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Some Of The Best Answers From Latest Asked Questions

Show loading gif after clicking form submit using jQuery

The show() method only affects the display CSS setting. If you want to set the visibility you need to do it directly. Also, the .load_button element is a button and does not raise a submit event. You would need to change your selector to the form for that to work:

$('#login_form').submit(function() {
    $('#gif').css('visibility', 'visible');
});

Also note that return true; is redundant in your logic, so it can be removed.

Python3: ImportError: No module named '_ctypes' when using Value from module multiprocessing

Installing libffi-dev and re-installing python3.7 fixed the problem for me.

to cleanly build py 3.7 libffi-dev is required or else later stuff will fail

If using RHEL/Fedora:

yum install libffi-devel

or

sudo dnf install libffi-devel

If using Debian/Ubuntu:

sudo apt-get install libffi-dev

How to fix request failed on channel 0

This is what which helped me from the various answers provided.

  • Try logging in as root, that will get you in most of the times
  • Try logging in as a different user, it successful, it means that the problem is with a specific account & it implies that there are some process(es) already started by the problematic account which are consuming resources preventing login(most likely no of processes)
  • Increase the limit in /etc/security/limits.d/20-nproc.conf as mentioned by xmduhan above
  • Try to ssh again, it should work

Eclipse: Java was started but returned error code=13

This is often caused by the (accidental) removal of the JRE folder that is set in the Eclipse configuration. You can try following these instructions from the Eclipse wiki on how to configure the eclipse.ini file to include the the JRE location, or alternatively, launch eclipse from the command prompt using VM arguments. I have tried them both myself and in my opinion, the command prompt option works much better.

Once you are able to launch Eclipse, make sure you verify the installed JRE location under Java --> Installed JREs in the Preferences window.

Move seaborn plot legend to a different position?

If you wish to customize your legend, just use the add_legend method. It takes the same parameters as matplotlib plt.legend.

import seaborn as sns
sns.set(style="whitegrid")

titanic = sns.load_dataset("titanic")

g = sns.factorplot("class", "survived", "sex",
                    data=titanic, kind="bar",
                    size=6, palette="muted",
                   legend_out=False)
g.despine(left=True)
g.set_ylabels("survival probability")
g.add_legend(bbox_to_anchor=(1.05, 0), loc=2, borderaxespad=0.)

pandas groupby sort descending order

Other instance of preserving the order or sort by descending:

In [97]: import pandas as pd                                                                                                    

In [98]: df = pd.DataFrame({'name':['A','B','C','A','B','C','A','B','C'],'Year':[2003,2002,2001,2003,2002,2001,2003,2002,2001]})

#### Default groupby operation:
In [99]: for each in df.groupby(["Year"]): print each                                                                           
(2001,    Year name
2  2001    C
5  2001    C
8  2001    C)
(2002,    Year name
1  2002    B
4  2002    B
7  2002    B)
(2003,    Year name
0  2003    A
3  2003    A
6  2003    A)

### order preserved:
In [100]: for each in df.groupby(["Year"], sort=False): print each                                                               
(2003,    Year name
0  2003    A
3  2003    A
6  2003    A)
(2002,    Year name
1  2002    B
4  2002    B
7  2002    B)
(2001,    Year name
2  2001    C
5  2001    C
8  2001    C)

In [106]: df.groupby(["Year"], sort=False).apply(lambda x: x.sort_values(["Year"]))                        
Out[106]: 
        Year name
Year             
2003 0  2003    A
     3  2003    A
     6  2003    A
2002 1  2002    B
     4  2002    B
     7  2002    B
2001 2  2001    C
     5  2001    C
     8  2001    C

In [107]: df.groupby(["Year"], sort=False).apply(lambda x: x.sort_values(["Year"])).reset_index(drop=True)
Out[107]: 
   Year name
0  2003    A
1  2003    A
2  2003    A
3  2002    B
4  2002    B
5  2002    B
6  2001    C
7  2001    C
8  2001    C

R - " missing value where TRUE/FALSE needed "

check the command : NA!=NA : you'll get the result NA, hence the error message.

You have to use the function is.na for your ifstatement to work (in general, it is always better to use this function to check for NA values) :

comments = c("no","yes",NA)
for (l in 1:length(comments)) {
    if (!is.na(comments[l])) print(comments[l])
}
[1] "no"
[1] "yes"

Matplotlib legends in subplot

What you want cannot be done, because plt.legend() places a legend in the current axes, in your case in the last one.

If, on the other hand, you can be content with placing a comprehensive legend in the last subplot, you can do like this

f, (ax1, ax2, ax3) = plt.subplots(3, sharex=True, sharey=True)
l1,=ax1.plot(x,y, color='r', label='Blue stars')
l2,=ax2.plot(x,y, color='g')
l3,=ax3.plot(x,y, color='b')
ax1.set_title('2012/09/15')
plt.legend([l1, l2, l3],["HHZ 1", "HHN", "HHE"])
plt.show()

enter image description here

Note that you pass to legend not the axes, as in your example code, but the lines as returned by the plot invocation.

PS

Of course you can invoke legend after each subplot, but in my understanding you already knew that and were searching for a method for doing it at once.

socket connect() vs bind()

The one liner : bind() to own address, connect() to remote address.

Quoting from the man page of bind()

bind() assigns the address specified by addr to the socket referred to by the file descriptor sockfd. addrlen specifies the size, in bytes, of the address structure pointed to by addr. Traditionally, this operation is called "assigning a name to a socket".

and, from the same for connect()

The connect() system call connects the socket referred to by the file descriptor sockfd to the address specified by addr.

To clarify,

  • bind() associates the socket with its local address [that's why server side binds, so that clients can use that address to connect to server.]
  • connect() is used to connect to a remote [server] address, that's why is client side, connect [read as: connect to server] is used.

How to determine tables size in Oracle

Here is a query, you can run it in SQL Developer (or SQL*Plus):

SELECT DS.TABLESPACE_NAME, SEGMENT_NAME, ROUND(SUM(DS.BYTES) / (1024 * 1024)) AS MB
  FROM DBA_SEGMENTS DS
  WHERE SEGMENT_NAME IN (SELECT TABLE_NAME FROM DBA_TABLES)
 GROUP BY DS.TABLESPACE_NAME,
       SEGMENT_NAME;

How can I fix the 'Missing Cross-Origin Resource Sharing (CORS) Response Header' webfont issue?

If you are just interested in the use of Access-Control-Allow-Origin:*

You can do that with this .htaccess file at the site root.

Header set Access-Control-Allow-Origin "*"

Some useful information here: http://enable-cors.org/server_apache.html

Python find min max and average of a list (array)

from __future__ import division

somelist =  [1,12,2,53,23,6,17] 
max_value = max(somelist)
min_value = min(somelist)
avg_value = 0 if len(somelist) == 0 else sum(somelist)/len(somelist)

If you want to manually find the minimum as a function:

somelist =  [1,12,2,53,23,6,17] 

def my_min_function(somelist):
    min_value = None
    for value in somelist:
        if not min_value:
            min_value = value
        elif value < min_value:
            min_value = value
    return min_value

Python 3.4 introduced the statistics package, which provides mean and additional stats:

from statistics import mean, median

somelist =  [1,12,2,53,23,6,17]
avg_value = mean(somelist)
median_value = median(somelist)

Calculate days between two Dates in Java 8

Use the DAYS in enum java.time.temporal.ChronoUnit . Below is the Sample Code :

Output : *Number of days between the start date : 2015-03-01 and end date : 2016-03-03 is ==> 368. **Number of days between the start date : 2016-03-03 and end date : 2015-03-01 is ==> -368*

package com.bitiknow.date;

import java.time.LocalDate;
import java.time.temporal.ChronoUnit;

/**
 * 
 * @author pradeep
 *
 */
public class LocalDateTimeTry {
    public static void main(String[] args) {

        // Date in String format.
        String dateString = "2015-03-01";

        // Converting date to Java8 Local date
        LocalDate startDate = LocalDate.parse(dateString);
        LocalDate endtDate = LocalDate.now();
        // Range = End date - Start date
        Long range = ChronoUnit.DAYS.between(startDate, endtDate);
        System.out.println("Number of days between the start date : " + dateString + " and end date : " + endtDate
                + " is  ==> " + range);

        range = ChronoUnit.DAYS.between(endtDate, startDate);
        System.out.println("Number of days between the start date : " + endtDate + " and end date : " + dateString
                + " is  ==> " + range);

    }

}

How can I execute Python scripts using Anaconda's version of Python?

don't know windows 8 but you can probably set the default prog for a specific extension, for example on windows 7 you do right click => open with, then you select the prog you want and select 'use this prog as default', or you can remove your old version of python from your path and add the one of the anaconda

How can I return the difference between two lists?

