Programs & Examples On #Isaserver

0

How to add images in select list?

I tried several jquery based custom select with images, but none worked in responsive layouts. Finally i came accross Bootstrap-Select. After some modifications i was able to produce this code.

Code and github repo here

enter image description here

Center Div inside another (100% width) div

The below style to the inner div will center it.

margin: 0 auto;

Error "initializer element is not constant" when trying to initialize variable with const

It's a limitation of the language. In section 6.7.8/4:

All the expressions in an initializer for an object that has static storage duration shall be constant expressions or string literals.

In section 6.6, the spec defines what must considered a constant expression. No where does it state that a const variable must be considered a constant expression. It is legal for a compiler to extend this (6.6/10 - An implementation may accept other forms of constant expressions) but that would limit portability.

If you can change my_foo so it does not have static storage, you would be okay:

int main()
{
    foo_t my_foo = foo_init;
    return 0;
}

Error parsing XHTML: The content of elements must consist of well-formed character data or markup

Sometimes you will need this :

 /*<![CDATA[*/
 /*]]>*/

and not only this :

 <![CDATA[
 ]]>

Java method to sum any number of ints

You could do, assuming you have an array with value and array length: arrayVal[i], arrayLength:

int sum = 0;
for (int i = 0; i < arrayLength; i++) {
    sum += arrayVal[i];
}

System.out.println("the sum is" + sum);

I hope this helps.

Select first 10 distinct rows in mysql

SELECT  DISTINCT *
FROM    people
WHERE   names = 'Smith'
ORDER BY
        names
LIMIT 10

Android SQLite: Update Statement

you can always execute SQL.

update [your table] set [your column]=value

for example

update Foo set Bar=125

How to set the Default Page in ASP.NET?

Tip #84: Did you know… How to set a Start page for your Web Site in Visual Web Developer?

Simply right click on the page you want to be the start page and say "set as start page".

As noted in the comment below by Adam Tuliper - MSFT, this only works for debugging, not deployment.

Convert list or numpy array of single element to float in python

Just access the first item of the list/array, using the index access and the index 0:

>>> list_ = [4]
>>> list_[0]
4
>>> array_ = np.array([4])
>>> array_[0]
4

This will be an int since that was what you inserted in the first place. If you need it to be a float for some reason, you can call float() on it then:

>>> float(list_[0])
4.0

How to get response body using HttpURLConnection, when code other than 2xx is returned?

This is an easy way to get a successful response from the server like PHP echo otherwise an error message.

BufferedReader br = null;
if (conn.getResponseCode() == 200) {
    br = new BufferedReader(new InputStreamReader(conn.getInputStream()));
    String strCurrentLine;
        while ((strCurrentLine = br.readLine()) != null) {
               System.out.println(strCurrentLine);
        }
} else {
    br = new BufferedReader(new InputStreamReader(conn.getErrorStream()));
    String strCurrentLine;
        while ((strCurrentLine = br.readLine()) != null) {
               System.out.println(strCurrentLine);
        }
}

Format date in a specific timezone

You can Try this ,

Here you can get the date based on the Client Timezone (Browser).

moment(new Date().getTime()).zone(new Date().toString().match(/([-\+][0-9]+)\s/)[1]).format('YYYY-MM-DD HH:mm:ss')

The regex basically gets you the offset value.

Cheers!!

Good Hash Function for Strings

Guava's HashFunction (javadoc) provides decent non-crypto-strong hashing.

Find distance between two points on map using Google Map API V2

try this

double distance;
Location locationA = new Location("");
locationA.setLatitude(main_Latitude);
locationA.setLongitude(main_Longitude);
Location locationB = new Location("");
locationB.setLatitude(sub_Latitude);
locationB.setLongitude(sub_Longitude);
distance = locationA.distanceTo(locationB)/1000;
kmeter.setText(String.valueOf(distance));
Toast.makeText(getApplicationContext(), ""+distance, Toast.LENGTH_LONG).show();double distance;

Check If only numeric values were entered in input. (jQuery)

You can use jQuery method to check whether a value is numeric or other type.

$.isNumeric()

Example

$.isNumeric("46")

true

$.isNumeric(46)

true

$.isNumeric("dfd")

false

Most efficient way to reverse a numpy array

Expanding on what others have said I will give a short example.

If you have a 1D array ...

>>> import numpy as np
>>> x = np.arange(4) # array([0, 1, 2, 3])
>>> x[::-1] # returns a view
Out[1]: 
array([3, 2, 1, 0])

But if you are working with a 2D array ...

>>> x = np.arange(10).reshape(2, 5)
>>> x
Out[2]:
array([[0, 1, 2, 3, 4],
       [5, 6, 7, 8, 9]])

>>> x[::-1] # returns a view:
Out[3]: array([[5, 6, 7, 8, 9],
               [0, 1, 2, 3, 4]])

This does not actually reverse the Matrix.

Should use np.flip to actually reverse the elements

>>> np.flip(x)
Out[4]: array([[9, 8, 7, 6, 5],
               [4, 3, 2, 1, 0]])

If you want to print the elements of a matrix one-by-one use flat along with flip

>>> for el in np.flip(x).flat:
>>>     print(el, end = ' ')
9 8 7 6 5 4 3 2 1 0

How to convert string to integer in C#

int a = int.Parse(myString);

or better yet, look into int.TryParse(string)

How to use sessions in an ASP.NET MVC 4 application?

Due to the stateless nature of the web, sessions are also an extremely useful way of persisting objects across requests by serialising them and storing them in a session.

A perfect use case of this could be if you need to access regular information across your application, to save additional database calls on each request, this data can be stored in an object and unserialised on each request, like so:

Our reusable, serializable object:

[Serializable]
public class UserProfileSessionData
{
    public int UserId { get; set; }

    public string EmailAddress { get; set; }

    public string FullName { get; set; }
}

Use case:

public class LoginController : Controller {

    [HttpPost]
    public ActionResult Login(LoginModel model)
    {
        if (ModelState.IsValid)
        {
            var profileData = new UserProfileSessionData {
                UserId = model.UserId,
                EmailAddress = model.EmailAddress,
                FullName = model.FullName
            }

            this.Session["UserProfile"] = profileData;
        }
    }

    public ActionResult LoggedInStatusMessage()
    {
        var profileData = this.Session["UserProfile"] as UserProfileSessionData;

        /* From here you could output profileData.FullName to a view and
        save yourself unnecessary database calls */
    }

}

Once this object has been serialised, we can use it across all controllers without needing to create it or query the database for the data contained within it again.

Inject your session object using Dependency Injection

In a ideal world you would 'program to an interface, not implementation' and inject your serializable session object into your controller using your Inversion of Control container of choice, like so (this example uses StructureMap as it's the one I'm most familiar with).

public class WebsiteRegistry : Registry
{
    public WebsiteRegistry()
    {
        this.For<IUserProfileSessionData>().HybridHttpOrThreadLocalScoped().Use(() => GetUserProfileFromSession());   
    }

    public static IUserProfileSessionData GetUserProfileFromSession()
    {
        var session = HttpContext.Current.Session;
        if (session["UserProfile"] != null)
        {
            return session["UserProfile"] as IUserProfileSessionData;
        }

        /* Create new empty session object */
        session["UserProfile"] = new UserProfileSessionData();

        return session["UserProfile"] as IUserProfileSessionData;
    }
}

You would then register this in your Global.asax.cs file.

For those that aren't familiar with injecting session objects, you can find a more in-depth blog post about the subject here.

A word of warning:

It's worth noting that sessions should be kept to a minimum, large sessions can start to cause performance issues.

It's also recommended to not store any sensitive data in them (passwords, etc).

get one item from an array of name,value JSON

Find one element

To find the element with a given name in an array you can use find:

arr.find(item=>item.name=="k1");

Note that find will return just one item (namely the first match):

{
  "name": "k1",
  "value": "abc"
}

Find all elements

In your original array there's only one item occurrence of each name.

If the array contains multiple elements with the same name and you want them all then use filter, which will return an array.

_x000D_
_x000D_
var arr = [];_x000D_
arr.push({name:"k1", value:"abc"});_x000D_
arr.push({name:"k2", value:"hi"});_x000D_
arr.push({name:"k3", value:"oa"});_x000D_
arr.push({name:"k1", value:"def"});_x000D_
_x000D_
var item;_x000D_
_x000D_
// find the first occurrence of item with name "k1"_x000D_
item = arr.find(item=>item.name=="k1");_x000D_
console.log(item);_x000D_
_x000D_
// find all occurrences of item with name "k1"_x000D_
// now item is an array_x000D_
item = arr.filter(item=>item.name=="k1");_x000D_
console.log(item);
_x000D_
_x000D_
_x000D_

Find indices

Similarly, for indices you can use findIndex (for finding the first match) and filter + map to find all indices.

_x000D_
_x000D_
var arr = [];_x000D_
arr.push({name:"k1", value:"abc"});_x000D_
arr.push({name:"k2", value:"hi"});_x000D_
arr.push({name:"k3", value:"oa"});_x000D_
arr.push({name:"k1", value:"def"});_x000D_
_x000D_
var idx;_x000D_
_x000D_
// find index of the first occurrence of item with name "k1"_x000D_
idx = arr.findIndex(item=>item.name == "k1");_x000D_
console.log(idx, arr[idx].value);_x000D_
_x000D_
// find indices of all occurrences of item with name "k1"_x000D_
// now idx is an array_x000D_
idx = arr.map((item, i) => item.name == "k1" ? i : '').filter(String);_x000D_
console.log(idx);
_x000D_
_x000D_
_x000D_

How to avoid the "divide by zero" error in SQL?

Here is a situation where you can divide by zero. The business rule is that to calculate inventory turns, you take cost of goods sold for a period, annualize it. After you have the annualized number, you divide by the average inventory for the period.

I'm looking at calculating the number of inventory turns that occur in a three month period. I have calculated that I have Cost of Goods sold during the three month period of $1,000. The annual rate of sales is $4,000 ($1,000/3)*12. The beginning inventory is 0. The ending inventory is 0. My average inventory is now 0. I have sales of $4000 per year, and no inventory. This yields an infinite number of turns. This means that all my inventory is being converted and purchased by customers.

This is a business rule of how to calculate inventory turns.

In C#, what is the difference between public, private, protected, and having no access modifier?

enter image description here

using System;

namespace ClassLibrary1
{
    public class SameAssemblyBaseClass
    {
        public string publicVariable = "public";
        protected string protectedVariable = "protected";
        protected internal string protected_InternalVariable = "protected internal";
        internal string internalVariable = "internal";
        private string privateVariable = "private";
        public void test()
        {
            // OK
            Console.WriteLine(privateVariable);

            // OK
            Console.WriteLine(publicVariable);

            // OK
            Console.WriteLine(protectedVariable);

            // OK
            Console.WriteLine(internalVariable);

            // OK
            Console.WriteLine(protected_InternalVariable);
        }
    }

    public class SameAssemblyDerivedClass : SameAssemblyBaseClass
    {
        public void test()
        {
            SameAssemblyDerivedClass p = new SameAssemblyDerivedClass();

            // NOT OK
            // Console.WriteLine(privateVariable);

            // OK
            Console.WriteLine(p.publicVariable);

            // OK
            Console.WriteLine(p.protectedVariable);

            // OK
            Console.WriteLine(p.internalVariable);

            // OK
            Console.WriteLine(p.protected_InternalVariable);
        }
    }

    public class SameAssemblyDifferentClass
    {
        public SameAssemblyDifferentClass()
        {
            SameAssemblyBaseClass p = new SameAssemblyBaseClass();

            // OK
            Console.WriteLine(p.publicVariable);

            // OK
            Console.WriteLine(p.internalVariable);

            // NOT OK
            // Console.WriteLine(privateVariable);

            // Error : 'ClassLibrary1.SameAssemblyBaseClass.protectedVariable' is inaccessible due to its protection level
            //Console.WriteLine(p.protectedVariable);

            // OK
            Console.WriteLine(p.protected_InternalVariable);
        }
    }
}

 using System;
        using ClassLibrary1;
        namespace ConsoleApplication4

{
    class DifferentAssemblyClass
    {
        public DifferentAssemblyClass()
        {
            SameAssemblyBaseClass p = new SameAssemblyBaseClass();

            // NOT OK
            // Console.WriteLine(p.privateVariable);

            // NOT OK
            // Console.WriteLine(p.internalVariable);

            // OK
            Console.WriteLine(p.publicVariable);

            // Error : 'ClassLibrary1.SameAssemblyBaseClass.protectedVariable' is inaccessible due to its protection level
            // Console.WriteLine(p.protectedVariable);

            // Error : 'ClassLibrary1.SameAssemblyBaseClass.protected_InternalVariable' is inaccessible due to its protection level
            // Console.WriteLine(p.protected_InternalVariable);
        }
    }

    class DifferentAssemblyDerivedClass : SameAssemblyBaseClass
    {
        static void Main(string[] args)
        {
            DifferentAssemblyDerivedClass p = new DifferentAssemblyDerivedClass();

            // NOT OK
            // Console.WriteLine(p.privateVariable);

            // NOT OK
            //Console.WriteLine(p.internalVariable);

            // OK
            Console.WriteLine(p.publicVariable);

            // OK
            Console.WriteLine(p.protectedVariable);

            // OK
            Console.WriteLine(p.protected_InternalVariable);

            SameAssemblyDerivedClass dd = new SameAssemblyDerivedClass();
            dd.test();
        }
    }
}

Using psql to connect to PostgreSQL in SSL mode

On psql client v12, I could not find option in psql client to activate sslmode=verify-full.

I ended up using environment variables :

PGSSLMODE=verify-full PGSSLROOTCERT=server-ca.pem psql -h your_host -U your_user -W -d your_db

log4net vs. Nlog

You might also consider Microsoft Enterprise Library Logging Block. It comes with nice designer.

Could not load file or assembly 'System.Net.Http.Formatting' or one of its dependencies. The system cannot find the path specified

  1. Remove all code references to System.Net.*
  2. Uninstall: Package Microsoft.AspNet.WebApi and its dependencies.
  3. Reinstall all: Package Microsoft.AspNet.WebApi and its dependencies.
  4. Clean and rebuild your project

What is the simplest method of inter-process communication between 2 C# processes?

If your processes in same computer, you can simply use stdio.

This is my usage, a web page screenshooter:

var jobProcess = new Process();

jobProcess.StartInfo.FileName = Assembly.GetExecutingAssembly().Location;
jobProcess.StartInfo.Arguments = "job";

jobProcess.StartInfo.CreateNoWindow = false;
jobProcess.StartInfo.UseShellExecute = false;

jobProcess.StartInfo.RedirectStandardInput = true;
jobProcess.StartInfo.RedirectStandardOutput = true;
jobProcess.StartInfo.RedirectStandardError = true;

// Just Console.WriteLine it.
jobProcess.ErrorDataReceived += jp_ErrorDataReceived;

jobProcess.Start();

jobProcess.BeginErrorReadLine();

try
{
    jobProcess.StandardInput.WriteLine(url);
    var buf = new byte[int.Parse(jobProcess.StandardOutput.ReadLine())];
    jobProcess.StandardOutput.BaseStream.Read(buf, 0, buf.Length);
    return Deserz<Bitmap>(buf);
}
finally
{
    if (jobProcess.HasExited == false)
        jobProcess.Kill();
}

Detect args on Main

static void Main(string[] args)
{
    if (args.Length == 1 && args[0]=="job")
    {
        //because stdout has been used by send back, our logs should put to stderr
        Log.SetLogOutput(Console.Error); 

        try
        {
            var url = Console.ReadLine();
            var bmp = new WebPageShooterCr().Shoot(url);
            var buf = Serz(bmp);
            Console.WriteLine(buf.Length);
            System.Threading.Thread.Sleep(100);
            using (var o = Console.OpenStandardOutput())
                o.Write(buf, 0, buf.Length);
        }
        catch (Exception ex)
        {
            Log.E("Err:" + ex.Message);
        }
    }
    //...
}

Callback after all asynchronous forEach callbacks are completed

Array.forEach does not provide this nicety (oh if it would) but there are several ways to accomplish what you want:

Using a simple counter

function callback () { console.log('all done'); }

var itemsProcessed = 0;

[1, 2, 3].forEach((item, index, array) => {
  asyncFunction(item, () => {
    itemsProcessed++;
    if(itemsProcessed === array.length) {
      callback();
    }
  });
});

(thanks to @vanuan and others) This approach guarantees that all items are processed before invoking the "done" callback. You need to use a counter that gets updated in the callback. Depending on the value of the index parameter does not provide the same guarantee, because the order of return of the asynchronous operations is not guaranteed.

