Programs & Examples On #Microsoft ajax minifier

What is so bad about singletons?

  1. It is easily (ab)used as a global variable.
  2. Classes that depend on singletons are relatively harder to unit test in isolation.

Clear text from textarea with selenium

Option a)

If you want to ensure keyboard events are fired, consider using sendKeys(CharSequence).

Example 1:

 from selenium.webdriver.common.keys import Keys
 # ...
 webElement.sendKeys(Keys.CONTROL + "a");
 webElement.sendKeys(Keys.DELETE);

Example 2:

 from selenium.webdriver.common.keys import Keys
 # ...
 webElement.sendKeys(Keys.BACK_SPACE); //do repeatedly, e.g. in while loop

WebElement

There are many ways to get the required WebElement, e.g.:

  • driver.find_element_by_id
  • driver.find_element_by_xpath
  • driver.find_element

Option b)

 webElement.clear();

If this element is a text entry element, this will clear the value.

Note that the events fired by this event may not be as you'd expect. In particular, we don't fire any keyboard or mouse events.

ITSAppUsesNonExemptEncryption export compliance while internal testing?

The same error solved like this

enter image description here

    using UnityEngine;
    using System.Collections;
    using UnityEditor.Callbacks;
    using UnityEditor;
    using System;
    using UnityEditor.iOS.Xcode;
    using System.IO;

public class AutoIncrement : MonoBehaviour {

    [PostProcessBuild]
    public static void ChangeXcodePlist(BuildTarget buildTarget, string pathToBuiltProject)
    {

        if (buildTarget == BuildTarget.iOS)
        {

            // Get plist
            string plistPath = pathToBuiltProject + "/Info.plist";
            var plist = new PlistDocument();
            plist.ReadFromString(File.ReadAllText(plistPath));

            // Get root
            var rootDict = plist.root;

            // Change value of NSCameraUsageDescription in Xcode plist
            var buildKey = "NSCameraUsageDescription";
            rootDict.SetString(buildKey, "Taking screenshots");

            var buildKey2 = "ITSAppUsesNonExemptEncryption";
            rootDict.SetString(buildKey2, "false");


            // Write to file
            File.WriteAllText(plistPath, plist.WriteToString());
        }
    }
    // Use this for initialization
    void Start () {

    }

    // Update is called once per frame
    void Update () {

    }

    [PostProcessBuild]
    public static void OnPostprocessBuild(BuildTarget target, string pathToBuiltProject)
    {
        //A new build has happened so lets increase our version number
        BumpBundleVersion();
    }


    // Bump version number in PlayerSettings.bundleVersion
    private static void BumpBundleVersion()
    {
        float versionFloat;

        if (float.TryParse(PlayerSettings.bundleVersion, out versionFloat))
        {
            versionFloat += 0.01f;
            PlayerSettings.bundleVersion = versionFloat.ToString();
        }
    }
    [MenuItem("Leman/Build iOS Development", false, 10)]
    public static void CustomBuild()
    {
        BumpBundleVersion();
        var levels= new String[] { "Assets\\ShootTheBall\\Scenes\\MainScene.unity" };
        BuildPipeline.BuildPlayer(levels, 
            "iOS", BuildTarget.iOS, BuildOptions.Development);
    }

}

Vue component event after render

updated might be what you're looking for. https://vuejs.org/v2/api/#updated

A SELECT statement that assigns a value to a variable must not be combined with data-retrieval operations

Column values from the SELECT statement are assigned into @low and @day local variables; the @adjustedLow value is not assigned into any variable and it causes the problem:

The problem is here:

select 
    top 1 @low = low
    , @day = day
    , @adjustedLow  -- causes error!
--select high
from 
    securityquote sq
...

Detailed explanation and workaround: SQL Server Error Messages - Msg 141 - A SELECT statement that assigns a value to a variable must not be combined with data-retrieval operations.

Angularjs action on click of button

The calculation occurs immediately since the calculation call is bound in the template, which displays its result when quantity changes.

Instead you could try the following approach. Change your markup to the following:

<div ng-controller="myAppController" style="text-align:center">
  <p style="font-size:28px;">Enter Quantity:
      <input type="text" ng-model="quantity"/>
  </p>
  <button ng-click="calculateQuantity()">Calculate</button>
  <h2>Total Cost: Rs.{{quantityResult}}</h2>
</div>

Next, update your controller:

myAppModule.controller('myAppController', function($scope,calculateService) {
  $scope.quantity=1;
  $scope.quantityResult = 0;

  $scope.calculateQuantity = function() {
    $scope.quantityResult = calculateService.calculate($scope.quantity, 10);
  };
});

Here's a JSBin example that demonstrates the above approach.

The problem with this approach is the calculated result remains visible with the old value till the button is clicked. To address this, you could hide the result whenever the quantity changes.

This would involve updating the template to add an ng-change on the input, and an ng-if on the result:

<input type="text" ng-change="hideQuantityResult()" ng-model="quantity"/>

and

<h2 ng-if="showQuantityResult">Total Cost: Rs.{{quantityResult}}</h2>

In the controller add:

$scope.showQuantityResult = false;

$scope.calculateQuantity = function() {
  $scope.quantityResult = calculateService.calculate($scope.quantity, 10);
  $scope.showQuantityResult = true;
};

$scope.hideQuantityResult = function() {
  $scope.showQuantityResult = false;
}; 

These updates can be seen in this JSBin demo.

Does Python have a toString() equivalent, and can I convert a db.Model element to String?

In python, the str() method is similar to the toString() method in other languages. It is called passing the object to convert to a string as a parameter. Internally it calls the __str__() method of the parameter object to get its string representation.

In this case, however, you are comparing a UserProperty author from the database, which is of type users.User with the nickname string. You will want to compare the nickname property of the author instead with todo.author.nickname in your template.

How do I find an element position in std::vector?

You could use std::numeric_limits<size_t>::max() for elements that was not found. It is a valid value, but it is impossible to create container with such max index. If std::vector has size equal to std::numeric_limits<size_t>::max(), then maximum allowed index will be (std::numeric_limits<size_t>::max()-1), since elements counted from 0.

What does template <unsigned int N> mean?

It's perfectly possible to template a class on an integer rather than a type. We can assign the templated value to a variable, or otherwise manipulate it in a way we might with any other integer literal:

unsigned int x = N;

In fact, we can create algorithms which evaluate at compile time (from Wikipedia):

template <int N>
struct Factorial 
{
     enum { value = N * Factorial<N - 1>::value };
};

template <>
struct Factorial<0> 
{
    enum { value = 1 };
};

// Factorial<4>::value == 24
// Factorial<0>::value == 1
void foo()
{
    int x = Factorial<4>::value; // == 24
    int y = Factorial<0>::value; // == 1
}

Show DataFrame as table in iPython Notebook

from IPython.display import display
display(df)  # OR
print df.to_html()

Where's the DateTime 'Z' format specifier?

When you use DateTime you are able to store a date and a time inside a variable.

The date can be a local time or a UTC time, it depend on you.

For example, I'm in Italy (+2 UTC)

var dt1 = new DateTime(2011, 6, 27, 12, 0, 0); // store 2011-06-27 12:00:00
var dt2 = dt1.ToUniversalTime()  // store 2011-06-27 10:00:00

So, what happen when I print dt1 and dt2 including the timezone?

dt1.ToString("MM/dd/yyyy hh:mm:ss z") 
// Compiler alert...
// Output: 06/27/2011 12:00:00 +2

dt2.ToString("MM/dd/yyyy hh:mm:ss z") 
// Compiler alert...
// Output: 06/27/2011 10:00:00 +2

dt1 and dt2 contain only a date and a time information. dt1 and dt2 don't contain the timezone offset.

So where the "+2" come from if it's not contained in the dt1 and dt2 variable?

It come from your machine clock setting.

The compiler is telling you that when you use the 'zzz' format you are writing a string that combine "DATE + TIME" (that are store in dt1 and dt2) + "TIMEZONE OFFSET" (that is not contained in dt1 and dt2 because they are DateTyme type) and it will use the offset of the server machine that it's executing the code.

The compiler tell you "Warning: the output of your code is dependent on the machine clock offset"

If i run this code on a server that is positioned in London (+1 UTC) the result will be completly different: instead of "+2" it will write "+1"

...
dt1.ToString("MM/dd/yyyy hh:mm:ss z") 
// Output: 06/27/2011 12:00:00 +1

dt2.ToString("MM/dd/yyyy hh:mm:ss z") 
// Output: 06/27/2011 10:00:00 +1

The right solution is to use DateTimeOffset data type in place of DateTime. It's available in sql Server starting from the 2008 version and in the .Net framework starting from the 3.5 version

CertificateException: No name matching ssl.someUrl.de found

I created a method fixUntrustCertificate(), so when I am dealing with a domain that is not in trusted CAs you can invoke the method before the request. This code will gonna work after java1.4. This method applies for all hosts:

public void fixUntrustCertificate() throws KeyManagementException, NoSuchAlgorithmException{


        TrustManager[] trustAllCerts = new TrustManager[]{
            new X509TrustManager() {
                public java.security.cert.X509Certificate[] getAcceptedIssuers() {
                    return null;
                }

                public void checkClientTrusted(X509Certificate[] certs, String authType) {
                }

                public void checkServerTrusted(X509Certificate[] certs, String authType) {
                }

            }
        };

        SSLContext sc = SSLContext.getInstance("SSL");
        sc.init(null, trustAllCerts, new java.security.SecureRandom());
        HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());

        HostnameVerifier allHostsValid = new HostnameVerifier() {
            public boolean verify(String hostname, SSLSession session) {
                return true;
            }
        };

        // set the  allTrusting verifier
        HttpsURLConnection.setDefaultHostnameVerifier(allHostsValid);
}

How do I test a private function or a class that has private methods, fields or inner classes?

Private methods are consumed by public ones. Otherwise, they're dead code. That's why you test the public method, asserting the expected results of the public method and thereby, the private methods it consumes.

Testing private methods should be tested by debugging before running your unit tests on public methods.

They may also be debugged using test-driven development, debugging your unit tests until all your assertions are met.

I personally believe it is better to create classes using TDD; creating the public method stubs, then generating unit tests with all the assertions defined in advance, so the expected outcome of the method is determined before you code it. This way, you don't go down the wrong path of making the unit test assertions fit the results. Your class is then robust and meets requirements when all your unit tests pass.

-bash: syntax error near unexpected token `newline'

The characters '<', and '>', are to indicate a place-holder, you should remove them to read:

php /usr/local/solusvm/scripts/pass.php --type=admin --comm=change --username=ADMINUSERNAME

Difference between break and continue statement

Simple program to understand difference between continue and break

When continue is used

    public static void main(String[] args) {
    System.out.println("HelloWorld");
    for (int i = 0; i < 5; i++){
        System.out.println("Start For loop i = " + i);
        if(i==2){
            System.out.println("Inside if Statement for i = "+i);
           continue;
        }
        System.out.println("End For loop i = " + i);
    }
    System.out.println("Completely out of For loop");
}


OutPut:
HelloWorld
Start For loop i = 0
End For loop i = 0
Start For loop i = 1
End For loop i = 1
Start For loop i = 2
Inside if Statement for i = 2
Start For loop i = 3
End For loop i = 3
Start For loop i = 4
End For loop i = 4
Completely out of For loop

When break is used

public static void main(String[] args) {
    System.out.println("HelloWorld");
    for (int i = 0; i < 5; i++){
        System.out.println("Start For loop i = " + i);
        if(i==2){
            System.out.println("Inside if Statement for i = "+i);
           break;
        }
        System.out.println("End For loop i = " + i);
    }
    System.out.println("Completely out of For loop");
}

Output:
HelloWorld
Start For loop i = 0
End For loop i = 0
Start For loop i = 1
End For loop i = 1
Start For loop i = 2
Inside if Statement for i = 2
Completely out of For loop

How to re-render flatlist?

I solved this problem by adding extraData={this.state} Please check code below for more detail

render() {
    return (
      <View style={styles.container}>
        <FlatList
          data={this.state.arr}
          extraData={this.state}
          renderItem={({ item }) => <Text style={styles.item}>{item}</Text>}
        />
      </View>
    );
  }

Why use @PostConstruct?

Consider the following scenario:

public class Car {
  @Inject
  private Engine engine;  

  public Car() {
    engine.initialize();  
  }
  ...
}

Since Car has to be instantiated prior to field injection, the injection point engine is still null during the execution of the constructor, resulting in a NullPointerException.

This problem can be solved either by JSR-330 Dependency Injection for Java constructor injection or JSR 250 Common Annotations for the Java @PostConstruct method annotation.

@PostConstruct

JSR-250 defines a common set of annotations which has been included in Java SE 6.

The PostConstruct annotation is used on a method that needs to be executed after dependency injection is done to perform any initialization. This method MUST be invoked before the class is put into service. This annotation MUST be supported on all classes that support dependency injection.

JSR-250 Chap. 2.5 javax.annotation.PostConstruct

The @PostConstruct annotation allows for the definition of methods to be executed after the instance has been instantiated and all injects have been performed.

public class Car {
  @Inject
  private Engine engine;  

  @PostConstruct
  public void postConstruct() {
    engine.initialize();  
  }
  ...
} 

Instead of performing the initialization in the constructor, the code is moved to a method annotated with @PostConstruct.

The processing of post-construct methods is a simple matter of finding all methods annotated with @PostConstruct and invoking them in turn.

private  void processPostConstruct(Class type, T targetInstance) {
  Method[] declaredMethods = type.getDeclaredMethods();

  Arrays.stream(declaredMethods)
      .filter(method -> method.getAnnotation(PostConstruct.class) != null) 
      .forEach(postConstructMethod -> {
         try {
           postConstructMethod.setAccessible(true);
           postConstructMethod.invoke(targetInstance, new Object[]{});
        } catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException ex) {      
          throw new RuntimeException(ex);
        }
      });
}

The processing of post-construct methods has to be performed after instantiation and injection have been completed.

Is it possible in Java to check if objects fields are null and then add default value to all those attributes?

This is not to check for null, instead this will be helpful in converting an existing object to an empty object(fresh object). I dont know whether this is relevant or not, but I had such a requirement.

@SuppressWarnings({ "unchecked" })
static void emptyObject(Object obj) 
{
    Class c1 = obj.getClass();
    Field[] fields = c1.getDeclaredFields();

    for(Field field : fields)
    {
        try
        {
            if(field.getType().getCanonicalName() == "boolean")
            {
                field.set(obj, false);
            }
            else if(field.getType().getCanonicalName() == "char")
            {
                field.set(obj, '\u0000');
            }
            else if((field.getType().isPrimitive()))
            {
                field.set(obj, 0);
            }
            else
            {
                field.set(obj, null);
            }
        }
        catch(Exception ex)
        {

        }
    }
}

Exception : AAPT2 error: check logs for details

I had this error and no meaningful message to tell me what was wrong. I finally removed this line from gradle.properties and got a meaningful error message.

android.enableAapt2=false

In my case somebody on the team had changed a .jpg extension to a .png and the file header didn't match the extension. Fun.

org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/CollegeWebsite]]

This error happens because of your Jre version of Eclipse and Tomcat are mismatched ..either change eclipse one to tomcat one or ViceVersa..

Both should be same ..Java version mismatched ..Check it

Determining the version of Java SDK on the Mac

In /System/Library/Frameworks/JavaVM.framework/Versions you'll see all the installed JDKs. There is a symbolic link named CurrentJDK pointing the active JDK.

How to get cookie's expire time

To get cookies expire time, use this simple method.

