Programs & Examples On #Showuserlocation

How to change Elasticsearch max memory size

Updated on Nov 24, 2016: Elasticsearch 5 apparently has changed the way to configure the JVM. See this answer here. The answer below still applies to versions < 5.

tirdadc, thank you for pointing this out in your comment below.


I have a pastebin page that I share with others when wondering about memory and ES. It's worked OK for me: http://pastebin.com/mNUGQCLY. I'll paste the contents here as well:

References:

https://github.com/grigorescu/Brownian/wiki/ElasticSearch-Configuration http://www.elasticsearch.org/guide/reference/setup/installation/

Edit the following files to modify memory and file number limits. These instructions assume Ubuntu 10.04, may work on later versions and other distributions/OSes. (Edit: This works for Ubuntu 14.04 as well.)

/etc/security/limits.conf:

elasticsearch - nofile 65535
elasticsearch - memlock unlimited

/etc/default/elasticsearch (on CentOS/RH: /etc/sysconfig/elasticsearch ):

ES_HEAP_SIZE=512m
MAX_OPEN_FILES=65535
MAX_LOCKED_MEMORY=unlimited

/etc/elasticsearch/elasticsearch.yml:

bootstrap.mlockall: true

PostgreSQL: Which version of PostgreSQL am I running?

Using CLI:

Server version:

$ postgres -V  # Or --version.  Use "locate bin/postgres" if not found.
postgres (PostgreSQL) 9.6.1
$ postgres -V | awk '{print $NF}'  # Last column is version.
9.6.1
$ postgres -V | egrep -o '[0-9]{1,}\.[0-9]{1,}'  # Major.Minor version
9.6

If having more than one installation of PostgreSQL, or if getting the "postgres: command not found" error:

$ locate bin/postgres | xargs -i xargs -t '{}' -V  # xargs is intentionally twice.
/usr/pgsql-9.3/bin/postgres -V 
postgres (PostgreSQL) 9.3.5
/usr/pgsql-9.6/bin/postgres -V 
postgres (PostgreSQL) 9.6.1

If locate doesn't help, try find:

$ sudo find / -wholename '*/bin/postgres' 2>&- | xargs -i xargs -t '{}' -V  # xargs is intentionally twice.
/usr/pgsql-9.6/bin/postgres -V 
postgres (PostgreSQL) 9.6.1

Although postmaster can also be used instead of postgres, using postgres is preferable because postmaster is a deprecated alias of postgres.

Client version:

As relevant, login as postgres.

$ psql -V  # Or --version
psql (PostgreSQL) 9.6.1

If having more than one installation of PostgreSQL:

$ locate bin/psql | xargs -i xargs -t '{}' -V  # xargs is intentionally twice.
/usr/bin/psql -V 
psql (PostgreSQL) 9.3.5
/usr/pgsql-9.2/bin/psql -V 
psql (PostgreSQL) 9.2.9
/usr/pgsql-9.3/bin/psql -V 
psql (PostgreSQL) 9.3.5

Using SQL:

Server version:

=> SELECT version();
                                                   version                                                    
--------------------------------------------------------------------------------------------------------------
 PostgreSQL 9.2.9 on x86_64-unknown-linux-gnu, compiled by gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-4), 64-bit

=> SHOW server_version;
 server_version 
----------------
 9.2.9

=> SHOW server_version_num;
 server_version_num 
--------------------
 90209

If more curious, try => SHOW all;.

Client version:

For what it's worth, a shell command can be executed within psql to show the client version of the psql executable in the path. Note that the running psql can potentially be different from the one in the path.

=> \! psql -V
psql (PostgreSQL) 9.2.9

Select From all tables - MySQL

As Suhel Meman said in the comments:

SELECT column1, column2, column3 FROM table 1
UNION
SELECT column1, column2, column3 FROM table 2
...

would work.

But all your SELECTS would have to consist of the same amount of columns. And because you are displaying it in one resulting table they should contain the same information.

What you might want to do, is a JOIN on Product ID or something like that. This way you would get more columns, which makes more sense most of the time.

How to clone an InputStream?

You can't clone it, and how you are going to solve your problem depends on what the source of the data is.