First convert list to sets.

// create an empty set 
Set<T> set = new HashSet<>(); 

// Add each element of list into the set 
for (T t : list) 
    set.add(t); 

You can use Sets.difference(Set1, Set2), which returns extra items present in Set1.
You can use Sets.difference(Set2, Set1), which returns extra items present in Set2.

What steps are needed to stream RTSP from FFmpeg?

An alternative that I used instead of FFServer was Red5 Pro, on Ubuntu, I used this line: ffmpeg -f pulse -i default -f video4linux2 -thread_queue_size 64 -framerate 25 -video_size 640x480 -i /dev/video0 -pix_fmt yuv420p -bsf:v h264_mp4toannexb -profile:v baseline -level:v 3.2 -c:v libx264 -x264-params keyint=120:scenecut=0 -c:a aac -b:a 128k -ar 44100 -f rtsp -muxdelay 0.1 rtsp://localhost:8554/live/paul

How to get Toolbar from fragment?

From your Fragment: ( get Toolbar from fragment?)

// get toolbar
((MainAcivity)this.getActivity()).getToolbar();  // getToolbar will be method in Activity that returns Toolbar!!  don't use getSupportActionBar for getting toolbar!!
// get action bar
this.getActivity().getSupportActionBar();

this is very helpful when you are using spinner in Toolbar and call the spinner or custom views in Toolbar from a fragment!

From your Activity:

// get toolbar
this.getToolbar();
// get Action Bar
this.getSupportActionBar();

Google Chrome: This setting is enforced by your administrator

Actually, I've got a bit more precise solution, which might be useful if you don't want to change/delete anything else.

Run regedit, and at the HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Chrome key you should have a PasswordManagerEnabled property, which probably is set to 0.

Simply change it to 1.

Edit: I tried it on some other computer and it didn't want to work, so I rebooted my computer, made sure Chrome is closed, then changed it in the registry, and finally it worked. So make sure Chrome is closed when you do this.

How can you test if an object has a specific property?

Just check against null.

($myObject.MyProperty -ne $null)

If you have not set PowerShell to StrictMode, this works even if the property does not exist:

$obj = New-Object PSObject;                                                   
Add-Member -InputObject $obj -MemberType NoteProperty -Name Foo -Value "Bar";
$obj.Foo; # Bar                                                                  
($obj.MyProperty -ne $null);  # False, no exception

Ignoring upper case and lower case in Java

You have to use the String method .toLowerCase() or .toUpperCase() on both the input and the string you are trying to match it with.

Example:

public static void findPatient() {
    System.out.print("Enter part of the patient name: ");
    String name = sc.nextLine();

    System.out.print(myPatientList.showPatients(name));
}

//the other class
ArrayList<String> patientList;

public void showPatients(String name) {
    boolean match = false;

    for(String matchingname : patientList) {
        if (matchingname.toLowerCase().contains(name.toLowerCase())) {
            match = true;
        }
    }
}

Set proxy through windows command line including login parameters

IE can set username and password proxies, so maybe setting it there and import does work

reg add "HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings" /v ProxyEnable /t REG_DWORD /d 1
reg add "HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings" /v ProxyServer /t REG_SZ /d name:port
reg add "HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings" /v ProxyUser /t REG_SZ /d username
reg add "HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings" /v ProxyPass /t REG_SZ /d password
netsh winhttp import proxy source=ie

Calculate time difference in minutes in SQL Server

Try this..

select starttime,endtime, case
  when DATEDIFF(minute,starttime,endtime) < 60  then DATEDIFF(minute,starttime,endtime) 
  when DATEDIFF(minute,starttime,endtime) >= 60
  then '60,'+ cast( (cast(DATEDIFF(minute,starttime,endtime) as int )-60) as nvarchar(50) )
end from TestTable123416

All You need is DateDiff..

Best way to find os name and version in Unix/Linux platform

With and Linux::Distribution, the cleanest solution for an old problem :

#!/bin/sh

perl -e '
    use Linux::Distribution qw(distribution_name distribution_version);

    my $linux = Linux::Distribution->new;
    if(my $distro = $linux->distribution_name()) {
          my $version = $linux->distribution_version();
          print "you are running $distro";
          print " version $version" if $version;
          print "\n";
    } else {
          print "distribution unknown\n";
    }
'

Play multiple CSS animations at the same time

In case anyone new is coming along and catching this thread, you can specify multiple animations--each with their own properties--with a comma.

Example:

animation: rotate 1s, spin 3s;

Meaning of end='' in the statement print("\t",end='')?

The default value of end is \n meaning that after the print statement it will print a new line. So simply stated end is what you want to be printed after the print statement has been executed

Eg: - print ("hello",end=" +") will print hello +

An error when I add a variable to a string

You have empty $entry_database variable. As you see in error: ListEmail, Title FROM WHERE ID bewteen FROM and WHERE should be name of table. Proper syntax of SELECT:

SELECT columns FROM table [optional things as WHERE/ORDER/GROUP/JOIN etc]

which in your way should become:

SELECT ID, ListStID, ListEmail, Title FROM some_table_you_got WHERE ID = '4'

Error:Unable to locate adb within SDK in Android Studio

You can download from terminal or cmd like this:

$sudo apt update 
$sudo apt install android-tools-adb android-tools-fastboot

//check version or test adb is running or not
$adb version

If you can decode JWT, how are they secure?

Ref - JWT Structure and Security

It is important to note that JWT are used for authorization and not authentication. So a JWT will be created for you only after you have been authenticated by the server by may be specifying the credentials. Once JWT has been created for all future interactions with server JWT can be used. So JWT tells that server that this user has been authenticated, let him access the particular resource if he has the role.
Information in the payload of the JWT is visible to everyone. There can be a "Man in the Middle" attack and the contents of the JWT can be changed. So we should not pass any sensitive information like passwords in the payload. We can encrypt the payload data if we want to make it more secure. If Payload is tampered with server will recognize it.
So suppose a user has been authenticated and provided with a JWT. Generated JWT has a claim specifying role of Admin. Also the Signature is generated with

enter image description here

This JWT is now tampered with and suppose the role is changed to Super Admin
Then when the server receives this token it will again generate the signature using the secret key(which only the server has) and the payload. It will not match the signature in the JWT. So the server will know that the JWT has been tampered with.

How to load local file in sc.textFile, instead of HDFS

This has been discussed into spark mailing list, and please refer this mail.

You should use hadoop fs -put <localsrc> ... <dst> copy the file into hdfs:

${HADOOP_COMMON_HOME}/bin/hadoop fs -put /path/to/README.md README.md

Read file from aws s3 bucket using node fs

I had exactly the same issue when downloading from S3 very large files.

The example solution from AWS docs just does not work:

var file = fs.createWriteStream(options.filePath);
        file.on('close', function(){
            if(self.logger) self.logger.info("S3Dataset file download saved to %s", options.filePath );
            return callback(null,done);
        });
        s3.getObject({ Key:  documentKey }).createReadStream().on('error', function(err) {
            if(self.logger) self.logger.error("S3Dataset download error key:%s error:%@", options.fileName, error);
            return callback(error);
        }).pipe(file);

While this solution will work:

    var file = fs.createWriteStream(options.filePath);
    s3.getObject({ Bucket: this._options.s3.Bucket, Key: documentKey })
    .on('error', function(err) {
        if(self.logger) self.logger.error("S3Dataset download error key:%s error:%@", options.fileName, error);
        return callback(error);
    })
    .on('httpData', function(chunk) { file.write(chunk); })
    .on('httpDone', function() { 
        file.end(); 
        if(self.logger) self.logger.info("S3Dataset file download saved to %s", options.filePath );
        return callback(null,done);
    })
    .send();

The createReadStream attempt just does not fire the end, close or error callback for some reason. See here about this.