<?php

//#############PART 1#############
//expiration time (a*b*c*d) <- change D corresponding to number of days for cookie expiration
$time = time()+(60*60*24*365);
$timeMemo = (string)$time;

//sets cookie with expiration time defined above
setcookie("testCookie", "" . $timeMemo . "", $time);

//#############PART 2#############
//this function will convert seconds to days.
function secToDays($sec){

    return ($sec / 60 / 60 / 24);

}
//checks if cookie is set and prints out expiration time in days
if(isset($_COOKIE['testCookie'])){

    echo "Cookie is set<br />";
    if(round(secToDays((intval($_COOKIE['testCookie']) - time())),1) < 1){
        echo "Cookie will expire today.";
    }else{
        echo "Cookie will expire in " . round(secToDays((intval($_COOKIE['testCookie']) - time())),1) . " day(s)";
    }

}else{
    echo "not set...";
}

?>

You need to keep Part 1 and Part 2 in different files, otherwise you will get the same expire date everytime.

A table name as a variable

Use:

CREATE PROCEDURE [dbo].[GetByName]
    @TableName NVARCHAR(100)
    AS
BEGIN
    -- SET NOCOUNT ON added to prevent extra result sets from
    -- interfering with SELECT statements.
    SET NOCOUNT ON;
    DECLARE @sSQL nvarchar(500);

    SELECT @sSQL = N'SELECT * FROM' + QUOTENAME(@TableName);

    EXEC sp_executesql @sSQL
END

How do I add a bullet symbol in TextView?

Prolly a better solution out there somewhere, but this is what I did.

<TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        >
        <TableRow>    
            <TextView
                android:layout_column="1"
                android:text="•"></TextView>
            <TextView
                android:layout_column="2"
                android:layout_width="wrap_content"
                android:text="First line"></TextView>
        </TableRow>
        <TableRow>    
            <TextView
                android:layout_column="1"
                android:text="•"></TextView>
            <TextView
                android:layout_column="2"
                android:layout_width="wrap_content"
                android:text="Second line"></TextView>
        </TableRow>
  </TableLayout>

It works like you want, but a workaround really.

Commenting multiple lines in DOS batch file

If you want to add REM at the beginning of each line instead of using GOTO, you can use Notepad++ to do this easily following these steps:

  1. Select the block of lines
  2. hit Ctrl-Q

Repeat steps to uncomment

How to overcome root domain CNAME restrictions?

CNAME'ing a root record is technically not against RFC, but does have limitations meaning it is a practice that is not recommended.

Normally your root record will have multiple entries. Say, 3 for your name servers and then one for an IP address.

Per RFC:

If a CNAME RR is present at a node, no other data should be present;

And Per IETF 'Common DNS Operational and Configuration Errors' Document:

This is often attempted by inexperienced administrators as an obvious way to allow your domain name to also be a host. However, DNS servers like BIND will see the CNAME and refuse to add any other resources for that name. Since no other records are allowed to coexist with a CNAME, the NS entries are ignored. Therefore all the hosts in the podunk.xx domain are ignored as well!

References:

How to normalize an array in NumPy to a unit vector?

If you're using scikit-learn you can use sklearn.preprocessing.normalize:

import numpy as np
from sklearn.preprocessing import normalize

x = np.random.rand(1000)*10
norm1 = x / np.linalg.norm(x)
norm2 = normalize(x[:,np.newaxis], axis=0).ravel()
print np.all(norm1 == norm2)
# True

Regex not operator

Not quite, although generally you can usually use some workaround on one of the forms

  • [^abc], which is character by character not a or b or c,
  • or negative lookahead: a(?!b), which is a not followed by b
  • or negative lookbehind: (?<!a)b, which is b not preceeded by a

Extracting text from a PDF file using PDFMiner in python?

terrific answer from DuckPuncher, for Python3 make sure you install pdfminer2 and do:

import io

from pdfminer.pdfinterp import PDFResourceManager, PDFPageInterpreter
from pdfminer.converter import TextConverter
from pdfminer.layout import LAParams
from pdfminer.pdfpage import PDFPage


def convert_pdf_to_txt(path):
    rsrcmgr = PDFResourceManager()
    retstr = io.StringIO()
    codec = 'utf-8'
    laparams = LAParams()
    device = TextConverter(rsrcmgr, retstr, codec=codec, laparams=laparams)
    fp = open(path, 'rb')
    interpreter = PDFPageInterpreter(rsrcmgr, device)
    password = ""
    maxpages = 0
    caching = True
    pagenos = set()

    for page in PDFPage.get_pages(fp, pagenos, maxpages=maxpages,
                                  password=password,
                                  caching=caching,
                                  check_extractable=True):
        interpreter.process_page(page)



    fp.close()
    device.close()
    text = retstr.getvalue()
    retstr.close()
    return text

ORA-12154 could not resolve the connect identifier specified

I am going to assume you are using the tnsnames.ora file to specify your available database services. If so connection errors usually come down to two things.

  1. The application cannot find the TNS entry you specified in the connection string.

  2. The TNS entry was found, but the IP or host is not correct in the tnsnames.ora file.

To expand on number 1 (which I think is your problem). When you tell Oracle to connect using something like:

sqlplus user/pass@service

The service is defined in the tnsnames.ora file. If I attempt to connect with a service that is not defined in my tnsnames.ora, I get the error you get:

[sodonnel@home ~]$ sqlplus sodonnel/sodonnel@nowhere

SQL*Plus: Release 11.2.0.1.0 Production on Mon Oct 31 21:42:15 2011

Copyright (c) 1982, 2009, Oracle.  All rights reserved.

ERROR:
ORA-12154: TNS:could not resolve the connect identifier specified

So you need to check a few things:

  1. Is there a tnsnames.ora file - I think yes because your console can connect
  2. Is there an entry in the file for the service - I think also yes as the console connects
  3. Can the application find the tnsnames.ora?

Your problem may well be number 3 - does the application run as a different user than when you run the console?

Oracle looks for the tnsnames.ora file in the directory defined in the TNS_ADMIN environment variable - If you are running as different users, then maybe the TNS_ADMIN environment variable is not set, and therefore it cannot find the file?

How to edit HTML input value colour?

Please try this:

<input class="col-xs-12 col-sm-8 col-sm-offset-2 col-md-8 col-md-offset-2" type="text" name="name" value="" placeholder="Your Name" style="background-color:blue;"/>

You basically put all the CSS inside the style part of the input tag and it works.

PHP Fatal error: Class 'PDO' not found

If you have upgraded your PHP version, make sure that the old PHP version configuration in your .htaccess has been deleted. For more info, check this https://www.hostgator.com/help/article/php-configuration-plugin

see if two files have the same content in python

Yes, I think hashing the file would be the best way if you have to compare several files and store hashes for later comparison. As hash can clash, a byte-by-byte comparison may be done depending on the use case.

Generally byte-by-byte comparison would be sufficient and efficient, which filecmp module already does + other things too.

See http://docs.python.org/library/filecmp.html e.g.

>>> import filecmp
>>> filecmp.cmp('file1.txt', 'file1.txt')
True
>>> filecmp.cmp('file1.txt', 'file2.txt')
False

Speed consideration: Usually if only two files have to be compared, hashing them and comparing them would be slower instead of simple byte-by-byte comparison if done efficiently. e.g. code below tries to time hash vs byte-by-byte

Disclaimer: this is not the best way of timing or comparing two algo. and there is need for improvements but it does give rough idea. If you think it should be improved do tell me I will change it.

import random
import string
import hashlib
import time

def getRandText(N):
    return  "".join([random.choice(string.printable) for i in xrange(N)])

N=1000000
randText1 = getRandText(N)
randText2 = getRandText(N)

def cmpHash(text1, text2):
    hash1 = hashlib.md5()
    hash1.update(text1)
    hash1 = hash1.hexdigest()

    hash2 = hashlib.md5()
    hash2.update(text2)
    hash2 = hash2.hexdigest()

    return  hash1 == hash2

def cmpByteByByte(text1, text2):
    return text1 == text2

for cmpFunc in (cmpHash, cmpByteByByte):
    st = time.time()
    for i in range(10):
        cmpFunc(randText1, randText2)
    print cmpFunc.func_name,time.time()-st

and the output is

cmpHash 0.234999895096
cmpByteByByte 0.0

Best way to do multi-row insert in Oracle?

Here is a very useful step by step guideline for insert multi rows in Oracle:

https://livesql.oracle.com/apex/livesql/file/content_BM1LJQ87M5CNIOKPOWPV6ZGR3.html

The last step:

INSERT ALL
/* Everyone is a person, so insert all rows into people */
WHEN 1=1 THEN
INTO people (person_id, given_name, family_name, title)
VALUES (id, given_name, family_name, title)
/* Only people with an admission date are patients */
WHEN admission_date IS NOT NULL THEN
INTO patients (patient_id, last_admission_date)
VALUES (id, admission_date)
/* Only people with a hired date are staff */
WHEN hired_date IS NOT NULL THEN
INTO staff (staff_id, hired_date)
VALUES (id, hired_date)
  WITH names AS (
    SELECT 4 id, 'Ruth' given_name, 'Fox' family_name, 'Mrs' title,
           NULL hired_date, DATE'2009-12-31' admission_date
    FROM   dual UNION ALL
    SELECT 5 id, 'Isabelle' given_name, 'Squirrel' family_name, 'Miss' title ,
           NULL hired_date, DATE'2014-01-01' admission_date
    FROM   dual UNION ALL
    SELECT 6 id, 'Justin' given_name, 'Frog' family_name, 'Master' title,
           NULL hired_date, DATE'2015-04-22' admission_date
    FROM   dual UNION ALL
    SELECT 7 id, 'Lisa' given_name, 'Owl' family_name, 'Dr' title,
           DATE'2015-01-01' hired_date, NULL admission_date
    FROM   dual
  )
  SELECT * FROM names

Exception of type 'System.OutOfMemoryException' was thrown. Why?

Where does it fail?

I agree that your issue is probably that your dataset of 600,000 rows is probably just too large. I see that you are then adding it to Session. If you are using Sql session state, it will have to serialize that data as well.

Even if you dispose of your objects properly, you will always have at least 2 copies of this dataset in memory if you run it twice, once in session, once in procedural code. This will never scale in a web application.

Do the math, 600,000 rows, at even 1-128 bit guid per row would yield 9.6 megabytes (600k * 128 / 8) of just data, not to mention the dataset overhead.

Trim down your results.

How do I concatenate strings and variables in PowerShell?

As noted elsewhere, you can use join.

If you are using commands as inputs (as I was), use the following syntax:

-join($(Command1), "," , $(Command2))

This would result in the two outputs separated by a comma.

See https://stackoverflow.com/a/34720515/11012871 for related comment

How to close a GUI when I push a JButton?

By using System.exit(0); you would close the entire process. Is that what you wanted or did you intend to close only the GUI window and allow the process to continue running?

The quickest, easiest and most robust way to simply close a JFrame or JPanel with the click of a JButton is to add an actionListener to the JButton which will execute the line of code below when the JButton is clicked:

this.dispose();

If you are using the NetBeans GUI designer, the easiest way to add this actionListener is to enter the GUI editor window and double click the JButton component. Doing this will automatically create an actionListener and actionEvent, which can be modified manually by you.

How to get Locale from its String representation in Java?

Because I have just implemented it:

In Groovy/Grails it would be:

def locale = Locale.getAvailableLocales().find { availableLocale ->
      return availableLocale.toString().equals(searchedLocale)
}

substring index range

For substring(startIndex, endIndex), startIndex is inclusive and endIndex are exclusive. The startIndex and endIndex are very confusing. I would understand substring(startIndex, length) to remember that.

How can I make robocopy silent in the command line except for progress?

There's no need to redirect to a file and delete it later. Try:

Robocopy src dest > null 

How to install OpenSSL for Python

SSL development libraries have to be installed

CentOS:

$ yum install openssl-devel libffi-devel

Ubuntu:

$ apt-get install libssl-dev libffi-dev

OS X (with Homebrew installed):

$ brew install openssl

Rollback transaction after @Test

The answers mentioning adding @Transactional are correct, but for simplicity you could just have your test class extends AbstractTransactionalJUnit4SpringContextTests.

Changing the tmp folder of mysql

You can also set the TMPDIR environment variable.

In some situations (Docker in my case) it's more convenient to set an environment variable than to update a config file.

How to delete a character from a string using Python

UserString.MutableString

Mutable way:

import UserString

s = UserString.MutableString("EXAMPLE")

>>> type(s)
<type 'str'>

# Delete 'M'
del s[3]

# Turn it for immutable:
s = str(s)

Updating the value of data attribute using jQuery

$('.toggle img').each(function(index) { 
    if($(this).attr('data-id') == '4')
    {
        $(this).attr('data-block', 'something');
        $(this).attr('src', 'something.jpg');
    }
});

or

$('.toggle img[data-id="4"]').attr('data-block', 'something');
$('.toggle img[data-id="4"]').attr('src', 'something.jpg');

How do I show the changes which have been staged?

If you'd be interested in a visual side-by-side view, the diffuse visual diff tool can do that. It will even show three panes if some but not all changes are staged. In the case of conflicts, there will even be four panes.

Screenshot of diffuse with staged and unstaged edits

Invoke it with

diffuse -m

in your Git working copy.

If you ask me, the best visual differ I've seen for a decade. Also, it is not specific to Git: It interoperates with a plethora of other VCS, including SVN, Mercurial, Bazaar, ...

See also: Show both staged & working tree in git diff?

Python socket connection timeout

For setting the Socket timeout, you need to follow these steps:

import socket
socks = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
socks.settimeout(10.0) # settimeout is the attr of socks.

Set Culture in an ASP.Net MVC app

1: Create a custom attribute and override method like this:

public class CultureAttribute : ActionFilterAttribute
{
    public override void OnActionExecuting(ActionExecutingContext filterContext)
    {
    // Retreive culture from GET
    string currentCulture = filterContext.HttpContext.Request.QueryString["culture"];

    // Also, you can retreive culture from Cookie like this :
    //string currentCulture = filterContext.HttpContext.Request.Cookies["cookie"].Value;

    // Set culture
    Thread.CurrentThread.CurrentCulture = new CultureInfo(currentCulture);
    Thread.CurrentThread.CurrentUICulture = CultureInfo.CreateSpecificCulture(currentCulture);
    }
}

2: In App_Start, find FilterConfig.cs, add this attribute. (this works for WHOLE application)

public class FilterConfig
{
    public static void RegisterGlobalFilters(GlobalFilterCollection filters)
    {
    // Add custom attribute here
    filters.Add(new CultureAttribute());
    }
}    

That's it !

If you want to define culture for each controller/action in stead of whole application, you can use this attribute like this:

[Culture]
public class StudentsController : Controller
{
}

Or:

[Culture]
public ActionResult Index()
{
    return View();
}

rails simple_form - hidden field - create?

Shortest Yet !!!

=f.hidden_field :title, :value => "some value"

Shorter, DRYer and perhaps more obvious.

Of course with ruby 1.9 and the new hash format we can go 3 characters shorter with...

=f.hidden_field :title, value: "some value"

Maven Unable to locate the Javac Compiler in:

Though there are a few non-Eclipse answers above for this question that does not mention Eclipse, they require path variable changes. An alternative is to use the command line option, java.home, e.g.:

mvn package -Djava.home="C:\Program Files\Java\jdk1.8.0_161\jre"

Notice the \jre at the end - a surprising necessity.

Should I use "camel case" or underscores in python?

for everything related to Python's style guide: i'd recommend you read PEP8.

To answer your question:

Function names should be lowercase, with words separated by underscores as necessary to improve readability.

How to write :hover using inline style?

Not gonna happen with CSS only

Inline javascript

<a href='index.html' 
    onmouseover='this.style.textDecoration="none"' 
    onmouseout='this.style.textDecoration="underline"'>
    Click Me
</a>

In a working draft of the CSS2 spec it was declared that you could use pseudo-classes inline like this:

<a href="http://www.w3.org/Style/CSS"
   style="{color: blue; background: white}  /* a+=0 b+=0 c+=0 */
      :visited {color: green}           /* a+=0 b+=1 c+=0 */
      :hover {background: yellow}       /* a+=0 b+=1 c+=0 */
      :visited:hover {color: purple}    /* a+=0 b+=2 c+=0 */
     ">
</a>

but it was never implemented in the release of the spec as far as I know.

http://www.w3.org/TR/2002/WD-css-style-attr-20020515#pseudo-rules

How to Deep clone in javascript

There should be no real world need for such a function anymore. This is mere academic interest.

