/var/lib/mysql -d mysql

You can store data either on host (in directory mounted as volume) or in special data-only container(s). Read more about it

Upgrading applications (eg. with yum/apt-get upgrade) within containers is considered to be an anti-pattern. Application containers are supposed to be immutable, which shall guarantee reproducible behavior. Some official application images (mysql:5.6 in particular) are not even designed to self-update (apt-get upgrade won't work).

I'd like to thank everybody who gave their answers, so we could see all different approaches.

How to insert strings containing slashes with sed?

A very useful but lesser-known fact about sed is that the familiar s/foo/bar/ command can use any punctuation, not only slashes. A common alternative is s@foo@bar@, from which it becomes obvious how to solve your problem.

Getting the first index of an object

To get the first key of your object

const myObject = {
   'foo1': { name: 'myNam1' },
   'foo2': { name: 'myNam2' }
}

const result = Object.keys(myObject)[0];

// result will return 'foo1'

How to Right-align flex item?

Or you could just use justify-content: flex-end

.main { display: flex; }
.c { justify-content: flex-end; }

Reading data from XML

Try GetElementsByTagName method of XMLDocument class to read specific data or LoadXml method to read all data to xml document.

How to add a "confirm delete" option in ASP.Net Gridview?

I like this way of adding a confirmation prompt before deleting a record from a gridview. This is the CommandField definition nested within a GridView web control in the aspx page. There's nothing fancy here--just a straightforward Commandfield.

_x000D_
_x000D_
<asp:CommandField ShowEditButton="true" UpdateText="Save" ShowDeleteButton="True">_x000D_
  <ControlStyle CssClass="modMarketAdjust" />_x000D_
</asp:CommandField>
_x000D_
_x000D_
_x000D_

Then, all I had to do was add some code to the RowDeleting event of the GridView control. This event fires before the row is actually deleted, which allows you to get the user's confirmation, and to cancel the event if he doesn't want to cancel after all. Here is the code that I put in the RowDeleting event handler:

Private Sub grdMarketAdjustment_RowDeleting(sender As Object, e As GridViewDeleteEventArgs) Handles grdMarketAdjustment.RowDeleting
  Dim confirmed As Integer = MsgBox("Are you sure that you want to delete this market adjustment?", MsgBoxStyle.YesNo + MsgBoxStyle.MsgBoxSetForeground, "Confirm Delete")
  If Not confirmed = MsgBoxResult.Yes Then
    e.Cancel = True 'Cancel the delete.
  End If
End Sub

And that seems to work fine.

how to delete installed library form react native project

I followed the following steps:--

  1. react-native unlink <lib name> -- this command has done the unlinking of the library from both platforms.

  2. react-native uninstall <lib name> -- this has uninstalled the library from the node modules and its dependencies

  3. Manually removed the library name from package.json -- somehow the --save command was not working for me to remove the library declaration from package.json.

After this I have manually deleted the empty react-native library from the node_modules folder

Moving from JDK 1.7 to JDK 1.8 on Ubuntu

Most of the answers for this question can not helped me in 2020.

This notification from download site of Oracle may be the reason:

Important Oracle JDK License Update

The Oracle JDK License has changed for releases starting April 16, 2019.

I try to google a little bit and those tutorials below helped me a lot.

  1. Remove completely the previous version of JVM installed on your PC.

    sudo update-alternatives --remove-all java
    sudo update-alternatives --remove-all javac
    sudo update-alternatives --remove-all javaws
    
    # /usr/lib/jvm/jdk1.7.0 is the path you installed the previous version of JVM on your PC
    sudo rm -rf /usr/lib/jvm/jdk1.7.0 
    

    Check to see whether java is uninstalled or not

    java -version
    
  2. Install Java 8 JDK.

    • Download Java 8 from Oracle's website. The version being used is 1.8.0_251. Pay attention to this value, you may need it to edit commands in this answer when Java 8 is upgraded to another version.
    • Extract the compressed file to the place where you want to install.

    cd /usr/lib/jvm
    sudo tar xzf ~/Downloads/jdk-8u251-linux-x64.tar.gz
    
    • Edit environment file

    sudo gedit /etc/environment
    
    • Edit the PATH's value by appending the string below to the current value

    :/usr/lib/jvm/jdk1.8.0_251/bin:/usr/lib/jvm/jdk1.8.0_251/jre/bin
    
    • Append those strings to the environment file

    J2SDKDIR="/usr/lib/jvm/jdk1.8.0_251"
    J2REDIR="/usr/lib/jvm/jdk1.8.0_251/jre"
    JAVA_HOME="/usr/lib/jvm/jdk1.8.0_251"
    
    • Complete the installation by running commands below

    sudo update-alternatives --install "/usr/bin/java" "java" "/usr/lib/jvm/jdk1.8.0_251/bin/java" 0
    sudo update-alternatives --install "/usr/bin/javac" "javac" "/usr/lib/jvm/jdk1.8.0_251/bin/javac" 0
    sudo update-alternatives --set java /usr/lib/jvm/jdk1.8.0_251/bin/java
    sudo update-alternatives --set javac /usr/lib/jvm/jdk1.8.0_251/bin/javac
    
    update-alternatives --list java
    update-alternatives --list javac
    

Prevent nginx 504 Gateway timeout using PHP set_time_limit()

I solve this trouble with config APACHE ! All methods (in this topic) is incorrect for me... Then I try chanche apache config:

Timeout 3600

Then my script worked!

This Handler class should be static or leaks might occur: IncomingHandler

This way worked well for me, keeps code clean by keeping where you handle the message in its own inner class.

The handler you wish to use

Handler mIncomingHandler = new Handler(new IncomingHandlerCallback());

The inner class

class IncomingHandlerCallback implements Handler.Callback{

        @Override
        public boolean handleMessage(Message message) {

            // Handle message code

            return true;
        }
}

Stacked bar chart

You will need to melt your dataframe to get it into the so-called long format:

require(reshape2)
sample.data.M <- melt(sample.data)

Now your field values are represented by their own rows and identified through the variable column. This can now be leveraged within the ggplot aesthetics:

require(ggplot2)
c <- ggplot(sample.data.M, aes(x = Rank, y = value, fill = variable))
c + geom_bar(stat = "identity")

Instead of stacking you may also be interested in showing multiple plots using facets:

c <- ggplot(sample.data.M, aes(x = Rank, y = value))
c + facet_wrap(~ variable) + geom_bar(stat = "identity")

how to append a css class to an element by javascript?

You should be able to set the className property of the element. You could do a += to append it.

div with dynamic min-height based on browser window height

It's hard to do this.

There is a min-height: css style, but it doesn't work in all browsers. You can use it, but the biggest problem is that you will need to set it to something like 90% or numbers like that (percents), but the top and bottom divs use fixed pixel sizes, and you won't be able to reconcile them.

 var minHeight = $(window).height() -
                 $('#a').outerHeight(true) -
                 $('#c').outerHeight(true));

if($('#b').height() < minHeight) $('#b').height(minHeight);

I know a and c have fixed heights, but I rather measure them in case they change later.