Using ES6 Promises

(a promise library can be used for older browsers):

  1. Process all requests guaranteeing synchronous execution (e.g. 1 then 2 then 3)

    function asyncFunction (item, cb) {
      setTimeout(() => {
        console.log('done with', item);
        cb();
      }, 100);
    }
    
    let requests = [1, 2, 3].reduce((promiseChain, item) => {
        return promiseChain.then(() => new Promise((resolve) => {
          asyncFunction(item, resolve);
        }));
    }, Promise.resolve());
    
    requests.then(() => console.log('done'))
    
  2. Process all async requests without "synchronous" execution (2 may finish faster than 1)

    let requests = [1,2,3].map((item) => {
        return new Promise((resolve) => {
          asyncFunction(item, resolve);
        });
    })
    
    Promise.all(requests).then(() => console.log('done'));
    

Using an async library

There are other asynchronous libraries, async being the most popular, that provide mechanisms to express what you want.

Edit

The body of the question has been edited to remove the previously synchronous example code, so i've updated my answer to clarify. The original example used synchronous like code to model asynchronous behaviour, so the following applied:

array.forEach is synchronous and so is res.write, so you can simply put your callback after your call to foreach:

  posts.foreach(function(v, i) {
    res.write(v + ". index " + i);
  });

  res.end();

WCF - How to Increase Message Size Quota

Another important thing to consider from my experience..

I would strongly advice NOT to maximize maxBufferPoolSize, because buffers from the pool are never released until the app-domain (ie the Application Pool) recycles.

A period of high traffic could cause a lot of memory to be used and never released.

More details here:

How to place the cursor (auto focus) in text box when a page gets loaded without javascript support?

<body onLoad="self.focus();document.formname.name.focus()" >

formname is <form action="xxx.php" method="POST" name="formname" >
and name is <input type="text" tabindex="1" name="name" />

it works for me, checked using IE and mozilla.
autofocus, somehow didn't work for me.

Good examples of python-memcache (memcached) being used in Python?

It's fairly simple. You write values using keys and expiry times. You get values using keys. You can expire keys from the system.

Most clients follow the same rules. You can read the generic instructions and best practices on the memcached homepage.

If you really want to dig into it, I'd look at the source. Here's the header comment:

"""
client module for memcached (memory cache daemon)

Overview
========

See U{the MemCached homepage<http://www.danga.com/memcached>} for more about memcached.

Usage summary
=============

This should give you a feel for how this module operates::

    import memcache
    mc = memcache.Client(['127.0.0.1:11211'], debug=0)

    mc.set("some_key", "Some value")
    value = mc.get("some_key")

    mc.set("another_key", 3)
    mc.delete("another_key")

    mc.set("key", "1")   # note that the key used for incr/decr must be a string.
    mc.incr("key")
    mc.decr("key")

The standard way to use memcache with a database is like this::

    key = derive_key(obj)
    obj = mc.get(key)
    if not obj:
        obj = backend_api.get(...)
        mc.set(key, obj)

    # we now have obj, and future passes through this code
    # will use the object from the cache.

Detailed Documentation
======================

More detailed documentation is available in the L{Client} class.
"""

Trust Store vs Key Store - creating with keytool

These are the steps to create a Truststore in your local machine using Keytool. Steps to create truststore for a URL in your local machine.

1) Hit the url in the browser using chrome

2) Check for the "i" icon to the left of the url in the chrome and click it

3) Check for certificate option and click it and a Dialog box will open

4) check the "certificate path" tab for the number of certificates available to create the truststore

5) Go the "details" tab -> click"Copy to File" -> Give the path and the name for the certificate you want to create.

6) Check if it has parent certificates and follow the point "5".

7) After all the certificates are being create open Command Prompt and navigate to the path where you created the certificates.

8) provide the below Keytool command to add the certificates and create a truststore.

Sample: 
   keytool -import -alias abcdefg -file abcdefg.cer -keystore cacerts
        where "abcdefg" is the alias name and "abcdefg.cer" is the actual certificate name and "cacerts" is the truststore name

9) Provide the keytool command for all the certificates and add them to the trust store.

    keytool -list -v -keystore cacerts

Are there pointers in php?

To answer the second part of your question - there are no pointers in PHP.

When working with objects, you generally pass by reference rather than by value - so in some ways this operates like a pointer, but is generally completely transparent.

This does depend on the version of PHP you are using.

How do I display image in Alert/confirm box in Javascript?

I created a function that might help. All it does is imitate the alert but put an image instead of text.

function alertImage(imgsrc) {
$('.d').css({
    'position': 'absolute',
    'top': '0',
    'left': '50%',
    '-webkit-transform': 'translate(-50%, 0)'
});
$('.d').animate({
    opacity: 0
}, 0)
$('.d').animate({
    opacity: 1,
    top: "10px"
}, 250)
$('.d').append('An embedded page on this page says')
$('.d').append('<br><img src="' + imgsrc + '">')
$('.b').css({
  'position':'absolute',
  '-webkit-transform': 'translate(-100%, -100%)',
  'top':'100%',
  'left':'100%',
  'display':'inline',
  'background-color':'#598cbd',
  'border-radius':'4px',
  'color':'white',
  'border':'none',
  'width':'66',
  'height':'33'
})
}
<script type="text/javascript" src="https://code.jquery.com/jquery-latest.min.js"></script>
<div class="d"><button onclick="$('.d').html('')" class="b">OK</button></div>
.d{
font-size: 17px;
  font-family: sans-serif;
}
.b{
  display: none;
}

Display image as grayscale using matplotlib

try this:

import pylab
from scipy import misc

pylab.imshow(misc.lena(),cmap=pylab.gray())
pylab.show()

JavaScript: Get image dimensions

This uses the function and waits for it to complete.

http://jsfiddle.net/SN2t6/118/

function getMeta(url){
    var r = $.Deferred();

  $('<img/>').attr('src', url).load(function(){
     var s = {w:this.width, h:this.height};
     r.resolve(s)
  });
  return r;
}

getMeta("http://www.google.hr/images/srpr/logo3w.png").done(function(test){
    alert(test.w + ' ' + test.h);
});

Copy directory to another directory using ADD command

You can use COPY. You need to specify the directory explicitly. It won't be created by itself

COPY go /usr/local/go

Reference: Docker CP reference

SQL Server - NOT IN

It's because of the way NOT IN works.

To avoid these headaches (and for a faster query in many cases), I always prefer NOT EXISTS:

SELECT  *  
FROM Table1 t1 
WHERE NOT EXISTS (
    SELECT * 
    FROM Table2 t2 
    WHERE t1.MAKE = t2.MAKE
    AND   t1.MODEL = t2.MODEL
    AND   t1.[Serial Number] = t2.[serial number]);

How to change color of ListView items on focus and on click

Here's a good article on how to use selectors with lists.

Instead of setting it to be the android:background of the ListView, I believe you want to set android:listSelector as shown below:

<ListView android:id="@+id/list" 
  android:layout_width="fill_parent"
  android:layout_height="wrap_content" 
  android:layout_gravity="center"
  android:divider="@null" 
  android:dividerHeight="0dip"
  android:listSelector="@drawable/list_selector" />

C++ multiline string literal

You can just do this:

const char *text = "This is my string it is "
     "very long";

/usr/lib/libstdc++.so.6: version `GLIBCXX_3.4.15' not found

I've had a similar issue, and I've resolved it by statically linking libstdc++ into the program I was compiling, like so:

$ LIBS=-lstdc++ ./configure ... etc.

instead of the usual

$ ./configure ... etc.

There might be problems with this solution to do with loading shared libraries at runtime, but I haven't looked into the issue deeply enough to comment.

HttpServletRequest - Get query string parameters, no form data

I am afraid there is no way to get the query string parameters parsed separately from the post parameters. BTW the fact that such API absent may mean that probably you should check your design. Why are you using query string when sending POST? If you really want to send more data into URL use REST-like convention, e.g. instead of sending

http://mycompany.com/myapp/myservlet?first=11&second=22

say:

http://mycompany.com/myapp/myservlet/11/22

Find duplicate characters in a String and count the number of occurances using Java

You can also achieve it by iterating over your String and using a switch to check each individual character, adding a counter whenever it finds a match. Ah, maybe some code will make it clearer:

Main Application:

public static void main(String[] args) {

        String test = "The quick brown fox jumped over the lazy dog.";

        int countA = 0, countO = 0, countSpace = 0, countDot = 0;

        for (int i = 0; i < test.length(); i++) {
            switch (test.charAt(i)) {
                case 'a':
                case 'A': countA++; break;
                case 'o':
                case 'O': countO++; break;
                case ' ': countSpace++; break;
                case '.': countDot++; break;
            }
        }

        System.out.printf("%s%d%n%s%d%n%s%d%n%s%d", "A: ", countA, "O: ", countO, "Space: ", countSpace, "Dot: ", countDot);

    }

Output:

A: 1
O: 4
Space: 8
Dot: 1

Asynchronous method call in Python?

My solution is:

import threading

class TimeoutError(RuntimeError):
    pass

class AsyncCall(object):
    def __init__(self, fnc, callback = None):
        self.Callable = fnc
        self.Callback = callback

    def __call__(self, *args, **kwargs):
        self.Thread = threading.Thread(target = self.run, name = self.Callable.__name__, args = args, kwargs = kwargs)
        self.Thread.start()
        return self

    def wait(self, timeout = None):
        self.Thread.join(timeout)
        if self.Thread.isAlive():
            raise TimeoutError()
        else:
            return self.Result

    def run(self, *args, **kwargs):
        self.Result = self.Callable(*args, **kwargs)
        if self.Callback:
            self.Callback(self.Result)

class AsyncMethod(object):
    def __init__(self, fnc, callback=None):
        self.Callable = fnc
        self.Callback = callback

    def __call__(self, *args, **kwargs):
        return AsyncCall(self.Callable, self.Callback)(*args, **kwargs)

def Async(fnc = None, callback = None):
    if fnc == None:
        def AddAsyncCallback(fnc):
            return AsyncMethod(fnc, callback)
        return AddAsyncCallback
    else:
        return AsyncMethod(fnc, callback)

And works exactly as requested:

@Async
def fnc():
    pass

Understanding Matlab FFT example

The reason why your X-axis plots frequencies only till 500 Hz is your command statement 'f = Fs/2*linspace(0,1,NFFT/2+1);'. Your Fs is 1000. So when you divide it by 2 & then multiply by values ranging from 0 to 1, it returns a vector of length NFFT/2+1. This vector consists of equally spaced frequency values, ranging from 0 to Fs/2 (i.e. 500 Hz). Since you plot using 'plot(f,2*abs(Y(1:NFFT/2+1)))' command, your X-axis limit is 500 Hz.

how to get session id of socket.io client in Client

Try this way.

                var socket = io.connect('http://...');
                console.log(socket.Socket.sessionid);

"Couldn't read dependencies" error with npm

I had an "Invalid Name"

I switched from "name": "Some Name",... to "name": "Some-Name",...

Guess name needs to be a sluggy string.

Parsing string as JSON with single quotes?

var str =  "{'a':1}";
str = str.replace(/'/g, '"')
obj = JSON.parse(str);
console.log(obj);

This solved the problem for me.

How to change the name of an iOS app?

  1. Select the top most line to the left (with you project name, number of targets, etc).
  2. Select the target you wish to rename.
  3. Click on the name of the target again.
  4. Type the new name.
  5. Press enter.

String contains - ignore case

You can use java.util.regex.Pattern with the CASE_INSENSITIVE flag for case insensitive matching:

Pattern.compile(Pattern.quote(strptrn), Pattern.CASE_INSENSITIVE).matcher(str1).find();

How to set MouseOver event/trigger for border in XAML?

Yes, this is confusing...

According to this blog post, it looks like this is an omission from WPF.

To make it work you need to use a style:

    <Border Name="ClearButtonBorder" Grid.Column="1" CornerRadius="0,3,3,0">
        <Border.Style>
            <Style>
                <Setter Property="Border.Background" Value="Blue"/>
                <Style.Triggers>
                    <Trigger Property="Border.IsMouseOver" Value="True">
                        <Setter Property="Border.Background" Value="Green" />
                    </Trigger>
                </Style.Triggers>
            </Style>
        </Border.Style>
        <TextBlock HorizontalAlignment="Center" VerticalAlignment="Center" Text="X" />
    </Border>

I guess this problem isn't that common as most people tend to factor out this sort of thing into a style, so it can be used on multiple controls.

How to substitute shell variables in complex text files

Actually you need to change your read to read -r which will make it ignore backslashes.

Also, you should escape quotes and backslashes. So

while read -r line; do
  line="${line//\\/\\\\}"
  line="${line//\"/\\\"}"
  line="${line//\`/\\\`}"
  eval echo "\"$line\""
done > destination.txt < source.txt

Still a terrible way to do expansion though.

Exporting results of a Mysql query to excel?

In my case, I need to dump the sql result into a file on the client side. This is the most typical use case to off load data from the database. In many situations, you don't have access to the server or don't want to write your result to the server.

mysql -h hostname -u username -ppwd -e "mysql simple sql statement that last for less than a line" DATABASE_NAME > outputfile_on_the.client

The problem comes when you have a complicated query that last for several lines; you cannot use the command line to dump the result to a file easily. In such cases, you can put your complicated query into a file, such as longquery_file.sql, then execute the command.

mysql -h hn -u un -ppwd < longquery_file.sql DBNAME > output.txt

This worked for me. The only difficulty with me is the tab character; sometimes I use for group_cancat(foo SEPARATOR 0x09) will be written as '\t' in the output file. The 0x09 character is ASCII TAB. But this problem is not particular to the way we dump sql results to file. It may be related to my pager. Let me know when you find an answer to this problem. I will update this post.

How to retrieve a single file from a specific revision in Git?

If you wish to replace/overwrite the content of a file in your current branch with the content of the file from a previous commit or a different branch, you can do so with these commands:

git checkout 08618129e66127921fbfcbc205a06153c92622fe path/to/file.txt

or

git checkout mybranchname path/to/file.txt

You will then have to commit those changes in order for them to be effective in the current branch.

Optional args in MATLAB functions

There are a few different options on how to do this. The most basic is to use varargin, and then use nargin, size etc. to determine whether the optional arguments have been passed to the function.

% Function that takes two arguments, X & Y, followed by a variable 
% number of additional arguments
function varlist(X,Y,varargin)
   fprintf('Total number of inputs = %d\n',nargin);

   nVarargs = length(varargin);
   fprintf('Inputs in varargin(%d):\n',nVarargs)
   for k = 1:nVarargs
      fprintf('   %d\n', varargin{k})
   end

A little more elegant looking solution is to use the inputParser class to define all the arguments expected by your function, both required and optional. inputParser also lets you perform type checking on all arguments.