As purely an exercise, this is a more functional way of doing it. It's an extension of @tfmontague's answer as I'd suggested adding a guard block there. But seeing as I feel compelled to ES6 and functionalise all the things, here's my pimped version. It complicates the logic as you have to map over the array and reduce over the object, but it avoids any mutations.

_x000D_
_x000D_
const cloner = (x) => {
    const recurseObj = x => (typeof x === 'object') ? cloner(x) : x
    const cloneObj = (y, k) => {
        y[k] = recurseObj(x[k])
        return y
    }
    // Guard blocks
    // Add extra for Date / RegExp if you want
    if (!x) {
        return x
    }
    if (Array.isArray(x)) {
        return x.map(recurseObj)
    }
    return Object.keys(x).reduce(cloneObj, {})
}
const tests = [
    null,
    [],
    {},
    [1,2,3],
    [1,2,3, null],
    [1,2,3, null, {}],
    [new Date('2001-01-01')], // FAIL doesn't work with Date
    {x:'', y: {yx: 'zz', yy: null}, z: [1,2,3,null]},
    {
        obj : new function() {
            this.name = "Object test";
        }
    } // FAIL doesn't handle functions
]
tests.map((x,i) => console.log(i, cloner(x)))
_x000D_
_x000D_
_x000D_

What is the use of join() in Python threading?

"What's the use of using join()?" you say. Really, it's the same answer as "what's the use of closing files, since python and the OS will close my file for me when my program exits?".

It's simply a matter of good programming. You should join() your threads at the point in the code that the thread should not be running anymore, either because you positively have to ensure the thread is not running to interfere with your own code, or that you want to behave correctly in a larger system.

You might say "I don't want my code to delay giving an answer" just because of the additional time that the join() might require. This may be perfectly valid in some scenarios, but you now need to take into account that your code is "leaving cruft around for python and the OS to clean up". If you do this for performance reasons, I strongly encourage you to document that behavior. This is especially true if you're building a library/package that others are expected to utilize.

There's no reason to not join(), other than performance reasons, and I would argue that your code does not need to perform that well.

Pass a reference to DOM object with ng-click

The angular way is shown in the angular docs :)

https://docs.angularjs.org/api/ng/directive/ngReadonly

Here is the example they use:

<body>
    Check me to make text readonly: <input type="checkbox" ng-model="checked"><br/>
    <input type="text" ng-readonly="checked" value="I'm Angular"/>
</body>

Basically the angular way is to create a model object that will hold whether or not the input should be readonly and then set that model object accordingly. The beauty of angular is that most of the time you don't need to do any dom manipulation. You just have angular render the view they way your model is set (let angular do the dom manipulation for you and keep your code clean).

So basically in your case you would want to do something like below or check out this working example.

<button ng-click="isInput1ReadOnly = !isInput1ReadOnly">Click Me</button>
<input type="text" ng-readonly="isInput1ReadOnly" value="Angular Rules!"/>

How to have conditional elements and keep DRY with Facebook React's JSX?

As already mentioned in the answers, JSX presents you with two options

  • Ternary operator

    { this.state.price ? <div>{this.state.price}</div> : null }

  • Logical conjunction

    { this.state.price && <div>{this.state.price}</div> }


However, those don't work for price == 0.

JSX will render the false branch in the first case and in case of logical conjunction, nothing will be rendered. If the property may be 0, just use if statements outside of your JSX.

Sorting rows in a data table

I'm afraid you can't easily do an in-place sort of a DataTable like it sounds like you want to do.

What you can do is create a new DataTable from a DataView that you create from your original DataTable. Apply whatever sorts and/or filters you want on the DataView and then create a new DataTable from the DataView using the DataView.ToTable method:

   DataView dv = ft.DefaultView;
   dv.Sort = "occr desc";
   DataTable sortedDT = dv.ToTable();

How to close <img> tag properly?

Actually, only the first one is valid in HTML5

<img src='stackoverflow.png'>  

Only the last two are valid in XHTML

<img src='stackoverflow.png'></img>  
<img src='stackoverflow.png' />

(Though not stricly required, an alt attribute _usually_ should also be included).

That said, your HTML5 page will probably display as intended because browsers will rewrite or interpret your html to what it thinks you meant. That may mean it turns a tag, for example, from
<div /> into <div></div>. Or maybe it just ignores the final slash on <img ... />.
see 2016: Serve HTML5 as XHTML 5.0 for legacy validation.
see: 2011 discussion and additional links here, though over time some bits may have changed

Partly this is because browsers try very hard to error correct. Also, because there has much confusion about self-closing tags, and void tags. Finally, The spec has changed, or hasn't always been clear, and browsers try to be backwards compatible.

So, while you can probably get away with any of the three options,
only the first adheres to the HTML5 standard, and is guaranteed to pass a HTML5 validator.

A sound strategy might be to:

  • Write new code without the closing slash.
  • When re-factoring code, update nearby image tags, as you run across them.
  • Not overly worry about tags in legacy files that you do not touch, unless a particular need arises.

Here is a list of tags that should not be closed in HTML5:

 <br>    <hr>    <input>       
 <img>  <link>   <source>  
 <col>  <area>   <base>
 <meta> <embed>  <param>  
<track>  <wbr>   <keygen> (HTML 5.2 Draft removed)

Convert pandas DataFrame into list of lists

EDIT: as_matrix is deprecated since version 0.23.0

You can use the built in values or to_numpy (recommended option) method on the dataframe:

In [8]:
df.to_numpy()

Out[8]:
array([[  0.9,   7. ,   5.2, ...,  13.3,  13.5,   8.9],
   [  0.9,   7. ,   5.2, ...,  13.3,  13.5,   8.9],
   [  0.8,   6.1,   5.4, ...,  15.9,  14.4,   8.6],
   ..., 
   [  0.2,   1.3,   2.3, ...,  16.1,  16.1,  10.8],
   [  0.2,   1.3,   2.4, ...,  16.5,  15.9,  11.4],
   [  0.2,   1.3,   2.4, ...,  16.5,  15.9,  11.4]])

If you explicitly want lists and not a numpy array add .tolist():

df.to_numpy().tolist()

How to get terminal's Character Encoding

Check encoding and language:

$ echo $LC_CTYPE
ISO-8859-1
$ echo $LANG
pt_BR

Get all languages:

$ locale -a

Change to pt_PT.utf8:

$ export LC_ALL=pt_PT.utf8 
$ export LANG="$LC_ALL"

How to easily import multiple sql files into a MySQL database?

  1. Goto cmd

  2. Type in command prompt C:\users\Usersname>cd [.sql tables folder path ]
    Press Enter
    Ex: C:\users\Usersname>cd E:\project\database

  3. Type command prompt
    C:\users\Usersname>[.sql folder's drive (directory)name]
    Press Enter
    Ex: C:\users\Usersname>E:

  4. Type command prompt for marge all .sql file(table) in a single file
    copy /b *.sql newdatabase.sql
    Press Enter
    EX: E:\project\database>copy /b *.sql newdatabase.sql

  5. You can see Merge Multiple .sql(file) tables Files Into A Single File in your directory folder
    Ex: E:\project\database

http://localhost:50070 does not work HADOOP

if you are running and old version of Hadoop (hadoop 1.2) you got an error because http://localhost:50070/dfshealth.html does'nt exit. Check http://localhost:50070/dfshealth.jsp which works !

Identify duplicate values in a list in Python

These answers are O(n), so a little more code than using mylist.count() but much more efficient as mylist gets longer

If you just want to know the duplicates, use collections.Counter

from collections import Counter
mylist = [20, 30, 25, 20]
[k for k,v in Counter(mylist).items() if v>1]

If you need to know the indices,

from collections import defaultdict
D = defaultdict(list)
for i,item in enumerate(mylist):
    D[item].append(i)
D = {k:v for k,v in D.items() if len(v)>1}

How can I use console logging in Internet Explorer?

For IE8 or console support limited to console.log (no debug, trace, ...) you can do the following:

  • If console OR console.log undefined: Create dummy functions for console functions (trace, debug, log, ...)

    window.console = { debug : function() {}, ...};

  • Else if console.log is defined (IE8) AND console.debug (any other) is not defined: redirect all logging functions to console.log, this allows to keep those logs !

    window.console = { debug : window.console.log, ...};

Not sure about the assert support in various IE versions, but any suggestions are welcome.

Getting list of tables, and fields in each, in a database

Your other inbuilt friend here is the system sproc SP_HELP.

sample usage ::

sp_help <MyTableName>

It returns a lot more info than you will really need, but at least 90% of your possible requirements will be catered for.

Unit testing private methods in C#

From the book Working Effectively with Legacy Code:

"If we need to test a private method, we should make it public. If making it public bothers us, in most cases, it means that our class is doing too much and we ought to fix it."

The way to fix it, according to the author, is by creating a new class and adding the method as public.

The author explains further:

"Good design is testable, and design that isn't testable is bad."

So, within these limits, your only real option is to make the method public, either in the current or a new class.

Where is the Keytool application?

keytool is a tool to manage (public/private) security keys and certificates and store them in a Java KeyStore file (stored_file_name.jks).
It is provided with any standard JDK/JRE distributions.
You can find it under the following folder %JAVA_HOME%\bin.

SQL: Group by minimum value in one field while selecting distinct rows

select 
    department, 
    min_salary, 
    (select s1.last_name from staff s1 where s1.salary=s3.min_salary ) lastname 
from 
    (select department, min (salary) min_salary from staff s2 group by s2.department) s3

What's the best way to send a signal to all members of a process group?

brad's answer is what I'd recommend too, except that you can do away with awk altogether if you use the --ppid option to ps.

for child in $(ps -o pid -ax --ppid $PPID) do ....... done

How can JavaScript save to a local file?

So, your real question is: "How can JavaScript save to a local file?"

Take a look at http://www.tiddlywiki.com/

They save their HTML page locally after you have "changed" it internally.

[ UPDATE 2016.01.31 ]

TiddlyWiki original version saved directly. It was quite nice, and saved to a configurable backup directory with the timestamp as part of the backup filename.

TiddlyWiki current version just downloads it as any file download. You need to do your own backup management. :(

[ END OF UPDATE

The trick is, you have to open the page as file:// not as http:// to be able to save locally.

The security on your browser will not let you save to _someone_else's_ local system, only to your own, and even then it isn't trivial.

-Jesse

Keep overflow div scrolled to bottom unless user scrolls up

The following does what you need (I did my best, with loads of google searches along the way):

<html>
<head>
  <script>
    // no jquery, or other craziness. just
    // straight up vanilla javascript functions
    // to scroll a div's content to the bottom
    // if the user has not scrolled up.  Includes
    // a clickable "alert" for when "content" is
    // changed.

    // this should work for any kind of content
    // be it images, or links, or plain text
    // simply "append" the new element to the
    // div, and this will handle the rest as
    // proscribed.

    let scrolled = false; // at bottom?
    let scrolling = false; // scrolling in next msg?
    let listener = false; // does element have content changed listener?
    let contentChanged = false; // kind of obvious
    let alerted = false; // less obvious

    function innerHTMLChanged() {
      // this is here in case we want to
      // customize what goes on in here.
      // for now, just:
      contentChanged = true;
    }

    function scrollToBottom(id) {
      if (!id) { id = "scrollable_element"; }
      let DEBUG = 0; // change to 1 and open console
      let dstr = "";

      let e = document.getElementById(id);
      if (e) {
        if (!listener) {
          dstr += "content changed listener not active\n";
          e.addEventListener("DOMSubtreeModified", innerHTMLChanged);
          listener = true;
        } else {
          dstr += "content changed listener active\n";
        }
        let height = (e.scrollHeight - e.offsetHeight); // this isn't perfect
        let offset = (e.offsetHeight - e.clientHeight); // and does this fix it? seems to...
        let scrollMax = height + offset;

        dstr += "offsetHeight: " + e.offsetHeight + "\n";
        dstr += "clientHeight: " + e.clientHeight + "\n";
        dstr += "scrollHeight: " + e.scrollHeight + "\n";
        dstr += "scrollTop: " + e.scrollTop + "\n";
        dstr += "scrollMax: " + scrollMax + "\n";
        dstr += "offset: " + offset + "\n";
        dstr += "height: " + height + "\n";
        dstr += "contentChanged: " + contentChanged + "\n";

        if (!scrolled && !scrolling) {
          dstr += "user has not scrolled\n";
          if (e.scrollTop != scrollMax) {
            dstr += "scroll not at bottom\n";
            e.scroll({
              top: scrollMax,
              left: 0,
              behavior: "auto"
            })
            e.scrollTop = scrollMax;
            scrolling = true;
          } else {
            if (alerted) {
              dstr += "alert exists\n";
            } else {
              dstr += "alert does not exist\n";
            }
            if (contentChanged) { contentChanged = false; }
          }
        } else {
          dstr += "user scrolled away from bottom\n";
          if (!scrolling) {
            dstr += "not auto-scrolling\n";

            if (e.scrollTop >= scrollMax) {
              dstr += "scroll at bottom\n";
              scrolled = false;

              if (alerted) {
                dstr += "alert exists\n";
                let n = document.getElementById("alert");
                n.remove();
                alerted = false;
                contentChanged = false;
                scrolled = false;
              }
            } else {
              dstr += "scroll not at bottom\n";
              if (contentChanged) {
                dstr += "content changed\n";
                if (!alerted) {
                  dstr += "alert not displaying\n";
                  let n = document.createElement("div");
                  e.append(n);
                  n.id = "alert";
                  n.style.position = "absolute";
                  n.classList.add("normal-panel");
                  n.classList.add("clickable");
                  n.classList.add("blink");
                  n.innerHTML = "new content!";

                  let nposy = parseFloat(getComputedStyle(e).height) + 18;
                  let nposx = 18 + (parseFloat(getComputedStyle(e).width) / 2) - (parseFloat(getComputedStyle(n).width) / 2);
                  dstr += "nposx: " + nposx + "\n";
                  dstr += "nposy: " + nposy + "\n";
                  n.style.left = nposx;
                  n.style.top = nposy;

                  n.addEventListener("click", () => {
                    dstr += "clearing alert\n";
                    scrolled = false;
                    alerted = false;
                    contentChanged = false;
                    n.remove();
                  });

                  alerted = true;
                } else {
                  dstr += "alert already displayed\n";
                }
              } else {
                alerted = false;
              }
            }
          } else {
            dstr += "auto-scrolling\n";
            if (e.scrollTop >= scrollMax) {
              dstr += "done scrolling";
              scrolling = false;
              scrolled = false;
            } else {
              dstr += "still scrolling...\n";
            }
          }
        }
      }

      if (DEBUG && dstr) console.log("stb:\n" + dstr);

      setTimeout(() => { scrollToBottom(id); }, 50);
    }

    function scrollMessages(id) {
      if (!id) { id = "scrollable_element"; }
      let DEBUG = 1;
      let dstr = "";

      if (scrolled) {
        dstr += "already scrolled";
      } else {
        dstr += "got scrolled";
        scrolled = true;
      }
      dstr += "\n";

      if (contentChanged && alerted) {
        dstr += "content changed, and alerted\n";
        let n = document.getElementById("alert");
        if (n) {
          dstr += "alert div exists\n";
          let e = document.getElementById(id);
          let nposy = parseFloat(getComputedStyle(e).height) + 18;
          dstr += "nposy: " + nposy + "\n";
          n.style.top = nposy;
        } else {
          dstr += "alert div does not exist!\n";
        }
      } else {
        dstr += "content NOT changed, and not alerted";
      }

      if (DEBUG && dstr) console.log("sm: " + dstr);
    }

    setTimeout(() => { scrollToBottom("messages"); }, 1000);

    /////////////////////
    // HELPER FUNCTION
    //   simulates adding dynamic content to "chat" div
    let count = 0;
    function addContent() {
      let e = document.getElementById("messages");
      if (e) {
        let br = document.createElement("br");
        e.append("test " + count);
        e.append(br);
        count++;
      }
    }
  </script>

  <style>
    button {
      border-radius: 5px;
    }

    #container {
      padding: 5px;
    }

    #messages {
      background-color: blue;
      border: 1px inset black;
      border-radius: 3px;
      color: white;
      padding: 5px;
      overflow-x: none;
      overflow-y: auto;
      max-height: 100px;
      width: 100px;
      margin-bottom: 5px;
      text-align: left;
    }

    .bordered {
      border: 1px solid black;
      border-radius: 5px;
    }

    .inline-block {
      display: inline-block;
    }

    .centered {
      text-align: center;
    }

    .normal-panel {
      background-color: #888888;
      border: 1px solid black;
      border-radius: 5px;
      padding: 2px;
    }

    .clickable {
      cursor: pointer;
    }
  </style>
</head>
<body>
<div id="container" class="bordered inline-block centered">
  <div class="inline-block">My Chat</div>

  <div id="messages" onscroll="scrollMessages('messages')">
    test<br>
    test<br>
    test<br>
    test<br>
    test<br>
    test<br>
    test<br>
    test<br>
    test<br>
    test<br>
  </div>

  <button onclick="addContent();">Add Content</button>
</div>
</body>
</html>

Note: You may have to adjust the alert position (nposx and nposy) in both scrollToBottom and scrollMessages to match your needs...