I'm using that solution also for writing down archives to gzip, since the first one (AWS example) does not work in this case either:

        var gunzip = zlib.createGunzip();
        var file = fs.createWriteStream( options.filePath );

        s3.getObject({ Bucket: this._options.s3.Bucket, Key: documentKey })
        .on('error', function (error) {
            if(self.logger) self.logger.error("%@",error);
            return callback(error);
        })
        .on('httpData', function (chunk) {
            file.write(chunk);
        })
        .on('httpDone', function () {

            file.end();

            if(self.logger) self.logger.info("downloadArchive downloaded %s", options.filePath);

            fs.createReadStream( options.filePath )
            .on('error', (error) => {
                return callback(error);
            })
            .on('end', () => {
                if(self.logger) self.logger.info("downloadArchive unarchived %s", options.fileDest);
                return callback(null, options.fileDest);
            })
            .pipe(gunzip)
            .pipe(fs.createWriteStream(options.fileDest))
        })
        .send();

How To Pass GET Parameters To Laravel From With GET Method ?

Router

Route::get('search/{id}', ['as' => 'search', 'uses' => 'SearchController@search']);

Controller

class SearchController extends BaseController {

    public function search(Request $request){

        $id= $request->id ; // or any params

        ...
    }
}

Concatenate strings from several rows using Pandas groupby

For me the above solutions were close but added some unwanted /n's and dtype:object, so here's a modified version:

df.groupby(['name', 'month'])['text'].apply(lambda text: ''.join(text.to_string(index=False))).str.replace('(\\n)', '').reset_index()

Google reCAPTCHA: How to get user response and validate in the server side?

Here is complete demo code to understand client side and server side process. you can copy paste it and just replace google site key and google secret key.

<?php 
if(!empty($_REQUEST))
{
      //  echo '<pre>'; print_r($_REQUEST); die('END');
        $post = [
            'secret' => 'Your Secret key',
            'response' => $_REQUEST['g-recaptcha-response'],
        ];
        $ch = curl_init();

        curl_setopt($ch, CURLOPT_URL,"https://www.google.com/recaptcha/api/siteverify");
        curl_setopt($ch, CURLOPT_POST, 1);
        curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($post));
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

        $server_output = curl_exec($ch);

        curl_close ($ch);
        echo '<pre>'; print_r($server_output); die('ss');
}
?>
<html>
  <head>
    <title>reCAPTCHA demo: Explicit render for multiple widgets</title>
    <script type="text/javascript">
      var site_key = 'Your Site key';
      var verifyCallback = function(response) {
        alert(response);
      };
      var widgetId1;
      var widgetId2;
      var onloadCallback = function() {
        // Renders the HTML element with id 'example1' as a reCAPTCHA widget.
        // The id of the reCAPTCHA widget is assigned to 'widgetId1'.
        widgetId1 = grecaptcha.render('example1', {
          'sitekey' : site_key,
          'theme' : 'light'
        });
        widgetId2 = grecaptcha.render(document.getElementById('example2'), {
          'sitekey' : site_key
        });
        grecaptcha.render('example3', {
          'sitekey' : site_key,
          'callback' : verifyCallback,
          'theme' : 'dark'
        });
      };
    </script>
  </head>
  <body>
    <!-- The g-recaptcha-response string displays in an alert message upon submit. -->
    <form action="javascript:alert(grecaptcha.getResponse(widgetId1));">
      <div id="example1"></div>
      <br>
      <input type="submit" value="getResponse">
    </form>
    <br>
    <!-- Resets reCAPTCHA widgetId2 upon submit. -->
    <form action="javascript:grecaptcha.reset(widgetId2);">
      <div id="example2"></div>
      <br>
      <input type="submit" value="reset">
    </form>
    <br>
    <!-- POSTs back to the page's URL upon submit with a g-recaptcha-response POST parameter. -->
    <form action="?" method="POST">
      <div id="example3"></div>
      <br>
      <input type="submit" value="Submit">
    </form>
    <script src="https://www.google.com/recaptcha/api.js?onload=onloadCallback&render=explicit"
        async defer>
    </script>
  </body>
</html>

Creating self signed certificate for domain and subdomains - NET::ERR_CERT_COMMON_NAME_INVALID

I think it may be a bug in chrome. There was a similar issue long back: See this.

Try in a different browser. I think it should work fine.

How does Google reCAPTCHA v2 work behind the scenes?

A new paper has been released with several tests against reCAPTCHA:

https://www.blackhat.com/docs/asia-16/materials/asia-16-Sivakorn-Im-Not-a-Human-Breaking-the-Google-reCAPTCHA-wp.pdf

Some highlights:

  • By keeping a cookie active for +9 days (by browsing sites with Google resources), you can then pass reCAPTCHA by only clicking the checkbox;
  • There are no restrictions based on requests per IP;
  • The browser's user agent must be real, and Google run tests against your environment to ensure it matches the user agent;
  • Google tests if the browser can render a Canvas;
  • Screen resolution and mouse events don't affect the results;

Google has already fixed the cookie vulnerability and is probably restricting some behaviors based on IPs.

Another interesting finding is that Google runs a VM in JavaScript that obfuscates much of reCAPTCHA code and behavior. This VM is known as botguard and is used to protect other services besides reCAPTCHA:

https://github.com/neuroradiology/InsideReCaptcha

UPDATE 2017

A recent paper (from August) was published on WOOT 2017 achieving 85% accuracy in solving noCAPTCHA reCAPTCHA audio challenges:

http://uncaptcha.cs.umd.edu/papers/uncaptcha_woot17.pdf

UPDATE 2018

Google is introducing reCAPTCHA v3, which looks like a "human score prediction engine" that is calibrated per website. It can be installed into different pages of a website (working like a Google Analytics script) to help reCAPTCHA and the website owner to understand the behaviour of humans vs. bots before filling a reCAPTCHA.

https://www.google.com/recaptcha/intro/v3beta.html

How do I dynamically set HTML5 data- attributes using react?

Note - if you want to pass a data attribute to a React Component, you need to handle them a little differently than other props.

2 options

Don't use camel case

<Option data-img-src='value' ... />

And then in the component, because of the dashes, you need to refer to the prop in quotes.

// @flow
class Option extends React.Component {

  props: {
    'data-img-src': string
  }

And when you refer to it later, you don't use the dot syntax

  render () {
    return (
      <option data-img-src={this.props['data-img-src']} >...</option>
    )
  }
}

Or use camel case

<Option dataImgSrc='value' ... />

And then in the component, you need to convert.

// @flow
class Option extends React.Component {

  props: {
    dataImgSrc: string
  }

And when you refer to it later, you don't use the dot syntax

  render () {
    return (
      <option data-img-src={this.props.dataImgSrc} >...</option>
    )
  }
}

Mainly just realize data- attributes and aria- attributes are treated specially. You are allowed to use hyphens in the attribute name in those two cases.

How do I resolve this "ORA-01109: database not open" error?

As the error states - the database is not open - it was previously shut down, and someone left it in the middle of the startup process. They may either be intentional, or unintentional (i.e., it was supposed to be open, but failed to do so).

Assuming that's nothing wrong with the database itself, you could open it with a simple statement:(Since the question is asked specifically in the context of SQLPlus, kindly remember to put a statement terminator(Semicolon) at the end mandatorily, otherwise, it will result in an error.)