Also, I am measuring the height of b (I don't want to make is smaller after all), but if there is an image in there that did not load the height can change, so watch out for things like that.

It may be safer to do:

$('#b').prepend('<div style="float: left; width: 1px; height: ' + minHeight + 'px;">&nbsp;</div>');

Which simply adds an element into that div with the correct height - that effectively acts as min-height even for browsers that don't have it. (You may want to add the element into your markup, and then just control the height of it via javascript instead of also adding it that way, that way you can take it into account when designing the layout.)

How can I put a database under git (version control)?

I'm starting to think of a really simple solution, don't know why I didn't think of it before!!

  • Duplicate the database, (both the schema and the data).
  • In the branch for the new-major-changes, simply change the project configuration to use the new duplicate database.

This way I can switch branches without worrying about database schema changes.

EDIT:

By duplicate, I mean create another database with a different name (like my_db_2); not doing a dump or anything like that.

Spring .properties file: get element as an Array

If you define your array in properties file like:

base.module.elementToSearch=1,2,3,4,5,6

You can load such array in your Java class like this:

  @Value("${base.module.elementToSearch}")
  private String[] elementToSearch;

How to use Python's "easy_install" on Windows ... it's not so easy

For one thing, it says you already have that module installed. If you need to upgrade it, you should do something like this:

easy_install -U packageName

Of course, easy_install doesn't work very well if the package has some C headers that need to be compiled and you don't have the right version of Visual Studio installed. You might try using pip or distribute instead of easy_install and see if they work better.

How to send image to PHP file using Ajax?

<html>
  <head>
    <script src="http://code.jquery.com/jquery-1.9.1.js"></script>
    <script>
      $(function () {

        $('#abc').on('submit', function (e) {

          e.preventDefault();

          $.ajax({
            url: 'post.php',
            method:'POST',
            data: new FormData(this),
            contentType: false,
            cache:false,
            processData:false,
            success: function (data) {
              alert(data);
              location.reload();
            }
          });

        });

      });
    </script>
  </head>
  <body>
    <form enctype= "multipart/form-data" id="abc">
      <input name="fname" ><br>
      <input name="lname"><br>
      <input type="file" name="file" required=""><br>
      <input name="submit" type="submit" value="Submit">
    </form>
  </body>
</html>

Export data to Excel file with ASP.NET MVC 4 C# is rendering into view

I used a list in my controller class to set data into grid view. The code works fine for me:

public ActionResult ExpExcl()
{
  List<PersonModel> person= new List<PersonModel>
   { 
    new PersonModel() {FirstName= "Jenny", LastName="Mathew", Age= 23},
    new PersonModel() {FirstName= "Paul", LastName="Meehan", Age=25}
   };
   var grid= new GridView();
   grid.DataSource= person;
   grid.DataBind();

   Response.ClearContent();
   Response.AddHeader("content-disposition","attachement; filename=data.xls");
   Response.ContentType="application/excel";
   StringWriter sw= new StringWriter();
   HtmlTextWriter htw= new HtmlTextWriter(sw); 
   grid.RenderControl(htw);
   Response.Output.Write(sw.ToString());
   Response.Flush();
   Response.End();
   return View();
 }

Get installed applications in a system

Your best bet is to use WMI. Specifically the Win32_Product class.

"Could not find bundler" error

I got this after upgrading to ruby 2.1.0. My PATH was set in my login script to include .gem/ruby/2.0.0/bin. Updating the version number fixed it.

Tomcat 404 error: The origin server did not find a current representation for the target resource or is not willing to disclose that one exists

Hope this helps. From eclipse, you right click the project -> Run As -> Run on Server and then it worked for me. I used Eclipse Jee Neon and Apache Tomcat 9.0. :)

I just removed the head portion in index.html file and it worked fine.This is the head tag in html file

When would you use the Builder Pattern?

Consider a restaurant. The creation of "today's meal" is a factory pattern, because you tell the kitchen "get me today's meal" and the kitchen (factory) decides what object to generate, based on hidden criteria.

The builder appears if you order a custom pizza. In this case, the waiter tells the chef (builder) "I need a pizza; add cheese, onions and bacon to it!" Thus, the builder exposes the attributes the generated object should have, but hides how to set them.

Laravel 4: Redirect to a given url

You can use different types of redirect method in laravel -

return redirect()->intended('http://heera.it');

OR

return redirect()->to('http://heera.it');

OR

use Illuminate\Support\Facades\Redirect;

return Redirect::to('/')->with(['type' => 'error','message' => 'Your message'])->withInput(Input::except('password'));

OR

return redirect('/')->with(Auth::logout());

OR

return redirect()->route('user.profile', ['step' => $step, 'id' => $id]);

Excel data validation with suggestions/autocomplete

There's a messy workaround at http://www.ozgrid.com/Excel/autocomplete-validation.htm that basically works like this:

  1. Enable "Autocomplete for Cell Values" on Tools - Options > Edit;
  2. Recreate the list of valid items on the cell immediately above the one with the validation criteria;
  3. Hide the lines with the list of valid items.

Windows.history.back() + location.reload() jquery

You can't do window.history.back(); and location.reload(); in the same function.

window.history.back() breaks the javascript flow and redirects to previous page, location.reload() is never processed.

location.reload() has to be called on the page you redirect to when using window.history.back().

I would used an url to redirect instead of history.back, that gives you both a redirect and refresh.

Get date from input form within PHP

Validate the INPUT.

$time = strtotime($_POST['dateFrom']);
if ($time) {
  $new_date = date('Y-m-d', $time);
  echo $new_date;
} else {
   echo 'Invalid Date: ' . $_POST['dateFrom'];
  // fix it.
}

Getting results between two dates in PostgreSQL

Looking at the dates for which it doesn't work -- those where the day is less than or equal to 12 -- I'm wondering whether it's parsing the dates as being in YYYY-DD-MM format?

What is the difference between Normalize.css and Reset CSS?

Sometimes, the best solution is to use both. Sometimes, it is to use neither. And sometimes, it is to use one or the other. If you want all the styles, including margin and padding reset across all browsers, use reset.css. Then apply all decorations and stylings yourself. If you simply like the built-in stylings but want more cross-browser synchronicity i.e. normalizations then use normalize.css. But if you choose to use both reset.css and normalize.css, link the reset.css stylesheet first and then the normalize.css stylesheet (immediately) afterwards. Sometimes it's not always a matter of which is better, but when to use which one versus when to use both versus when to use neither. IMHO.