Get the latest record from mongodb collection

This will give you one last document for a collection

db.collectionName.findOne({}, {sort:{$natural:-1}})

$natural:-1 means order opposite of the one that records are inserted in.

Edit: For all the downvoters, above is a Mongoose syntax, mongo CLI syntax is: db.collectionName.find({}).sort({$natural:-1}).limit(1)

Request redirect to /Account/Login?ReturnUrl=%2f since MVC 3 install on server

I fixed it this way

  1. Go to IIS
  2. Select your Project
  3. Click on "Authentication"
  4. Click on "Anonymous Authentication" > Edit > select "Application pool identity" instead of "Specific User".
  5. Done.

How can I add a space in between two outputs?

import java.util.Scanner;
public class class2 {

    public void Multipleclass(){
       String x,y;
       Scanner sc=new Scanner(System.in);

       System.out.println("Enter your First name");
       x=sc.next();
       System.out.println("Enter your Last name");
       y=sc.next();

       System.out.println(x+  " "  +y );
   }
}

CSS3 Transform Skew One Side

you can make that using transform and transform origins.

Combining various transfroms gives similar result. I hope you find it helpful. :) See these examples for simpler transforms. this has left point :

_x000D_
_x000D_
div {    _x000D_
    width: 300px;_x000D_
    height:200px;_x000D_
    background-image: url('data:image/gif;base64,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');_x000D_
    -webkit-transform: perspective(300px) rotateX(-30deg);_x000D_
    -o-transform: perspective(300px) rotateX(-30deg);_x000D_
    -moz-transform: perspective(300px) rotateX(-30deg);_x000D_
    -webkit-transform-origin: 100% 50%;_x000D_
    -moz-transform-origin: 100% 50%;_x000D_
    -o-transform-origin: 100% 50%;_x000D_
    transform-origin: 100% 50%;_x000D_
    margin: 10px 90px;_x000D_
}
_x000D_
<div></div>
_x000D_
_x000D_
_x000D_

This has right skew point :

_x000D_
_x000D_
div {    _x000D_
    width: 300px;_x000D_
    height:200px;_x000D_
    background-image: url('data:image/gif;base64,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');_x000D_
    -webkit-transform: perspective(300px) rotateX(-30deg);_x000D_
    -o-transform: perspective(300px) rotateX(-30deg);_x000D_
    -moz-transform: perspective(300px) rotateX(-30deg);_x000D_
    -webkit-transform-origin: 0% 50%;_x000D_
    -moz-transform-origin: 0% 50%;_x000D_
    -o-transform-origin: 0% 50%;_x000D_
    transform-origin: 0% 50%;_x000D_
    margin: 10px 90px;_x000D_
}
_x000D_
<div></div>
_x000D_
_x000D_
_x000D_

what transform: 0% 50%; does is it sets the origin to vertical middle and horizontal left of the element. so the perspective is not visible at the left part of the image, so it looks flat. Perspective effect is there at the right part, so it looks slanted.

Rails: Check output of path helper from console

you can also

include Rails.application.routes.url_helpers

from inside a console sessions to access the helpers:

url_for controller: :users, only_path: true
users_path
# => '/users'

or

Rails.application.routes.url_helpers.users_path

/usr/lib/x86_64-linux-gnu/libstdc++.so.6: version CXXABI_1.3.8' not found

I had the same problem on my Ubuntu 14.04 when tried to install TopTracker. I got such errors:

/usr/share/toptracker/bin/TopTracker: /usr/lib/x86_64-linux-gnu/libstdc++.so.6: version 'CXXABI_1.3.8' not found (required by /usr/share/toptracker/bin/TopTracker) /usr/share/toptracker/bin/TopTracker: /usr/lib/x86_64-linux-gnu/libstdc++.so.6: version 'GLIBCXX_3.4.21' not found (required by /usr/share/toptracker/bin/TopTracker) /usr/share/toptracker/bin/TopTracker: /usr/lib/x86_64-linux-gnu/libstdc++.so.6: version 'CXXABI_1.3.9' not found (required by /usr/share/toptracker/bin/TopTracker)

But I then installed gcc 4.9 version and problem gone:

sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt-get update
sudo apt-get install gcc-4.9 g++-4.9

Split (explode) pandas dataframe string entry to separate rows

My version of the solution to add to this collection! :-)

# Original problem
from pandas import DataFrame
import numpy as np
a = DataFrame([{'var1': 'a,b,c', 'var2': 1},
               {'var1': 'd,e,f', 'var2': 2}])
b = DataFrame([{'var1': 'a', 'var2': 1},
               {'var1': 'b', 'var2': 1},
               {'var1': 'c', 'var2': 1},
               {'var1': 'd', 'var2': 2},
               {'var1': 'e', 'var2': 2},
               {'var1': 'f', 'var2': 2}])
### My solution
import pandas as pd
import functools
def expand_on_cols(df, fuse_cols, delim=","):
    def expand_on_col(df, fuse_col):
        col_order = df.columns
        df_expanded = pd.DataFrame(
            df.set_index([x for x in df.columns if x != fuse_col])[fuse_col]
            .apply(lambda x: x.split(delim))
            .explode()
        ).reset_index()
        return df_expanded[col_order]
    all_expanded = functools.reduce(expand_on_col, fuse_cols, df)
    return all_expanded

assert(b.equals(expand_on_cols(a, ["var1"], delim=",")))

open() in Python does not create a file if it doesn't exist

Good practice is to use the following:

import os

writepath = 'some/path/to/file.txt'

mode = 'a' if os.path.exists(writepath) else 'w'
with open(writepath, mode) as f:
    f.write('Hello, world!\n')

Create new XML file and write data to it?

With FluidXML you can generate and store an XML document very easily.

$doc = fluidxml();

$doc->add('Album', true)
        ->add('Track', 'Track Title');

$doc->save('album.xml');

Loading a document from a file is equally simple.

$doc = fluidify('album.xml');

$doc->query('//Track')
        ->attr('id', 123);

https://github.com/servo-php/fluidxml

Unit tests vs Functional tests

Unit Test - testing an individual unit, such as a method (function) in a class, with all dependencies mocked up.

Functional Test - AKA Integration Test, testing a slice of functionality in a system. This will test many methods and may interact with dependencies like Databases or Web Services.

Mixing a PHP variable with a string literal

You can use {} arround your variable, to separate it from what's after:

echo "{$test}y"

As reference, you can take a look to the Variable parsing - Complex (curly) syntax section of the PHP manual.

Constructor overloading in Java - best practice

Constructor overloading is like method overloading. Constructors can be overloaded to create objects in different ways.

The compiler differentiates constructors based on how many arguments are present in the constructor and other parameters like the order in which the arguments are passed.

For further details about java constructor, please visit https://tecloger.com/constructor-in-java/

How to get element-wise matrix multiplication (Hadamard product) in numpy?

import numpy as np
x = np.array([[1,2,3], [4,5,6]])
y = np.array([[-1, 2, 0], [-2, 5, 1]])

x*y
Out: 
array([[-1,  4,  0],
       [-8, 25,  6]])

%timeit x*y
1000000 loops, best of 3: 421 ns per loop

np.multiply(x,y)
Out: 
array([[-1,  4,  0],
       [-8, 25,  6]])

%timeit np.multiply(x, y)
1000000 loops, best of 3: 457 ns per loop

Both np.multiply and * would yield element wise multiplication known as the Hadamard Product

%timeit is ipython magic

Java generics - why is "extends T" allowed but not "implements T"?

We are used to

class ClassTypeA implements InterfaceTypeA {}
class ClassTypeB extends ClassTypeA {}

and any slight deviation from these rules greatly confuses us.

The syntax of a type bound is defined as

TypeBound:
    extends TypeVariable 
    extends ClassOrInterfaceType {AdditionalBound}

(JLS 12 > 4.4. Type Variables > TypeBound)

If we were to change it, we would surely add the implements case

TypeBound:
    extends TypeVariable 
    extends ClassType {AdditionalBound}
    implements InterfaceType {AdditionalBound}

and end up with two identically processed clauses

ClassOrInterfaceType:
    ClassType 
    InterfaceType

(JLS 12 > 4.3. Reference Types and Values > ClassOrInterfaceType)

except we would also need to take care of implements, which would complicate things further.

I believe it's the main reason why extends ClassOrInterfaceType is used instead of extends ClassType and implements InterfaceType - to keep things simple within the complicated concept. The problem is we don't have the right word to cover both extends and implements and we definitely don't want to introduce one.

<T is ClassTypeA>
<T is InterfaceTypeA>

Although extends brings some mess when it goes along with an interface, it's a broader term and it can be used to describe both cases. Try to tune your mind to the concept of extending a type (not extending a class, not implementing an interface). You restrict a type parameter by another type and it doesn't matter what that type actually is. It only matters that it's its upper bound and it's its supertype.

Border around each cell in a range

I have a set of 15 subroutines I add to every Coded Excel Workbook I create and this is one of them. The following routine clears the area and creates a border.

Sample Call:

Call BoxIt(Range("A1:z25"))

Subroutine:

Sub BoxIt(aRng As Range)
On Error Resume Next

    With aRng

        'Clear existing
        .Borders.LineStyle = xlNone

        'Apply new borders
        .BorderAround xlContinuous, xlThick, 0
        With .Borders(xlInsideVertical)
            .LineStyle = xlContinuous
            .ColorIndex = 0
            .Weight = xlMedium
        End With
        With .Borders(xlInsideHorizontal)
            .LineStyle = xlContinuous
            .ColorIndex = 0
            .Weight = xlMedium
        End With
    End With

End Sub

How do I create a new user in a SQL Azure database?

create a user and then add user to a specific role:

CREATE USER [test] WITH PASSWORD=N'<strong password>'
go
ALTER ROLE [db_datareader] ADD MEMBER [test]
go

How should I choose an authentication library for CodeIgniter?

I use a customized version of DX Auth. I found it simple to use, extremely easy to modify and it has a user guide (with great examples) that is very similar to Code Igniter's.

maven command line how to point to a specific settings.xml for a single command?

You can simply use:

mvn --settings YourOwnSettings.xml clean install

or

mvn -s YourOwnSettings.xml clean install

How to save a spark DataFrame as csv on disk?

I had similar problem. I needed to write down csv file on driver while I was connect to cluster in client mode.

I wanted to reuse the same CSV parsing code as Apache Spark to avoid potential errors.

I checked spark-csv code and found code responsible for converting dataframe into raw csv RDD[String] in com.databricks.spark.csv.CsvSchemaRDD.

Sadly it is hardcoded with sc.textFile and the end of relevant method.

I copy-pasted that code and removed last lines with sc.textFile and returned RDD directly instead.

My code:

/*
  This is copypasta from com.databricks.spark.csv.CsvSchemaRDD
  Spark's code has perfect method converting Dataframe -> raw csv RDD[String]
  But in last lines of that method it's hardcoded against writing as text file -
  for our case we need RDD.
 */
object DataframeToRawCsvRDD {

  val defaultCsvFormat = com.databricks.spark.csv.defaultCsvFormat

  def apply(dataFrame: DataFrame, parameters: Map[String, String] = Map())
           (implicit ctx: ExecutionContext): RDD[String] = {
    val delimiter = parameters.getOrElse("delimiter", ",")
    val delimiterChar = if (delimiter.length == 1) {
      delimiter.charAt(0)
    } else {
      throw new Exception("Delimiter cannot be more than one character.")
    }

    val escape = parameters.getOrElse("escape", null)
    val escapeChar: Character = if (escape == null) {
      null
    } else if (escape.length == 1) {
      escape.charAt(0)
    } else {
      throw new Exception("Escape character cannot be more than one character.")
    }

    val quote = parameters.getOrElse("quote", "\"")
    val quoteChar: Character = if (quote == null) {
      null
    } else if (quote.length == 1) {
      quote.charAt(0)
    } else {
      throw new Exception("Quotation cannot be more than one character.")
    }

    val quoteModeString = parameters.getOrElse("quoteMode", "MINIMAL")
    val quoteMode: QuoteMode = if (quoteModeString == null) {
      null
    } else {
      QuoteMode.valueOf(quoteModeString.toUpperCase)
    }

    val nullValue = parameters.getOrElse("nullValue", "null")

    val csvFormat = defaultCsvFormat
      .withDelimiter(delimiterChar)
      .withQuote(quoteChar)
      .withEscape(escapeChar)
      .withQuoteMode(quoteMode)
      .withSkipHeaderRecord(false)
      .withNullString(nullValue)

    val generateHeader = parameters.getOrElse("header", "false").toBoolean
    val headerRdd = if (generateHeader) {
      ctx.sparkContext.parallelize(Seq(
        csvFormat.format(dataFrame.columns.map(_.asInstanceOf[AnyRef]): _*)
      ))
    } else {
      ctx.sparkContext.emptyRDD[String]
    }

    val rowsRdd = dataFrame.rdd.map(row => {
      csvFormat.format(row.toSeq.map(_.asInstanceOf[AnyRef]): _*)
    })

    headerRdd union rowsRdd
  }

}

Easy pretty printing of floats in python?

Note that you can also multiply a string like "%.2f" (example: "%.2f "*10).

>>> print "%.2f "*len(yourlist) % tuple(yourlist)
2.00 33.00 4.42 0.31 

How to make a phone call programmatically?

Take a look there : http://developer.android.com/guide/topics/intents/intents-filters.html

DO you have update your manifest file in order to give call rights ?

How to drop columns using Rails migration

To remove the column from table you have to run following migration:

rails g migration remove_column_name_from_table_name column_name:data_type

Then run command:

rake db:migrate

Best way to script remote SSH commands in Batch (Windows)

The -m switch of PuTTY takes a path to a script file as an argument, not a command.

Reference: https://the.earth.li/~sgtatham/putty/latest/htmldoc/Chapter3.html#using-cmdline-m

So you have to save your command (command_run) to a plain text file (e.g. c:\path\command.txt) and pass that to PuTTY:

putty.exe -ssh user@host -pw password -m c:\path\command.txt

Though note that you should use Plink (a command-line connection tool from PuTTY suite). It's a console application, so you can redirect its output to a file (what you cannot do with PuTTY).

A command-line syntax is identical, an output redirection added:

plink.exe -ssh user@host -pw password -m c:\path\command.txt > output.txt

See Using the command-line connection tool Plink.

And with Plink, you can actually provide the command directly on its command-line:

plink.exe -ssh user@host -pw password command > output.txt

Similar questions:
Automating running command on Linux from Windows using PuTTY
Executing command in Plink from a batch file

What's the whole point of "localhost", hosts and ports at all?

In computer networking, localhost (meaning "this computer") is the standard hostname given to the address of the loopback network interface.

Localhost always translates to the loopback IP address 127.0.0.1 in IPv4.

It is also used instead of the hostname of a computer. For example, directing a web browser installed on a system running an HTTP server to http://localhost will display the home page of the local web site.

Source: Wikipedia - Localhost.


The :80 part is the TCP port. You can consider these ports as communications endpoints on a particular IP address (in the case of localhost - 127.0.0.1). The IANA is responsible for maintaining the official assignments of standard port numbers for specific services. Port 80 happens to be the standard port for HTTP.

Are there any style options for the HTML5 Date picker?

I used a combination of the above solutions and some trial and error to come to this solution. Took me an annoying amount of time so I hope this can help someone else in the future. I also noticed that the date picker input is not at all supported by Safari...