ALTER DATABASE OPEN;

Unsupported operation :not writeable python

You open the variable "file" as a read only then attempt to write to it:

file = open('ValidEmails.txt','r')

Instead, use the 'w' flag.

file = open('ValidEmails.txt','w')
...
file.write(email)

Powershell get ipv4 address into a variable

# Patrick Burwell's Ping Script - [email protected] #
$Output= @() #sets an array
$names = Get-Content ".\input\ptd.pc_list.txt" #sets a list to use, like a DNS dump
foreach ($name in $names){ #sets the input by enumerating a text file to loop through and sets a variable to execute against 
  if ($IPV4 = Test-Connection -Delay 15 -ComputerName $name -Count 1 -ErrorAction SilentlyContinue|select IPV4Address #run ping and sets only IPV4Address response variable
  ){# If true then run...
   $Output+= $Name,($IPV4.IPV4Address).IPAddressToString # Fills the array with the #true response
   Write-Host $Name',','Ping,'($IPV4.IPV4Address).IPAddressToString -ForegroundColor Green #Sets the output to receive the Name, result and IPV4Address and prints the reply to the console with specific colors
  }
  else{#If false then run...
    $Output+= "$name," #Fills the array with the #false response
    Write-Host "$Name," -ForegroundColor Red #Prints the reply to the console with specific colors 
  }
}

#$Output | Out-file ".\output\result.csv" #<-- use to export to a text file (Set path as needed)
#$Output | Export-CSV ".\output\result.csv" -NoTypeInformation #<-- use to export to a csv file (Set path as needed)

#If you choose, you can merely have the reply by the name and IP, and the Name and no IP by removing the Ping comments

Adding a view controller as a subview in another view controller

Thanks to Rob. Adding detailed syntax for your second observation :

let controller:MyView = self.storyboard!.instantiateViewControllerWithIdentifier("MyView") as! MyView
controller.ANYPROPERTY=THEVALUE // If you want to pass value
controller.view.frame = self.view.bounds
self.view.addSubview(controller.view)
self.addChildViewController(controller)
controller.didMoveToParentViewController(self)

And to remove the viewcontroller :

self.willMoveToParentViewController(nil)
self.view.removeFromSuperview()
self.removeFromParentViewController() 

pandas: best way to select all columns whose names start with X

In my case I needed a list of prefixes

colsToScale=["production", "test", "development"]
dc[dc.columns[dc.columns.str.startswith(tuple(colsToScale))]]

How to use su command over adb shell?

for my use case, i wanted to grab the SHA1 hash from the magisk config file. the below worked for me.

adb shell "su -c "cat /sbin/.magisk/config | grep SHA | awk -F= '{ print $2 }'""

How to validate Google reCAPTCHA v3 on server side?

Private key safety

While the answers here are definately working, they are using a GET request, which exposes your private key (even though https is used). On Google Developers the specified method is POST.

For a little bit more detail: https://stackoverflow.com/a/323286/1680919

Verification via POST

function isValid() 
{
    try {

        $url = 'https://www.google.com/recaptcha/api/siteverify';
        $data = ['secret'   => '[YOUR SECRET KEY]',
                 'response' => $_POST['g-recaptcha-response'],
                 'remoteip' => $_SERVER['REMOTE_ADDR']];
                 
        $options = [
            'http' => [
                'header'  => "Content-type: application/x-www-form-urlencoded\r\n",
                'method'  => 'POST',
                'content' => http_build_query($data) 
            ]
        ];
    
        $context  = stream_context_create($options);
        $result = file_get_contents($url, false, $context);
        return json_decode($result)->success;
    }
    catch (Exception $e) {
        return null;
    }
}

Array Syntax: I use the "new" array syntax ( [ and ] instead of array(..) ). If your php version does not support this yet, you will have to edit those 3 array definitions accordingly (see comment).

Return Values: This function returns true if the user is valid, false if not, and null if an error occured. You can use it for example simply by writing if (isValid()) { ... }

Cannot install packages inside docker Ubuntu image

You need to update the package list in your Ubuntu:

$ sudo apt-get update
$ sudo apt-get install <package_name>

What does "collect2: error: ld returned 1 exit status" mean?

clrscr is not standard C function. According to internet, it used to be a thing in old Borland C.
Is clrscr(); a function in C++?

IE11 Document mode defaults to IE7. How to reset?

If the problem is happening on a specific computer,then please try the following fix provided you have Internet Explorer 11.

Please open regedit.exe as an Administrator. Navigate to the following path/paths:

  1. For 32 bit machine:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BROWSER_EMULATION
    
  2. For 64 bit machine:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BROWSER_EMULATION & 
    HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BROWSER_EMULATION
    

And delete the REG_DWORD value iexplore.exe.

Please close and relaunch the website using Internet Explorer 11, it will default to Edge as Document Mode.

how to create virtual host on XAMPP

<VirtualHost *:80>
    DocumentRoot "D:/projects/yourdirectry name"
    ServerName local.yourdomain.com
    <Directory "D:/projects/yourdirectry name">
        Require all granted 
    </Directory>
</VirtualHost>

Save the Apache configuration file.

for detailed info refer to this

No process is on the other end of the pipe (SQL Server 2012)

If you are trying to login with SQL credentials, you can also try changing the LoginMode for SQL Server in the registry to allow both SQL Server and Windows Authentication.

  1. Open regedit
  2. Go to the SQL instance key (may vary depending on your instance name): Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL14.SQLEXPRESS\MSSQLServer\
  3. Set LoginMode to 2

enter image description here

  1. Restart SQL service and SQL Server Management Studio and try again.

Pandas column of lists, create a row for each list element

you can also use pd.concat and pd.melt for this:

>>> objs = [df, pd.DataFrame(df['samples'].tolist())]
>>> pd.concat(objs, axis=1).drop('samples', axis=1)
   subject  trial_num     0     1     2
0        1          1 -0.49 -1.00  0.44
1        1          2 -0.28  1.48  2.01
2        1          3 -0.52 -1.84  0.02
3        2          1  1.23 -1.36 -1.06
4        2          2  0.54  0.18  0.51
5        2          3 -2.18 -0.13 -1.35
>>> pd.melt(_, var_name='sample_num', value_name='sample', 
...         value_vars=[0, 1, 2], id_vars=['subject', 'trial_num'])
    subject  trial_num sample_num  sample
0         1          1          0   -0.49
1         1          2          0   -0.28
2         1          3          0   -0.52
3         2          1          0    1.23
4         2          2          0    0.54
5         2          3          0   -2.18
6         1          1          1   -1.00
7         1          2          1    1.48
8         1          3          1   -1.84
9         2          1          1   -1.36
10        2          2          1    0.18
11        2          3          1   -0.13
12        1          1          2    0.44
13        1          2          2    2.01
14        1          3          2    0.02
15        2          1          2   -1.06
16        2          2          2    0.51
17        2          3          2   -1.35

last, if you need you can sort base on the first the first three columns.

Python: find position of element in array

In the NumPy array, you can use where like this:

np.where(npArray == 20)

Calling a phone number in swift

Swift 3, iOS 10

func call(phoneNumber:String) {
        let cleanPhoneNumber = phoneNumber.components(separatedBy: CharacterSet.decimalDigits.inverted).joined(separator: "")
        let urlString:String = "tel://\(cleanPhoneNumber)"
        if let phoneCallURL = URL(string: urlString) {
            if (UIApplication.shared.canOpenURL(phoneCallURL)) {
                UIApplication.shared.open(phoneCallURL, options: [:], completionHandler: nil)
            }
        }
  }

Is it possible to use vh minus pixels in a CSS calc()?

It does work indeed. Issue was with my less compiler. It was compiled in to:

.container {
  min-height: calc(-51vh);
}

Fixed with the following code in less file:

.container {
  min-height: calc(~"100vh - 150px");
}

Thanks to this link: Less Aggressive Compilation with CSS3 calc

Laravel Update Query

This error would suggest that User::where('email', '=', $userEmail)->first() is returning null, rather than a problem with updating your model.

Check that you actually have a User before attempting to change properties on it, or use the firstOrFail() method.

$UpdateDetails = User::where('email', $userEmail)->first();

if (is_null($UpdateDetails)) {
    return false;
}

or using the firstOrFail() method, theres no need to check if the user is null because this throws an exception (ModelNotFoundException) when a model is not found, which you can catch using App::error() http://laravel.com/docs/4.2/errors#handling-errors

$UpdateDetails = User::where('email', $userEmail)->firstOrFail();

How to subtract 30 days from the current date using SQL Server

TRY THIS:

Cast your VARCHAR value to DATETIME and add -30 for subtraction. Also, In sql-server the format Fri, 14 Nov 2014 23:03:35 GMT was not converted to DATETIME. Try substring for it:

SELECT DATEADD(dd, -30, 
       CAST(SUBSTRING ('Fri, 14 Nov 2014 23:03:35 GMT', 6, 21) 
       AS DATETIME))

How to open html file?