FloatingActionButton example with Support Library

So in your build.gradle file, add this:

compile 'com.android.support:design:27.1.1'

AndroidX Note: Google is introducing new AndroidX extension libraries to replace the older Support Libraries. To use AndroidX, first make sure you've updated your gradle.properties file, edited build.gradle to set compileSdkVersion to 28 (or higher), and use the following line instead of the previous compile one.

implementation 'com.google.android.material:material:1.0.0'

Next, in your themes.xml or styles.xml or whatever, make sure you set this- it's your app's accent color-- and the color of your FAB unless you override it (see below):

        <item name="colorAccent">@color/floating_action_button_color</item>

In the layout's XML:

<RelativeLayout
 ...
 xmlns:app="http://schemas.android.com/apk/res-auto">

       <android.support.design.widget.FloatingActionButton
            android:id="@+id/myFAB"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@drawable/ic_plus_sign"
            app:elevation="4dp"
            ... />

</RelativeLayout>

Or if you are using the AndroidX material library above, you'd instead use this:

<RelativeLayout
 ...
 xmlns:app="http://schemas.android.com/apk/res-auto">

       <com.google.android.material.floatingactionbutton.FloatingActionButton
            android:id="@+id/myFAB"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:srcCompat="@drawable/ic_plus_sign"
            app:elevation="4dp"
            ... />

</RelativeLayout>

You can see more options in the docs (material docs here) (setRippleColor, etc.), but one of note is:

    app:fabSize="mini"

Another interesting one-- to change the background color of just one FAB, add:

    app:backgroundTint="#FF0000"

(for example to change it to red) to the XML above.

Anyway, in code, after the Activity/Fragment's view is inflated....

    FloatingActionButton myFab = (FloatingActionButton)  myView.findViewById(R.id.myFAB);
    myFab.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            doMyThing();
        }
    });

Observations:

  • If you have one of those buttons that's on a "seam" splitting two views (using a RelativeLayout, for example) with, say, a negative bottom layout margin to overlap the border, you'll notice an issue: the FAB's size is actually very different on lollipop vs. pre-lollipop. You can actually see this in AS's visual layout editor when you flip between APIs-- it suddenly "puffs out" when you switch to pre-lollipop. The reason for the extra size seems to be that the shadow expands the size of the view in every direction. So you have to account for this when you're adjusting the FAB's margins if it's close to other stuff.
  • Here's a way to remove or change the padding if there's too much:

    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
        RelativeLayout.LayoutParams p = (RelativeLayout.LayoutParams) myFab.getLayoutParams();
        p.setMargins(0, 0, 0, 0); // get rid of margins since shadow area is now the margin
        myFab.setLayoutParams(p);
    }
    
  • Also, I was going to programmatically place the FAB on the "seam" between two areas in a RelativeLayout by grabbing the FAB's height, dividing by two, and using that as the margin offset. But myFab.getHeight() returned zero, even after the view was inflated, it seemed. Instead I used a ViewTreeObserver to get the height only after it's laid out and then set the position. See this tip here. It looked like this:

        ViewTreeObserver viewTreeObserver = closeButton.getViewTreeObserver();
        if (viewTreeObserver.isAlive()) {
            viewTreeObserver.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
                @Override
                public void onGlobalLayout() {
                    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) {
                        closeButton.getViewTreeObserver().removeGlobalOnLayoutListener(this);
                    } else {
                        closeButton.getViewTreeObserver().removeOnGlobalLayoutListener(this);
                    }
                    // not sure the above is equivalent, but that's beside the point for this example...
                    RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams) closeButton.getLayoutParams();
                    params.setMargins(0, 0, 16, -closeButton.getHeight() / 2); // (int left, int top, int right, int bottom)
                    closeButton.setLayoutParams(params);
                }
            });
        }
    

    Not sure if this is the right way to do it, but it seems to work.

  • It seems you can make the shadow-space of the button smaller by decreasing the elevation.
  • If you want the FAB on a "seam" you can use layout_anchor and layout_anchorGravity here is an example:

    <android.support.design.widget.FloatingActionButton
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        app:layout_anchor="@id/appbar"
        app:layout_anchorGravity="bottom|right|end"
        android:src="@drawable/ic_discuss"
        android:layout_margin="@dimen/fab_margin"
        android:clickable="true"/>
    

Remember that you can automatically have the button jump out of the way when a Snackbar comes up by wrapping it in a CoordinatorLayout.

More:

How can I detect Internet Explorer (IE) and Microsoft Edge using JavaScript?

I'm using UAParser https://github.com/faisalman/ua-parser-js

var a = new UAParser();
var name = a.getResult().browser.name;
var version = a.getResult().browser.version;

Simple way to encode a string according to a password?

An other implementation of @qneill code which include CRC checksum of the original message, it throw an exception if the check fail:

import hashlib
import struct
import zlib

def vigenere_encode(text, key):
    text = '{}{}'.format(text, struct.pack('i', zlib.crc32(text)))

    enc = []
    for i in range(len(text)):
        key_c = key[i % len(key)]
        enc_c = chr((ord(text[i]) + ord(key_c)) % 256)
        enc.append(enc_c)

    return base64.urlsafe_b64encode("".join(enc))


def vigenere_decode(encoded_text, key):
    dec = []
    encoded_text = base64.urlsafe_b64decode(encoded_text)
    for i in range(len(encoded_text)):
        key_c = key[i % len(key)]
        dec_c = chr((256 + ord(encoded_text[i]) - ord(key_c)) % 256)
        dec.append(dec_c)

    dec = "".join(dec)
    checksum = dec[-4:]
    dec = dec[:-4]

    assert zlib.crc32(dec) == struct.unpack('i', checksum)[0], 'Decode Checksum Error'

    return dec

"Eliminate render-blocking CSS in above-the-fold content"

Hi For jQuery You can only use like this

Use async and type="text/javascript" only

Using Java generics for JPA findAll() query with WHERE clause

Hat tip to Adam Bien if you don't want to use createQuery with a String and want type safety:

 @PersistenceContext
 EntityManager em;

 public List<ConfigurationEntry> allEntries() {
        CriteriaBuilder cb = em.getCriteriaBuilder();
        CriteriaQuery<ConfigurationEntry> cq = cb.createQuery(ConfigurationEntry.class);
        Root<ConfigurationEntry> rootEntry = cq.from(ConfigurationEntry.class);
        CriteriaQuery<ConfigurationEntry> all = cq.select(rootEntry);
        TypedQuery<ConfigurationEntry> allQuery = em.createQuery(all);
        return allQuery.getResultList();
 }

http://www.adam-bien.com/roller/abien/entry/selecting_all_jpa_entities_as

How to replace a string in multiple files in linux command line

To replace a string in multiple files you can use:

grep -rl string1 somedir/ | xargs sed -i 's/string1/string2/g'

E.g.

grep -rl 'windows' ./ | xargs sed -i 's/windows/linux/g'

Source blog

Create component to specific module with Angular-CLI

First run ng g module newModule . Then run ng g component newModule/newModule --flat

Open Sublime Text from Terminal in macOS

I am using Oh-My-Zshell and the previous aliases stated didn't work for me so I wrote a simple bash function that will allow you to open Sublime from the command line by using sublime to open the current folder in the editor. With the addition functionality to specify a file to open the editor from.

# Open Sublime from current folder or specified folder
sublime(){
  /Applications/Sublime\ Text.app/Contents/SharedSupport/bin/subl ./$1
}

Usage to open current folder in terminal:

$ sublime

Usage to open specific folder:

$ sublime path/to/the/file/to/open

Command-line Tool to find Java Heap Size and Memory Used (Linux)?

Each Java process has a pid, which you first need to find with the jps command.