And a link to my own working example, hosted on my server: https://night-stand.ca/jaretts_tests/chat_scroll.html

Left Outer Join using + sign in Oracle 11g

Those two queries are performing OUTER JOIN. See below

Oracle recommends that you use the FROM clause OUTER JOIN syntax rather than the Oracle join operator. Outer join queries that use the Oracle join operator (+) are subject to the following rules and restrictions, which do not apply to the FROM clause OUTER JOIN syntax:

  • You cannot specify the (+) operator in a query block that also contains FROM clause join syntax.

  • The (+) operator can appear only in the WHERE clause or, in the context of left- correlation (when specifying the TABLE clause) in the FROM clause, and can be applied only to a column of a table or view.

  • If A and B are joined by multiple join conditions, then you must use the (+) operator in all of these conditions. If you do not, then Oracle Database will return only the rows resulting from a simple join, but without a warning or error to advise you that you do not have the results of an outer join.

  • The (+) operator does not produce an outer join if you specify one table in the outer query and the other table in an inner query.

  • You cannot use the (+) operator to outer-join a table to itself, although self joins are valid. For example, the following statement is not valid:

    -- The following statement is not valid:
    SELECT employee_id, manager_id
       FROM employees
       WHERE employees.manager_id(+) = employees.employee_id;
    

    However, the following self join is valid:

    SELECT e1.employee_id, e1.manager_id, e2.employee_id
       FROM employees e1, employees e2
       WHERE e1.manager_id(+) = e2.employee_id
       ORDER BY e1.employee_id, e1.manager_id, e2.employee_id;
    
  • The (+) operator can be applied only to a column, not to an arbitrary expression. However, an arbitrary expression can contain one or more columns marked with the (+) operator.

  • A WHERE condition containing the (+) operator cannot be combined with another condition using the OR logical operator.

  • A WHERE condition cannot use the IN comparison condition to compare a column marked with the (+) operator with an expression.

If the WHERE clause contains a condition that compares a column from table B with a constant, then the (+) operator must be applied to the column so that Oracle returns the rows from table A for which it has generated nulls for this column. Otherwise Oracle returns only the results of a simple join.

In a query that performs outer joins of more than two pairs of tables, a single table can be the null-generated table for only one other table. For this reason, you cannot apply the (+) operator to columns of B in the join condition for A and B and the join condition for B and C. Refer to SELECT for the syntax for an outer join.

Taken from http://download.oracle.com/docs/cd/B28359_01/server.111/b28286/queries006.htm

Gerrit error when Change-Id in commit messages are missing

Try this:

git commit --amend

Then copy and paste the Change-Id: I55862204ef71f69bc88c79fe2259f7cb8365699a at the end of the file.

Save it and push it again!

Python MySQLdb TypeError: not all arguments converted during string formatting

Instead of this:

cur.execute( "SELECT * FROM records WHERE email LIKE '%s'", search )

Try this:

cur.execute( "SELECT * FROM records WHERE email LIKE %s", [search] )

See the MySQLdb documentation. The reasoning is that execute's second parameter represents a list of the objects to be converted, because you could have an arbitrary number of objects in a parameterized query. In this case, you have only one, but it still needs to be an iterable (a tuple instead of a list would also be fine).

In Spring MVC, how can I set the mime type header when using @ResponseBody

I don't think you can, apart from response.setContentType(..)

Easiest way to toggle 2 classes in jQuery

Here is a simplified version: (albeit not elegant, but easy-to-follow)

$("#yourButton").toggle(function() 
{
        $('#target').removeClass("a").addClass("b"); //Adds 'a', removes 'b'

}, function() {
        $('#target').removeClass("b").addClass("a"); //Adds 'b', removes 'a'

});

Alternatively, a similar solution:

$('#yourbutton').click(function()
{
     $('#target').toggleClass('a b'); //Adds 'a', removes 'b' and vice versa
});

How do I show a console output/window in a forms application?

You can call AttachConsole using pinvoke to get a console window attached to a WinForms project: http://www.csharp411.com/console-output-from-winforms-application/

You may also want to consider Log4net ( http://logging.apache.org/log4net/index.html ) for configuring log output in different configurations.

Checking if an object is a given type in Swift

Be warned about this:

var string = "Hello" as NSString
var obj1:AnyObject = string
var obj2:NSObject = string

print(obj1 is NSString)
print(obj2 is NSString)
print(obj1 is String)
print(obj2 is String) 

All of the four last lines return true, this is because if you type

var r1:CGRect = CGRect()
print(r1 is String)

... it prints "false" of course, but a Warning says that the Cast from CGRect to String fails. So some type are bridged, ans the 'is' keyword calls an implicit cast.

You should better use one of these:

myObject.isKind(of: MyClass.self)) 
myObject.isMember(of: MyClass.self))

Matrix Multiplication in pure Python?

All the below answers would return you the list.Your need to convert it to matrix

def MATMUL(X, Y):
    rows_A = len(X)
    cols_A = len(X[0])
    rows_B = len(Y)
    cols_B = len(Y[0])

    if cols_A != rows_B:
        print "Matrices are not compatible to Multiply. Check condition C1==R2"
        return

    # Create the result matrix
    # Dimensions would be rows_A x cols_B
    C = [[0 for row in range(cols_B)] for col in range(rows_A)]
    print C

    for i in range(rows_A):
        for j in range(cols_B):
            for k in range(cols_A):
                C[i][j] += A[i][k] * B[k][j]

    C = numpy.matrix(C).reshape(len(A),len(B[0]))

    return C

How to convert std::chrono::time_point to calendar datetime string with fractional seconds?

I would have put this in a comment on the accepted answer, since that's where it belongs, but I can't. So, just in case anyone gets unreliable results, this could be why.

Be careful of the accepted answer, it fails if the time_point is before the epoch.

This line of code:

std::size_t fractional_seconds = ms.count() % 1000;

will yield unexpected values if ms.count() is negative (since size_t is not meant to hold negative values).

Visual Studio 2015 Update 3 Offline Installer (ISO)

You can check Visual Studio Downloads for available Visual Studio Community, Visual Studio Professional, Visual Studio Enterprise and Visual Studio Code download links.


Update!

There is no direct links of Visual Studio 2015 at Visual Studio Downloads anymore. but the below links still works.


OR simply click on direct links below (for .iso/.exe file):


VSCode area:

Automatically open Chrome developer tools when new tab/new window is opened

On opening the developer tools, with the developer tools window in focus, press F1. This will open a settings page. Check the "Auto-open DevTools for popups".

This worked for me.

Screenshot

Installing Google Protocol Buffers on mac

If you landed here looking for how to install Protocol Buffers on Mac, it can be done using Homebrew by running the command below

brew install protobuf

It installs the latest version of protobuf available. For me, at the time of writing, this installed the v3.7.1

If you'd like to install an older version, please look up the available ones from the package page Protobuf Package - Homebrew and install that specific version of the package.

The oldest available protobuf version in this package is v3.6.1.3

Unable to locate Spring NamespaceHandler for XML schema namespace [http://www.springframework.org/schema/security]

I had the same problem. The only thing that solved it was merge the content of META-INF/spring.handler and META-INF/spring.schemas of each spring jar file into same file names under my META-INF project.

This two threads explain it better:

You don't have write permissions for the /var/lib/gems/2.3.0 directory

Reinstalling Compass worked for me.. It's a magic!

sudo gem install -n /usr/local/bin compass

Automatically accept all SDK licences

Ok FOR ANYONE HAVING THIS ISSUE AS OF 2018. The above answers did NOT work for me at all. What DID work was opening Android SDK - clicking the DOWNLOAD button on the tool bar and selecting the appropriate packages. After they finish downloading, it will let you accept the license agreement.

enter image description here

How to add a scrollbar to an HTML5 table?

My simplest solution is based on fixed columns layout. You'll have to set the width of each column, for example: 4 columns 100px each is equal to 400px total width.

table {
  table-layout: fixed;
  width: 400px;
}
td, th {
  width: 100px;
}

The fixed table layout algorithm has many advantages over the automatic table layout algorithm (for example: the horizontal layout only depends on the table's width and the width of the columns, not the contents of the cells; allows a browser to lay out the table faster than the automatic table layout; the browser can begin to display the table once the first row has been received; etc.)

Then, you'll have to separate the thead from the tbody by forcing their display style to block rather than to the default table-*

thead tr {
  display: block;
}
tbody {
  display: block;
  height: 256px;
  overflow-y: auto;
}

That what will make the tbody scrollable as a separate box and the thead unrelated from it. And that's the main reason why you had to fix the column widths as done above.

Working JsFiddle: https://jsfiddle.net/angiolep/65q1gdcy/1/

Date format in the json output using spring boot

Starting from Spring Boot version 1.2.0.RELEASE , there is a property you can add to your application.properties to set a default date format to all of your classes spring.jackson.date-format.

For your date format example, you would add this line to your properties file:

spring.jackson.date-format=yyyy-MM-dd

Reference https://docs.spring.io/spring-boot/docs/1.2.0.RELEASE/reference/html/common-application-properties.html

Is there a way to programmatically scroll a scroll view to a specific edit text?

I think I have found more elegant and less error prone solution using

ScrollView.requestChildRectangleOnScreen

There is no math involved, and contrary to other proposed solutions, it will handle correctly scrolling both up and down.

/**
 * Will scroll the {@code scrollView} to make {@code viewToScroll} visible
 * 
 * @param scrollView parent of {@code scrollableContent}
 * @param scrollableContent a child of {@code scrollView} whitch holds the scrollable content (fills the viewport).
 * @param viewToScroll a child of {@code scrollableContent} to whitch will scroll the the {@code scrollView}
 */
void scrollToView(ScrollView scrollView, ViewGroup scrollableContent, View viewToScroll) {
    Rect viewToScrollRect = new Rect(); //coordinates to scroll to
    viewToScroll.getHitRect(viewToScrollRect); //fills viewToScrollRect with coordinates of viewToScroll relative to its parent (LinearLayout) 
    scrollView.requestChildRectangleOnScreen(scrollableContent, viewToScrollRect, false); //ScrollView will make sure, the given viewToScrollRect is visible
}

It is a good idea to wrap it into postDelayed to make it more reliable, in case the ScrollView is being changed at the moment

/**
 * Will scroll the {@code scrollView} to make {@code viewToScroll} visible
 * 
 * @param scrollView parent of {@code scrollableContent}
 * @param scrollableContent a child of {@code scrollView} whitch holds the scrollable content (fills the viewport).
 * @param viewToScroll a child of {@code scrollableContent} to whitch will scroll the the {@code scrollView}
 */
private void scrollToView(final ScrollView scrollView, final ViewGroup scrollableContent, final View viewToScroll) {
    long delay = 100; //delay to let finish with possible modifications to ScrollView
    scrollView.postDelayed(new Runnable() {
        public void run() {
            Rect viewToScrollRect = new Rect(); //coordinates to scroll to
            viewToScroll.getHitRect(viewToScrollRect); //fills viewToScrollRect with coordinates of viewToScroll relative to its parent (LinearLayout) 
            scrollView.requestChildRectangleOnScreen(scrollableContent, viewToScrollRect, false); //ScrollView will make sure, the given viewToScrollRect is visible
        }
    }, delay);
}

Jquery Ajax Posting json to webservice

I have encountered this one too and this is my solution.

If you are encountering an invalid json object exception when parsing data, even though you know that your json string is correct, stringify the data you received in your ajax code before parsing it to JSON:

$.post(CONTEXT+"servlet/capture",{
        yesTransactionId : yesTransactionId, 
        productOfferId : productOfferId
        },
        function(data){
            try{
                var trimData = $.trim(JSON.stringify(data));
                var obj      = $.parseJSON(trimData);
                if(obj.success == 'true'){ 
                    //some codes ...

Connect Device to Mac localhost Server?

make sure you phone and mac machine both connected to the same wifi and you good to go your http://<machine-name>.local

How to deep watch an array in angularjs?

There are performance consequences to deep-diving an object in your $watch. Sometimes (for example, when changes are only pushes and pops), you might want to $watch an easily calculated value, such as array.length.

How to measure time taken between lines of code in python?

I always prefer to check time in hours, minutes and seconds (%H:%M:%S) format:

from datetime import datetime
start = datetime.now()
# your code
end = datetime.now()
time_taken = end - start
print('Time: ',time_taken) 

output:

Time:  0:00:00.000019

Checking if a variable exists in javascript

if (variable) can be used if variable is guaranteed to be an object, or if false, 0, etc. are considered "default" values (hence equivalent to undefined or null).

typeof variable == 'undefined' can be used in cases where a specified null has a distinct meaning to an uninitialised variable or property. This check will not throw and error is variable is not declared.

Most efficient way to append arrays in C#?