CODE:

import codecs

path="D:\\Users\\html\\abc.html" 
file=codecs.open(path,"rb")
file1=file.read()
file1=str(file1)

How do I execute .js files locally in my browser?

Around 1:51 in the video, notice how she puts a <script> tag in there? The way it works is like this:

Create an html file (that's just a text file with a .html ending) somewhere on your computer. In the same folder that you put index.html, put a javascript file (that's just a textfile with a .js ending - let's call it game.js). Then, in your index.html file, put some html that includes the script tag with game.js, like Mary did in the video. index.html should look something like this:

<html>
    <head>
        <script src="game.js"></script>
    </head>
</html>

Now, double click on that file in finder, and it should open it up in your browser. To open up the console to see the output of your javascript code, hit Command-alt-j (those three buttons at the same time).

Good luck on your journey, hope it's as fun for you as it has been for me so far :)

Sending a file over TCP sockets in Python

Client need to notify that it finished sending, using socket.shutdown (not socket.close which close both reading/writing part of the socket):

...
print "Done Sending"
s.shutdown(socket.SHUT_WR)
print s.recv(1024)
s.close()

UPDATE

Client sends Hello server! to the server; which is written to the file in the server side.

s.send("Hello server!")

Remove above line to avoid it.

variable is not declared it may be inaccessible due to its protection level

I have found that you have to comment out the namespace wrapping the the class at time when moving between version of Visual Studio:

'Namespace FormsAuth

'End Namespace

and at other times, I have to uncomment the namespace.

This happened to me several times when other developers edited the same solution using a different version of VS and/or I moved (copied) the solution to another location

Display curl output in readable JSON format in Unix shell script

Motivation: You want to print prettify JSON response after curl command request.

Solution: json_pp - commandline tool that converts between some input and output formats (one of them is JSON). This program was copied from json_xs and modified. The default input format is json and the default output format is json with pretty option.

Synposis: json_pp [-v] [-f from_format] [-t to_format] [-json_opt options_to_json1[,options_to_json2[,...]]]

Formula: <someCommand> | json_pp

Example:

Request

curl -X https://jsonplaceholder.typicode.com/todos/1 | json_pp 

Response

{
   "completed" : false,
   "id" : 1,
   "title" : "delectus aut autem",
   "userId" : 1
}

What does `ValueError: cannot reindex from a duplicate axis` mean?

I came across this error today when I wanted to add a new column like this

df_temp['REMARK_TYPE'] = df.REMARK.apply(lambda v: 1 if str(v)!='nan' else 0)

I wanted to process the REMARK column of df_temp to return 1 or 0. However I typed wrong variable with df. And it returned error like this:

----> 1 df_temp['REMARK_TYPE'] = df.REMARK.apply(lambda v: 1 if str(v)!='nan' else 0)

/usr/lib64/python2.7/site-packages/pandas/core/frame.pyc in __setitem__(self, key, value)
   2417         else:
   2418             # set column
-> 2419             self._set_item(key, value)
   2420 
   2421     def _setitem_slice(self, key, value):

/usr/lib64/python2.7/site-packages/pandas/core/frame.pyc in _set_item(self, key, value)
   2483 
   2484         self._ensure_valid_index(value)
-> 2485         value = self._sanitize_column(key, value)
   2486         NDFrame._set_item(self, key, value)
   2487 

/usr/lib64/python2.7/site-packages/pandas/core/frame.pyc in _sanitize_column(self, key, value, broadcast)
   2633 
   2634         if isinstance(value, Series):
-> 2635             value = reindexer(value)
   2636 
   2637         elif isinstance(value, DataFrame):

/usr/lib64/python2.7/site-packages/pandas/core/frame.pyc in reindexer(value)
   2625                     # duplicate axis
   2626                     if not value.index.is_unique:
-> 2627                         raise e
   2628 
   2629                     # other

ValueError: cannot reindex from a duplicate axis

As you can see it, the right code should be

df_temp['REMARK_TYPE'] = df_temp.REMARK.apply(lambda v: 1 if str(v)!='nan' else 0)

Because df and df_temp have a different number of rows. So it returned ValueError: cannot reindex from a duplicate axis.

Hope you can understand it and my answer can help other people to debug their code.

Correct way of getting Client's IP Addresses from http.Request

In PHP there are a lot of variables that I should check. Is it the same on Go?

This has nothing to do with Go (or PHP for that matter). It just depends on what the client, proxy, load-balancer, or server is sending. Get the one you need depending on your environment.

http.Request.RemoteAddr contains the remote IP address. It may or may not be your actual client.

And is the request case sensitive? for example x-forwarded-for is the same as X-Forwarded-For and X-FORWARDED-FOR? (from req.Header.Get("X-FORWARDED-FOR"))

No, why not try it yourself? http://play.golang.org/p/YMf_UBvDsH

How to decode a QR-code image in (preferably pure) Python?

I'm answering only the part of the question about zbar installation.

I spent nearly half an hour a few hours to make it work on Windows + Python 2.7 64-bit, so here are additional notes to the accepted answer:

PS: Making it work with Python 3.x is even more difficult: Compile zbar for Python 3.x.

PS2: I just tested pyzbar with pip install pyzbar and it's MUCH easier, it works out-of-the-box (the only thing is you need to have VC Redist 2013 files installed). It is also recommended to use this library in this pyimagesearch.com article.

Laravel, sync() - how to sync an array and also pass additional pivot fields?

Attaching / Detaching

Eloquent also provides a few additional helper methods to make working with related models more convenient. For example, let's imagine a user can have many roles and a role can have many users. To attach a role to a user by inserting a record in the intermediate table that joins the models, use the attach method:

$user = App\User::find(1);

$user->roles()->attach($roleId);

When attaching a relationship to a model, you may also pass an array of additional data to be inserted into the intermediate table:

$user->roles()->attach($roleId, ['expires' => $expires]);

You can also use Sync if you want to remove old roles and only keep the new ones you are attaching now

$user->roles()->sync([1 => ['expires' => $expires], 2 => ['expires' => $expires]);

The default behaviour can be changed by passing a 'false' as a second argument. This will attach the roles with ids 1,2,3 without affecting the existing roles.

In this mode sync behaves similar to the attach method.

$user->roles()->sync([1 => ['expires' => $expires], 2 => ['expires' => $expires], false);

Reference: https://laravel.com/docs/5.4/eloquent-relationships

Java 8 stream map on entry set

Question might be a little dated, but you could simply use AbstractMap.SimpleEntry<> as follows:

private Map<String, AttributeType> mapConfig(
    Map<String, String> input, String prefix) {
       int subLength = prefix.length();
       return input.entrySet()
          .stream()
          .map(e -> new AbstractMap.SimpleEntry<>(
               e.getKey().substring(subLength),
               AttributeType.GetByName(e.getValue()))
          .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));

any other Pair-like value object would work too (ie. ApacheCommons Pair tuple).

Differences Between vbLf, vbCrLf & vbCr Constants

 Constant   Value               Description
 ----------------------------------------------------------------
 vbCr       Chr(13)             Carriage return
 vbCrLf     Chr(13) & Chr(10)   Carriage return–linefeed combination
 vbLf       Chr(10)             Line feed
  • vbCr : - return to line beginning
    Represents a carriage-return character for print and display functions.

  • vbCrLf : - similar to pressing Enter
    Represents a carriage-return character combined with a linefeed character for print and display functions.

  • vbLf : - go to next line
    Represents a linefeed character for print and display functions.