I am using styled-components to render a transparent date picker input as shown in the image below:

image of date picker input

const StyledInput = styled.input`
  appearance: none;
  box-sizing: border-box;
  border: 1px solid black;
  background: transparent;
  font-size: 1.5rem;
  padding: 8px;
  ::-webkit-datetime-edit-text { padding: 0 2rem; }
  ::-webkit-datetime-edit-month-field { text-transform: uppercase; }
  ::-webkit-datetime-edit-day-field { text-transform: uppercase; }
  ::-webkit-datetime-edit-year-field { text-transform: uppercase; }
  ::-webkit-inner-spin-button { display: none; }
  ::-webkit-calendar-picker-indicator { background: transparent;}
`

When should you use a class vs a struct in C++?

Just to address this from a C++20 Standardese perspective (working from N4860)...

A class is a type. The keywords "class" and "struct" (and "union") are - in the C++ grammar - class-keys, and the only functional significance of the choice of class or struct is:

The class-key determines whether ... access is public or private by default (11.9).

Data member default accessibility

That the class keyword results in private-by-default members, and `struct keyword results in public-by-default members, is documented by the examples in 11.9.1:

class X { int a; // X::a is private by default: class used

...vs...

struct S { int a; // S::a is public by default: struct used

Base class default accessibility

1.9 also says:

In the absence of an access-specifier for a base class, public is assumed when the derived class is defined with the class-key struct and private is assumed when the class is defined with the class-key class.

Circumstances where consistent use of struct or class is required...

There's a requirement:

In a redeclaration, partial specialization, explicit specialization or explicit instantiation of a class template, the class-key shall agree in kind with the original class template declaration (9.2.8.3).

...in any elaborated-type-specifier, the enum keyword shall be used to refer to an enumeration (9.7.1), the union class-key shall be used to refer to a union (11.5), and either the class or struct class-key shall be used to refer to a non-union class (11.1).

The following example (of when consistency is not required) is provided:

struct S { } s; class S* p = &s; // OK

Still, some compilers may warn about this.


Interestingly, while the types you create with struct, class and union are all termed "classes", we have...

A standard-layout struct is a standard layout class defined with the class-key struct or the class-key class.

...so in Standardese, when there's talk of a standard-layout struct it's using "struct" to imply "not a union"s.

I'm curious if there are similar use of "struct" in other terminology, but it's too big a job to do an exhaustive search of the Standard. Comments about that welcome.

error MSB6006: "cmd.exe" exited with code 1

Another solution could be, that you deleted a file from your Project by just removing it in your file system, instead of removing it within your project.

How to replace (or strip) an extension from a filename in Python?

I'm surprised nobody has mentioned pathlib's with_name. This solution works with multiple extensions (i.e. it replaces all of the extensions.)

import pathlib

p = pathlib.Path('/some/path/somefile.txt')
p = p.with_name(p.stem).with_suffix('.jpg')

Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect)

I also ran into this error when attempting to update an existing row after creating a new one, and spent ages scratching my head, digging through transaction and version logic, until I realised that I had used the wrong type for one of my primary key columns.

I used LocalDate when I should have been using LocalDateTime – I think this was causing hibernate to not be able to distinguish entities, leading to this error.

After changing the key to be a LocalDateTime, the error went away. Also, updating individual rows began to work as well – previously it would fail to find a row for updating, and testing this separate issue was actually what led me to my conclusions regarding the primary key mapping.

How to make a flex item not fill the height of the flex container?

When you create a flex container various default flex rules come into play.

Two of these default rules are flex-direction: row and align-items: stretch. This means that flex items will automatically align in a single row, and each item will fill the height of the container.

If you don't want flex items to stretch – i.e., like you wrote:

make its height the minimum required for holding its content

... then simply override the default with align-items: flex-start.

_x000D_
_x000D_
#a {_x000D_
  display: flex;_x000D_
  align-items: flex-start; /* NEW */_x000D_
}_x000D_
#a > div {_x000D_
  background-color: red;_x000D_
  padding: 5px;_x000D_
  margin: 2px;_x000D_
}_x000D_
#b {_x000D_
  height: auto;_x000D_
}
_x000D_
<div id="a">_x000D_
  <div id="b">left</div>_x000D_
  <div>_x000D_
    right<br>right<br>right<br>right<br>right<br>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Here's an illustration from the flexbox spec that highlights the five values for align-items and how they position flex items within the container. As mentioned before, stretch is the default value.

enter image description here Source: W3C

Facebook page automatic "like" URL (for QR Code)

For a hyperlink just use www.facebook.com/++page ID++/like

Eg: www.facebook.com/MYPAGEISAWESOME/like

To make it work with m.facebook.com here's what you do:

Open the Facebook page you're looking for then change the URL to the mobile URL ( which is www.m.facebook.com/MYPAGEISAWESOME ).

Now you should see a big version of the mobile Facebook page. Copy the target URL of the like button.

Pop that URL into the QR generator to make a "scan to like" barcode. This will open the m.Facebook page in the browser of most mobiles directly from the QR reader. If they are not logged into Facebook then they will be prompted to log in and then click 'like'. If logged in, it will auto like.

Hope this helps!

Also, definitely include something with a "click here/scan here to like us on Facebook"

TypeError: $(...).modal is not a function with bootstrap Modal

i just want to emphasize what mwebber said in the comment:

also check if jQuery is not included twice

:)

it was the issue for me

How to move table from one tablespace to another in oracle 11g

Use sql from sql:

spool output of this to a file:

select 'alter index '||owner||'.'||index_name||' rebuild tablespace TO_TABLESPACE_NAME;' from all_indexes where owner='OWNERNAME';

spoolfile will have something like this:

alter index OWNER.PK_INDEX rebuild tablespace CORRECT_TS_NAME;

Why is this printing 'None' in the output?

Because of double print function. I suggest you to use return instead of print inside the function definition.

def lyrics():
    return "The very first line"
print(lyrics())

OR

def lyrics():
    print("The very first line")
lyrics()

Set Radiobuttonlist Selected from Codebehind

We can change the item by value, here is the trick:

radio1.ClearSelection();
radio1.Items.FindByValue("1").Selected = true;// 1 is the value of option2

How to Get XML Node from XDocument

test.xml:

<?xml version="1.0" encoding="utf-8"?>
<Contacts>
  <Node>
    <ID>123</ID>
    <Name>ABC</Name>
  </Node>
  <Node>
    <ID>124</ID>
    <Name>DEF</Name>
  </Node>
</Contacts>

Select a single node:

XDocument XMLDoc = XDocument.Load("test.xml");
string id = "123"; // id to be selected

XElement Contact = (from xml2 in XMLDoc.Descendants("Node")
                    where xml2.Element("ID").Value == id
                    select xml2).FirstOrDefault();

Console.WriteLine(Contact.ToString());

Delete a single node:

XDocument XMLDoc = XDocument.Load("test.xml");
string id = "123";

var Contact = (from xml2 in XMLDoc.Descendants("Node")
               where xml2.Element("ID").Value == id
               select xml2).FirstOrDefault();

Contact.Remove();
XMLDoc.Save("test.xml");

Add new node:

XDocument XMLDoc = XDocument.Load("test.xml");

XElement newNode = new XElement("Node",
    new XElement("ID", "500"),
    new XElement("Name", "Whatever")
);

XMLDoc.Element("Contacts").Add(newNode);
XMLDoc.Save("test.xml");

/exclude in xcopy just for a file type

The /EXCLUDE: argument expects a file containing a list of excluded files.

So create a file called excludedfileslist.txt containing:

.cs\

Then a command like this:

xcopy /r /d /i /s /y /exclude:excludedfileslist.txt C:\dev\apan C:\web\apan

Alternatively you could use Robocopy, but would require installing / copying a robocopy.exe to the machines.

Update

An anonymous comment edit which simply stated "This Solution exclude also css file!"

This is true creating a excludedfileslist.txt file contain just:

.cs

(note no backslash on the end)

Will also exclude all of the following:

  • file1.cs
  • file2.css
  • dir1.cs\file3.txt
  • dir2\anyfile.cs.something.txt

Sometimes people don't read or understand the XCOPY command's help, here is an item I would like to highlight:

Using /exclude

  • List each string in a separate line in each file. If any of the listed strings match any part of the absolute path of the file to be copied, that file is then excluded from the copying process. For example, if you specify the string "\Obj\", you exclude all files underneath the Obj directory. If you specify the string ".obj", you exclude all files with the .obj extension.

As the example states it excludes "all files with the .obj extension" but it doesn't state that it also excludes files or directories named file1.obj.tmp or dir.obj.output\example2.txt.

There is a way around .css files being excluded also, change the excludedfileslist.txt file to contain just:

.cs\

(note the backslash on the end).

Here is a complete test sequence for your reference:

C:\test1>ver

Microsoft Windows [Version 6.1.7601]

C:\test1>md src
C:\test1>md dst
C:\test1>md src\dir1
C:\test1>md src\dir2.cs
C:\test1>echo "file contents" > src\file1.cs
C:\test1>echo "file contents" > src\file2.css
C:\test1>echo "file contents" > src\dir1\file3.txt
C:\test1>echo "file contents" > src\dir1\file4.cs.txt
C:\test1>echo "file contents" > src\dir2.cs\file5.txt

C:\test1>xcopy /r /i /s /y .\src .\dst
.\src\file1.cs
.\src\file2.css
.\src\dir1\file3.txt
.\src\dir1\file4.cs.txt
.\src\dir2.cs\file5.txt
5 File(s) copied

C:\test1>echo .cs > excludedfileslist.txt
C:\test1>xcopy /r /i /s /y /exclude:excludedfileslist.txt .\src .\dst
.\src\dir1\file3.txt
1 File(s) copied

C:\test1>echo .cs\ > excludedfileslist.txt
C:\test1>xcopy /r /i /s /y /exclude:excludedfileslist.txt .\src .\dst
.\src\file2.css
.\src\dir1\file3.txt
.\src\dir1\file4.cs.txt
3 File(s) copied

This test was completed on a Windows 7 command line and retested on Windows 10 "10.0.14393".

Note that the last example does exclude .\src\dir2.cs\file5.txt which may or may not be unexpected for you.

Text in a flex container doesn't wrap in IE11

Somehow all these solutions didn't work for me. There is clearly an IE bug in flex-direction:column.

I only got it working after removing flex-direction:

flex-wrap: wrap;
align-items: center;
align-content: center;

Could not load file or assembly System.Web.Http.WebHost after published to Azure web site

I had the same problem in my Application.

System.web.http.webhost not found.

You just need to copy the system.web.http.webhost file from your main project which you run in Visual Studio and paste it into your published project bin directory.

After this it may show the same error but the directory name is changed it may be system.web.http. Follow same procedure as above. It will work after all the files are uploaded. This due to the nuget package in Visual Studio they download from the internet but on server it not able to download it.

You can find this file in your project bin directory.

npm - EPERM: operation not permitted on Windows

If cleaning the cache(npm cache clean --force) doesn't help you just delete manually the folder C:\Users\%USER_NAME%\AppData\Roaming\npm-cacheand and reinstall NodeJS

How do I convert a javascript object array to a string array of the object attribute I want?

Use the map() function native on JavaScript arrays:

var yourArray = [ {
    'id':1,
    'name':'john'
},{
    'id':2,
    'name':'jane'
}........,{
    'id':2000,
    'name':'zack'
}];

var newArray = yourArray.map( function( el ){ 
                                return el.name; 
                               });

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

If I'm correct in thinking that you want to find the minimum value of a function for all possible pairs of 2 elements from a list...

l = [1,2,3,4,5]

def f(i,j):
   return i+j 

# Prints min value of f(i,j) along with i and j
print min( (f(i,j),i,j) for i in l for j in l)

Python convert object to float

I eventually used:

weather["Temp"] = weather["Temp"].convert_objects(convert_numeric=True)

It worked just fine, except that I got the following message.

C:\ProgramData\Anaconda3\lib\site-packages\ipykernel_launcher.py:3: FutureWarning:
convert_objects is deprecated.  Use the data-type specific converters pd.to_datetime, pd.to_timedelta and pd.to_numeric.

Default value of function parameter

Default arguments must be specified with the first occurrence of the function name—typically, in the function prototype. If the function prototype is omitted because the function definition also serves as the prototype, then the default arguments should be specified in the function header.

How can I validate a string to only allow alphanumeric characters in it?

Same answer as here.

If you want a non-regex ASCII A-z 0-9 check, you cannot use char.IsLetterOrDigit() as that includes other Unicode characters.

What you can do is check the character code ranges.

  • 48 -> 57 are numerics
  • 65 -> 90 are capital letters
  • 97 -> 122 are lower case letters

The following is a bit more verbose, but it's for ease of understanding rather than for code golf.

    public static bool IsAsciiAlphaNumeric(this string str)
    {
        if (string.IsNullOrEmpty(str))
        {
            return false;
        }

        for (int i = 0; i < str.Length; i++)
        {
            if (str[i] < 48) // Numeric are 48 -> 57
            {
                return false;
            }

            if (str[i] > 57 && str[i] < 65) // Capitals are 65 -> 90
            {
                return false;
            }

            if (str[i] > 90 && str[i] < 97) // Lowers are 97 -> 122
            {
                return false;
            }

            if (str[i] > 122)
            {
                return false;
            }
        }

        return true;
    }

Difference between jar and war in Java

A .war file has a specific structure in terms of where certain files will be. Other than that, yes, it's just a .jar.

How to sanity check a date in Java

As shown by @Maglob, the basic approach is to test the conversion from string to date using SimpleDateFormat.parse. That will catch invalid day/month combinations like 2008-02-31.

However, in practice that is rarely enough since SimpleDateFormat.parse is exceedingly liberal. There are two behaviours you might be concerned with:

Invalid characters in the date string Surprisingly, 2008-02-2x will "pass" as a valid date with locale format = "yyyy-MM-dd" for example. Even when isLenient==false.

Years: 2, 3 or 4 digits? You may also want to enforce 4-digit years rather than allowing the default SimpleDateFormat behaviour (which will interpret "12-02-31" differently depending on whether your format was "yyyy-MM-dd" or "yy-MM-dd")

A Strict Solution with the Standard Library

So a complete string to date test could look like this: a combination of regex match, and then a forced date conversion. The trick with the regex is to make it locale-friendly.

  Date parseDate(String maybeDate, String format, boolean lenient) {
    Date date = null;

    // test date string matches format structure using regex
    // - weed out illegal characters and enforce 4-digit year
    // - create the regex based on the local format string
    String reFormat = Pattern.compile("d+|M+").matcher(Matcher.quoteReplacement(format)).replaceAll("\\\\d{1,2}");
    reFormat = Pattern.compile("y+").matcher(reFormat).replaceAll("\\\\d{4}");
    if ( Pattern.compile(reFormat).matcher(maybeDate).matches() ) {

      // date string matches format structure, 
      // - now test it can be converted to a valid date
      SimpleDateFormat sdf = (SimpleDateFormat)DateFormat.getDateInstance();
      sdf.applyPattern(format);
      sdf.setLenient(lenient);
      try { date = sdf.parse(maybeDate); } catch (ParseException e) { }
    } 
    return date;
  } 

  // used like this:
  Date date = parseDate( "21/5/2009", "d/M/yyyy", false);

Note that the regex assumes the format string contains only day, month, year, and separator characters. Aside from that, format can be in any locale format: "d/MM/yy", "yyyy-MM-dd", and so on. The format string for the current locale could be obtained like this:

Locale locale = Locale.getDefault();
SimpleDateFormat sdf = (SimpleDateFormat)DateFormat.getDateInstance(DateFormat.SHORT, locale );
String format = sdf.toPattern();

Joda Time - Better Alternative?