Once you have the pid, you can use jstat -gc [insert-pid-here] to find statistics of the behavior of the garbage collected heap.

  • jstat -gccapacity [insert-pid-here] will present information about memory pool generation and space capabilities.

  • jstat -gcutil [insert-pid-here] will present the utilization of each generation as a percentage of its capacity. Useful to get an at a glance view of usage.

See jstat docs on Oracle's site.

Overloading operators in typedef structs (c++)

The breakdown of your declaration and its members is somewhat littered:

Remove the typedef

The typedef is neither required, not desired for class/struct declarations in C++. Your members have no knowledge of the declaration of pos as-written, which is core to your current compilation failure.

Change this:

typedef struct {....} pos;

To this:

struct pos { ... };

Remove extraneous inlines

You're both declaring and defining your member operators within the class definition itself. The inline keyword is not needed so long as your implementations remain in their current location (the class definition)


Return references to *this where appropriate

This is related to an abundance of copy-constructions within your implementation that should not be done without a strong reason for doing so. It is related to the expression ideology of the following:

a = b = c;

This assigns c to b, and the resulting value b is then assigned to a. This is not equivalent to the following code, contrary to what you may think:

a = c;
b = c;

Therefore, your assignment operator should be implemented as such:

pos& operator =(const pos& a)
{
    x = a.x;
    y = a.y;
    return *this;
}

Even here, this is not needed. The default copy-assignment operator will do the above for you free of charge (and code! woot!)

Note: there are times where the above should be avoided in favor of the copy/swap idiom. Though not needed for this specific case, it may look like this:

pos& operator=(pos a) // by-value param invokes class copy-ctor
{
    this->swap(a);
    return *this;
}

Then a swap method is implemented:

void pos::swap(pos& obj)
{
    // TODO: swap object guts with obj
}

You do this to utilize the class copy-ctor to make a copy, then utilize exception-safe swapping to perform the exchange. The result is the incoming copy departs (and destroys) your object's old guts, while your object assumes ownership of there's. Read more the copy/swap idiom here, along with the pros and cons therein.


Pass objects by const reference when appropriate

All of your input parameters to all of your members are currently making copies of whatever is being passed at invoke. While it may be trivial for code like this, it can be very expensive for larger object types. An exampleis given here:

Change this:

bool operator==(pos a) const{
    if(a.x==x && a.y== y)return true;
    else return false;
}

To this: (also simplified)

bool operator==(const pos& a) const
{
    return (x == a.x && y == a.y);
}

No copies of anything are made, resulting in more efficient code.


Finally, in answering your question, what is the difference between a member function or operator declared as const and one that is not?

A const member declares that invoking that member will not modifying the underlying object (mutable declarations not withstanding). Only const member functions can be invoked against const objects, or const references and pointers. For example, your operator +() does not modify your local object and thus should be declared as const. Your operator =() clearly modifies the local object, and therefore the operator should not be const.


Summary

struct pos
{
    int x;
    int y;

    // default + parameterized constructor
    pos(int x=0, int y=0) 
        : x(x), y(y)
    {
    }

    // assignment operator modifies object, therefore non-const
    pos& operator=(const pos& a)
    {
        x=a.x;
        y=a.y;
        return *this;
    }

    // addop. doesn't modify object. therefore const.
    pos operator+(const pos& a) const
    {
        return pos(a.x+x, a.y+y);
    }

    // equality comparison. doesn't modify object. therefore const.
    bool operator==(const pos& a) const
    {
        return (x == a.x && y == a.y);
    }
};

EDIT OP wanted to see how an assignment operator chain works. The following demonstrates how this:

a = b = c;

Is equivalent to this:

b = c;
a = b;

And that this does not always equate to this:

a = c;
b = c;

Sample code:

#include <iostream>
#include <string>
using namespace std;

struct obj
{
    std::string name;
    int value;

    obj(const std::string& name, int value)
        : name(name), value(value)
    {
    }

    obj& operator =(const obj& o)
    {
        cout << name << " = " << o.name << endl;
        value = (o.value+1); // note: our value is one more than the rhs.
        return *this;
    }    
};

int main(int argc, char *argv[])
{

    obj a("a", 1), b("b", 2), c("c", 3);

    a = b = c;
    cout << "a.value = " << a.value << endl;
    cout << "b.value = " << b.value << endl;
    cout << "c.value = " << c.value << endl;

    a = c;
    b = c;
    cout << "a.value = " << a.value << endl;
    cout << "b.value = " << b.value << endl;
    cout << "c.value = " << c.value << endl;

    return 0;
}

Output

b = c
a = b
a.value = 5
b.value = 4
c.value = 3
a = c
b = c
a.value = 4
b.value = 4
c.value = 3

Creating a simple configuration file and parser in C++

In general, it's easiest to parse such typical config files in two stages: first read the lines, and then parse those one by one.
In C++, lines can be read from a stream using std::getline(). While by default it will read up to the next '\n' (which it will consume, but not return), you can pass it some other delimiter, too, which makes it a good candidate for reading up-to-some-char, like = in your example.

For simplicity, the following presumes that the = are not surrounded by whitespace. If you want to allow whitespaces at these positions, you will have to strategically place is >> std::ws before reading the value and remove trailing whitespaces from the keys. However, IMO the little added flexibility in the syntax is not worth the hassle for a config file reader.

const char config[] = "url=http://example.com\n"
                      "file=main.exe\n"
                      "true=0";

std::istringstream is_file(config);

std::string line;
while( std::getline(is_file, line) )
{
  std::istringstream is_line(line);
  std::string key;
  if( std::getline(is_line, key, '=') )
  {
    std::string value;
    if( std::getline(is_line, value) ) 
      store_line(key, value);
  }
}

(Adding error handling is left as an exercise to the reader.)

Differences between git pull origin master & git pull origin/master

git pull origin master will fetch all the changes from the remote's master branch and will merge it into your local.We generally don't use git pull origin/master.We can do the same thing by git merge origin/master.It will merge all the changes from "cached copy" of origin's master branch into your local branch.In my case git pull origin/master is throwing the error.

Save Screen (program) output to a file

The following might be useful (tested on: Linux/Ubuntu 12.04 (Precise Pangolin)):

cat /dev/ttyUSB0

Using the above, you can then do all the re-directions that you need. For example, to dump output to your console while saving to your file, you'd do:

cat /dev/ttyUSB0 | tee console.log

How to escape a while loop in C#

If you need to continue with additional logic use...

break;

or if you have a value to return...

return my_value_to_be_returned;

However, looking at your code, I believe you will control the loop with the revised example below without using a break or return...

private void CheckLog()
        {
            bool continueLoop = true;
            while (continueLoop)
            {
                Thread.Sleep(5000);
                if (!System.IO.File.Exists("Command.bat")) continue;
                using (System.IO.StreamReader sr = System.IO.File.OpenText("Command.bat"))
                {
                    string s = "";
                    while (continueLoop && (s = sr.ReadLine()) != null)
                    {
                        if (s.Contains("mp4:production/CATCHUP/"))
                        {
                            RemoveEXELog();

                            Process p = new Process();
                            p.StartInfo.WorkingDirectory = "dump";
                            p.StartInfo.FileName = "test.exe"; 
                            p.StartInfo.Arguments = s; 
                            p.Start();
                            continueLoop = false;
                        }
                    }
                }
            }
        }

Django development IDE

The Wingware editor from http://www.wingware.com is Python-specific with very good auto-completion for Python/Django/Zope, etc.