Read More from Constants Class

Bootstrap collapse animation not smooth

Mine got smoother not by wrapping each child but wrapping whole markup with a helper div. Like this:

<div class="accordeonBigWrapper">
    <div class="panel-group accordion partnersAccordeonWrapper" id="partnersAccordeon" role="tablist" aria-multiselectable="false">
         accordeon markup inside...
    </div>
</div>

VBA Print to PDF and Save with Automatic File Name

Hopefully this is self explanatory enough. Use the comments in the code to help understand what is happening. Pass a single cell to this function. The value of that cell will be the base file name. If the cell contains "AwesomeData" then we will try and create a file in the current users desktop called AwesomeData.pdf. If that already exists then try AwesomeData2.pdf and so on. In your code you could just replace the lines filename = Application..... with filename = GetFileName(Range("A1"))

Function GetFileName(rngNamedCell As Range) As String
    Dim strSaveDirectory As String: strSaveDirectory = ""
    Dim strFileName As String: strFileName = ""
    Dim strTestPath As String: strTestPath = ""
    Dim strFileBaseName As String: strFileBaseName = ""
    Dim strFilePath As String: strFilePath = ""
    Dim intFileCounterIndex As Integer: intFileCounterIndex = 1

    ' Get the users desktop directory.
    strSaveDirectory = Environ("USERPROFILE") & "\Desktop\"
    Debug.Print "Saving to: " & strSaveDirectory

    ' Base file name
    strFileBaseName = Trim(rngNamedCell.Value)
    Debug.Print "File Name will contain: " & strFileBaseName

    ' Loop until we find a free file number
    Do
        If intFileCounterIndex > 1 Then
            ' Build test path base on current counter exists.
            strTestPath = strSaveDirectory & strFileBaseName & Trim(Str(intFileCounterIndex)) & ".pdf"
        Else
            ' Build test path base just on base name to see if it exists.
            strTestPath = strSaveDirectory & strFileBaseName & ".pdf"
        End If

        If (Dir(strTestPath) = "") Then
            ' This file path does not currently exist. Use that.
            strFileName = strTestPath
        Else
            ' Increase the counter as we have not found a free file yet.
            intFileCounterIndex = intFileCounterIndex + 1
        End If

    Loop Until strFileName <> ""

    ' Found useable filename
    Debug.Print "Free file name: " & strFileName
    GetFileName = strFileName

End Function

The debug lines will help you figure out what is happening if you need to step through the code. Remove them as you see fit. I went a little crazy with the variables but it was to make this as clear as possible.

In Action

My cell O1 contained the string "FileName" without the quotes. Used this sub to call my function and it saved a file.

Sub Testing()
    Dim filename As String: filename = GetFileName(Range("o1"))

    ActiveWorkbook.Worksheets("Sheet1").Range("A1:N24").ExportAsFixedFormat Type:=xlTypePDF, _
                                              filename:=filename, _
                                              Quality:=xlQualityStandard, _
                                              IncludeDocProperties:=True, _
                                              IgnorePrintAreas:=False, _
                                              OpenAfterPublish:=False
End Sub

Where is your code located in reference to everything else? Perhaps you need to make a module if you have not already and move your existing code into there.

Link a .css on another folder

check this quick reminder of file path

Here is all you need to know about relative file paths:

  • Starting with "/" returns to the root directory and starts there
  • Starting with "../" moves one directory backwards and starts there
  • Starting with "../../" moves two directories backwards and starts there (and so on...)
  • To move forward, just start with the first subdirectory and keep moving forward

HTML5 tag for horizontal line break

You can make a div that has the same attributes as the <hr> tag. This way it is fully able to be customized. Here is some sample code:

The HTML:

<h3>This is a header.</h3>
<div class="customHr">.</div>

<p>Here is some sample paragraph text.<br>
This demonstrates what could go below a custom hr.</p>

The CSS:

.customHr {
    width: 95%
    font-size: 1px;
    color: rgba(0, 0, 0, 0);
    line-height: 1px;

    background-color: grey;
    margin-top: -6px;
    margin-bottom: 10px;
}

To see how the project turns out, here is a JSFiddle for the above code: http://jsfiddle.net/SplashHero/qmccsc06/1/

Postgres: How to convert a json string to text?

There is no way in PostgreSQL to deconstruct a scalar JSON object. Thus, as you point out,

select  length(to_json('Some "text"'::TEXT) ::TEXT);

is 15,

The trick is to convert the JSON into an array of one JSON element, then extract that element using ->>.

select length( array_to_json(array[to_json('Some "text"'::TEXT)])->>0 );

will return 11.

How to create circular ProgressBar in android?

You can try this Circle Progress library

enter image description here

enter image description here

NB: please always use same width and height for progress views

DonutProgress:

 <com.github.lzyzsd.circleprogress.DonutProgress
        android:id="@+id/donut_progress"
        android:layout_marginLeft="50dp"
        android:layout_width="100dp"
        android:layout_height="100dp"
        custom:circle_progress="20"/>

CircleProgress:

  <com.github.lzyzsd.circleprogress.CircleProgress
        android:id="@+id/circle_progress"
        android:layout_marginLeft="50dp"
        android:layout_width="100dp"
        android:layout_height="100dp"
        custom:circle_progress="20"/>

ArcProgress:

<com.github.lzyzsd.circleprogress.ArcProgress
        android:id="@+id/arc_progress"
        android:background="#214193"
        android:layout_marginLeft="50dp"
        android:layout_width="100dp"
        android:layout_height="100dp"
        custom:arc_progress="55"
        custom:arc_bottom_text="MEMORY"/>

Angular ng-repeat add bootstrap row every 3 or 4 cols

You can do it without a directive but i'm not sure it's the best way. To do this you must create array of array from the data you want to display in the table, and after that use 2 ng-repeat to iterate through the array.

to create the array for display use this function like that products.chunk(3)

Array.prototype.chunk = function(chunkSize) {
    var array=this;
    return [].concat.apply([],
        array.map(function(elem,i) {
            return i%chunkSize ? [] : [array.slice(i,i+chunkSize)];
        })
    );
}

and then do something like that using 2 ng-repeat

<div class="row" ng-repeat="row in products.chunk(3)">
  <div class="col-sm4" ng-repeat="item in row">
    {{item}}
  </div>
</div>

Find Process Name by its Process ID

The basic one, ask tasklist to filter its output and only show the indicated process id information

tasklist /fi "pid eq 4444" 

To only get the process name, the line must be splitted

for /f "delims=," %%a in ('
    tasklist /fi "pid eq 4444" /nh /fo:csv
') do echo %%~a

In this case, the list of processes is retrieved without headers (/nh) in csv format (/fo:csv). The commas are used as token delimiters and the first token in the line is the image name

note: In some windows versions (one of them, my case, is the spanish windows xp version), the pid filter in the tasklist does not work. In this case, the filter over the list of processes must be done out of the command

for /f "delims=," %%a in ('
    tasklist /fo:csv /nh ^| findstr /b /r /c:"[^,]*,\"4444\","
') do echo %%~a

This will generate the task list and filter it searching for the process id in the second column of the csv output.

edited: alternatively, you can suppose what has been made by the team that translated the OS to spanish. I don't know what can happen in other locales.

tasklist /fi "idp eq 4444" 

RecyclerView expand/collapse items

I know it has been a long time since the original question was posted. But i think for slow ones like me a bit of explanation of @Heisenberg's answer would help.

Declare two variable in the adapter class as

private int mExpandedPosition= -1;
private RecyclerView recyclerView = null;

Then in onBindViewHolder following as given in the original answer.

      // This line checks if the item displayed on screen 
      // was expanded or not (Remembering the fact that Recycler View )
      // reuses views so onBindViewHolder will be called for all
      // items visible on screen.
    final boolean isExpanded = position==mExpandedPosition;

        //This line hides or shows the layout in question
        holder.details.setVisibility(isExpanded?View.VISIBLE:View.GONE);

        // I do not know what the heck this is :)
        holder.itemView.setActivated(isExpanded);

        // Click event for each item (itemView is an in-built variable of holder class)
        holder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

 // if the clicked item is already expaned then return -1 
//else return the position (this works with notifyDatasetchanged )
                mExpandedPosition = isExpanded ? -1:position;
    // fancy animations can skip if like
                TransitionManager.beginDelayedTransition(recyclerView);
    //This will call the onBindViewHolder for all the itemViews on Screen
                notifyDataSetChanged();
            }
        });

And lastly to get the recyclerView object in the adapter override

@Override
public void onAttachedToRecyclerView(@NonNull RecyclerView recyclerView) {
    super.onAttachedToRecyclerView(recyclerView);

    this.recyclerView = recyclerView;
}

Hope this Helps.

Angularjs on page load call function

    var someVr= element[0].querySelector('#showSelector');
        myfunction(){
        alert("hi");
        }   
        angular.element(someVr).ready(function () {
           myfunction();
            });

This will do the job.

How to properly highlight selected item on RecyclerView?

This is much simple way to do it.