I've been hearing about joda time recently and thought I'd compare. Two points:

  1. Seems better at being strict about invalid characters in the date string, unlike SimpleDateFormat
  2. Can't see a way to enforce 4-digit years with it yet (but I guess you could create your own DateTimeFormatter for this purpose)

It's quite simple to use:

import org.joda.time.format.*;
import org.joda.time.DateTime;

org.joda.time.DateTime parseDate(String maybeDate, String format) {
  org.joda.time.DateTime date = null;
  try {
    DateTimeFormatter fmt = DateTimeFormat.forPattern(format);
    date =  fmt.parseDateTime(maybeDate);
  } catch (Exception e) { }
  return date;
}

correct way to use super (argument passing)

As explained in Python's super() considered super, one way is to have class eat the arguments it requires, and pass the rest on. Thus, when the call-chain reaches object, all arguments have been eaten, and object.__init__ will be called without arguments (as it expects). So your code should look like this:

class A(object):
    def __init__(self, *args, **kwargs):
        print "A"
        super(A, self).__init__(*args, **kwargs)

class B(object):
    def __init__(self, *args, **kwargs):
        print "B"
        super(B, self).__init__(*args, **kwargs)

class C(A):
    def __init__(self, arg, *args, **kwargs):
        print "C","arg=",arg
        super(C, self).__init__(*args, **kwargs)

class D(B):
    def __init__(self, arg, *args, **kwargs):
        print "D", "arg=",arg
        super(D, self).__init__(*args, **kwargs)

class E(C,D):
    def __init__(self, arg, *args, **kwargs):
        print "E", "arg=",arg
        super(E, self).__init__(*args, **kwargs)

print "MRO:", [x.__name__ for x in E.__mro__]
E(10, 20, 30)

Count unique values using pandas groupby

I think you can use SeriesGroupBy.nunique:

print (df.groupby('param')['group'].nunique())
param
a    2
b    1
Name: group, dtype: int64

Another solution with unique, then create new df by DataFrame.from_records, reshape to Series by stack and last value_counts:

a = df[df.param.notnull()].groupby('group')['param'].unique()
print (pd.DataFrame.from_records(a.values.tolist()).stack().value_counts())
a    2
b    1
dtype: int64

How do you add PostgreSQL Driver as a dependency in Maven?

Updating for latest release:

<dependency>
    <groupId>org.postgresql</groupId>
    <artifactId>postgresql</artifactId>
    <version>42.2.14</version>
</dependency>

Source

Hope it helps!

LF will be replaced by CRLF in git - What is that and is it important?

In Unix systems the end of a line is represented with a line feed (LF). In windows a line is represented with a carriage return (CR) and a line feed (LF) thus (CRLF). when you get code from git that was uploaded from a unix system they will only have an LF.

If you are a single developer working on a windows machine, and you don't care that git automatically replaces LFs to CRLFs, you can turn this warning off by typing the following in the git command line

git config core.autocrlf true

If you want to make an intelligent decision how git should handle this, read the documentation

Here is a snippet

Formatting and Whitespace

Formatting and whitespace issues are some of the more frustrating and subtle problems that many developers encounter when collaborating, especially cross-platform. It’s very easy for patches or other collaborated work to introduce subtle whitespace changes because editors silently introduce them, and if your files ever touch a Windows system, their line endings might be replaced. Git has a few configuration options to help with these issues.

core.autocrlf

If you’re programming on Windows and working with people who are not (or vice-versa), you’ll probably run into line-ending issues at some point. This is because Windows uses both a carriage-return character and a linefeed character for newlines in its files, whereas Mac and Linux systems use only the linefeed character. This is a subtle but incredibly annoying fact of cross-platform work; many editors on Windows silently replace existing LF-style line endings with CRLF, or insert both line-ending characters when the user hits the enter key.

Git can handle this by auto-converting CRLF line endings into LF when you add a file to the index, and vice versa when it checks out code onto your filesystem. You can turn on this functionality with the core.autocrlf setting. If you’re on a Windows machine, set it to true – this converts LF endings into CRLF when you check out code:

$ git config --global core.autocrlf true

If you’re on a Linux or Mac system that uses LF line endings, then you don’t want Git to automatically convert them when you check out files; however, if a file with CRLF endings accidentally gets introduced, then you may want Git to fix it. You can tell Git to convert CRLF to LF on commit but not the other way around by setting core.autocrlf to input:

$ git config --global core.autocrlf input

This setup should leave you with CRLF endings in Windows checkouts, but LF endings on Mac and Linux systems and in the repository.

If you’re a Windows programmer doing a Windows-only project, then you can turn off this functionality, recording the carriage returns in the repository by setting the config value to false:

$ git config --global core.autocrlf false

How to stop/shut down an elasticsearch node?

Answer for Elasticsearch inside Docker:

Just stop the docker container. It seems to stop gracefully because it logs:

[INFO ][o.e.n.Node               ] [elastic] stopping ...

Can pandas automatically recognize dates?

While loading csv file contain date column.We have two approach to to make pandas to recognize date column i.e

  1. Pandas explicit recognize the format by arg date_parser=mydateparser

  2. Pandas implicit recognize the format by agr infer_datetime_format=True

Some of the date column data

01/01/18

01/02/18

Here we don't know the first two things It may be month or day. So in this case we have to use Method 1:- Explicit pass the format

    mydateparser = lambda x: pd.datetime.strptime(x, "%m/%d/%y")
    df = pd.read_csv(file_name, parse_dates=['date_col_name'],
date_parser=mydateparser)

Method 2:- Implicit or Automatically recognize the format

df = pd.read_csv(file_name, parse_dates=[date_col_name],infer_datetime_format=True)

The CodeDom provider type "Microsoft.CodeDom.Providers.DotNetCompilerPlatform.CSharpCodeProvider" could not be located

ASP.NET does not search bin/debug or any subfolder under bin for assemblies like other types of applications do. You can instruct the runtime to look in a different place using the following configuration:

<configuration>
   <runtime>   
      <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
         <probing privatePath="bin;bin\Debug;bin\Release"/>
      </assemblyBinding>
   </runtime>   
</configuration>

Copying a rsa public key to clipboard

For using Git bash on Windows:

cat ~/.ssh/id_rsa.pub > /dev/clipboard

(modified from Jupiter St John's post on Coderwall)

sklearn plot confusion matrix with labels

I found a function that can plot the confusion matrix which generated from sklearn.

import numpy as np


def plot_confusion_matrix(cm,
                          target_names,
                          title='Confusion matrix',
                          cmap=None,
                          normalize=True):
    """
    given a sklearn confusion matrix (cm), make a nice plot

    Arguments
    ---------
    cm:           confusion matrix from sklearn.metrics.confusion_matrix

    target_names: given classification classes such as [0, 1, 2]
                  the class names, for example: ['high', 'medium', 'low']

    title:        the text to display at the top of the matrix

    cmap:         the gradient of the values displayed from matplotlib.pyplot.cm
                  see http://matplotlib.org/examples/color/colormaps_reference.html
                  plt.get_cmap('jet') or plt.cm.Blues

    normalize:    If False, plot the raw numbers
                  If True, plot the proportions

    Usage
    -----
    plot_confusion_matrix(cm           = cm,                  # confusion matrix created by
                                                              # sklearn.metrics.confusion_matrix
                          normalize    = True,                # show proportions
                          target_names = y_labels_vals,       # list of names of the classes
                          title        = best_estimator_name) # title of graph

    Citiation
    ---------
    http://scikit-learn.org/stable/auto_examples/model_selection/plot_confusion_matrix.html

    """
    import matplotlib.pyplot as plt
    import numpy as np
    import itertools

    accuracy = np.trace(cm) / np.sum(cm).astype('float')
    misclass = 1 - accuracy

    if cmap is None:
        cmap = plt.get_cmap('Blues')

    plt.figure(figsize=(8, 6))
    plt.imshow(cm, interpolation='nearest', cmap=cmap)
    plt.title(title)
    plt.colorbar()

    if target_names is not None:
        tick_marks = np.arange(len(target_names))
        plt.xticks(tick_marks, target_names, rotation=45)
        plt.yticks(tick_marks, target_names)

    if normalize:
        cm = cm.astype('float') / cm.sum(axis=1)[:, np.newaxis]


    thresh = cm.max() / 1.5 if normalize else cm.max() / 2
    for i, j in itertools.product(range(cm.shape[0]), range(cm.shape[1])):
        if normalize:
            plt.text(j, i, "{:0.4f}".format(cm[i, j]),
                     horizontalalignment="center",
                     color="white" if cm[i, j] > thresh else "black")
        else:
            plt.text(j, i, "{:,}".format(cm[i, j]),
                     horizontalalignment="center",
                     color="white" if cm[i, j] > thresh else "black")


    plt.tight_layout()
    plt.ylabel('True label')
    plt.xlabel('Predicted label\naccuracy={:0.4f}; misclass={:0.4f}'.format(accuracy, misclass))
    plt.show()

It will look like this enter image description here

How to create nonexistent subdirectories recursively using Bash?

$ mkdir -p "$BACKUP_DIR/$client/$year/$month/$day"

Pandas DataFrame: replace all values in a column, based on condition

Another option is to use a list comprehension:

df['First Season'] = [1 if year > 1990 else year for year in df['First Season']]

Using the Underscore module with Node.js

Or :

    var _ = require('underscore')._;

How to copy a string of std::string type in C++?

strcpy is only for C strings. For std::string you copy it like any C++ object.

std::string a = "text";
std::string b = a; // copy a into b

If you want to concatenate strings you can use the + operator:

std::string a = "text";
std::string b = "image";
a = a + b; // or a += b;

You can even do many at once:

std::string c = a + " " + b + "hello";

Although "hello" + " world" doesn't work as you might expect. You need an explicit std::string to be in there: std::string("Hello") + "world"

Extract images from PDF without resampling, in python?

In Python with PyPDF2 for CCITTFaxDecode filter:

import PyPDF2
import struct

"""
Links:
PDF format: http://www.adobe.com/content/dam/Adobe/en/devnet/acrobat/pdfs/pdf_reference_1-7.pdf
CCITT Group 4: https://www.itu.int/rec/dologin_pub.asp?lang=e&id=T-REC-T.6-198811-I!!PDF-E&type=items
Extract images from pdf: http://stackoverflow.com/questions/2693820/extract-images-from-pdf-without-resampling-in-python
Extract images coded with CCITTFaxDecode in .net: http://stackoverflow.com/questions/2641770/extracting-image-from-pdf-with-ccittfaxdecode-filter
TIFF format and tags: http://www.awaresystems.be/imaging/tiff/faq.html
"""


def tiff_header_for_CCITT(width, height, img_size, CCITT_group=4):
    tiff_header_struct = '<' + '2s' + 'h' + 'l' + 'h' + 'hhll' * 8 + 'h'
    return struct.pack(tiff_header_struct,
                       b'II',  # Byte order indication: Little indian
                       42,  # Version number (always 42)
                       8,  # Offset to first IFD
                       8,  # Number of tags in IFD
                       256, 4, 1, width,  # ImageWidth, LONG, 1, width
                       257, 4, 1, height,  # ImageLength, LONG, 1, lenght
                       258, 3, 1, 1,  # BitsPerSample, SHORT, 1, 1
                       259, 3, 1, CCITT_group,  # Compression, SHORT, 1, 4 = CCITT Group 4 fax encoding
                       262, 3, 1, 0,  # Threshholding, SHORT, 1, 0 = WhiteIsZero
                       273, 4, 1, struct.calcsize(tiff_header_struct),  # StripOffsets, LONG, 1, len of header
                       278, 4, 1, height,  # RowsPerStrip, LONG, 1, lenght
                       279, 4, 1, img_size,  # StripByteCounts, LONG, 1, size of image
                       0  # last IFD
                       )

pdf_filename = 'scan.pdf'
pdf_file = open(pdf_filename, 'rb')
cond_scan_reader = PyPDF2.PdfFileReader(pdf_file)
for i in range(0, cond_scan_reader.getNumPages()):
    page = cond_scan_reader.getPage(i)
    xObject = page['/Resources']['/XObject'].getObject()
    for obj in xObject:
        if xObject[obj]['/Subtype'] == '/Image':
            """
            The  CCITTFaxDecode filter decodes image data that has been encoded using
            either Group 3 or Group 4 CCITT facsimile (fax) encoding. CCITT encoding is
            designed to achieve efficient compression of monochrome (1 bit per pixel) image
            data at relatively low resolutions, and so is useful only for bitmap image data, not
            for color images, grayscale images, or general data.

            K < 0 --- Pure two-dimensional encoding (Group 4)
            K = 0 --- Pure one-dimensional encoding (Group 3, 1-D)
            K > 0 --- Mixed one- and two-dimensional encoding (Group 3, 2-D)
            """
            if xObject[obj]['/Filter'] == '/CCITTFaxDecode':
                if xObject[obj]['/DecodeParms']['/K'] == -1:
                    CCITT_group = 4
                else:
                    CCITT_group = 3
                width = xObject[obj]['/Width']
                height = xObject[obj]['/Height']
                data = xObject[obj]._data  # sorry, getData() does not work for CCITTFaxDecode
                img_size = len(data)
                tiff_header = tiff_header_for_CCITT(width, height, img_size, CCITT_group)
                img_name = obj[1:] + '.tiff'
                with open(img_name, 'wb') as img_file:
                    img_file.write(tiff_header + data)
                #
                # import io
                # from PIL import Image
                # im = Image.open(io.BytesIO(tiff_header + data))
pdf_file.close()

How to take a first character from the string

"ABCDEFG".First returns "A"

Dim s as string

s = "Rajan"
s.First
'R

s = "Sajan"
s.First
'S

Sending HTTP Post request with SOAP action using org.apache.http

This is a full working example :

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost; 
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;

public void callWebService(String soapAction, String soapEnvBody)  throws IOException {
    // Create a StringEntity for the SOAP XML.
    String body ="<?xml version=\"1.0\" encoding=\"UTF-8\"?><SOAP-ENV:Envelope xmlns:SOAP-ENV=\"http://schemas.xmlsoap.org/soap/envelope/\" xmlns:ns1=\"http://example.com/v1.0/Records\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:SOAP-ENC=\"http://schemas.xmlsoap.org/soap/encoding/\" SOAP-ENV:encodingStyle=\"http://schemas.xmlsoap.org/soap/encoding/\"><SOAP-ENV:Body>"+soapEnvBody+"</SOAP-ENV:Body></SOAP-ENV:Envelope>";
    StringEntity stringEntity = new StringEntity(body, "UTF-8");
    stringEntity.setChunked(true);

    // Request parameters and other properties.
    HttpPost httpPost = new HttpPost("http://example.com?soapservice");
    httpPost.setEntity(stringEntity);
    httpPost.addHeader("Accept", "text/xml");
    httpPost.addHeader("SOAPAction", soapAction);

    // Execute and get the response.
    HttpClient httpClient = new DefaultHttpClient();
    HttpResponse response = httpClient.execute(httpPost);
    HttpEntity entity = response.getEntity();

    String strResponse = null;
    if (entity != null) {
        strResponse = EntityUtils.toString(entity);
    }
}

grep for special characters in Unix

You could try removing any alphanumeric characters and space. And then use -n will give you the line number. Try following:

grep -vn "^[a-zA-Z0-9 ]*$" application.log

Get User Selected Range

This depends on what you mean by "get the range of selection". If you mean getting the range address (like "A1:B1") then use the Address property of Selection object - as Michael stated Selection object is much like a Range object, so most properties and methods works on it.

Sub test()
    Dim myString As String
    myString = Selection.Address
End Sub

How to code a BAT file to always run as admin mode?

  1. My experimenting indicates that the runas command must include the admin user's domain (at least it does in my organization's environmental setup):

    runas /user:AdminDomain\AdminUserName ExampleScript.bat
    

    If you don’t already know the admin user's domain, run an instance of Command Prompt as the admin user, and enter the following command:

    echo %userdomain%
    
  2. The answers provided by both Kerrek SB and Ed Greaves will execute the target file under the admin user but, if the file is a Command script (.bat file) or VB script (.vbs file) which attempts to operate on the normal-login user’s environment (such as changing registry entries), you may not get the desired results because the environment under which the script actually runs will be that of the admin user, not the normal-login user! For example, if the file is a script that operates on the registry’s HKEY_CURRENT_USER hive, the affected “current-user” will be the admin user, not the normal-login user.