It has a built in Python shell to run snippets (or select and run) and support for Mercurial/Git, etc. and a built-in unittest/nose/doctest test runner. It's commercial though, but as it is written in Python, it's cross platform.

I bought it a while ago, and thought it looked dorky, but I've tried them all and keep coming back. Caveat that I am a Windows guy with no Emacs or Vim skills, so leveraging that was not an option. And the Mac version requires X Window and seems to be more glitchy.

C#/Linq: Apply a mapping function to each element in an IEnumerable?

You're looking for Select which can be used to transform\project the input sequence:

IEnumerable<string> strings = integers.Select(i => i.ToString());

A more useful statusline in vim?

I currently use this statusbar settings:

set laststatus=2
set statusline=\ %f%m%r%h%w\ %=%({%{&ff}\|%{(&fenc==\"\"?&enc:&fenc).((exists(\"+bomb\")\ &&\ &bomb)?\",B\":\"\")}%k\|%Y}%)\ %([%l,%v][%p%%]\ %)

My complete .vimrc file: http://gabriev82.altervista.org/projects/vim-configuration/

curl : (1) Protocol https not supported or disabled in libcurl

This is specifically mentioned in the libcurl FAQ entry "Protocol xxx not supported or disabled in libcurl".

For your pleasure I'm embedding the explanation here too:

When passing on a URL to curl to use, it may respond that the particular protocol is not supported or disabled. The particular way this error message is phrased is because curl doesn't make a distinction internally of whether a particular protocol is not supported (ie never got any code added that knows how to speak that protocol) or if it was explicitly disabled. curl can be built to only support a given set of protocols, and the rest would then be disabled or not supported.

Note that this error will also occur if you pass a wrongly spelled protocol part as in "htpt://example.com" or as in the less evident case if you prefix the protocol part with a space as in " http://example.com/".

How to retrieve an Oracle directory path?

The ALL_DIRECTORIES data dictionary view will have information about all the directories that you have access to. That includes the operating system path

SELECT owner, directory_name, directory_path
  FROM all_directories

How do you loop in a Windows batch file?

If you want to do something x times, you can do this:

Example (x = 200):

FOR /L %%A IN (1,1,200) DO (
  ECHO %%A
)

1,1,200 means:

  • Start = 1
  • Increment per step = 1
  • End = 200

convert strtotime to date time format in php

$unixtime = 1307595105;
echo $time = date("m/d/Y h:i:s A T",$unixtime);

Where

http://php.net/manual/en/function.date.php

How to save a pandas DataFrame table as a png

Although I am not sure if this is the result you expect, you can save your DataFrame in png by plotting the DataFrame with Seaborn Heatmap with annotations on, like this:

http://stanford.edu/~mwaskom/software/seaborn/generated/seaborn.heatmap.html#seaborn.heatmap

Example of Seaborn heatmap with annotations on

It works right away with a Pandas Dataframe. You can look at this example: Efficiently ploting a table in csv format using Python

You might want to change the colormap so it displays a white background only.

Hope this helps.

How do I delete an entity from symfony2

DELETE FROM ... WHERE id=...;

protected function templateRemove($id){
            $em = $this->getDoctrine()->getManager();
            $entity = $em->getRepository('XXXBundle:Templates')->findOneBy(array('id' => $id));

            if ($entity != null){
                $em->remove($entity);
                $em->flush();
            }
        }

How do I grant myself admin access to a local SQL Server instance?

Here's a script that claims to be able to fix this.

Get admin rights to your local SQL Server Express with this simple script

Download link to the script

Description

This command script allows you to easily add yourself to the sysadmin role of a local SQL Server instance. You must be a member of the Windows local Administrators group, or have access to the credentials of a user who is. The script supports SQL Server 2005 and later.

The script is most useful if you are a developer trying to use SQL Server 2008 Express that was installed by someone else. In this situation you usually won't have admin rights to the SQL Server 2008 Express instance, since by default only the person installing SQL Server 2008 is granted administrative privileges.

The user who installed SQL Server 2008 Express can use SQL Server Management Studio to grant the necessary privileges to you. But what if SQL Server Management Studio was not installed? Or worse if the installing user is not available anymore?

This script fixes the problem in just a few clicks!

Note: You will need to provide the BAT file with an 'Instance Name' (Probably going to be 'MSSQLSERVER' - but it might not be): you can get the value by first running the following in the "Microsoft SQL Server Management Console":

 SELECT @@servicename

Then copy the result to use when the BAT file prompts for 'SQL instance name'.