Have a private int selectedPos = RecyclerView.NO_POSITION; in the RecyclerView Adapter class, and under onBindViewHolder method try:

@Override
public void onBindViewHolder(ViewHolder viewHolder, int position) {   
    viewHolder.itemView.setSelected(selectedPos == position);

}

And in your OnClick event modify:

@Override
public void onClick(View view) {
     notifyItemChanged(selectedPos);
     selectedPos = getLayoutPosition();
     notifyItemChanged(selectedPos); 
}

Works like a charm for Navigtional Drawer and other RecyclerView Item Adapters.

Note: Be sure to use a background color in your layout using a selector like colabug clarified:

<selector xmlns:android="http://schemas.android.com/apk/res/android">
  <item android:drawable="@color/pressed_color" android:state_pressed="true"/>
  <item android:drawable="@color/selected_color" android:state_selected="true"/>
  <item android:drawable="@color/focused_color" android:state_focused="true"/>
</selector>

Otherwise setSelected(..) will do nothing, rendering this solution useless.

pass JSON to HTTP POST Request

According to doc: https://github.com/request/request

The example is:

  multipart: {
      chunked: false,
      data: [
        {
          'content-type': 'application/json', 
          body: JSON.stringify({foo: 'bar', _attachments: {'message.txt': {follows: true, length: 18, 'content_type': 'text/plain' }}})
        },
      ]
    }

I think you send an object where a string is expected, replace

body: requestData

by

body: JSON.stringify(requestData)

java.lang.UnsatisfiedLinkError: dalvik.system.PathClassLoader

What helped me was to register the source directory for jni files in the build.gradle file. Add this to your gradle file:

android {
    sourceSets {
        main {
            jniLibs.srcDir '[YOUR_JNI_DIR]' // i.e. 'libs'
        }
    }
}

What is the difference between absolute and relative xpaths? Which is preferred in Selenium automation testing?

An absolute xpath in HTML DOM starts with /html e.g.

/html/body/div[5]/div[2]/div/div[2]/div[2]/h2[1]

and a relative xpath finds the closed id to the dom element and generates xpath starting from that element e.g.

.//*[@id='answers']/h2[1]/a[1]

You can use firepath (firebug) for generating both types of xpaths

It won't make any difference which xpath you use in selenium, the former may be faster than the later one (but it won't be observable)

Absolute xpaths are prone to more regression as slight change in DOM makes them invalid or refer to a wrong element

Getting the difference between two Dates (months/days/hours/minutes/seconds) in Swift

This is the shorter version: Basically I try to get the difference between the post timestamp with the Date() now.

// MARK: - UPDATE Time Stamp
static func updateTimeStampPost(postTimeStamp: Date?, _ completion: (_ finalString: String?) -> Void) {
    // date in the current state
    let date = Date()
    let dateComponentFormatter = DateComponentsFormatter()

    // change the styling date, wether second minute or hour
    dateComponentFormatter.unitsStyle = .abbreviated
    dateComponentFormatter.allowedUnits = [.second, .minute, .hour, .day, .weekOfMonth]
    dateComponentFormatter.maximumUnitCount = 1

    // return the date new format as a string in the completion
    completion(dateComponentFormatter.string(from: postTimeStamp!, to: date))
}

cannot resolve symbol javafx.application in IntelliJ Idea IDE

I had the same problem, in my case i resolved it by:

1) going to File-->Project Structure---->Global libraries 2) looking for jfxrt.jar included as default in the jdk1.8.0_241\lib (after installing it) 3)click on + on top left to add new global library and i specified the path of my jdk1.8.0_241 Ex :(C:\Program Files\Java\jdk1.8.0_241).

I hope this will help you

Android studio takes too much memory

To reduce the lag i would recommend the follwing steps

my pc specs : 2 gb ram, processor: intel core2 duo

first kill all background process, if you have server or database running you could stop them first with following commands

sudo service apache2 stop

sudo service mysql stop

Then enable power saving mode in android studio by file>powersaving mode

It could disable background process, and then studio appears to go well

How to add/update child entities when updating a parent entity in EF

I've been messing about with something like this...

protected void UpdateChildCollection<Tparent, Tid , Tchild>(Tparent dbItem, Tparent newItem, Func<Tparent, IEnumerable<Tchild>> selector, Func<Tchild, Tid> idSelector) where Tchild : class
    {
        var dbItems = selector(dbItem).ToList();
        var newItems = selector(newItem).ToList();

        if (dbItems == null && newItems == null)
            return;

        var original = dbItems?.ToDictionary(idSelector) ?? new Dictionary<Tid, Tchild>();
        var updated = newItems?.ToDictionary(idSelector) ?? new Dictionary<Tid, Tchild>();

        var toRemove = original.Where(i => !updated.ContainsKey(i.Key)).ToArray();
        var removed = toRemove.Select(i => DbContext.Entry(i.Value).State = EntityState.Deleted).ToArray();

        var toUpdate = original.Where(i => updated.ContainsKey(i.Key)).ToList();
        toUpdate.ForEach(i => DbContext.Entry(i.Value).CurrentValues.SetValues(updated[i.Key]));

        var toAdd = updated.Where(i => !original.ContainsKey(i.Key)).ToList();
        toAdd.ForEach(i => DbContext.Set<Tchild>().Add(i.Value));
    }

which you can call with something like:

UpdateChildCollection(dbCopy, detached, p => p.MyCollectionProp, collectionItem => collectionItem.Id)

Unfortunately, this kinda falls over if there are collection properties on the child type which also need to be updated. Considering trying to solve this by passing an IRepository (with basic CRUD methods) which would be responsible for calling UpdateChildCollection on its own. Would call the repo instead of direct calls to DbContext.Entry.

Have no idea how this will all perform at scale, but not sure what else to do with this problem.

Find empty or NaN entry in Pandas Dataframe

Another opltion covering cases where there might be severar spaces is by using the isspace() python function.

df[df.col_name.apply(lambda x:x.isspace() == False)] # will only return cases without empty spaces

adding NaN values:

df[(df.col_name.apply(lambda x:x.isspace() == False) & (~df.col_name.isna())] 

How to convert Blob to File in JavaScript

Use saveAs on FileSaver.js github project.

FileSaver.js implements the saveAs() FileSaver interface in browsers that do not natively support it.

docker: executable file not found in $PATH

In the error message shown:

Error response from daemon: Cannot start container foo_1: \
    exec: "grunt serve": executable file not found in $PATH

It is complaining that it cannot find the executable grunt serve, not that it could not find the executable grunt with the argument serve. The most likely explanation for that specific error is running the command with the json syntax:

[ "grunt serve" ]

in something like your compose file. That's invalid since the json syntax requires you to split up each parameter that would normally be split by the shell on each space for you. E.g.:

[ "grunt", "serve" ]

The other possible way you can get both of those into a single parameter is if you were to quote them into a single arg in your docker run command, e.g.

docker run your_image_name "grunt serve"

and in that case, you need to remove the quotes so it gets passed as separate args to the run command:

docker run your_image_name grunt serve

For others seeing this, the executable file not found means that Linux does not see the binary you are trying to run inside your container with the default $PATH value. That could mean lots of possible causes, here are a few:

  • Did you remember to include the binary inside your image? If you run a multi-stage image, make sure that binary install is run in the final stage. Run your image with an interactive shell and verify it exists:

    docker run -it --rm your_image_name /bin/sh
    
  • Your path when shelling into the container may be modified for the interactive shell, particularly if you use bash, so you may need to specify the full path to the binary inside the container, or you may need to update the path in your Dockerfile with:

    ENV PATH=$PATH:/custom/dir/bin
    
  • The binary may not have execute bits set on it, so you may need to make it executable. Do that with chmod:

    RUN chmod 755 /custom/dir/bin/executable
    
  • If you run the image with a volume, that volume can overlay the directory where the executable exists in your image. Volumes do not merge with the image, they get mounted in the filesystem tree same as any other Linux filesystem mount. That means files from the parent filesystem at the mount point are no longer visible. (Note that named volumes are initialized by docker from the image content, but this only happens when the named volume is empty.) So the fix is to not mount volumes on top of paths where you have executables you want to run from the image.