Here is a usable class based on what Constantin said:

class Program
{
    static void Main(string[] args)
    {
        FastConcat<int> i = new FastConcat<int>();
        i.Add(new int[] { 0, 1, 2, 3, 4 });
        Console.WriteLine(i[0]);
        i.Add(new int[] { 5, 6, 7, 8, 9 });
        Console.WriteLine(i[4]);

        Console.WriteLine("Enumerator:");
        foreach (int val in i)
            Console.WriteLine(val);

        Console.ReadLine();
    }
}

class FastConcat<T> : IEnumerable<T>
{
    LinkedList<T[]> _items = new LinkedList<T[]>();
    int _count;

    public int Count
    {
        get
        {
            return _count;
        }
    }

    public void Add(T[] items)
    {
        if (items == null)
            return;
        if (items.Length == 0)
            return;

        _items.AddLast(items);
        _count += items.Length;
    }

    private T[] GetItemIndex(int realIndex, out int offset)
    {
        offset = 0; // Offset that needs to be applied to realIndex.
        int currentStart = 0; // Current index start.

        foreach (T[] items in _items)
        {
            currentStart += items.Length;
            if (currentStart > realIndex)
                return items;
            offset = currentStart;
        }
        return null;
    }

    public T this[int index]
    {
        get
        {
            int offset;
            T[] i = GetItemIndex(index, out offset);
            return i[index - offset];
        }
        set
        {
            int offset;
            T[] i = GetItemIndex(index, out offset);
            i[index - offset] = value;
        }
    }

    #region IEnumerable<T> Members

    public IEnumerator<T> GetEnumerator()
    {
        foreach (T[] items in _items)
            foreach (T item in items)
                yield return item;
    }

    #endregion

    #region IEnumerable Members

    System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
    {
        return GetEnumerator();
    }

    #endregion
}

Simplest way to read json from a URL in java

I wanted to add an updated answer here since (somewhat) recent updates to the JDK have made it a bit easier to read the contents of an HTTP URL. Like others have said, you'll still need to use a JSON library to do the parsing, since the JDK doesn't currently contain one. Here are a few of the most commonly used JSON libraries for Java:

To retrieve JSON from a URL, this seems to be the simplest way using strictly JDK classes (but probably not something you'd want to do for large payloads), Java 9 introduced: https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/io/InputStream.html#readAllBytes()

try(java.io.InputStream is = new java.net.URL("https://graph.facebook.com/me").openStream()) {
    String contents = new String(is.readAllBytes());
}

To parse the JSON using the GSON library, for example

com.google.gson.JsonElement element = com.google.gson.JsonParser.parseString(contents); //from 'com.google.code.gson:gson:2.8.6'

Call PowerShell script PS1 from another PS1 script inside Powershell ISE

To execute easily a script file in the same folder (or subfolder of) as the caller you can use this:

# Get full path to the script:
$ScriptRoute = [System.IO.Path]::GetFullPath([System.IO.Path]::Combine($PSScriptRoot, "Scriptname.ps1"))

# Execute script at location:
&"$ScriptRoute"

Decimal separator comma (',') with numberDecimal inputType in EditText

Following Code Currency Mask for EditText ($ 123,125.155)

Xml Layout

  <EditText
    android:inputType="numberDecimal"
    android:layout_height="wrap_content"
    android:layout_width="200dp"
    android:digits="0123456789.,$" />

Code

EditText testFilter=...
testFilter.addTextChangedListener( new TextWatcher() {
        boolean isEdiging;
        @Override public void onTextChanged(CharSequence s, int start, int before, int count) { }
        @Override public void beforeTextChanged(CharSequence s, int start, int count, int after) { }

        @Override public void afterTextChanged(Editable s) {
            if(isEdiging) return;
            isEdiging = true;

            String str = s.toString().replaceAll( "[^\\d]", "" );
            double s1 = Double.parseDouble(str);

            NumberFormat nf2 = NumberFormat.getInstance(Locale.ENGLISH);
            ((DecimalFormat)nf2).applyPattern("$ ###,###.###");
            s.replace(0, s.length(), nf2.format(s1));

            isEdiging = false;
        }
    });

Hibernate Query By Example and Projections

I do not really think so, what I can find is the word "this." causes the hibernate not to include any restrictions in its query, which means it got all the records lists. About the hibernate bug that was reported, I can see it's reported as fixed but I totally failed to download the Patch.

How to make a Java thread wait for another thread's output?

You could do it using an Exchanger object shared between the two threads:

private Exchanger<String> myDataExchanger = new Exchanger<String>();

// Wait for thread's output
String data;
try {
  data = myDataExchanger.exchange("");
} catch (InterruptedException e1) {
  // Handle Exceptions
}

And in the second thread:

try {
    myDataExchanger.exchange(data)
} catch (InterruptedException e) {

}

As others have said, do not take this light-hearted and just copy-paste code. Do some reading first.

Error in finding last used cell in Excel with VBA

Find Last Row in a Column OR a Table Column(ListObject) by range

Finding the last row requires:

  1. Specifying several parameters (table name, column inside table relative to first column, worksheet, range).
  2. May require switching between methods. e.g. if the range is a Table (List Object) or not. Using the wrong search type will return wrong results.

This proposed solution is more general, requires only the range ,less chance of typos and is short (just calling MyLastRow function).

Sub test()
Dim rng As Range
Dim Result As Long
Set rng = Worksheets(1).Range("D4")
Result = MyLastRow(rng)
End Sub
    Function MyLastRow(FirstRow As Range) As Long
    Dim WS As Worksheet
    Dim TableName As String
    Dim ColNumber As Long
    Dim LastRow As Long
    Dim FirstColumnTable As Long
    Dim ColNumberTable As Long
    Set WS = FirstRow.Worksheet
    TableName = GetTableName(FirstRow)
    ColNumber = FirstRow.Column
    
    ''If the table (ListObject) does not start in column "A" we need to calculate the 
    ''first Column table and how many Columns from its beginning the Column is located.
    If TableName <> vbNullString Then
     FirstColumnTable = WS.ListObjects(TableName).ListColumns(1).Range.Column
     ColNumberTable = ColNumber - FirstColumnTable + 1
    End If 

    If TableName = vbNullString Then
    LastRow = WS.Cells(WS.Rows.Count, ColNumber).End(xlUp).Row
    Else
    LastRow = WS.ListObjects(TableName).ListColumns(ColNumberTable).Range.Find( _
               What:="*", SearchOrder:=xlByRows, SearchDirection:=xlPrevious).Row
    End If
    MyLastRow = LastRow
    End Function
    
    ''Get Table Name by Cell Range
    Function GetTableName(CellRange As Range) As String
        If CellRange.ListObject Is Nothing Then
            GetTableName = vbNullString
        Else
            GetTableName = CellRange.ListObject.Name
        End If
    End Function

Rails - Could not find a JavaScript runtime?

if you already install nodejs from source for example, and execjs isn't recognizing it you might want to try this tip: https://coderwall.com/p/hyjdlw

git remote add with other SSH port

For those of you editing the ./.git/config

[remote "external"]                                                                                                                                                                                                                                                            
  url = ssh://[email protected]:11720/aaa/bbb/ccc                                                                                                                                                                                                               
  fetch = +refs/heads/*:refs/remotes/external/* 

PLS-00201 - identifier must be declared

you should give permission on your db

grant execute on (packageName or tableName) to user;

How do I get an OAuth 2.0 authentication token in C#

Here is a complete example. Right click on the solution to manage nuget packages and get Newtonsoft and RestSharp:

using Newtonsoft.Json.Linq;
using RestSharp;
using System;


namespace TestAPI
{
    class Program
    {
        static void Main(string[] args)
        {
            String id = "xxx";
            String secret = "xxx";

            var client = new RestClient("https://xxx.xxx.com/services/api/oauth2/token");
            var request = new RestRequest(Method.POST);
            request.AddHeader("cache-control", "no-cache");
            request.AddHeader("content-type", "application/x-www-form-urlencoded");
            request.AddParameter("application/x-www-form-urlencoded", "grant_type=client_credentials&scope=all&client_id=" + id + "&client_secret=" + secret, ParameterType.RequestBody);
            IRestResponse response = client.Execute(request);

            dynamic resp = JObject.Parse(response.Content);
            String token = resp.access_token;            

            client = new RestClient("https://xxx.xxx.com/services/api/x/users/v1/employees");
            request = new RestRequest(Method.GET);
            request.AddHeader("authorization", "Bearer " + token);
            request.AddHeader("cache-control", "no-cache");
            response = client.Execute(request);
        }        
    }
}

Convert UTC to local time in Rails 3

It is easy to configure it using your system local zone, Just in your application.rb add this

config.time_zone = Time.now.zone

Then, rails should show you timestamps in your localtime or you can use something like this instruction to get the localtime

Post.created_at.localtime

What is the most efficient way to create HTML elements using jQuery?

You'll have to understand that the significance of element creation performance is irrelevant in the context of using jQuery in the first place.

Keep in mind, there's no real purpose of creating an element unless you're actually going to use it.

You may be tempted to performance test something like $(document.createElement('div')) vs. $('<div>') and get great performance gains from using $(document.createElement('div')) but that's just an element that isn't in the DOM yet.

However, in the end of the day, you'll want to use the element anyway so the real test should include f.ex. .appendTo();

Let's see, if you test the following against each other:

var e = $(document.createElement('div')).appendTo('#target');
var e = $('<div>').appendTo('#target');
var e = $('<div></div>').appendTo('#target');
var e = $('<div/>').appendTo('#target');

You will notice the results will vary. Sometimes one way is better performing than the other. And this is only because the amount of background tasks on your computer change over time.

Test yourself here

So, in the end of the day, you do want to pick the smallest and most readable way of creating an element. That way, at least, your script files will be smallest possible. Probably a more significant factor on the performance point than the way of creating an element before you use it in the DOM.

How to determine previous page URL in Angular?

I had similar problem when I had wanted to back to previous page. Solution was easier than I could imagine.

<button [routerLink]="['../']">
   Back
</button>

And it returns to parent url. I hope it will help someone ;)

How can I implement a theme from bootswatch or wrapbootstrap in an MVC 5 project?

I do have an article on MSDN - Creating ASP.NET MVC with custom bootstrap theme / layout using VS 2012, VS 2013 and VS 2015, also have a demo code sample attached.. Please refer below link. https://code.msdn.microsoft.com/ASPNET-MVC-application-62ffc106

Difference between DOMContentLoaded and load events

Here's some code that works for us. We found MSIE to be hit and miss with DomContentLoaded, there appears to be some delay when no additional resources are cached (up to 300ms based on our console logging), and it triggers too fast when they are cached. So we resorted to a fallback for MISE. You also want to trigger the doStuff() function whether DomContentLoaded triggers before or after your external JS files.

// detect MSIE 9,10,11, but not Edge
ua=navigator.userAgent.toLowerCase();isIE=/msie/.test(ua);

function doStuff(){
    //
}
if(isIE){
    // play it safe, very few users, exec ur JS when all resources are loaded
    window.onload=function(){doStuff();}
} else {
    // add event listener to trigger your function when DOMContentLoaded
    if(document.readyState==='loading'){
        document.addEventListener('DOMContentLoaded',doStuff);
    } else {
        // DOMContentLoaded already loaded, so better trigger your function
        doStuff();
    }
}

How to access array elements in a Django template?

You can access sequence elements with arr.0 arr.1 and so on. See The Django template system chapter of the django book for more information.

AngularJs ReferenceError: angular is not defined

Always make sure that js file (angular.min.js) is referenced first in the HTML file. For example:

----------------- This reference will THROW error -------------------------

< script src="otherXYZ.js"></script>
< script src="angular.min.js"></script>

----------------- This reference will WORK as expected -------------------

< script src="angular.min.js"></script>
< script src="otherXYZ.js"></script>

HTML character codes for this ? or this ?

You don't need to use character codes; just use UTF-8 and put them in literally; like so:

??

If you absolutely must use the entites, they are &#x25b2; and &#x25bc;, respectively.

What is the intended use-case for git stash?

You can use the following commands:

  • To save your uncommitted changes

    git stash

  • To list your saved stashes

    git stash list

  • To apply/get back the uncommited changes where x is 0,1,2...

    git stash apply stash@{x}

Note:

  • To apply a stash and remove it from the stash list

    git stash pop stash@{x}

  • To apply a stash and keep it in the stash list

    git stash apply stash@{x}

How to use glob() to find files recursively?

If the files are on a remote file system or inside an archive, you can use an implementation of the fsspec AbstractFileSystem class. For example, to list all the files in a zipfile:

from fsspec.implementations.zip import ZipFileSystem
fs = ZipFileSystem("/tmp/test.zip")
fs.glob("/**")  # equivalent: fs.find("/")

or to list all the files in a publicly available S3 bucket:

from s3fs import S3FileSystem
fs_s3 = S3FileSystem(anon=True)
fs_s3.glob("noaa-goes16/ABI-L1b-RadF/2020/045/**")  # or use fs_s3.find

you can also use it for a local filesystem, which may be interesting if your implementation should be filesystem-agnostic:

from fsspec.implementations.local import LocalFileSystem
fs = LocalFileSystem()
fs.glob("/tmp/test/**")

Other implementations include Google Cloud, Github, SFTP/SSH, Dropbox, and Azure. For details, see the fsspec API documentation.

how to parse json using groovy

That response is a Map, with a single element with key '212315952136472'. There's no 'data' key in the Map. If you want to loop through all entries, use something like this:

JSONObject userJson = JSON.parse(jsonResponse)
userJson.each { id, data -> println data.link }

If you know it's a single-element Map then you can directly access the link:

def data = userJson.values().iterator().next()
String link = data.link

And if you knew the id (e.g. if you used it to make the request) then you can access the value more concisely:

String id = '212315952136472'
...
String link = userJson[id].link

Opening a CHM file produces: "navigation to the webpage was canceled"

Summary

Microsoft Security Updates 896358 & 840315 block display of CHM file contents when opened from a network drive (or a UNC path). This is Windows' attempt to stop attack vectors for viruses/malware from infecting your computer and has blocked out the .chm file that draw data over the "InfoTech" protocol, which this chm file uses.

Microsoft's summary of the problem: http://support.microsoft.com/kb/896054

Solutions

  1. If you are using Windows Server 2008, Windows 7, windows has created a quick fix. Right click the chm file, and you will get the "yourfile.chm Properties" dialog box, at the bottom, a button called "Unblock" appears. Click Unblock and press OK, and try to open the chm file again, it works correctly. This option is not available for earlier versions of Windows before WindowsXP (SP3).

  2. Solve the problem by moving your chm file OFF the network drive. You may be unaware you are using a network drive, double check now: Right click your .chm file, click properties and look at the "location" field. If it starts with two backslashes like this: \\epicserver\blah\, then you are using a networked drive. So to fix it, Copy the chm file, and paste it into a local drive, like C:\ or E:. Then try to reopen the chm file, windows does not freak out.

  3. Last resort, if you can't copy/move the file off the networked drive. If you must open it where it sits, and you are using a lesser version of windows like XP, Vista, ME or other, you will have to manually tell Windows not to freak out over this .chm file. HHReg (HTML Help Registration Utility) Utility Automates this Task. Basically you download the HHReg utility, load your .chm file, press OK, and it will create the necessary registry keys to tell Windows not to block it. For more info: http://www.winhelponline.com/blog/fix-cannot-view-chm-files-network-xp-2003-vista/

Windows 8 or 10? --> Upgrade to Windows XP.

cannot download, $GOPATH not set

(for MAC)

I tried all these answers and, for some still unknown reason, none of them worked.

I had to "force feed" the GOPATH by setting the environment variable per every command that required it. For example:

sudo env GOPATH=$HOME/goWorkDirectory go build ...

Even glide was giving me the GOPATH not set error. Resolved it, again, by "force feeding": I tried all these answers and, for some still unknown reason, none of them worked.

I had to "force feed" the GOPATH by setting the environment variable per every command that required it.

sudo env GOPATH=$HOME/goWorkDirectory glide install

Hope this helps someone.

Google Play Services GCM 9.2.0 asks to "update" back to 9.0.0

I didn't have an issue with this until I tried to use the Location Services, at which point I had to put the apply plugin: 'com.google.gms.google-services' at the bottom of the file, rather than the top. The reason being that when you have it at the top there are collision issues, and by placing it at the bottom, you avoid those issue.

how to add a day to a date using jquery datepicker

The datepicker('setDate') sets the date in the datepicket not in the input.

You should add the date and set it in the input.

var date2 = $('.pickupDate').datepicker('getDate');
var nextDayDate = new Date();
nextDayDate.setDate(date2.getDate() + 1);
$('input').val(nextDayDate);

How to highlight text using javascript

Since HTML5 you can use the <mark></mark> tags to highlight text. You can use javascript to wrap some text/keyword between these tags. Here is a little example of how to mark and unmark text.

JSFIDDLE DEMO

Where/how can I download (and install) the Microsoft.Jet.OLEDB.4.0 for Windows 8, 64 bit?

On modern Windows this driver isn't available by default anymore, but you can download as Microsoft Access Database Engine 2010 Redistributable on the MS site. If your app is 32 bits be sure to download and install the 32 bits variant because to my knowledge the 32 and 64 bit variant cannot coexist.