  @echo off 
    rem 
    rem **************************************************************************** 
    rem 
    rem    Copyright (c) Microsoft Corporation. All rights reserved. 
    rem    This code is licensed under the Microsoft Public License. 
    rem    THIS CODE IS PROVIDED *AS IS* WITHOUT WARRANTY OF 
    rem    ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING ANY 
    rem    IMPLIED WARRANTIES OF FITNESS FOR A PARTICULAR 
    rem    PURPOSE, MERCHANTABILITY, OR NON-INFRINGEMENT. 
    rem 
    rem **************************************************************************** 
    rem 
    rem CMD script to add a user to the SQL Server sysadmin role 
    rem 
    rem Input:  %1 specifies the instance name to be modified. Defaults to SQLEXPRESS. 
    rem         %2 specifies the principal identity to be added (in the form "<domain>\<user>"). 
    rem            If omitted, the script will request elevation and add the current user (pre-elevation) to the sysadmin role. 
    rem            If provided explicitly, the script is assumed to be running elevated already. 
    rem 
    rem Method: 1) restart the SQL service with the '-m' option, which allows a single connection from a box admin 
    rem            (the box admin is temporarily added to the sysadmin role with this start option) 
    rem         2) connect to the SQL instance and add the user to the sysadmin role 
    rem         3) restart the SQL service for normal connections 
    rem 
    rem Output: Messages indicating success/failure. 
    rem         Note that if elevation is done by this script, a new command process window is created: the output of this 
    rem         window is not directly accessible to the caller. 
    rem 
    rem 
    setlocal 
    set sqlresult=N/A 
    if .%1 == . (set /P sqlinstance=Enter SQL instance name, or default to SQLEXPRESS: ) else (set sqlinstance=%1) 
    if .%sqlinstance% == . (set sqlinstance=SQLEXPRESS) 
    if /I %sqlinstance% == MSSQLSERVER (set sqlservice=MSSQLSERVER) else (set sqlservice=MSSQL$%sqlinstance%) 
    if .%2 == . (set sqllogin="%USERDOMAIN%\%USERNAME%") else (set sqllogin=%2) 
    rem remove enclosing quotes 
    for %%i in (%sqllogin%) do set sqllogin=%%~i 
    @echo Adding '%sqllogin%' to the 'sysadmin' role on SQL Server instance '%sqlinstance%'. 
    @echo Verify the '%sqlservice%' service exists ... 
    set srvstate=0 
    for /F "usebackq tokens=1,3" %%i in (`sc query %sqlservice%`) do if .%%i == .STATE set srvstate=%%j 
    if .%srvstate% == .0 goto existerror 
    rem 
    rem elevate if <domain/user> was defaulted 
    rem 
    if NOT .%2 == . goto continue 
    echo new ActiveXObject("Shell.Application").ShellExecute("cmd.exe", "/D /Q /C pushd \""+WScript.Arguments(0)+"\" & \""+WScript.Arguments(1)+"\" %sqlinstance% \""+WScript.Arguments(2)+"\"", "", "runas"); >"%TEMP%\addsysadmin{7FC2CAE2-2E9E-47a0-ADE5-C43582022EA8}.js" 
    call "%TEMP%\addsysadmin{7FC2CAE2-2E9E-47a0-ADE5-C43582022EA8}.js" "%cd%" %0 "%sqllogin%" 
    del "%TEMP%\addsysadmin{7FC2CAE2-2E9E-47a0-ADE5-C43582022EA8}.js" 
    goto :EOF 
    :continue 
    rem 
    rem determine if the SQL service is running 
    rem 
    set srvstarted=0 
    set srvstate=0 
    for /F "usebackq tokens=1,3" %%i in (`sc query %sqlservice%`) do if .%%i == .STATE set srvstate=%%j 
    if .%srvstate% == .0 goto queryerror 
    rem 
    rem if required, stop the SQL service 
    rem 
    if .%srvstate% == .1 goto startm 
    set srvstarted=1 
    @echo Stop the '%sqlservice%' service ... 
    net stop %sqlservice% 
    if errorlevel 1 goto stoperror 
    :startm 
    rem 
    rem start the SQL service with the '-m' option (single admin connection) and wait until its STATE is '4' (STARTED) 
    rem also use trace flags as follows: 
    rem     3659 - log all errors to errorlog 
    rem     4010 - enable shared memory only (lpc:) 
    rem     4022 - do not start autoprocs 
    rem 
    @echo Start the '%sqlservice%' service in maintenance mode ... 
    sc start %sqlservice% -m -T3659 -T4010 -T4022 >nul 
    if errorlevel 1 goto startmerror 
    :checkstate1 
    set srvstate=0 
    for /F "usebackq tokens=1,3" %%i in (`sc query %sqlservice%`) do if .%%i == .STATE set srvstate=%%j 
    if .%srvstate% == .0 goto queryerror 
    if .%srvstate% == .1 goto startmerror 
    if NOT .%srvstate% == .4 goto checkstate1 
    rem 
    rem add the specified user to the sysadmin role 
    rem access tempdb to avoid a misleading shutdown error 
    rem 
    @echo Add '%sqllogin%' to the 'sysadmin' role ... 
    for /F "usebackq tokens=1,3" %%i in (`sqlcmd -S np:\\.\pipe\SQLLocal\%sqlinstance% -E -Q "create table #foo (bar int); declare @rc int; execute @rc = sp_addsrvrolemember '$(sqllogin)', 'sysadmin'; print 'RETURN_CODE : '+CAST(@rc as char)"`) do if .%%i == .RETURN_CODE set sqlresult=%%j 
    rem 
    rem stop the SQL service 
    rem 
    @echo Stop the '%sqlservice%' service ... 
    net stop %sqlservice% 
    if errorlevel 1 goto stoperror 
    if .%srvstarted% == .0 goto exit 
    rem 
    rem start the SQL service for normal connections 
    rem 
    net start %sqlservice% 
    if errorlevel 1 goto starterror 
    goto exit 
    rem 
    rem handle unexpected errors 
    rem 
    :existerror 
    sc query %sqlservice% 
    @echo '%sqlservice%' service is invalid 
    goto exit 
    :queryerror 
    @echo 'sc query %sqlservice%' failed 
    goto exit 
    :stoperror 
    @echo 'net stop %sqlservice%' failed 
    goto exit 
    :startmerror 
    @echo 'sc start %sqlservice% -m' failed 
    goto exit 
    :starterror 
    @echo 'net start %sqlservice%' failed 
    goto exit 
    :exit 
    if .%sqlresult% == .0 (@echo '%sqllogin%' was successfully added to the 'sysadmin' role.) else (@echo '%sqllogin%' was NOT added to the 'sysadmin' role: SQL return code is %sqlresult%.) 
    endlocal 
    pause

Sass calculate percent minus px

There is a calc function in both SCSS [compile-time] and CSS [run-time]. You're likely invoking the former instead of the latter.

For obvious reasons mixing units won't work compile-time, but will at run-time.

You can force the latter by using unquote, a SCSS function.

.selector { height: unquote("-webkit-calc(100% - 40px)"); }

How to change cursor from pointer to finger using jQuery?

How do you change your cursor to the finger (like for clicking on links) instead of the regular pointer?

This is very simple to achieve using the CSS property cursor, no jQuery needed.

You can read more about in: CSS cursor property and cursor - CSS | MDN

_x000D_
_x000D_
.default {_x000D_
  cursor: default;_x000D_
}_x000D_
.pointer {_x000D_
  cursor: pointer;_x000D_
}
_x000D_
<a class="default" href="#">default</a>_x000D_
_x000D_
<a class="pointer" href="#">pointer</a>
_x000D_
_x000D_
_x000D_

Get each line from textarea

$content = $_POST['content_name'];
$lines = explode("\n", $content);

foreach( $lines as $index => $line )
{
    $lines[$index] = $line . '<br/>';
}

// $lines contains your lines

Center Contents of Bootstrap row container

For Bootstrap 4, use the below code:

<div class="mx-auto" style="width: 200px;">
  Centered element
</div>

Ref: https://getbootstrap.com/docs/4.0/utilities/spacing/#horizontal-centering

Open a local HTML file using window.open in Chrome

window.location.href = 'file://///fileserver/upload/Old_Upload/05_06_2019/THRESHOLD/BBH/Look/chrs/Delia';

Nothing Worked for me.

Running windows shell commands with python

Refactoring of @srini-beerge's answer which gets the output and the return code

import subprocess
def run_win_cmd(cmd):
    result = []
    process = subprocess.Popen(cmd,
                               shell=True,
                               stdout=subprocess.PIPE,
                               stderr=subprocess.PIPE)
    for line in process.stdout:
        result.append(line)
    errcode = process.returncode
    for line in result:
        print(line)
    if errcode is not None:
        raise Exception('cmd %s failed, see above for details', cmd)

How to use '-prune' option of 'find' in sh?