How to delete a record by id in Flask-SQLAlchemy

You can do this,

User.query.filter_by(id=123).delete()

or

User.query.filter(User.id == 123).delete()

Make sure to commit for delete() to take effect.

repository element was not specified in the POM inside distributionManagement element or in -DaltDep loymentRepository=id::layout::url parameter

In your pom.xml you should add distributionManagement configuration to where to deploy.

In the following example I have used file system as the locations.

<distributionManagement>
       <repository>
         <id>internal.repo</id>
         <name>Internal repo</name>
         <url>file:///home/thara/testesb/in</url>
       </repository>
   </distributionManagement>

you can add another location while deployment by using the following command (but to avoid above error you should have at least 1 repository configured) :

mvn deploy -DaltDeploymentRepository=internal.repo::default::file:///home/thara/testesb/in

NullPointerException: Attempt to invoke virtual method 'int java.util.ArrayList.size()' on a null object reference

Change

 mAdapter = new RecordingsListAdapter(this, recordings);

to

 mAdapter = new RecordingsListAdapter(getActivity(), recordings);

and also make sure that recordings!=null at mAdapter = new RecordingsListAdapter(this, recordings);

How to convert interface{} to string?

You don't need to use a type assertion, instead just use the %v format specifier with Sprintf:

hostAndPort := fmt.Sprintf("%v:%v", arguments["<host>"], arguments["<port>"])

ORA-01653: unable to extend table by in tablespace ORA-06512

To resolve this error:

ORA-01653 unable to extend table by 1024 in tablespace your-tablespace-name

Just run this PL/SQL command for extended tablespace size automatically on-demand:

alter database datafile '<your-tablespace-name>.dbf' autoextend on maxsize unlimited;

I get this error in import big dump file, just run this command without stopping import routine or restarting the database.

Note: each data file has a limit of 32GB of size if you need more than 32GB you should add a new data file to your existing tablespace.

More info: alter_autoextend_on

Asus Zenfone 5 not detected by computer

This are the steps :

  1. Download and install latest version of pclink for PC from here.
  2. Make sure PCLink is running in Foreground on Asus Zenfone 5 and in settings on rightmost topmost corner click on USB icon and then check the MTP checkbox.
  3. Click connect on PCLink on PC.
  4. If Asus USB Driver for Zenfone 5 is properly installed on your PC.You will see 'Asus Android Device' in your Device Manager otherwise install Asus USB Driver for Zenfone 5 from here then try again
  5. Now you will be able to see your device online in Android Studio and screen of your device on PCLink software on your PC.

I haven't tried for eclipse but it might work for that also.

What does %>% function mean in R?

%...% operators

%>% has no builtin meaning but the user (or a package) is free to define operators of the form %whatever% in any way they like. For example, this function will return a string consisting of its left argument followed by a comma and space and then it's right argument.

"%,%" <- function(x, y) paste0(x, ", ", y)

# test run

"Hello" %,% "World"
## [1] "Hello, World"

The base of R provides %*% (matrix mulitiplication), %/% (integer division), %in% (is lhs a component of the rhs?), %o% (outer product) and %x% (kronecker product). It is not clear whether %% falls in this category or not but it represents modulo.

expm The R package, expm, defines a matrix power operator %^%. For an example see Matrix power in R .

operators The operators R package has defined a large number of such operators such as %!in% (for not %in%). See http://cran.r-project.org/web/packages/operators/operators.pdf

igraph This package defines %--% , %->% and %<-% to select edges.

lubridate This package defines %m+% and %m-% to add and subtract months and %--% to define an interval. igraph also defines %--% .

Pipes

magrittr In the case of %>% the magrittr R package has defined it as discussed in the magrittr vignette. See http://cran.r-project.org/web/packages/magrittr/vignettes/magrittr.html

magittr has also defined a number of other such operators too. See the Additional Pipe Operators section of the prior link which discusses %T>%, %<>% and %$% and http://cran.r-project.org/web/packages/magrittr/magrittr.pdf for even more details.

dplyr The dplyr R package used to define a %.% operator which is similar; however, it has been deprecated and dplyr now recommends that users use %>% which dplyr imports from magrittr and makes available to the dplyr user. As David Arenburg has mentioned in the comments this SO question discusses the differences between it and magrittr's %>% : Differences between %.% (dplyr) and %>% (magrittr)

pipeR The R package, pipeR, defines a %>>% operator that is similar to magrittr's %>% and can be used as an alternative to it. See http://renkun.me/pipeR-tutorial/

The pipeR package also has defined a number of other such operators too. See: http://cran.r-project.org/web/packages/pipeR/pipeR.pdf

postlogic The postlogic package defined %if% and %unless% operators.

wrapr The R package, wrapr, defines a dot pipe %.>% that is an explicit version of %>% in that it does not do implicit insertion of arguments but only substitutes explicit uses of dot on the right hand side. This can be considered as another alternative to %>%. See https://winvector.github.io/wrapr/articles/dot_pipe.html

Bizarro pipe. This is not really a pipe but rather some clever base syntax to work in a way similar to pipes without actually using pipes. It is discussed in http://www.win-vector.com/blog/2017/01/using-the-bizarro-pipe-to-debug-magrittr-pipelines-in-r/ The idea is that instead of writing:

1:8 %>% sum %>% sqrt
## [1] 6

one writes the following. In this case we explicitly use dot rather than eliding the dot argument and end each component of the pipeline with an assignment to the variable whose name is dot (.) . We follow that with a semicolon.

1:8 ->.; sum(.) ->.; sqrt(.)
## [1] 6

Update Added info on expm package and simplified example at top. Added postlogic package.

Is it possible to use std::string in a constexpr?

Since the problem is the non-trivial destructor so if the destructor is removed from the std::string, it's possible to define a constexpr instance of that type. Like this

struct constexpr_str {
    char const* str;
    std::size_t size;

    // can only construct from a char[] literal
    template <std::size_t N>
    constexpr constexpr_str(char const (&s)[N])
        : str(s)
        , size(N - 1) // not count the trailing nul
    {}
};

int main()
{
    constexpr constexpr_str s("constString");

    // its .size is a constexpr
    std::array<int, s.size> a;
    return 0;
}

Failed to execute 'createObjectURL' on 'URL':

The problem is that the keys provided in the loop do not refer to the index of the file.

for (var i in this.files) {
    console.log(i);
}

The output of the above code is:

0
length
item

But what was expected was:

0
1
2
etc...

Then the error occurs when the browser tries to execute, for example:

window.URL.createObjectURL(this.files["length"])

I suggest implementation based on the following code:

var files = this.files;
for (var i = 0; i < files.length; i++) {
    var file = files[i],
        src = (window.URL || window.webkitURL).createObjectURL(file);
    ...
}

I hope this can help someone.

Greetings!

How to properly make a http web GET request

var request = (HttpWebRequest)WebRequest.Create("sendrequesturl");
var response = (HttpWebResponse)request.GetResponse();
string responseString;
using (var stream = response.GetResponseStream())
{
    using (var reader = new StreamReader(stream))
    {
        responseString = reader.ReadToEnd();
    }
}

Adding null values to arraylist

You could create Util class:

public final class CollectionHelpers {
    public static <T> boolean addNullSafe(List<T> list, T element) {
        if (list == null || element == null) {
            return false;
        }

        return list.add(element);
    }
}

And then use it:

Element element = getElementFromSomeWhere(someParameter);
List<Element> arrayList = new ArrayList<>();
CollectionHelpers.addNullSafe(list, element);

Storing an object in state of a React component?

In addition to kiran's post, there's the update helper (formerly a react addon). This can be installed with npm using npm install immutability-helper

import update from 'immutability-helper';

var abc = update(this.state.abc, {
   xyz: {$set: 'foo'}
});

this.setState({abc: abc});

This creates a new object with the updated value, and other properties stay the same. This is more useful when you need to do things like push onto an array, and set some other value at the same time. Some people use it everywhere because it provides immutability.

If you do this, you can have the following to make up for the performance of

shouldComponentUpdate: function(nextProps, nextState){
   return this.state.abc !== nextState.abc; 
   // and compare any props that might cause an update
}

TypeError: Converting circular structure to JSON in nodejs

It's because you don't an async response For example:

app.get(`${api}/users`, async (req, res) => {
    const users = await User.find()
    res.send(users);
   })