Depending on how your app locates its db driver, that might be all that's needed. However, if you use an UDL file there's one extra step - you need to edit that file. Unfortunately, on a 64bits machine the wizard used to edit UDL files is 64 bits by default, it won't see the JET driver and just slap whatever driver it finds first in the UDL file. There are 2 ways to solve this issue:

  1. start the 32 bits UDL wizard like this: C:\Windows\syswow64\rundll32.exe "C:\Program Files (x86)\Common Files\System\Ole DB\oledb32.dll",OpenDSLFile C:\path\to\your.udl. Note that I could use this technique on a Win7 64 Pro, but it didn't work on a Server 2008R2 (could be my mistake, just mentioning)
  2. open the UDL file in Notepad or another text editor, it should more or less have this format:

[oledb] ; Everything after this line is an OLE DB initstring Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Path\To\The\database.mdb;Persist Security Info=False

That should allow your app to start correctly.

What does request.getParameter return?

Both if (one.length() > 0) {} and if (!"".equals(one)) {} will check against an empty foo parameter, and an empty parameter is what you'd get if the the form is submitted with no value in the foo text field.

If there's any chance you can use the Expression Language to handle the parameter, you could access it with empty param.foo in an expression.

<c:if test='${not empty param.foo}'>
    This page code gets rendered.
</c:if>

How many socket connections can a web server handle?

In short: You should be able to achieve in the order of millions of simultaneous active TCP connections and by extension HTTP request(s). This tells you the maximum performance you can expect with the right platform with the right configuration.

Today, I was worried whether IIS with ASP.NET would support in the order of 100 concurrent connections (look at my update, expect ~10k responses per second on older ASP.Net Mono versions). When I saw this question/answers, I couldn't resist answering myself, many answers to the question here are completely incorrect.

Best Case

The answer to this question must only concern itself with the simplest server configuration to decouple from the countless variables and configurations possible downstream.

So consider the following scenario for my answer:

  1. No traffic on the TCP sessions, except for keep-alive packets (otherwise you would obviously need a corresponding amount of network bandwidth and other computer resources)
  2. Software designed to use asynchronous sockets and programming, rather than a hardware thread per request from a pool. (ie. IIS, Node.js, Nginx... webserver [but not Apache] with async designed application software)
  3. Good performance/dollar CPU / Ram. Today, arbitrarily, let's say i7 (4 core) with 8GB of RAM.
  4. A good firewall/router to match.
  5. No virtual limit/governor - ie. Linux somaxconn, IIS web.config...
  6. No dependency on other slower hardware - no reading from harddisk, because it would be the lowest common denominator and bottleneck, not network IO.

Detailed Answer

Synchronous thread-bound designs tend to be the worst performing relative to Asynchronous IO implementations.

WhatsApp can handle a million WITH traffic on a single Unix flavoured OS machine - https://blog.whatsapp.com/index.php/2012/01/1-million-is-so-2011/.

And finally, this one, http://highscalability.com/blog/2013/5/13/the-secret-to-10-million-concurrent-connections-the-kernel-i.html, goes into a lot of detail, exploring how even 10 million could be achieved. Servers often have hardware TCP offload engines, ASICs designed for this specific role more efficiently than a general purpose CPU.

Good software design choices

Asynchronous IO design will differ across Operating Systems and Programming platforms. Node.js was designed with asynchronous in mind. You should use Promises at least, and when ECMAScript 7 comes along, async/await. C#/.Net already has full asynchronous support like node.js. Whatever the OS and platform, asynchronous should be expected to perform very well. And whatever language you choose, look for the keyword "asynchronous", most modern languages will have some support, even if it's an add-on of some sort.

To WebFarm?

Whatever the limit is for your particular situation, yes a web-farm is one good solution to scaling. There are many architectures for achieving this. One is using a load balancer (hosting providers can offer these, but even these have a limit, along with bandwidth ceiling), but I don't favour this option. For Single Page Applications with long-running connections, I prefer to instead have an open list of servers which the client application will choose from randomly at startup and reuse over the lifetime of the application. This removes the single point of failure (load balancer) and enables scaling through multiple data centres and therefore much more bandwidth.

Busting a myth - 64K ports

To address the question component regarding "64,000", this is a misconception. A server can connect to many more than 65535 clients. See https://networkengineering.stackexchange.com/questions/48283/is-a-tcp-server-limited-to-65535-clients/48284

By the way, Http.sys on Windows permits multiple applications to share the same server port under the HTTP URL schema. They each register a separate domain binding, but there is ultimately a single server application proxying the requests to the correct applications.

Update 2019-05-30

Here is an up to date comparison of the fastest HTTP libraries - https://www.techempower.com/benchmarks/#section=data-r16&hw=ph&test=plaintext

  • Test date: 2018-06-06
  • Hardware used: Dell R440 Xeon Gold + 10 GbE
  • The leader has ~7M plaintext reponses per second (responses not connections)
  • The second one Fasthttp for golang advertises 1.5M concurrent connections - see https://github.com/valyala/fasthttp
  • The leading languages are Rust, Go, C++, Java, C, and even C# ranks at 11 (6.9M per second). Scala and Clojure rank further down. Python ranks at 29th at 2.7M per second.
  • At the bottom of the list, I note laravel and cakephp, rails, aspnet-mono-ngx, symfony, zend. All below 10k per second. Note, most of these frameworks are build for dynamic pages and quite old, there may be newer variants that feature higher up in the list.
  • Remember this is HTTP plaintext, not for the Websocket specialty: many people coming here will likely be interested in concurrent connections for websocket.

XPath:: Get following Sibling

You can go for identifying a list of elements with xPath:

//td[text() = ' Color Digest ']/following-sibling::td[1]

This will give you a list of two elements, than you can use the 2nd element as your intended one. For example:

List<WebElement> elements = driver.findElements(By.xpath("//td[text() = ' Color Digest ']/following-sibling::td[1]"))

Now, you can use the 2nd element as your intended element, which is elements.get(1)

How to get the Full file path from URI

This saved my day. The simplest approach to get the path from URI.

  //kotlin
  myuri = data.data
  val realPath = myuri.path
  Log.d(TAG, "path: $realPath")

Returns path :

 path: /storage/emulated/0/Download/CutOFF - Escuro (Original Mix).mp3

Prevent row names to be written to file when using write.csv

write.csv(t, "t.csv", row.names=FALSE)

From ?write.csv:

row.names: either a logical value indicating whether the row names of
          ‘x’ are to be written along with ‘x’, or a character vector
          of row names to be written.

Why does JSON.parse fail with the empty string?

JSON.parse expects valid notation inside a string, whether that be object {}, array [], string "" or number types (int, float, doubles).

If there is potential for what is parsing to be an empty string then the developer should check for it.

If it was built into the function it would add extra cycles, since built in functions are expected to be extremely performant, it makes sense to not program them for the race case.

How to put a tooltip on a user-defined function

Professional Excel Development by Stephen Bullen describes how to register UDFs, which allows a description to appear in the Function Arguments dialog:

Function IFERROR(ByRef ToEvaluate As Variant, ByRef Default As Variant) As Variant
    If IsError(ToEvaluate) Then
        IFERROR = Default
    Else
        IFERROR = ToEvaluate
    End If
End Function

Sub RegisterUDF()
    Dim s As String
    s = "Provides a shortcut replacement for the common worksheet construct" & vbLf _
    & "IF(ISERROR(<expression>), <default>, <expression>)"

    Application.MacroOptions macro:="IFERROR", Description:=s, Category:=9
End Sub

Sub UnregisterUDF()
    Application.MacroOptions Macro:="IFERROR", Description:=Empty, Category:=Empty
End Sub

From: http://www.ozgrid.com/forum/showthread.php?t=78123&page=1

To show the Function Arguments dialog, type the function name and press CtrlA. Alternatively, click the "fx" symbol in the formula bar:

enter image description here

How to increment a letter N times per iteration and store in an array?

Here is your solution for the problem,

$letter = array();
for ($i = 'A'; $i !== 'ZZ'; $i++){
        if(ord($i) % 2 != 0)
           $letter[] .= $i;
}
print_r($letter);

You need to get the ASCII value for that character which will solve your problem.

Here is ord doc and working code.

For your requirement, you can do like this,

for ($i = 'A'; $i !== 'ZZ'; ord($i)+$x){
  $letter[] .= $i;
}
print_r($letter);

Here set $x as per your requirement.

SQL Server 2012 column identity increment jumping from 6 to 1000+ on 7th entry

While trace flag 272 may work for many, it definitely won't work for hosted Sql Server Express installations. So, I created an identity table, and use this through an INSTEAD OF trigger. I'm hoping this helps someone else, and/or gives others an opportunity to improve my solution. The last line allows returning the last identity column added. Since I typically use this to add a single row, this works to return the identity of a single inserted row.

The identity table:

CREATE TABLE [dbo].[tblsysIdentities](
[intTableId] [int] NOT NULL,
[intIdentityLast] [int] NOT NULL,
[strTable] [varchar](100) NOT NULL,
[tsConcurrency] [timestamp] NULL,
CONSTRAINT [PK_tblsysIdentities] PRIMARY KEY CLUSTERED 
(
    [intTableId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF,  ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

and the insert trigger:

-- INSERT --
IF OBJECT_ID ('dbo.trgtblsysTrackerMessagesIdentity', 'TR') IS NOT NULL
   DROP TRIGGER dbo.trgtblsysTrackerMessagesIdentity;
GO
CREATE TRIGGER trgtblsysTrackerMessagesIdentity
ON dbo.tblsysTrackerMessages
INSTEAD OF INSERT AS 
BEGIN
    DECLARE @intTrackerMessageId INT
    DECLARE @intRowCount INT

    SET @intRowCount = (SELECT COUNT(*) FROM INSERTED)

    SET @intTrackerMessageId = (SELECT intIdentityLast FROM tblsysIdentities WHERE intTableId=1)
    UPDATE tblsysIdentities SET intIdentityLast = @intTrackerMessageId + @intRowCount WHERE intTableId=1

    INSERT INTO tblsysTrackerMessages( 
    [intTrackerMessageId],
    [intTrackerId],
    [strMessage],
    [intTrackerMessageTypeId],
    [datCreated],
    [strCreatedBy])
    SELECT @intTrackerMessageId + ROW_NUMBER() OVER (ORDER BY [datCreated]) AS [intTrackerMessageId], 
    [intTrackerId],
   [strMessage],
   [intTrackerMessageTypeId],
   [datCreated],
   [strCreatedBy] FROM INSERTED;

   SELECT TOP 1 @intTrackerMessageId + @intRowCount FROM INSERTED;
END

UnicodeDecodeError: 'ascii' codec can't decode byte 0xc2

I was running into a similar error in pywikipediabot. The .decode method is a step in the right direction but for me it didn't work without adding 'ignore':

ignore_encoding = lambda s: s.decode('utf8', 'ignore')

Ignoring encoding errors can lead to data loss or produce incorrect output. But if you just want to get it done and the details aren't very important this can be a good way to move faster.

html vertical align the text inside input type button

The simplest thing you can do is use reset.css. It normalizes the default stylesheet across browsers, and coincidentally allows button { vertical-align: middle; } to work just fine. Give it a shot - I use it in virtually all of my projects just to kill little bugs like this.

https://gist.github.com/nathansmith/288292

Why should hash functions use a prime number modulus?

I've read the popular wordpress website linked in some of the above popular answers at the top. From what I've understood, I'd like to share a simple observation I made.

You can find all the details in the article here, but assume the following holds true:

  • Using a prime number gives us the "best chance" of an unique value

A general hashmap implementation wants 2 things to be unique.

  • Unique hash code for the key
  • Unique index to store the actual value

How do we get the unique index? By making the initial size of the internal container a prime as well. So basically, prime is involved because it possesses this unique trait of producing unique numbers which we end up using to ID objects and finding indexes inside the internal container.

Example:

key = "key"

value = "value" uniqueId = "k" * 31 ^ 2 + "e" * 31 ^ 1` + "y"

maps to unique id

Now we want a unique location for our value - so we

uniqueId % internalContainerSize == uniqueLocationForValue , assuming internalContainerSize is also a prime.

I know this is simplified, but I'm hoping to get the general idea through.

How do I update pip itself from inside my virtual environment?

pip is just a PyPI package like any other; you could use it to upgrade itself the same way you would upgrade any package:

pip install --upgrade pip

On Windows the recommended command is:

python -m pip install --upgrade pip

JSONP call showing "Uncaught SyntaxError: Unexpected token : "

You're trying to access a JSON, not JSONP.

Notice the difference between your source:

https://api.flightstats.com/flex/schedules/rest/v1/json/flight/AA/100/departing/2013/10/4?appId=19d57e69&appKey=e0ea60854c1205af43fd7b1203005d59&callback=?

And actual JSONP (a wrapping function):

http://api.flickr.com/services/feeds/photos_public.gne?jsoncallback=processJSON&tags=monkey&tagmode=any&format=json

Search for JSON + CORS/Cross-domain policy and you will find hundreds of SO threads on this very topic.

Centos/Linux setting logrotate to maximum file size for all logs

It specifies the size of the log file to trigger rotation. For example size 50M will trigger a log rotation once the file is 50MB or greater in size. You can use the suffix M for megabytes, k for kilobytes, and G for gigabytes. If no suffix is used, it will take it to mean bytes. You can check the example at the end. There are three directives available size, maxsize, and minsize. According to manpage:

minsize size
              Log  files  are  rotated when they grow bigger than size bytes,
              but not before the additionally specified time interval (daily,
              weekly,  monthly, or yearly).  The related size option is simi-
              lar except that it is mutually exclusive with the time interval
              options,  and  it causes log files to be rotated without regard
              for the last rotation time.  When minsize  is  used,  both  the
              size and timestamp of a log file are considered.

size size
              Log files are rotated only if they grow bigger then size bytes.
              If size is followed by k, the size is assumed to  be  in  kilo-
              bytes.  If the M is used, the size is in megabytes, and if G is
              used, the size is in gigabytes. So size 100,  size  100k,  size
              100M and size 100G are all valid.
maxsize size
              Log files are rotated when they grow bigger than size bytes even before
              the additionally specified time interval (daily, weekly, monthly, 
              or yearly).  The related size option is  similar  except  that  it 
              is mutually exclusive with the time interval options, and it causes
              log files to be rotated without regard for the last rotation time.  
              When maxsize is used, both the size and timestamp of a log file are                  
              considered.

Here is an example:

"/var/log/httpd/access.log" /var/log/httpd/error.log {
           rotate 5
           mail [email protected]
           size 100k
           sharedscripts
           postrotate
               /usr/bin/killall -HUP httpd
           endscript
       }

Here is an explanation for both files /var/log/httpd/access.log and /var/log/httpd/error.log. They are rotated whenever it grows over 100k in size, and the old logs files are mailed (uncompressed) to [email protected] after going through 5 rotations, rather than being removed. The sharedscripts means that the postrotate script will only be run once (after the old logs have been compressed), not once for each log which is rotated. Note that the double quotes around the first filename at the beginning of this section allows logrotate to rotate logs with spaces in the name. Normal shell quoting rules apply, with ,, and \ characters supported.

How to add facebook share button on my website?

You don't need all that code. All you need are the following lines:

<a href="https://www.facebook.com/sharer/sharer.php?u=example.org" target="_blank">
  Share on Facebook
</a>

Documentation can be found at https://developers.facebook.com/docs/reference/plugins/share-links/

UUID max character length

Most databases have a native UUID type these days to make working with them easier. If yours doesn't, they're just 128-bit numbers, so you can use BINARY(16), and if you need the text format frequently, e.g. for troubleshooting, then add a calculated column to generate it automatically from the binary column. There is no good reason to store the (much larger) text form.

Editing dictionary values in a foreach loop

You need to create a new Dictionary from the old rather than modifying in place. Somethine like (also iterate over the KeyValuePair<,> rather than using a key lookup:

int otherCount = 0;
int totalCounts = colStates.Values.Sum();
var newDict = new Dictionary<string,int>();
foreach (var kv in colStates) {
  if (kv.Value/(double)totalCounts < 0.05) {
    otherCount += kv.Value;
  } else {
    newDict.Add(kv.Key, kv.Value);
  }
}
if (otherCount > 0) {
  newDict.Add("Other", otherCount);
}

colStates = newDict;

Javascript reduce() on Object

ES6 implementation: Object.entries()

const o = {
  a: {value: 1},
  b: {value: 2},
  c: {value: 3}
};

const total = Object.entries(o).reduce(function (total, pair) {
  const [key, value] = pair;
  return total + value;
}, 0);

Going to a specific line number using Less in Unix

With n being the line number:

  • ng: Jump to line number n. Default is the start of the file.
  • nG: Jump to line number n. Default is the end of the file.