Normally the native way we do things in linux and the way we think is from left to right.
So you would go and write what you are looking for first:

find / -name "*.php"

Then you probably hit enter and realize you are getting too many files from directories you wish not to. Let's exclude /media to avoid searching your mounted drives.
You should now just APPEND the following to the previous command:

-print -o -path '/media' -prune

so the final command is:

find / -name "*.php" -print -o -path '/media' -prune

...............|<--- Include --->|....................|<---------- Exclude --------->|

I think this structure is much easier and correlates to the right approach

Find a value anywhere in a database

It's my way to resolve this question. Tested on SQLServer2008R2

CREATE PROC SearchAllTables
@SearchStr nvarchar(100)
AS
BEGIN
DECLARE @dml nvarchar(max) = N''        
IF OBJECT_ID('tempdb.dbo.#Results') IS NOT NULL DROP TABLE dbo.#Results
CREATE TABLE dbo.#Results
 ([tablename] nvarchar(100), 
  [ColumnName] nvarchar(100), 
  [Value] nvarchar(max))  
SELECT @dml += ' SELECT ''' + s.name + '.' + t.name + ''' AS [tablename], ''' + 
                c.name + ''' AS [ColumnName], CAST(' + QUOTENAME(c.name) + 
               ' AS nvarchar(max)) AS [Value] FROM ' + QUOTENAME(s.name) + '.' + QUOTENAME(t.name) +
               ' (NOLOCK) WHERE CAST(' + QUOTENAME(c.name) + ' AS nvarchar(max)) LIKE ' + '''%' + @SearchStr + '%'''
FROM sys.schemas s JOIN sys.tables t ON s.schema_id = t.schema_id
                   JOIN sys.columns c ON t.object_id = c.object_id
                   JOIN sys.types ty ON c.system_type_id = ty.system_type_id AND c .user_type_id = ty .user_type_id
WHERE t.is_ms_shipped = 0 AND ty.name NOT IN ('timestamp', 'image', 'sql_variant')

INSERT dbo.#Results
EXEC sp_executesql @dml

SELECT *
FROM dbo.#Results
END

Executing multiple SQL queries in one statement with PHP

Pass 65536 to mysql_connect as 5th parameter.

Example:

$conn = mysql_connect('localhost','username','password', true, 65536 /* here! */) 
    or die("cannot connect");
mysql_select_db('database_name') or die("cannot use database");
mysql_query("
    INSERT INTO table1 (field1,field2) VALUES(1,2);

    INSERT INTO table2 (field3,field4,field5) VALUES(3,4,5);

    DELETE FROM table3 WHERE field6 = 6;

    UPDATE table4 SET field7 = 7 WHERE field8 = 8;

    INSERT INTO table5
       SELECT t6.field11, t6.field12, t7.field13
       FROM table6 t6
       INNER JOIN table7 t7 ON t7.field9 = t6.field10;

    -- etc
");

When you are working with mysql_fetch_* or mysql_num_rows, or mysql_affected_rows, only the first statement is valid.

For example, the following codes, the first statement is INSERT, you cannot execute mysql_num_rows and mysql_fetch_*. It is okay to use mysql_affected_rows to return how many rows inserted.

$conn = mysql_connect('localhost','username','password', true, 65536) or die("cannot connect");
mysql_select_db('database_name') or die("cannot use database");
mysql_query("
    INSERT INTO table1 (field1,field2) VALUES(1,2);
    SELECT * FROM table2;
");

Another example, the following codes, the first statement is SELECT, you cannot execute mysql_affected_rows. But you can execute mysql_fetch_assoc to get a key-value pair of row resulted from the first SELECT statement, or you can execute mysql_num_rows to get number of rows based on the first SELECT statement.

$conn = mysql_connect('localhost','username','password', true, 65536) or die("cannot connect");
mysql_select_db('database_name') or die("cannot use database");
mysql_query("
    SELECT * FROM table2;
    INSERT INTO table1 (field1,field2) VALUES(1,2);
");

What is "entropy and information gain"?

I really recommend you read about Information Theory, bayesian methods and MaxEnt. The place to start is this (freely available online) book by David Mackay:

http://www.inference.phy.cam.ac.uk/mackay/itila/

Those inference methods are really far more general than just text mining and I can't really devise how one would learn how to apply this to NLP without learning some of the general basics contained in this book or other introductory books on Machine Learning and MaxEnt bayesian methods.

The connection between entropy and probability theory to information processing and storing is really, really deep. To give a taste of it, there's a theorem due to Shannon that states that the maximum amount of information you can pass without error through a noisy communication channel is equal to the entropy of the noise process. There's also a theorem that connects how much you can compress a piece of data to occupy the minimum possible memory in your computer to the entropy of the process that generated the data.

I don't think it's really necessary that you go learning about all those theorems on communication theory, but it's not possible to learn this without learning the basics about what is entropy, how it's calculated, what is it's relationship with information and inference, etc...

Extract a single (unsigned) integer from a string

Depending on your use case, this might also be an option:

$str = 'In My Cart : 11 items';
$num = '';

for ($i = 0; $i < strlen($str); $i++) {

    if (is_numeric($str[$i])) {
        $num .= $str[$i];
    }
}

echo $num; // 11

Though I'd agree a regex or filter_var() would be more useful in the stated case.

implement addClass and removeClass functionality in angular2

If you want to due this in component.ts

HTML:

<button class="class1 class2" (click)="clicked($event)">Click me</button>

Component:

clicked(event) {
  event.target.classList.add('class3'); // To ADD
  event.target.classList.remove('class1'); // To Remove
  event.target.classList.contains('class2'); // To check
  event.target.classList.toggle('class4'); // To toggle
}

For more options, examples and browser compatibility visit this link.

What do $? $0 $1 $2 mean in shell script?

They are called the Positional Parameters.

3.4.1 Positional Parameters

A positional parameter is a parameter denoted by one or more digits, other than the single digit 0. Positional parameters are assigned from the shell’s arguments when it is invoked, and may be reassigned using the set builtin command. Positional parameter N may be referenced as ${N}, or as $N when N consists of a single digit. Positional parameters may not be assigned to with assignment statements. The set and shift builtins are used to set and unset them (see Shell Builtin Commands). The positional parameters are temporarily replaced when a shell function is executed (see Shell Functions).

When a positional parameter consisting of more than a single digit is expanded, it must be enclosed in braces.

Infinite Recursion with Jackson JSON and Hibernate JPA issue

This worked perfectly fine for me. Add the annotation @JsonIgnore on the child class where you mention the reference to the parent class.

@ManyToOne
@JoinColumn(name = "ID", nullable = false, updatable = false)
@JsonIgnore
private Member member;

Why ModelState.IsValid always return false in mvc

As Brad Wilson states in his answer here:

ModelState.IsValid tells you if any model errors have been added to ModelState.

The default model binder will add some errors for basic type conversion issues (for example, passing a non-number for something which is an "int"). You can populate ModelState more fully based on whatever validation system you're using.

Try using :-

if (!ModelState.IsValid)
{
    var errors = ModelState.SelectMany(x => x.Value.Errors.Select(z => z.Exception));

    // Breakpoint, Log or examine the list with Exceptions.
}

If it helps catching you the error. Courtesy this and this

omp parallel vs. omp parallel for

Here is example of using separated parallel and for here. In short it can be used for dynamic allocation of OpenMP thread-private arrays before executing for cycle in several threads. It is impossible to do the same initializing in parallel for case.