Url.Action parameters?

you can returns a private collection named HttpValueCollection even the documentation says it's a NameValueCollection using the ParseQueryString utility. Then add the keys manually, HttpValueCollection do the encoding for you. And then just append the QueryString manually :

var qs = HttpUtility.ParseQueryString(""); 
qs.Add("name", "John")
qs.Add("contact", "calgary");
qs.Add("contact", "vancouver")

<a href="<%: Url.Action("GetByList", "Listing")%>?<%:qs%>">
    <span>People</span>
</a>

Convert column classes in data.table

This is a BAD way to do it! I'm only leaving this answer in case it solves other weird problems. These better methods are the probably partly the result of newer data.table versions... so it's worth while to document this hard way. Plus, this is a nice syntax example for eval substitute syntax.

library(data.table)
dt <- data.table(ID = c(rep("A", 5), rep("B",5)), 
                 fac1 = c(1:5, 1:5), 
                 fac2 = c(1:5, 1:5) * 2, 
                 val1 = rnorm(10),
                 val2 = rnorm(10))

names_factors = c('fac1', 'fac2')
names_values = c('val1', 'val2')

for (col in names_factors){
  e = substitute(X := as.factor(X), list(X = as.symbol(col)))
  dt[ , eval(e)]
}
for (col in names_values){
  e = substitute(X := as.numeric(X), list(X = as.symbol(col)))
  dt[ , eval(e)]
}

str(dt)

which gives you

Classes ‘data.table’ and 'data.frame':  10 obs. of  5 variables:
 $ ID  : chr  "A" "A" "A" "A" ...
 $ fac1: Factor w/ 5 levels "1","2","3","4",..: 1 2 3 4 5 1 2 3 4 5
 $ fac2: Factor w/ 5 levels "2","4","6","8",..: 1 2 3 4 5 1 2 3 4 5
 $ val1: num  0.0459 2.0113 0.5186 -0.8348 -0.2185 ...
 $ val2: num  -0.0688 0.6544 0.267 -0.1322 -0.4893 ...
 - attr(*, ".internal.selfref")=<externalptr> 

Which version of C# am I using

Thanks to @fortesl and this answer

I'm using VS 2019 and it doesn't easily tell you the C# version you are using. I'm working with .Net Core 3.0, and VS 2019 using C# 8 in that environment. But "csc -langversion:?" makes this clear:

D:\>csc -langversion:?
Supported language versions:
default
1
2
3
4
5
6
7.0
7.1
7.2
7.3
8.0 (default)
latestmajor
preview
latest

Not sure what csc -version is identifying:

D:\>csc --version
Microsoft (R) Visual C# Compiler version 3.4.0-beta1-19462-14 (2f21c63b)
Copyright (C) Microsoft Corporation. All rights reserved.

Can I append an array to 'formdata' in javascript?

How about this?

formdata.append('tags', JSON.stringify(tags));

... and, correspondingly, using json_decode on server to deparse it. See, the second value of FormData.append can be...

a Blob, File, or a string, if neither, the value is converted to a string

The way I see it, your tags array contains objects (@Musa is right, btw; making this_tag an Array, then assigning string properties to it makes no sense; use plain object instead), so native conversion (with toString()) won't be enough. JSON'ing should get the info through, though.

As a sidenote, I'd rewrite the property assigning block just into this:

tags.push({article: article, gender: gender, brand: brand});

Regex to match string containing two names in any order

You can make use of regex's quantifier feature since lookaround may not be supported all the time.

(\bjames\b){1,}.*(\bjack\b){1,}|(\bjack\b){1,}.*(\bjames\b){1,}

Android: Clear Activity Stack

Here is a simple helper method for starting a new activity as the new top activity which works from API level 4 up until the current version 17:

static void startNewMainActivity(Activity currentActivity, Class<? extends Activity> newTopActivityClass) {
    Intent intent = new Intent(currentActivity, newTopActivityClass);
    intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB)
        intent.addFlags(0x8000); // equal to Intent.FLAG_ACTIVITY_CLEAR_TASK which is only available from API level 11
    currentActivity.startActivity(intent);
}

call it like this from your current activity:

startNewMainActivity(this, MainActivity.class);

How to set focus on input field?

I have found some of the other answers to be overly complicated when all you really need is this

app.directive('autoFocus', function($timeout) {
    return {
        restrict: 'AC',
        link: function(_scope, _element) {
            $timeout(function(){
                _element[0].focus();
            }, 0);
        }
    };
});

usage is

<input name="theInput" auto-focus>

We use the timeout to let things in the dom render, even though it is zero, it at least waits for that - that way this works in modals and whatnot too

retrieve data from db and display it in table in php .. see this code whats wrong with it?

Try this:

<?php

 # Init the MySQL Connection
  if( !( $db = mysql_connect( 'localhost' , 'root' , '' ) ) )
    die( 'Failed to connect to MySQL Database Server - #'.mysql_errno().': '.mysql_error();
  if( !mysql_select_db( 'ram' ) )
    die( 'Connected to Server, but Failed to Connect to Database - #'.mysql_errno().': '.mysql_error();

 # Prepare the INSERT Query
  $insertTPL = 'INSERT INTO `name` VALUES( "%s" , "%s" , "%s" , "%s" )';
  $insertSQL = sprintf( $insertTPL ,
                 mysql_real_escape_string( $name ) ,
                 mysql_real_escape_string( $add1 ) ,
                 mysql_real_escape_string( $add2 ) ,
                 mysql_real_escape_string( $mail ) );
 # Execute the INSERT Query
  if( !( $insertRes = mysql_query( $insertSQL ) ) ){
    echo '<p>Insert of Row into Database Failed - #'.mysql_errno().': '.mysql_error().'</p>';
  }else{
    echo '<p>Person\'s Information Inserted</p>'
  }

 # Prepare the SELECT Query
  $selectSQL = 'SELECT * FROM `names`';
 # Execute the SELECT Query
  if( !( $selectRes = mysql_query( $selectSQL ) ) ){
    echo 'Retrieval of data from Database Failed - #'.mysql_errno().': '.mysql_error();
  }else{
    ?>
<table border="2">
  <thead>
    <tr>
      <th>Name</th>
      <th>Address Line 1</th>
      <th>Address Line 2</th>
      <th>Email Id</th>
    </tr>
  </thead>
  <tbody>
    <?php
      if( mysql_num_rows( $selectRes )==0 ){
        echo '<tr><td colspan="4">No Rows Returned</td></tr>';
      }else{
        while( $row = mysql_fetch_assoc( $selectRes ) ){
          echo "<tr><td>{$row['name']}</td><td>{$row['addr1']}</td><td>{$row['addr2']}</td><td>{$row['mail']}</td></tr>\n";
        }
      }
    ?>
  </tbody>
</table>
    <?php
  }

?>

Notes, Cautions and Caveats

Your initial solution did not show any obvious santisation of the values before passing them into the Database. This is how SQL Injection attacks (or even un-intentional errors being passed through SQL) occur. Don't do it!

Your database does not seem to have a Primary Key. Whilst these are not, technically, necessary in all usage, they are a good practice, and make for a much more reliable way of referring to a specific row in a table, whether for adding related tables, or for making changes within that table.

You need to check every action, at every stage, for errors. Most PHP functions are nice enough to have a response they will return under an error condition. It is your job to check for those conditions as you go - never assume that PHP will do what you expect, how you expect, and in the order you expect. This is how accident happen...

My provided code above contains alot of points where, if an error has occured, a message will be returned. Try it, see if any error messages are reported, look at the Error Message, and, if applicable, the Error Code returned and do some research.

Good luck.

Angular 2 change event - model changes

Use the (ngModelChange) event to detect changes on the model

Java - Convert image to Base64

You can create a large array and then copy it to a new array using System.arrayCopy

        int contentLength = 100000000;
        byte[] byteArray = new byte[contentLength];

        BufferedInputStream inputStream = new BufferedInputStream(connection.getInputStream());
        while ((bytesRead = inputStream.read()) != -1)
        {
            byteArray[count++] = (byte)bytesRead;
        }

        byte[] destArray = new byte[count];
        System.arraycopy(byteArray, 0, destArray , 0, count);

destArray will contain the information you want

Embed youtube videos that play in fullscreen automatically

This was pretty well answered over here: How to make a YouTube embedded video a full page width one?

If you add '?rel=0&autoplay=1' to the end of the url in the embed code (like this)

<iframe id="video" src="//www.youtube.com/embed/5iiPC-VGFLU?rel=0&autoplay=1" frameborder="0" allowfullscreen></iframe>

of the video it should play on load. Here's a demo over at jsfiddle.

Is there an Eclipse plugin to run system shell in the Console?

Eclipse TCF team has just release terminal (SSH, Telnet, local)

originally named TCF Terminal, then renamed to TM Terminal

http://marketplace.eclipse.org/content/tcf-terminals

Finally Windows and Linux all supported

Support for Git Bash on Windows is resolved Bug 435014.

This plugin is included into Enide Studio 2014 and Enide 2015.

To access the terminal go to Window -> Show View -> Terminal or Ctrl+Alt+T

Convert NSData to String?

I believe your "P" as the dataWithBytes param

NSData *keydata = [NSData dataWithBytes:P length:len];

should be "buf"

NSData *keydata = [NSData dataWithBytes:buf length:len];

since i2d_PrivateKey puts the pointer to the output buffer p at the end of the buffer and waiting for further input, and buf is still pointing to the beginning of your buffer.

The following code works for me where pkey is a pointer to an EVP_PKEY:

unsigned char *buf, *pp;
int len = i2d_PrivateKey(pkey, NULL);
buf = OPENSSL_malloc(len); 
pp = buf;
i2d_PrivateKey(pkey, &pp);

NSData* pkeyData = [NSData dataWithBytes:(const void *)buf length:len];
DLog(@"Private key in hex (%d): %@", len, pkeyData);

You can use an online converter to convert your binary data into base 64 (http://tomeko.net/online_tools/hex_to_base64.php?lang=en) and compare it to the private key in your cert file after using the following command and checking the output of mypkey.pem:

openssl pkcs12 -in myCert.p12 -nocerts -nodes -out mypkey.pem

I referenced your question and this EVP function site for my answer.

Joda DateTime to Timestamp conversion

//This Works just fine
DateTime dt = new DateTime();
Log.d("ts",String.valueOf(dt.now()));               
dt=dt.plusYears(3);
dt=dt.minusDays(7);
Log.d("JODA DateTime",String.valueOf(dt));
Timestamp ts= new Timestamp(dt.getMillis());
Log.d("Coverted to java.sql.Timestamp",String.valueOf(ts));

Cannot import XSSF in Apache POI

I Got the Solution Guys

You need to keep some points in your mind .

  1. There are two different dependency one is (poi) & other dependency is (poi- ooxml) but make sure you must use poi-ooxml dependency in your code.

  2. Just Add the following dependency in pom.xml & Save it.

<dependency>
  <groupId>org.apache.poi</groupId>
  <artifactId>poi-ooxml</artifactId>
  <version>3.9</version>
  </dependency>

3 .After you have saved the pom.xml then you need to try a small thing ,Use (.) operator will try to import/fetch it & finally will not see any sort of error because now it has imported that thing in your package.

Sample Code to Understand Better !!

package ReadFile;// package   
import org.apache.poi.xssf.usermodel.XSSFWorkbook;  // automatically added to your code after importing
public class Test          
{  
public static void Hello() // Method  
{  
XSSFWorkbook workbook = new XSSFWorkbook();   
}  
}

I tried my best to give you the solution , If you face any issue comment here i will try
to solve it .

Keep Learning Guys !!

Internet Explorer cache location

If you are using Dot.Net then the code you need is

Environment.GetFolderPath(Environment.SpecialFolder.InternetCache)

Click my name if you want the code to delete these files plus FireFox temp files and Flash shared object/Flash Cookies

Weblogic Transaction Timeout : how to set in admin console in WebLogic AS 8.1

If you don't want to change the domain-wide default timeout, your best option is to change the deployment descriptor by setting the trans-timeout-seconds attribute in the weblogic-ejb-jar.xml - see http://docs.oracle.com/cd/E11035_01/wls100/jta/trxejb.html

This overrides the "Timeout Seconds" default, only for this specific EJB, while leaving all other EJB unaffected.

Returning unique_ptr from functions

This is in no way specific to std::unique_ptr, but applies to any class that is movable. It's guaranteed by the language rules since you are returning by value. The compiler tries to elide copies, invokes a move constructor if it can't remove copies, calls a copy constructor if it can't move, and fails to compile if it can't copy.

If you had a function that accepts std::unique_ptr as an argument you wouldn't be able to pass p to it. You would have to explicitly invoke move constructor, but in this case you shouldn't use variable p after the call to bar().

void bar(std::unique_ptr<int> p)
{
    // ...
}

int main()
{
    unique_ptr<int> p = foo();
    bar(p); // error, can't implicitly invoke move constructor on lvalue
    bar(std::move(p)); // OK but don't use p afterwards
    return 0;
}

Eclipse No tests found using JUnit 5 caused by NoClassDefFoundError for LauncherFactory

It may cause by the version of junit-platform-launcher / junit-platform-runner.

1.1.0 does not work

1.4.1 works in my setup.

I think this is a bug in eclipse as it is working with higher version libraries of junit and not other version.

This resolved my issue. The other resolution looked less feasible or risky to me. Thanks.

Converting a String to DateTime

Do you want it fast?

Let's say you have a date with format yyMMdd.

The fastest way to convert it that I found is:

var d = new DateTime(
(s[0] - '0') * 10 + s[1] - '0' + 2000, 
(s[2] - '0') * 10 + s[3] - '0', 
(s[4] - '0') * 10 + s[5] - '0')

Just, choose the indexes according to your date format of choice. If you need speed probably you don't mind the 'non-generic' way of the function.

This method takes about 10% of the time required by:

var d = DateTime.ParseExact(s, "yyMMdd", System.Globalization.CultureInfo.InvariantCulture);

How do I sort a Set to a List in Java?

Always safe to use either Comparator or Comparable interface to provide sorting implementation (if the object is not a String or Wrapper classes for primitive data types) . As an example for a comparator implementation to sort employees based on name

    List<Employees> empList = new LinkedList<Employees>(EmpSet);

    class EmployeeComparator implements Comparator<Employee> {

            public int compare(Employee e1, Employee e2) {
                return e1.getName().compareTo(e2.getName());
            }

        }

   Collections.sort(empList , new EmployeeComparator ());

Comparator is useful when you need to have different sorting algorithm on same object (Say emp name, emp salary, etc). Single mode sorting can be implemented by using Comparable interface in to the required object.

How to filter data in dataview

DataView view = new DataView();
view.Table = DataSet1.Tables["Suppliers"];
view.RowFilter = "City = 'Berlin'";
view.RowStateFilter = DataViewRowState.ModifiedCurrent;
view.Sort = "CompanyName DESC";

// Simple-bind to a TextBox control
Text1.DataBindings.Add("Text", view, "CompanyName");

Ref: http://www.csharp-examples.net/dataview-rowfilter/

http://msdn.microsoft.com/en-us/library/system.data.dataview.rowfilter.aspx

How do I programmatically set device orientation in iOS 7?

The only way that worked for me is presenting dummy modal view controller.