So to go to line number 320123, you would type 320123g.

Copy-pasted straight from Wikipedia.

Listing only directories using ls in Bash?

I use:

ls -d */ | cut -f1 -d'/'

This creates a single column without a trailing slash - useful in scripts.

Is it possible to serialize and deserialize a class in C++?

Here is a simple serializer library I knocked up. It's header only, c11 and has examples for serializing basic types. Here's one for a map to class.

https://github.com/goblinhack/simple-c-plus-plus-serializer

#include "c_plus_plus_serializer.h"

class Custom {
public:
    int a;
    std::string b;
    std::vector c;

    friend std::ostream& operator<<(std::ostream &out, 
                                    Bits my)
    {
        out << bits(my.t.a) << bits(my.t.b) << bits(my.t.c);
        return (out);
    }

    friend std::istream& operator>>(std::istream &in, 
                                    Bits my)
    {
        in >> bits(my.t.a) >> bits(my.t.b) >> bits(my.t.c);
        return (in);
    }

    friend std::ostream& operator<<(std::ostream &out, 
                                    class Custom &my)
    {
        out << "a:" << my.a << " b:" << my.b;

        out << " c:[" << my.c.size() << " elems]:";
        for (auto v : my.c) {
            out << v << " ";
        }
        out << std::endl;

        return (out);
    }
};

static void save_map_key_string_value_custom (const std::string filename)
{
    std::cout << "save to " << filename << std::endl;
    std::ofstream out(filename, std::ios::binary );

    std::map< std::string, class Custom > m;

    auto c1 = Custom();
    c1.a = 1;
    c1.b = "hello";
    std::initializer_list L1 = {"vec-elem1", "vec-elem2"};
    std::vector l1(L1);
    c1.c = l1;

    auto c2 = Custom();
    c2.a = 2;
    c2.b = "there";
    std::initializer_list L2 = {"vec-elem3", "vec-elem4"};
    std::vector l2(L2);
    c2.c = l2;

    m.insert(std::make_pair(std::string("key1"), c1));
    m.insert(std::make_pair(std::string("key2"), c2));

    out << bits(m);
}

static void load_map_key_string_value_custom (const std::string filename)
{
    std::cout << "read from " << filename << std::endl;
    std::ifstream in(filename);

    std::map< std::string, class Custom > m;

    in >> bits(m);
    std::cout << std::endl;

    std::cout << "m = " << m.size() << " list-elems { " << std::endl;
    for (auto i : m) {
        std::cout << "    [" << i.first << "] = " << i.second;
    }
    std::cout << "}" << std::endl;
}

void map_custom_class_example (void)
{
    std::cout << "map key string, value class" << std::endl;
    std::cout << "============================" << std::endl;
    save_map_key_string_value_custom(std::string("map_of_custom_class.bin"));
    load_map_key_string_value_custom(std::string("map_of_custom_class.bin"));
    std::cout << std::endl;
}

Output:

map key string, value class
============================
save to map_of_custom_class.bin
read from map_of_custom_class.bin

m = 2 list-elems {
    [key1] = a:1 b:hello c:[2 elems]:vec-elem1 vec-elem2
    [key2] = a:2 b:there c:[2 elems]:vec-elem3 vec-elem4
}

How to compare type of an object in Python?

I use type(x) == type(y)

For instance, if I want to check something is an array:

type( x ) == type( [] )

string check:

type( x ) == type( '' ) or type( x ) == type( u'' )

If you want to check against None, use is

x is None

Can I multiply strings in Java to repeat sequences?

A generalisation of Dave Hartnoll's answer (I am mainly taking the concept ad absurdum, maybe don't use that in anything where you need speed). This allows one to fill the String up with i characters following a given pattern.

int i = 3;
String someNum = "123";
String pattern = "789";
someNum += "00000000000000000000".replaceAll("0",pattern).substring(0, i);

If you don't need a pattern but just any single character you can use that (it's a tad faster):

int i = 3;
String someNum = "123";
char c = "7";
someNum += "00000000000000000000".replaceAll("0",c).substring(0, i);

Using Eloquent ORM in Laravel to perform search of database using LIKE

You're able to do database finds using LIKE with this syntax:

Model::where('column', 'LIKE', '%value%')->get();

Call JavaScript function on DropDownList SelectedIndexChanged Event:

Or you can do it like as well:

<asp:DropDownList ID="ddl" runat="server"  AutoPostBack="true" onchange="javascript:CalcTotalAmt();" OnSelectedIndexChanged="ddl_SelectedIndexChanged"></asp:DropDownList>

How to create full path with node's fs.mkdirSync?

How about this approach :

if (!fs.existsSync(pathToFile)) {
            var dirName = "";
            var filePathSplit = pathToFile.split('/');
            for (var index = 0; index < filePathSplit.length; index++) {
                dirName += filePathSplit[index]+'/';
                if (!fs.existsSync(dirName))
                    fs.mkdirSync(dirName);
            }
        }

This works for relative path.

LINQ extension methods - Any() vs. Where() vs. Exists()

Any() returns true if any of the elements in a collection meet your predicate's criteria.

Where() returns an enumerable of all elements in a collection that meet your predicate's criteria.

Exists() does the same thing as any except it's just an older implementation that was there on the IList back before Linq.

how to find array size in angularjs

You can find the number of members in a Javascript array by using its length property:

var number = $scope.names.length;

Docs - Array.prototype.length

Adding asterisk to required fields in Bootstrap 3

This CSS worked for me:

.form-group.required.control-label:before{
   color: red;
   content: "*";
   position: absolute;
   margin-left: -10px;
}

and this HTML:

<div class="form-group required control-label">
  <label for="emailField">Email</label>
  <input type="email" class="form-control" id="emailField" placeholder="Type Your Email Address Here" />
</div>

Convert XmlDocument to String

If you are using Windows.Data.Xml.Dom.XmlDocument version of XmlDocument (used in UWP apps for example), you can use yourXmlDocument.GetXml() to get the XML as a string.

How to extend available properties of User.Identity

Whenever you want to extend the properties of User.Identity with any additional properties like the question above, add these properties to the ApplicationUser class first like so:

public class ApplicationUser : IdentityUser
{
    public async Task<ClaimsIdentity> GenerateUserIdentityAsync(UserManager<ApplicationUser> manager)
    {
        // Note the authenticationType must match the one defined in CookieAuthenticationOptions.AuthenticationType
        var userIdentity = await manager.CreateIdentityAsync(this, DefaultAuthenticationTypes.ApplicationCookie);
        // Add custom user claims here
        return userIdentity;
    }

    // Your Extended Properties
    public long? OrganizationId { get; set; }
}

Then what you need is to create an extension method like so (I create mine in an new Extensions folder):

namespace App.Extensions
{
    public static class IdentityExtensions
    {
        public static string GetOrganizationId(this IIdentity identity)
        {
            var claim = ((ClaimsIdentity)identity).FindFirst("OrganizationId");
            // Test for null to avoid issues during local testing
            return (claim != null) ? claim.Value : string.Empty;
        }
    }
}

When you create the Identity in the ApplicationUser class, just add the Claim -> OrganizationId like so:

    public async Task<ClaimsIdentity> GenerateUserIdentityAsync(UserManager<ApplicationUser> manager)
    {
        // Note the authenticationType must match the one defined in CookieAuthenticationOptions.AuthenticationType
        var userIdentity = await manager.CreateIdentityAsync(this, DefaultAuthenticationTypes.ApplicationCookie);
        // Add custom user claims here => this.OrganizationId is a value stored in database against the user
        userIdentity.AddClaim(new Claim("OrganizationId", this.OrganizationId.ToString()));

        return userIdentity;
    }

Once you added the claim and have your extension method in place, to make it available as a property on your User.Identity, add a using statement on the page/file you want to access it:

in my case: using App.Extensions; within a Controller and @using. App.Extensions withing a .cshtml View file.

EDIT:

What you can also do to avoid adding a using statement in every View is to go to the Views folder, and locate the Web.config file in there. Now look for the <namespaces> tag and add your extension namespace there like so:

<add namespace="App.Extensions" />

Save your file and you're done. Now every View will know of your extensions.

You can access the Extension Method:

var orgId = User.Identity.GetOrganizationId();

How to disable gradle 'offline mode' in android studio?

Gradle is in offline mode, which means that it won't go to the network to resolve dependencies.

Go to Preferences > Gradle and uncheck "Offline work".

Android: How to Programmatically set the size of a Layout

LinearLayout YOUR_LinearLayout =(LinearLayout)findViewById(R.id.YOUR_LinearLayout)
    LinearLayout.LayoutParams param = new LinearLayout.LayoutParams(
                       /*width*/ ViewGroup.LayoutParams.MATCH_PARENT,
               /*height*/ 100,
               /*weight*/ 1.0f
                );
                YOUR_LinearLayout.setLayoutParams(param);

numpy max vs amax vs maximum

np.max is just an alias for np.amax. This function only works on a single input array and finds the value of maximum element in that entire array (returning a scalar). Alternatively, it takes an axis argument and will find the maximum value along an axis of the input array (returning a new array).

>>> a = np.array([[0, 1, 6],
                  [2, 4, 1]])
>>> np.max(a)
6
>>> np.max(a, axis=0) # max of each column
array([2, 4, 6])

The default behaviour of np.maximum is to take two arrays and compute their element-wise maximum. Here, 'compatible' means that one array can be broadcast to the other. For example:

>>> b = np.array([3, 6, 1])
>>> c = np.array([4, 2, 9])
>>> np.maximum(b, c)
array([4, 6, 9])

But np.maximum is also a universal function which means that it has other features and methods which come in useful when working with multidimensional arrays. For example you can compute the cumulative maximum over an array (or a particular axis of the array):

>>> d = np.array([2, 0, 3, -4, -2, 7, 9])
>>> np.maximum.accumulate(d)
array([2, 2, 3, 3, 3, 7, 9])

This is not possible with np.max.

You can make np.maximum imitate np.max to a certain extent when using np.maximum.reduce:

>>> np.maximum.reduce(d)
9
>>> np.max(d)
9

Basic testing suggests the two approaches are comparable in performance; and they should be, as np.max() actually calls np.maximum.reduce to do the computation.

Split text with '\r\n'

Reading the file is easier done with the static File class:

// First read all the text into a single string.
string text = File.ReadAllText(FileName);

// Then split the lines at "\r\n".   
string[] stringSeparators = new string[] { "\r\n" };
string[] lines = text.Split(stringSeparators, StringSplitOptions.None);

// Finally replace lonely '\r' and '\n' by  whitespaces in each line.
foreach (string s in lines) {
    Console.WriteLine(s.Replace('\r', ' ').Replace('\n', ' '));
}

Note: The text might also contain vertical tabulators \v. Those are used by Microsoft Word as manual linebreaks.

In order to catch any possible kind of breaks, you could use regex for the replacement

Console.WriteLine(Regex.Replace(s, @"[\f\n\r\t\v]", " "));

Parse JSON from HttpURLConnection object

You can get raw data using below method. BTW, this pattern is for Java 6. If you are using Java 7 or newer, please consider try-with-resources pattern.

public String getJSON(String url, int timeout) {
    HttpURLConnection c = null;
    try {
        URL u = new URL(url);
        c = (HttpURLConnection) u.openConnection();
        c.setRequestMethod("GET");
        c.setRequestProperty("Content-length", "0");
        c.setUseCaches(false);
        c.setAllowUserInteraction(false);
        c.setConnectTimeout(timeout);
        c.setReadTimeout(timeout);
        c.connect();
        int status = c.getResponseCode();

        switch (status) {
            case 200:
            case 201:
                BufferedReader br = new BufferedReader(new InputStreamReader(c.getInputStream()));
                StringBuilder sb = new StringBuilder();
                String line;
                while ((line = br.readLine()) != null) {
                    sb.append(line+"\n");
                }
                br.close();
                return sb.toString();
        }

    } catch (MalformedURLException ex) {
        Logger.getLogger(getClass().getName()).log(Level.SEVERE, null, ex);
    } catch (IOException ex) {
        Logger.getLogger(getClass().getName()).log(Level.SEVERE, null, ex);
    } finally {
       if (c != null) {
          try {
              c.disconnect();
          } catch (Exception ex) {
             Logger.getLogger(getClass().getName()).log(Level.SEVERE, null, ex);
          }
       }
    }
    return null;
}

And then you can use returned string with Google Gson to map JSON to object of specified class, like this:

String data = getJSON("http://localhost/authmanager.php");
AuthMsg msg = new Gson().fromJson(data, AuthMsg.class);
System.out.println(msg);

There is a sample of AuthMsg class:

public class AuthMsg {
    private int code;
    private String message;

    public int getCode() {
        return code;
    }
    public void setCode(int code) {
        this.code = code;
    }

    public String getMessage() {
        return message;
    }
    public void setMessage(String message) {
        this.message = message;
    }
}

JSON returned by http://localhost/authmanager.php must look like this:

{"code":1,"message":"Logged in"}

Regards

JavaScript - populate drop down list with array

You'll need to loop through your array elements, create a new DOM node for each and append it to your object.

var select = document.getElementById("selectNumber"); 
var options = ["1", "2", "3", "4", "5"]; 

for(var i = 0; i < options.length; i++) {
    var opt = options[i];
    var el = document.createElement("option");
    el.textContent = opt;
    el.value = opt;
    select.appendChild(el);
}?

Live example

Pass object to javascript function

when you pass an object within curly braces as an argument to a function with one parameter , you're assigning this object to a variable which is the parameter in this case

Remove values from select list based on condition

To remove options in a select by value I would do (in pure JS) :

[...document.getElementById('val').options]
    .filter(o => o.value === 'A' || o.value === 'C')
    .forEach(o => o.remove());

How to use a client certificate to authenticate and authorize in a Web API

I came upon a similar issue recently and following Fabian's advice actually led me to the solution. Turns out with client certs you have to ensure two things:

  1. The private key is actually being exported as part of the cert.

  2. The application pool identity running the app has access to said private key.

In our case I had to:

  1. Import the pfx file into the local server store while checking the export checkbox to ensure the private key was sent out.
  2. Using MMC console, grant the service account used access to the private key for the cert.

The trusted root issue explained in other answers is a valid one, it was just not the issue in our case.

How to resolve the "ADB server didn't ACK" error?

For me it didn't work , it was related to a path problem happened after android studio 2.0 preview 1, I needed to update genymotion and virtual box, and apparently they tried to use same port for adb.

Solution is explained here link! Basically you just need to:

1) open genymotion settings

2) specify sdk path for the adb manually

3) adb kill-server

4) adb start-server

Saving ssh key fails

I struggled with the same problem for a while just now (using Mac). Here is what I did and it finally worked:
(1) Confirm the .ssh directory exists:

#show all files including hidden
ls -a 

(2) Accept all default values by just pressing enter at the prompt

Enter file in which to save the key (/Users/username/.ssh/id_rsa): 
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 

You should get a message :

Your identification has been saved in /Users/username/.ssh/id_rsa.
Your public key has been saved in /Users/username/.ssh/id_rsa.pub.
The key fingerprint is:
BZA156:HVhsjsdhfdkjfdfhdX+BundfOytLezXvbx831/s [email protected]
The key's randomart image is:XXXXX

PS If you are configuring git for rails, do the following (source):

git config --global color.ui true
git config --global user.name "yourusername"
git config --global user.email "[email protected]"
ssh-keygen -t rsa -C "[email protected]" 

(then accept all defaults by pressing enter)

JavaScript query string

Or you could use the library sugar.js.