UPD: In the question example there is no difference between single pragma and two pragmas. But in practice you can make more thread aware behavior with separated parallel and for directives. Some code for example:

#pragma omp parallel
{ 
    double *data = (double*)malloc(...); // this data is thread private

    #pragma omp for
    for(1...100) // first parallelized cycle
    {
    }

    #pragma omp single 
    {} // make some single thread processing

    #pragma omp for // second parallelized cycle
    for(1...100)
    {
    }

    #pragma omp single 
    {} // make some single thread processing again

    free(data); // free thread private data
}

How to set default values for Angular 2 component properties?

That is interesting subject. You can play around with two lifecycle hooks to figure out how it works: ngOnChanges and ngOnInit.

Basically when you set default value to Input that's mean it will be used only in case there will be no value coming on that component. And the interesting part it will be changed before component will be initialized.

Let's say we have such components with two lifecycle hooks and one property coming from input.

@Component({
  selector: 'cmp',
})
export class Login implements OnChanges, OnInit {
  @Input() property: string = 'default';

  ngOnChanges(changes) {
    console.log('Changed', changes.property.currentValue, changes.property.previousValue);
  }

  ngOnInit() {
    console.log('Init', this.property);
  }

}

Situation 1

Component included in html without defined property value

As result we will see in console: Init default

That's mean onChange was not triggered. Init was triggered and property value is default as expected.

Situation 2

Component included in html with setted property <cmp [property]="'new value'"></cmp>

As result we will see in console:

Changed new value Object {}

Init new value

And this one is interesting. Firstly was triggered onChange hook, which setted property to new value, and previous value was empty object! And only after that onInit hook was triggered with new value of property.

HTML/CSS--Creating a banner/header

Remove the z-index value.

I would also recommend this approach.

HTML:

<header class="main-header" role="banner">
  <img src="mybannerimage.gif" alt="Banner Image"/>
</header>

CSS:

.main-header {
  text-align: center;
}

This will center your image with out stretching it out. You can adjust the padding as needed to give it some space around your image. Since this is at the top of your page you don't need to force it there with position absolute unless you want your other elements to go underneath it. In that case you'd probably want position:fixed; anyway.

Not equal string

It should be this:

if (myString!="-1")
{
//Do things
}

Your equals and exclamation are the wrong way round.

How to print the array?

It looks like you have a typo on your array, it should read:

int my_array[3][3] = {...

You don't have the _ or the {.

Also my_array[3][3] is an invalid location. Since computers begin counting at 0, you are accessing position 4. (Arrays are weird like that).

If you want just the last element:

printf("%d\n", my_array[2][2]);

If you want the entire array:

for(int i = 0; i < my_array.length; i++) {
  for(int j = 0; j < my_array[i].length; j++)
    printf("%d ", my_array[i][j]);
  printf("\n");
}

How to resume Fragment from BackStack if exists

Easier solution will be changing this line

ft.replace(R.id.content_frame, A); to ft.add(R.id.content_frame, A);

And inside your XML layout please use

  android:background="@color/white"
  android:clickable="true"
  android:focusable="true"

Clickable means that it can be clicked by a pointer device or be tapped by a touch device.

Focusable means that it can gain the focus from an input device like a keyboard. Input devices like keyboards cannot decide which view to send its input events to based on the inputs itself, so they send them to the view that has focus.

Node.js EACCES error when listening on most ports

This means the port is used somewhere else. so, you need to try another one or stop using the old port.

Float right and position absolute doesn't work together

I was able to absolutely position a right-floated element with one layer of nesting and a tricky margin:

_x000D_
_x000D_
function test() {_x000D_
  document.getElementById("box").classList.toggle("hide");_x000D_
}
_x000D_
.right {_x000D_
  float:right;_x000D_
}_x000D_
#box {_x000D_
  position:absolute; background:#feb;_x000D_
  width:20em; margin-left:-20em; padding:1ex;_x000D_
}_x000D_
#box.hide {_x000D_
  display:none;_x000D_
}
_x000D_
<div>_x000D_
  <div class="right">_x000D_
    <button onclick="test()">box</button>_x000D_
    <div id="box">Lorem ipsum dolor sit amet, consectetur adipiscing elit,_x000D_
      sed do eiusmod tempor incididunt ut labore et dolore magna aliqua._x000D_
      Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris_x000D_
      nisi ut aliquip ex ea commodo consequat._x000D_
    </div>_x000D_
  </div>_x000D_
  <p>_x000D_
    Lorem ipsum dolor sit amet, consectetur adipiscing elit,_x000D_
    sed do eiusmod tempor incididunt ut labore et dolore magna aliqua._x000D_
    Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris_x000D_
    nisi ut aliquip ex ea commodo consequat._x000D_
  </p>_x000D_
</div>
_x000D_
_x000D_
_x000D_

I decided to make this toggleable so you can see how it does not affect the flow of the surrounding text (run it and press the button to show/hide the floated absolute box).

How to get Bitmap from an Uri?

This is the easiest solution:

Bitmap bitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), uri);

Python: instance has no attribute

Your class doesn't have a __init__(), so by the time it's instantiated, the attribute atoms is not present. You'd have to do C.setdata('something') so C.atoms becomes available.

>>> C = Residues()
>>> C.atoms.append('thing')

Traceback (most recent call last):
  File "<pyshell#84>", line 1, in <module>
    B.atoms.append('thing')
AttributeError: Residues instance has no attribute 'atoms'

>>> C.setdata('something')
>>> C.atoms.append('thing')   # now it works
>>> 

Unlike in languages like Java, where you know at compile time what attributes/member variables an object will have, in Python you can dynamically add attributes at runtime. This also implies instances of the same class can have different attributes.

To ensure you'll always have (unless you mess with it down the line, then it's your own fault) an atoms list you could add a constructor:

def __init__(self):
    self.atoms = []

Parse (split) a string in C++ using string delimiter (standard C++)

std::vector<std::string> parse(std::string str,std::string delim){
    std::vector<std::string> tokens;
    char *str_c = strdup(str.c_str()); 
    char* token = NULL;

    token = strtok(str_c, delim.c_str()); 
    while (token != NULL) { 
        tokens.push_back(std::string(token));  
        token = strtok(NULL, delim.c_str()); 
    }

    delete[] str_c;

    return tokens;
}

builtins.TypeError: must be str, not bytes

Convert binary file to base64 & vice versa. Prove in python 3.5.2

import base64

read_file = open('/tmp/newgalax.png', 'rb')
data = read_file.read()

b64 = base64.b64encode(data)

print (b64)

# Save file
decode_b64 = base64.b64decode(b64)
out_file = open('/tmp/out_newgalax.png', 'wb')
out_file.write(decode_b64)

# Test in python 3.5.2

Check if string is in a pandas dataframe

a['Names'].str.contains('Mel') will return an indicator vector of boolean values of size len(BabyDataSet)

Therefore, you can use

mel_count=a['Names'].str.contains('Mel').sum()
if mel_count>0:
    print ("There are {m} Mels".format(m=mel_count))

Or any(), if you don't care how many records match your query

if a['Names'].str.contains('Mel').any():
    print ("Mel is there")