UIViewController* dummyVC = [[UIViewController alloc] init];
dummyVC.view = [[UIView alloc] init];
[self presentModalViewController:dummyVC animated:NO];
[self dismissModalViewControllerAnimated:NO];

Your VC will be asked for updated interface orientations when modal view controller is dismissed.

Curious thing is that UINavigationController does exactly this when pushing/popping child view controllers with different supported interface orientations (tested on iOS 6.1, 7.0).

Rendering HTML elements to <canvas>

According to the HTML specification you can't access the elements of the Canvas. You can get its context, and draw in it manipulate it, but that is all.

BUT, you can put both the Canvas and the html element in the same div with a aposition: relative and then set the canvas and the other element to position: absolute. This ways they will be on the top of each other. Then you can use the left and right CSS properties to position the html element.

If the element doesn't shows up, maybe the canvas is before it, so use the z-index CSS property to bring it before the canvas.

What is the difference between sed and awk?

1) What is the difference between awk and sed ?

Both are tools that transform text. BUT awk can do more things besides just manipulating text. Its a programming language by itself with most of the things you learn in programming, like arrays, loops, if/else flow control etc You can "program" in sed as well, but you won't want to maintain the code written in it.

2) What kind of application are best use cases for sed and awk tools ?

Conclusion: Use sed for very simple text parsing. Anything beyond that, awk is better. In fact, you can ditch sed altogether and just use awk. Since their functions overlap and awk can do more, just use awk. You will reduce your learning curve as well.

Start script missing error when running npm start

Try with these steps :

npm rm -g create-react-app

npm install -g create-react-app

npx create-react-app my-app

Definitely this works!!

How do I deserialize a complex JSON object in C# .NET?

You could use the nuget package Newtonsoft.JSON in order to achieve this:

JsonConvert.DeserializeObject<List<Response>>(yourJsonString)

How to Auto-start an Android Application?

If by autostart you mean auto start on phone bootup then you should register a BroadcastReceiver for the BOOT_COMPLETED Intent. Android systems broadcasts that intent once boot is completed.

Once you receive that intent you can launch a Service that can do whatever you want to do.

Keep note though that having a Service running all the time on the phone is generally a bad idea as it eats up system resources even when it is idle. You should launch your Service / application only when needed and then stop it when not required.

Regarding 'main(int argc, char *argv[])'

The arguments argc and argv of main is used as a way to send arguments to a program, the possibly most familiar way is to use the good ol' terminal where an user could type cat file. Here the word cat is a program that takes a file and outputs it to standard output (stdout).

The program receives the number of arguments in argc and the vector of arguments in argv, in the above the argument count would be two (The program name counts as the first argument) and the argument vector would contain [cat,file,null]. While the last element being a null-pointer.

Commonly, you would write it like this:

int  // Specifies that type of variable the function returns.
     // main() must return an integer
main ( int argc, char **argv ) {
     // code
     return 0; // Indicates that everything went well.
}

If your program does not require any arguments, it is equally valid to write a main-function in the following fashion:

int main() {
  // code
  return 0; // Zero indicates success, while any 
  // Non-Zero value indicates a failure/error
}

In the early versions of the C language, there was no int before main as this was implied. Today, this is considered to be an error.

On POSIX-compliant systems (and Windows), there exists the possibility to use a third parameter char **envp which contains a vector of the programs environment variables. Further variations of the argument list of the main function exists, but I will not detail it here since it is non-standard.

Also, the naming of the variables is a convention and has no actual meaning. It is always a good idea to adhere to this so that you do not confuse others, but it would be equally valid to define main as

int main(int c, char **v, char **e) {
   // code
   return 0;
}

And for your second question, there are several ways to send arguments to a program. I would recommend you to look at the exec*()family of functions which is POSIX-standard, but it is probably easier to just use system("command arg1 arg2"), but the use of system() is usually frowned upon as it is not guaranteed to work on every system. I have not tested it myself; but if there is no bash,zsh, or other shell installed on a *NIX-system, system() will fail.

Getting attribute of element in ng-click function in angularjs

Even more simple, pass the $event object to ng-click to access the event properties. As an example:

<a ng-click="clickEvent($event)" class="exampleClass" id="exampleID" data="exampleData" href="">Click Me</a>

Within your clickEvent() = function(obj) {} function you can access the data value like this:

var dataValue = obj.target.attributes.data.value;

Which would return exampleData.

Here's a full jsFiddle.

Cell spacing in UICollectionView

I stumbled upon a similar problem as OP. Unfortunately the accepted answer did not work for me since the content of the collectionView would not be centered properly. Therefore I came up with a different solution which only requires that all items in the collectionView are of the same width, which seems to be the case in the question:

#define cellSize 90

- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {
    float width = collectionView.frame.size.width;
    float spacing = [self collectionView:collectionView layout:collectionViewLayout minimumInteritemSpacingForSectionAtIndex:section];
    int numberOfCells = (width + spacing) / (cellSize + spacing);
    int inset = (width + spacing - numberOfCells * (cellSize + spacing) ) / 2;

    return UIEdgeInsetsMake(0, inset, 0, inset);
}

That code will ensure that the value returned by ...minimumInteritemSpacing... will be the exact spacing between every collectionViewCell and furthermore guarantee that the cells all together will be centered in the collectionView

How can I avoid Java code in JSP files, using JSP 2?

Using scriptlets in JSPs is not a good practice.

Instead, you can use:

  1. JSTL tags
  2. EL expressions
  3. Custom Tags- you can define your own tags to use.

Please refer to:

  1. http://docs.oracle.com/javaee/1.4/tutorial/doc/JSTL3.html
  2. EL

Concatenating variables in Bash

Try doing this, there's no special character to concatenate in bash :

mystring="${arg1}12${arg2}endoffile"

explanations

If you don't put brackets, you will ask to concatenate $arg112 + $argendoffile (I guess that's not what you asked) like in the following example :

mystring="$arg112$arg2endoffile"

The brackets are delimiters for the variables when needed. When not needed, you can use it or not.

another solution

(less portable : require bash > 3.1)

$ arg1=foo
$ arg2=bar
$ mystring="$arg1"
$ mystring+="12"
$ mystring+="$arg2"
$ mystring+="endoffile"
$ echo "$mystring"
foo12barendoffile

See http://mywiki.wooledge.org/BashFAQ/013

Get the real width and height of an image with JavaScript? (in Safari/Chrome)

I use different approach, simply make Ajax call to server to get image size when image object is in use.

//make json call to server to get image size
$.getJSON("http://server/getimagesize.php",
{"src":url},
SetImageWidth
);

//callback function
function SetImageWidth(data) {

    var wrap = $("div#image_gallery #image_wrap");

    //remove height
     wrap.find("img").removeAttr('height');
    //remove height
     wrap.find("img").removeAttr('width');

    //set image width
    if (data.width > 635) {
        wrap.find("img").width(635);
    }
    else {
         wrap.find("img").width(data.width);
    }
}

and of course server side code:

<?php

$image_width = 0;
$image_height = 0;

if (isset ($_REQUEST['src']) && is_file($_SERVER['DOCUMENT_ROOT'] . $_REQUEST['src'])) {

    $imageinfo = getimagesize($_SERVER['DOCUMENT_ROOT'].$_REQUEST['src']);
    if ($imageinfo) {
       $image_width=  $imageinfo[0];
       $image_height= $imageinfo[1];
    }
}

$arr = array ('width'=>$image_width,'height'=>$image_height);

echo json_encode($arr);

?>

Escape quote in web.config connection string

connectionString="Server=dbsrv;User ID=myDbUser;Password=somepass&quot;word"

Since the web.config is XML, you need to escape the five special characters:

&amp; -> & ampersand, U+0026
&lt; -> < left angle bracket, less-than sign, U+003C
&gt; -> > right angle bracket, greater-than sign, U+003E
&quot; -> " quotation mark, U+0022
&apos; -> ' apostrophe, U+0027

+ is not a problem, I suppose.


Duc Filan adds: You should also wrap your password with single quote ':

connectionString="Server=dbsrv;User ID=myDbUser;Password='somepass&quot;word'"

HttpWebRequest-The remote server returned an error: (400) Bad Request

400 Bad request Error will be thrown due to incorrect authentication entries.

  1. Check if your API URL is correct or wrong. Don't append or prepend spaces.
  2. Verify that your username and password are valid. Please check any spelling mistake(s) while entering.

Note: Mostly due to Incorrect authentication entries due to spell changes will occur 400 Bad request.

Conditional formatting, entire row based

Use RC addressing. So, if I want the background color of Col B to depend upon the value in Col C and apply that from Rows 2 though 20:

Steps:

  1. Select R2C2 to R20C2

  2. Click on Conditional Formatting

  3. Select "Use a formula to determine what cells to format"

  4. Type in the formula: =RC[1] > 25

  5. Create the formatting you want (i.e. background color "yellow")

  6. Applies to: Make sure it says: =R2C2:R20C2

** Note that the "magic" takes place in step 4 ... using RC addressing to look at the value one column to the right of the cell being formatted. In this example, I am checking to see if the value of the cell one column to the right of the cell being formatting contains a value greater than 25 (note that you can put pretty much any formula here that returns a T/F value)

How to convert Moment.js date to users local timezone?

Use utcOffset function.

var testDateUtc = moment.utc("2015-01-30 10:00:00");
var localDate = moment(testDateUtc).utcOffset(10 * 60); //set timezone offset in minutes
console.log(localDate.format()); //2015-01-30T20:00:00+10:00

How do I change tab size in Vim?

As a one-liner into vim:

:set tabstop=4 shiftwidth=4

For permanent setup, add these lines to ~/.vimrc:

set tabstop=4
set shiftwidth=4

NOTE: Add set expandtab if you prefer 4-spaces indentation, instead of a tab indentation.

An item with the same key has already been added

Most likely, you have model which contains the same property twice. Perhaps you are using new to hide the base property.

Solution is to override the property or use another name.

If you share your model, we would be able to elaborate more.

How to download an entire directory and subdirectories using wget?

You can use this in a shell:

wget -r -nH --cut-dirs=7 --reject="index.html*" \
      http://abc.tamu.edu/projects/tzivi/repository/revisions/2/raw/tzivi/

The Parameters are:

-r recursively download

-nH (--no-host-directories) cuts out hostname 

--cut-dirs=X (cuts out X directories)

space between divs - display table-cell

Make a new div with whatever name (I will just use table-split) and give it a width, without adding content to it, while placing it between necessary divs that need to be separated.

You can add whatever width you find necessary. I just used 0.6% because it's what I needed for when I had to do this.

_x000D_
_x000D_
.table-split {_x000D_
  display: table-cell;_x000D_
  width: 0.6%_x000D_
}
_x000D_
<div class="table-split"></div>
_x000D_
_x000D_
_x000D_

How to determine the number of days in a month in SQL Server?

You can use the following with the first day of the specified month:

datediff(day, @date, dateadd(month, 1, @date))

To make it work for every date:

datediff(day, dateadd(day, 1-day(@date), @date),
              dateadd(month, 1, dateadd(day, 1-day(@date), @date)))

Append a dictionary to a dictionary

dict.update() looks like it will do what you want...

>> orig.update(extra)
>>> orig
{'A': 1, 'C': 3, 'B': 2, 'E': 5, 'D': 4}
>>> 

Perhaps, though, you don't want to update your original dictionary, but work on a copy:

>>> dest = orig.copy()
>>> dest.update(extra)
>>> orig
{'A': 1, 'C': 3, 'B': 2}
>>> dest
{'A': 1, 'C': 3, 'B': 2, 'E': 5, 'D': 4}

Uses of Action delegate in C#

Well one thing you could do is if you have a switch:

switch(SomeEnum)
{
  case SomeEnum.One:
      DoThings(someUser);
      break;
  case SomeEnum.Two:
      DoSomethingElse(someUser);
      break;
}

And with the might power of actions you can turn that switch into a dictionary:

Dictionary<SomeEnum, Action<User>> methodList = 
    new Dictionary<SomeEnum, Action<User>>()

methodList.Add(SomeEnum.One, DoSomething);
methodList.Add(SomeEnum.Two, DoSomethingElse); 

...

methodList[SomeEnum](someUser);

Or you could take this farther:

SomeOtherMethod(Action<User> someMethodToUse, User someUser)
{
    someMethodToUse(someUser);
}  

....

var neededMethod = methodList[SomeEnum];
SomeOtherMethod(neededMethod, someUser);

Just a couple of examples. Of course the more obvious use would be Linq extension methods.

How do I enable FFMPEG logging and where can I find the FFMPEG log file?

I find the answer. 1/First put in the presets, i have this example "Output format MPEG2 DVD HQ"

-vcodec mpeg2video -vstats_file MFRfile.txt -r 29.97 -s 352x480 -aspect 4:3 -b 4000k -mbd rd -trellis -mv0 -cmp 2 -subcmp 2 -acodec mp2 -ab 192k -ar 48000 -ac 2

If you want a report includes the commands -vstats_file MFRfile.txt into the presets like the example. this can make a report which it's ubicadet in the folder source of your file Source. you can put any name if you want , i solved my problem "i write many times in this forum" reading a complete .docx about mpeg properties. finally i can do my progress bar reading this txt file generated.

Regards.

How can I change text color via keyboard shortcut in MS word 2010

You could use a macro, but it’s simpler to use styles. Define a character style that has the desired text color and assign a shortcut key to it, say Alt+R. In order to be able to switch color using just the keyboard, define another character style, say “normal”, that has no special feature—just for use to get normal text after switching to your colored style, and assign another shortcut to it, say Alt+N. Then you would just type text, press Alt+R to switch to colored text, type that text, press Alt+N to resume normal text color, etc.

Bootstrap Carousel : Remove auto slide

$(document).ready(function() {
  $('#media').carousel({
    pause: true,
    interval: 40000,
  });
});

By using the above script, you will be able to move the images automaticaly

$(document).ready(function() {
  $('#media').carousel({
    pause: true,
    interval: false,
  });
});

By using the above script, auto-rotation will be blocked because interval is false

enum to string in modern C++11 / C++14 / C++17 and future C++20

Magic Enum header-only library provides static reflection for enums (to string, from string, iteration) for C++17.

#include <magic_enum.hpp>

enum Color { RED = 2, BLUE = 4, GREEN = 8 };

Color color = Color::RED;
auto color_name = magic_enum::enum_name(color);
// color_name -> "RED"

std::string color_name{"GREEN"};
auto color = magic_enum::enum_cast<Color>(color_name)
if (color.has_value()) {
  // color.value() -> Color::GREEN
};

For more examples check home repository https://github.com/Neargye/magic_enum.

Where is the drawback?

This library uses a compiler-specific hack (based on __PRETTY_FUNCTION__ / __FUNCSIG__), which works on Clang >= 5, MSVC >= 15.3 and GCC >= 9.

Enum value must be in range [MAGIC_ENUM_RANGE_MIN, MAGIC_ENUM_RANGE_MAX].

  • By default MAGIC_ENUM_RANGE_MIN = -128, MAGIC_ENUM_RANGE_MAX = 128.

  • If need another range for all enum types by default, redefine the macro MAGIC_ENUM_RANGE_MIN and MAGIC_ENUM_RANGE_MAX.

  • MAGIC_ENUM_RANGE_MIN must be less or equals than 0 and must be greater than INT16_MIN.

  • MAGIC_ENUM_RANGE_MAX must be greater than 0 and must be less than INT16_MAX.

  • If need another range for specific enum type, add specialization enum_range for necessary enum type.

    #include <magic_enum.hpp>
    
    enum number { one = 100, two = 200, three = 300 };
    
    namespace magic_enum {
    template <>
      struct enum_range<number> {
        static constexpr int min = 100;
        static constexpr int max = 300;
    };
    }
    

Java "user.dir" property - what exactly does it mean?