From sugarjs.com:

Object.fromQueryString ( str , deep = true )

Converts the query string of a URL into an object. If deep is false, conversion will only accept shallow params (ie. no object or arrays with [] syntax) as these are not universally supported.

Object.fromQueryString('foo=bar&broken=wear') >{"foo":"bar","broken":"wear"}
Object.fromQueryString('foo[]=1&foo[]=2') >{"foo":[1,2]}

Example:

var queryString = Object.fromQueryString(location.search);
var foo = queryString.foo;

How to get the file-path of the currently executing javascript code

Refining upon the answers found here:

little trick

getCurrentScript and getCurrentScriptPath

I came up with the following:

//Thanks to https://stackoverflow.com/a/27369985/5175935
var getCurrentScript = function () {

    if ( document.currentScript && ( document.currentScript.src !== '' ) )
        return document.currentScript.src;
    var scripts = document.getElementsByTagName( 'script' ),
        str = scripts[scripts.length - 1].src;
    if ( str !== '' )
        return src;
    //Thanks to https://stackoverflow.com/a/42594856/5175935
    return new Error().stack.match(/(https?:[^:]*)/)[0];

};

//Thanks to https://stackoverflow.com/a/27369985/5175935
var getCurrentScriptPath = function () {
    var script = getCurrentScript(),
        path = script.substring( 0, script.lastIndexOf( '/' ) );
    return path;
};

Bootstrap control with multiple "data-toggle"

One more solution:

    <a data-toggle="modal" data-target="#exampleModalCenter">
      <span
        class="tags"
        data-toggle="tooltip"
        data-placement="right"
        title="Tooltip text"
      >
        Text
     </span>
   </a>

PHP multidimensional array search by value

$a = ['x' => ['eee', 'ccc'], 'b' => ['zzz']];

$found = null;
$search = 'eee';

array_walk($a, function ($k, $v) use ($search, &$found) {
    if (in_array($search, $k)) {
        $found = $v;
    }
});

var_dump($found);

How to get logged-in user's name in Access vba?

Try this:

Function UserNameWindows() As String
     UserName = Environ("USERNAME")
End Function

Programmatically set image to UIImageView with Xcode 6.1/Swift

In xcode 8 you can directly choose image from the selection window (NEW)...

  • You just need to type - "image" and you will get a suggestion box then select -"Image Literal" from list (see in attached picture) and

  • then tap on the square you will be able to see all images(see in
    second attached picture) which are in your image assets... or select other image from there.

enter image description here

  • Now tap on square box - (You will see that square box after selecting above option)

enter image description here

How to run the Python program forever?

sleep is a good way to avoid overload on the cpu

not sure if it's really clever, but I usually use

while(not sleep(5)):
    #code to execute

sleep method always returns None.

JavaScript - document.getElementByID with onClick

Sometimes JavaScript is not activated. Try something like:

<!DOCTYPE html>
<html>
  <head>

    <script type="text/javascript"> <!--
      function jActivator() {
        document.getElementById("demo").onclick = function() {myFunction()};
        document.getElementById("demo1").addEventListener("click", myFunction);
        }
      function myFunction( s ) {
        document.getElementById("myresult").innerHTML = s;
        }
    // --> </script>
    <noscript>JavaScript deactivated.</noscript>
    <style type="text/css">
    </style>
  </head>
  <body onload="jActivator()">
    <ul>
      <li id="demo">Click me -&gt; onclick.</li>
      <li id="demo1">Click me -&gt; click event.</li>
      <li onclick="myFunction('YOU CLICKED ME!')">Click me calling function.</li>
    </ul>
    <div id="myresult">&nbsp;</div>
  </body>
</html>

If you use the code inside a page, where no access to is possible, remove and tags and try to use 'onload=()' in a picture inside the image tag '

Ignore 'Security Warning' running script from command line

For those who want to access a file from an already loaded PowerShell session, either use Unblock-File to mark the file as safe (though you already need to have set a relaxed execution policy like Unrestricted for this to work), or change the execution policy just for the current PowerShell session:

Set-ExecutionPolicy -ExecutionPolicy Bypass -Scope Process

'setInterval' vs 'setTimeout'

setInterval repeats the call, setTimeout only runs it once.

Rails: Address already in use - bind(2) (Errno::EADDRINUSE)

If the above solutions don't work on ubuntu/linux then you can try this

sudo fuser -k -n tcp port

Run it several times to kill processes on your port of choosing. port could be 3000 for example. You would have killed all the processes if you see no output after running the command

Passing just a type as a parameter in C#

You can use an argument of type Type - iow, pass typeof(int). You can also use generics for a (probably more efficient) approach.

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

Assuming that you already downloaded chromeDriver, this error is also occurs when already multiple chrome tabs are open.

If you close all tabs and run again, the error should clear up.

How to find which columns contain any NaN value in Pandas dataframe

In datasets having large number of columns its even better to see how many columns contain null values and how many don't.

print("No. of columns containing null values")
print(len(df.columns[df.isna().any()]))

print("No. of columns not containing null values")
print(len(df.columns[df.notna().all()]))

print("Total no. of columns in the dataframe")
print(len(df.columns))

For example in my dataframe it contained 82 columns, of which 19 contained at least one null value.

Further you can also automatically remove cols and rows depending on which has more null values
Here is the code which does this intelligently:

df = df.drop(df.columns[df.isna().sum()>len(df.columns)],axis = 1)
df = df.dropna(axis = 0).reset_index(drop=True)

Note: Above code removes all of your null values. If you want null values, process them before.

Access restriction: Is not accessible due to restriction on required library ..\jre\lib\rt.jar

I'm responding to this question because I had a different way of fixing this problem than the other answers had. I had this problem when I refactored the name of the plugins that I was exporting. Eventually I had to make sure to fix/change the following.

  1. The product file's dependencies,
  2. The plugin.xml dependencies (and make sure it is not implicitly imported using the imported packages dialog).
  3. The run configuration plug-ins tab. Run As..->Run Configurations->Plug-ins tab. Uncheck the old plugins and then click Add Required Plug-ins.

This worked for me, but your mileage may vary.

Adding POST parameters before submit

You can do a form.serializeArray(), then add name-value pairs before posting:

var form = $(this).closest('form');

form = form.serializeArray();

form = form.concat([
    {name: "customer_id", value: window.username},
    {name: "post_action", value: "Update Information"}
]);

$.post('/change-user-details', form, function(d) {
    if (d.error) {
        alert("There was a problem updating your user details")
    } 
});

Precision String Format Specifier In Swift

This is a very fast and simple way who doesn't need complex solution.

let duration = String(format: "%.01f", 3.32323242)
// result = 3.3

Error in installation a R package

The solution indicated by Guannan Shen has one drawback that usually goes unnoticed.

When you run sudo R in order to run install.packages() as superuser, the directories in which you install the library end up belonging to root user, a.k.a., the superuser.

So, next time you need to update your libraries, you will not remember that you ran sudo, therefore leaving root as the owner of the files and directories; that eventually causes the error when trying to move files, because no one can overwrite root but themself.

That can be averted by running

sudo chown -R yourusername:yourusername *

in the directory lib that contains your local libraries, replacing yourusername by the adequated value in your installation. Then you try installing once again.

Format specifier %02x

%x is a format specifier that format and output the hex value. If you are providing int or long value, it will convert it to hex value.

%02x means if your provided value is less than two digits then 0 will be prepended.

You provided value 16843009 and it has been converted to 1010101 which a hex value.

Excel Validation Drop Down list using VBA

You are defining your array as xlValidateList(), so when you try to assign the type, it gets confused as to what you are trying to assign to the type.

Instead, try this:

Dim MyList(5) As String
MyList(0) = 1
MyList(1) = 2
MyList(2) = 3
MyList(3) = 4
MyList(4) = 5
MyList(5) = 6

With Range("A1").Validation
    .Delete
    .Add Type:=xlValidateList, AlertStyle:=xlValidAlertStop, _
         Operator:=xlBetween, Formula1:=Join(MyList, ",")
End With

Difference between break and continue in PHP?

break will exit the loop, while continue will start the next cycle of the loop immediately.

Regex: match word that ends with "Id"

Regex ids = new Regex(@"\w*Id\b", RegexOptions.None);

\b means "word break" and \w means any word character. So \w*Id\b means "{stuff}Id". By not including RegexOptions.IgnoreCase, it will be case sensitive.

SSIS Excel Import Forcing Incorrect Column Type

This worked for me. Select the problematic column in Excel - highlight the whole column. Change the format to "Text". Save the Excel file.

In your SSIS package, go to the Data Flow pane for your import. Double click the Excel Source node. It should warn you that the types have changed and ask you if you want to remap them. Click Yes. Executing should now work and bring in all values.

Note: I'm using Excel 2013 and Visual Studio 2015, but I assume these instructions would work for earlier versions too.

addID in jQuery?

I've used something like this before which addresses @scunliffes concern. It finds all instances of items with a class of (in this case .button), and assigns an ID and appends its index to the id name:

_x000D_
_x000D_
$(".button").attr('id', function (index) {_x000D_
 return "button-" + index;_x000D_
});
_x000D_
_x000D_
_x000D_

So let's say you have 3 items with the class name of .button on a page. The result would be adding a unique ID to all of them (in addition to their class of "button").

In this case, #button-0, #button-1, #button-2, respectively. This can come in very handy. Simply replace ".button" in the first line with whatever class you want to target, and replace "button" in the return statement with whatever you'd like your unique ID to be. Hope this helps!

Sys.WebForms.PageRequestManagerServerErrorException: An unknown error occurred while processing the request on the server."

answer for me was to fix a gridview control which contained a template field that had a dropdownlist which was loaded with a monstrous amount of selectable items- i replaced the DDL with a label field whose data is generated from a function. (i was originally going to allow gridview editing, but have switched to allowing edits on a separate panel displaying the DDL for that field for just that record). hope this might help someone.

Switch between python 2.7 and python 3.5 on Mac OS X

Similar to John Wilkey's answer I would run python2 by finding which python, something like using /usr/bin/python and then creating an alias in .bash_profile:

alias python2="/usr/bin/python"

I can now run python3 by calling python and python2 by calling python2.

npm install from Git in a specific version

If by version you mean a tag or a release, then github provides download links for those. For example, if I want to install fetch version 0.3.2 (it is not available on npm), then I add to my package.json under dependencies:

"fetch": "https://github.com/github/fetch/archive/v0.3.2.tar.gz",

The only disadvantage when compared with the commit hash approach is that a hash is guaranteed not to represent changed code, whereas a tag could be replaced. Thankfully this rarely happens.

Update:

These days the approach I use is the compact notation for a GitHub served dependency:

"dependencies": {
  "package": "github:username/package#commit"
}

Where commit can be anything commitish, like a tag. In the case of GitHub you can even drop the initial github: since it's the default.

SQL where datetime column equals today's date?

Easy way out is to use a condition like this ( use desired date > GETDATE()-1)

your sql statement "date specific" > GETDATE()-1

How do I remove link underlining in my HTML email?

<a href="#" style="text-decoration:none !important; text-decoration:none;">BOOK NOW</a>

Outlook will strip out the style with !important tag leaving the regular style, thus no underline. The !important tag will over rule the web based email clients' default style, thus leaving no underline.

Move all files except one

The following is not a 100% guaranteed method, and should not at all be attempted for scripting. But some times it is good enough for quick interactive shell usage. A file file glob like

[abc]*

(which will match all files with names starting with a, b or c) can be negated by inserting a "^" character first, i.e.

[^abc]*

I sometimes use this for not matching the "lost+found" directory, like for instance:

mv /mnt/usbdisk/[^l]* /home/user/stuff/.

Of course if there are other files starting with l I have to process those afterwards.

Difference between InvariantCulture and Ordinal string comparison

Although the question is about equality, for quick visual reference, here the order of some strings sorted using a couple of cultures illustrating some of the idiosyncrasies out there.

Ordinal          0 9 A Ab a aB aa ab ss Ä Äb ß ä äb ? ? ? ? ? A
IgnoreCase       0 9 a A aa ab Ab aB ss ä Ä äb Äb ß ? ? ? ? ? A
--------------------------------------------------------------------
InvariantCulture 0 9 a A A ä Ä aa ab aB Ab äb Äb ss ß ? ? ? ? ?
IgnoreCase       0 9 A a A Ä ä aa Ab aB ab Äb äb ß ss ? ? ? ? ?
--------------------------------------------------------------------
da-DK            0 9 a A A ab aB Ab ss ß ä Ä äb Äb aa ? ? ? ? ?
IgnoreCase       0 9 A a A Ab aB ab ß ss Ä ä Äb äb aa ? ? ? ? ?
--------------------------------------------------------------------
de-DE            0 9 a A A ä Ä aa ab aB Ab äb Äb ß ss ? ? ? ? ?
IgnoreCase       0 9 A a A Ä ä aa Ab aB ab Äb äb ss ß ? ? ? ? ?
--------------------------------------------------------------------
en-US            0 9 a A A ä Ä aa ab aB Ab äb Äb ß ss ? ? ? ? ?
IgnoreCase       0 9 A a A Ä ä aa Ab aB ab Äb äb ss ß ? ? ? ? ?
--------------------------------------------------------------------
ja-JP            0 9 a A A ä Ä aa ab aB Ab äb Äb ß ss ? ? ? ? ?
IgnoreCase       0 9 A a A Ä ä aa Ab aB ab Äb äb ss ß ? ? ? ? ?

Observations:

  • de-DE, ja-JP, and en-US sort the same way
  • Invariant only sorts ss and ß differently from the above three cultures
  • da-DK sorts quite differently
  • the IgnoreCase flag matters for all sampled cultures

The code used to generate above table:

var l = new List<string>
    { "0", "9", "A", "Ab", "a", "aB", "aa", "ab", "ss", "ß",
      "Ä", "Äb", "ä", "äb", "?", "?", "?", "?", "A", "?" };

foreach (var comparer in new[]
{
    StringComparer.Ordinal,
    StringComparer.OrdinalIgnoreCase,
    StringComparer.InvariantCulture,
    StringComparer.InvariantCultureIgnoreCase,
    StringComparer.Create(new CultureInfo("da-DK"), false),
    StringComparer.Create(new CultureInfo("da-DK"), true),
    StringComparer.Create(new CultureInfo("de-DE"), false),
    StringComparer.Create(new CultureInfo("de-DE"), true),
    StringComparer.Create(new CultureInfo("en-US"), false),
    StringComparer.Create(new CultureInfo("en-US"), true),
    StringComparer.Create(new CultureInfo("ja-JP"), false),
    StringComparer.Create(new CultureInfo("ja-JP"), true),
})
{
    l.Sort(comparer);
    Console.WriteLine(string.Join(" ", l));
}

What are the differences between the BLOB and TEXT datatypes in MySQL?

TEXT and CHAR will convert to/from the character set they have associated with time. BLOB and BINARY simply store bytes.

BLOB is used for storing binary data while Text is used to store large string.

BLOB values are treated as binary strings (byte strings). They have no character set, and sorting and comparison are based on the numeric values of the bytes in column values.

TEXT values are treated as nonbinary strings (character strings). They have a character set, and values are sorted and compared based on the collation of the character set.

http://dev.mysql.com/doc/refman/5.0/en/blob.html

How would I extract a single file (or changes to a file) from a git stash?

You can get the diff for a stash with "git show stash@{0}" (or whatever the number of the stash is; see "git stash list"). It's easy to extract the section of the diff for a single file.

Read file content from S3 bucket with boto3

boto3 offers a resource model that makes tasks like iterating through objects easier. Unfortunately, StreamingBody doesn't provide readline or readlines.

s3 = boto3.resource('s3')
bucket = s3.Bucket('test-bucket')
# Iterates through all the objects, doing the pagination for you. Each obj
# is an ObjectSummary, so it doesn't contain the body. You'll need to call
# get to get the whole body.
for obj in bucket.objects.all():
    key = obj.key
    body = obj.get()['Body'].read()