Typically this is the directory where your app (java) was started (working dir). "Typically" because it can be changed, eg when you run an app with Runtime.exec(String[] cmdarray, String[] envp, File dir)

MySQL: Invalid use of group function

First, the error you're getting is due to where you're using the COUNT function -- you can't use an aggregate (or group) function in the WHERE clause.

Second, instead of using a subquery, simply join the table to itself:

SELECT a.pid 
FROM Catalog as a LEFT JOIN Catalog as b USING( pid )
WHERE a.sid != b.sid
GROUP BY a.pid

Which I believe should return only rows where at least two rows exist with the same pid but there is are at least 2 sids. To make sure you get back only one row per pid I've applied a grouping clause.

vertical divider between two columns in bootstrap

_x000D_
_x000D_
.row.vertical-divider {_x000D_
  overflow: hidden;_x000D_
}_x000D_
.row.vertical-divider > div[class^="col-"] {_x000D_
  text-align: center;_x000D_
  padding-bottom: 100px;_x000D_
  margin-bottom: -100px;_x000D_
  border-left: 3px solid #F2F7F9;_x000D_
  border-right: 3px solid #F2F7F9;_x000D_
}_x000D_
.row.vertical-divider div[class^="col-"]:first-child {_x000D_
  border-left: none;_x000D_
}_x000D_
.row.vertical-divider div[class^="col-"]:last-child {_x000D_
  border-right: none;_x000D_
}
_x000D_
<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css" rel="stylesheet" />_x000D_
<div class="row vertical-divider" style="margin-top: 30px">_x000D_
  <div class="col-xs-6">Hi there</div>_x000D_
  <div class="col-xs-6">Hi world<br/>hi world</div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Function overloading in Python: Missing

You can pass a mutable container datatype into a function, and it can contain anything you want.

If you need a different functionality, name the functions differently, or if you need the same interface, just write an interface function (or method) that calls the functions appropriately based on the data received.

It took a while to me to get adjusted to this coming from Java, but it really isn't a "big handicap".

Implementing Singleton with an Enum (in Java)

In this Java best practices book by Joshua Bloch, you can find explained why you should enforce the Singleton property with a private constructor or an Enum type. The chapter is quite long, so keeping it summarized:

Making a class a Singleton can make it difficult to test its clients, as it’s impossible to substitute a mock implementation for a singleton unless it implements an interface that serves as its type. Recommended approach is implement Singletons by simply make an enum type with one element:

// Enum singleton - the preferred approach
public enum Elvis {
INSTANCE;
public void leaveTheBuilding() { ... }
}

This approach is functionally equivalent to the public field approach, except that it is more concise, provides the serialization machinery for free, and provides an ironclad guarantee against multiple instantiation, even in the face of sophisticated serialization or reflection attacks.

While this approach has yet to be widely adopted, a single-element enum type is the best way to implement a singleton.

adding css class to multiple elements

You need to qualify the a part of the selector too:

.button input, .button a {
    //css stuff here
}

Basically, when you use the comma to create a group of selectors, each individual selector is completely independent. There is no relationship between them.

Your original selector therefore matched "all elements of type 'input' that are descendants of an element with the class name 'button', and all elements of type 'a'".

Bizarre Error in Chrome Developer Console - Failed to load resource: net::ERR_CACHE_MISS

On Chrome's latest update (38.0.2125.104 m at the moment), Google added the option to know whether the files loaded to the website were newly downloaded from the server - or read from the local cache.

When an error like yours "hits" the console - you know the files were just downloaded from the server and not read from the local cache. You can recreate this error by clicking Ctrl + F5 (refresh and erase cache).

It fits your description where Firebug (or equivalents) doesn't fire any errors to the console - whilst Chrome does.

So, the bottom line is - your're just fine and you can ignore this error - it's merely an indicator.

Performing Breadth First Search recursively

I had to implement a heap traversal which outputs in a BFS order. It isn't actually BFS but accomplishes the same task.

private void getNodeValue(Node node, int index, int[] array) {
    array[index] = node.value;
    index = (index*2)+1;

    Node left = node.leftNode;
    if (left!=null) getNodeValue(left,index,array);
    Node right = node.rightNode;
    if (right!=null) getNodeValue(right,index+1,array);
}

public int[] getHeap() {
    int[] nodes = new int[size];
    getNodeValue(root,0,nodes);
    return nodes;
}

How to access the SMS storage on Android?

For a concrete example of accessing the SMS/MMS database, take a look at gTalkSMS.

Recover sa password

The best way is to simply reset the password by connecting with a domain/local admin (so you may need help from your system administrators), but this only works if SQL Server was set up to allow local admins (these are now left off the default admin group during setup).

If you can't use this or other existing methods to recover / reset the SA password, some of which are explained here:

Then you could always backup your important databases, uninstall SQL Server, and install a fresh instance.

You can also search for less scrupulous ways to do it (e.g. there are password crackers that I am not enthusiastic about sharing).

As an aside, the login properties for sa would never say Windows Authentication. This is by design as this is a SQL Authentication account. This does not mean that Windows Authentication is disabled at the instance level (in fact it is not possible to do so), it just doesn't apply for a SQL auth account.

I wrote a tip on using PSExec to connect to an instance using the NT AUTHORITY\SYSTEM account (which works < SQL Server 2012), and a follow-up that shows how to hack the SqlWriter service (which can work on more modern versions):

And some other resources:

Dealing with timestamps in R

You want the (standard) POSIXt type from base R that can be had in 'compact form' as a POSIXct (which is essentially a double representing fractional seconds since the epoch) or as long form in POSIXlt (which contains sub-elements). The cool thing is that arithmetic etc are defined on this -- see help(DateTimeClasses)

Quick example:

R> now <- Sys.time()
R> now
[1] "2009-12-25 18:39:11 CST"
R> as.numeric(now)
[1] 1.262e+09
R> now + 10  # adds 10 seconds
[1] "2009-12-25 18:39:21 CST"
R> as.POSIXlt(now)
[1] "2009-12-25 18:39:11 CST"
R> str(as.POSIXlt(now))
 POSIXlt[1:9], format: "2009-12-25 18:39:11"
R> unclass(as.POSIXlt(now))
$sec
[1] 11.79

$min
[1] 39

$hour
[1] 18

$mday
[1] 25

$mon
[1] 11

$year
[1] 109

$wday
[1] 5

$yday
[1] 358

$isdst
[1] 0

attr(,"tzone")
[1] "America/Chicago" "CST"             "CDT"            
R> 

As for reading them in, see help(strptime)

As for difference, easy too:

R> Jan1 <- strptime("2009-01-01 00:00:00", "%Y-%m-%d %H:%M:%S")
R> difftime(now, Jan1, unit="week")
Time difference of 51.25 weeks
R> 

Lastly, the zoo package is an extremely versatile and well-documented container for matrix with associated date/time indices.

Drop-down box dependent on the option selected in another drop-down box

You're better off making two selects and showing one while hiding the other.

It's easier, and adding options to selects with your method will not work in IE8 (if you care).

How to use background thread in swift?

Since the OP question has already been answered above I just want to add some speed considerations:

I don't recommend running tasks with the .background thread priority especially on the iPhone X where the task seems to be allocated on the low power cores.

Here is some real data from a computationally intensive function that reads from an XML file (with buffering) and performs data interpolation:

Device name / .background / .utility / .default / .userInitiated / .userInteractive

  1. iPhone X: 18.7s / 6.3s / 1.8s / 1.8s / 1.8s
  2. iPhone 7: 4.6s / 3.1s / 3.0s / 2.8s / 2.6s
  3. iPhone 5s: 7.3s / 6.1s / 4.0s / 4.0s / 3.8s

Note that the data set is not the same for all devices. It's the biggest on the iPhone X and the smallest on the iPhone 5s.

How to count objects in PowerShell?

As short as @jumbo's answer is :-) you can do it even more tersely. This just returns the Count property of the array returned by the antecedent sub-expression:

@(Get-Alias).Count

A couple points to note:

  1. You can put an arbitrarily complex expression in place of Get-Alias, for example:

    @(Get-Process | ? { $_.ProcessName -eq "svchost" }).Count
    
  2. The initial at-sign (@) is necessary for a robust solution. As long as the answer is two or greater you will get an equivalent answer with or without the @, but when the answer is zero or one you will get no output unless you have the @ sign! (It forces the Count property to exist by forcing the output to be an array.)

2012.01.30 Update

The above is true for PowerShell V2. One of the new features of PowerShell V3 is that you do have a Count property even for singletons, so the at-sign becomes unimportant for this scenario.

exclude @Component from @ComponentScan

In case of excluding test component or test configuration, Spring Boot 1.4 introduced new testing annotations @TestComponent and @TestConfiguration.

Constants in Kotlin -- what's a recommended way to create them?

Like val, variables defined with the const keyword are immutable. The difference here is that const is used for variables that are known at compile-time.

Declaring a variable const is much like using the static keyword in Java.

Let's see how to declare a const variable in Kotlin:

const val COMMUNITY_NAME = "wiki"

And the analogous code written in Java would be:

final static String COMMUNITY_NAME = "wiki";

Adding to the answers above -

@JvmField an be used to instruct the Kotlin compiler not to generate getters/setters for this property and expose it as a field.

 @JvmField
 val COMMUNITY_NAME: "Wiki"

Static fields

Kotlin properties declared in a named object or a companion object will have static backing fields either in that named object or in the class containing the companion object.

Usually these fields are private but they can be exposed in one of the following ways:

  • @JvmField annotation;
  • lateinit modifier;
  • const modifier.

More details here - https://kotlinlang.org/docs/reference/java-to-kotlin-interop.html#instance-fields

Object of class stdClass could not be converted to string

In General to get rid of

Object of class stdClass could not be converted to string.

try to use echo '<pre>'; print_r($sql_query); for my SQL Query got the result as

stdClass Object
(
    [num_rows] => 1
    [row] => Array
        (
            [option_id] => 2
            [type] => select
            [sort_order] => 0
        )

    [rows] => Array
        (
            [0] => Array
                (
                    [option_id] => 2
                    [type] => select
                    [sort_order] => 0
                )

        )

)

In order to acces there are different methods E.g.: num_rows, row, rows

echo $query2->row['option_id'];

Will give the result as 2

Add items in array angular 4

Your empList is object type but you are trying to push strings

Try this

this.empList.push({this.name,this.empoloyeeID});

jquery get all input from specific form

The below code helps to get the details of elements from the specific form with the form id,

$('#formId input, #formId select').each(
    function(index){  
        var input = $(this);
        alert('Type: ' + input.attr('type') + 'Name: ' + input.attr('name') + 'Value: ' + input.val());
    }
);

The below code helps to get the details of elements from all the forms which are place in the loading page,

$('form input, form select').each(
    function(index){  
        var input = $(this);
        alert('Type: ' + input.attr('type') + 'Name: ' + input.attr('name') + 'Value: ' + input.val());
    }
);

The below code helps to get the details of elements which are place in the loading page even when the element is not place inside the tag,

$('input, select').each(
    function(index){  
        var input = $(this);
        alert('Type: ' + input.attr('type') + 'Name: ' + input.attr('name') + 'Value: ' + input.val());
    }
);

NOTE: We add the more element tag name what we need in the object list like as below,

Example: to get name of attribute "textarea",

$('input, select, textarea').each(
    function(index){  
        var input = $(this);
        alert('Type: ' + input.attr('type') + 'Name: ' + input.attr('name') + 'Value: ' + input.val());
    }
);

Passing array in GET for a REST call

Collections are a resource so /appointments is fine as the resource.

Collections also typically offer filters via the querystring which is essentially what users=id1,id2... is.

So,

/appointments?users=id1,id2 

is fine as a filtered RESTful resource.

How to stop "setInterval"

Store the return of setInterval in a variable, and use it later to clear the interval.

var timer = null;
$("textarea").blur(function(){
    timer = window.setInterval(function(){ ... whatever ... }, 2000);
}).focus(function(){
    if(timer){
       window.clearInterval(timer);
       timer = null
    }
});

Is it possible to include one CSS file in another?

Import bootstrap with altervista and wordpress

I use this to import bootstrap.css in altervista with wordpress

@import url("https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css");

and it works fine, as it would delete the html link rel code if I put it into a page

How to append the output to a file?

Use >> to append:

command >> file

Dynamically adding elements to ArrayList in Groovy

What you actually created with:

MyType[] list = []

Was fixed size array (not list) with size of 0. You can create fixed size array of size for example 4 with:

MyType[] array = new MyType[4]

But there's no add method of course.

If you create list with def it's something like creating this instance with Object (You can read more about def here). And [] creates empty ArrayList in this case.

So using def list = [] you can then append new items with add() method of ArrayList

list.add(new MyType())

Or more groovy way with overloaded left shift operator:

list << new MyType() 

Aliases in Windows command prompt

First, you could create a file named np.cmd and put it in the folder which in PATH search list. Then, edit the np.cmd file as below:

@echo off
notepad++.exe

Should black box or white box testing be the emphasis for testers?

In my experience most developers naturally migrate towards white box testing. Since we need to ensure that the underlying algorithm is "correct", we tend to focus more on the internals. But, as has been pointed out, both white and black box testing is important.

Therefore, I prefer to have testers focus more on the Black Box tests, to cover for the fact that most developers don't really do it, and frequently aren't very good at it.

That isn't to say that testers should be kept in the dark about how the system works, just that I prefer them to focus more on the problem domain and how actual users interact with the system, not whether the function SomeMethod(int x) will correctly throw an exception if x is equal to 5.

How to remove default mouse-over effect on WPF buttons?

Using a template trigger:

<Style x:Key="ButtonStyle" TargetType="{x:Type Button}">
    <Setter Property="Background" Value="White"></Setter>
    ...
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type Button}">
                <Border Background="{TemplateBinding Background}">
                    <ContentPresenter HorizontalAlignment="Center" VerticalAlignment="Center"/>
                </Border>
                <ControlTemplate.Triggers>
                    <Trigger Property="IsMouseOver" Value="True">
                        <Setter Property="Background" Value="White"/>
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

Pandas DataFrame Groupby two columns and get counts

Inserting data into a pandas dataframe and providing column name.

import pandas as pd
df = pd.DataFrame([['A','C','A','B','C','A','B','B','A','A'], ['ONE','TWO','ONE','ONE','ONE','TWO','ONE','TWO','ONE','THREE']]).T
df.columns = [['Alphabet','Words']]
print(df)   #printing dataframe.

This is our printed data:

enter image description here

For making a group of dataframe in pandas and counter,
You need to provide one more column which counts the grouping, let's call that column as, "COUNTER" in dataframe.

Like this:

df['COUNTER'] =1       #initially, set that counter to 1.
group_data = df.groupby(['Alphabet','Words'])['COUNTER'].sum() #sum function
print(group_data)

OUTPUT:

enter image description here

How can I create a small color box using html and css?

You can create these easily using the floating ability of CSS, for example. I have created a small example on Jsfiddle over here, all the related css and html is also provided there.

_x000D_
_x000D_
.foo {_x000D_
  float: left;_x000D_
  width: 20px;_x000D_
  height: 20px;_x000D_
  margin: 5px;_x000D_
  border: 1px solid rgba(0, 0, 0, .2);_x000D_
}_x000D_
_x000D_
.blue {_x000D_
  background: #13b4ff;_x000D_
}_x000D_
_x000D_
.purple {_x000D_
  background: #ab3fdd;_x000D_
}_x000D_
_x000D_
.wine {_x000D_
  background: #ae163e;_x000D_
}
_x000D_
<div class="foo blue"></div>_x000D_
<div class="foo purple"></div>_x000D_
<div class="foo wine"></div>
_x000D_
_x000D_
_x000D_