One solution is to read all data from the InputStream into a byte array, and then create a ByteArrayInputStream around that byte array, and pass that input stream into your method.

Edit 1: That is, if the other method also needs to read the same data. I.e you want to "reset" the stream.

How a thread should close itself in Java?

If you simply call interrupt(), the thread will not automatically be closed. Instead, the Thread might even continue living, if isInterrupted() is implemented accordingly. The only way to guaranteedly close a thread, as asked for by OP, is

Thread.currentThread().stop();

Method is deprecated, however.

Calling return only returns from the current method. This only terminates the thread if you're at its top level.

Nevertheless, you should work with interrupt() and build your code around it.

Ideal way to cancel an executing AsyncTask

This is how I write my AsyncTask
the key point is add Thread.sleep(1);

@Override   protected Integer doInBackground(String... params) {

        Log.d(TAG, PRE + "url:" + params[0]);
        Log.d(TAG, PRE + "file name:" + params[1]);
        downloadPath = params[1];

        int returnCode = SUCCESS;
        FileOutputStream fos = null;
        try {
            URL url = new URL(params[0]);
            File file = new File(params[1]);
            fos = new FileOutputStream(file);

            long startTime = System.currentTimeMillis();
            URLConnection ucon = url.openConnection();
            InputStream is = ucon.getInputStream();
            BufferedInputStream bis = new BufferedInputStream(is);

            byte[] data = new byte[10240]; 
            int nFinishSize = 0;
            while( bis.read(data, 0, 10240) != -1){
                fos.write(data, 0, 10240);
                nFinishSize += 10240;
                **Thread.sleep( 1 ); // this make cancel method work**
                this.publishProgress(nFinishSize);
            }              
            data = null;    
            Log.d(TAG, "download ready in"
                  + ((System.currentTimeMillis() - startTime) / 1000)
                  + " sec");

        } catch (IOException e) {
                Log.d(TAG, PRE + "Error: " + e);
                returnCode = FAIL;
        } catch (Exception e){
                 e.printStackTrace();           
        } finally{
            try {
                if(fos != null)
                    fos.close();
            } catch (IOException e) {
                Log.d(TAG, PRE + "Error: " + e);
                e.printStackTrace();
            }
        }

        return returnCode;
    }

How to pass data from Javascript to PHP and vice versa?

You can pass data from PHP to javascript but the only way to get data from javascript to PHP is via AJAX.

The reason for that is you can build a valid javascript through PHP but to get data to PHP you will need to get PHP running again, and since PHP only runs to process the output, you will need a page reload or an asynchronous query.

Summing elements in a list

You can use sum to sum the elements of a list, however if your list is coming from raw_input, you probably want to convert the items to int or float first:

l = raw_input().split(' ')
sum(map(int, l))

Remove "whitespace" between div element

Although probably not the best method you could add:

#div1 {
    ...
    font-size:0;
}

Excel doesn't update value unless I hit Enter

Executive summary / TL;DR:
Try doing a find & replace of "=" with "=". Yes, replace the equals sign with itself. For my scenario, it forced everything to update.

Background:
I frequently make formulas across multiple columns then concatenate them together. After doing such, I'll copy & paste them as values to extract my created formula. After this process, they're typically stuck displaying a formula, and not displaying a value, unless I enter the cell and press Enter. Pressing F2 & Enter repeatedly is not fun.

Applying .gitignore to committed files

Follow these steps:

  1. Add path to gitignore file

  2. Run this command

    git rm -r --cached foldername
    
  3. commit changes as usually.

react-native: command not found

According to official documentation, the following command worked for me.

  • npx react-native run-android

Link is here

I was trying to run by "react-native run-android" command. make sure to have react-native cli installed globally!

Microsoft Azure: How to create sub directory in a blob container

In Azure Portal we have below option while uploading file :

enter image description here

How to retrieve checkboxes values in jQuery

If you want to insert the value of any checkbox immediately as it is being checked then this should work for you:

$(":checkbox").click(function(){
  $("#id").text(this.value)
})

Android Canvas: drawing too large bitmap

This can be an issue with Glide. Use this while you are trying to load to many images and some of them are very large:

Glide.load("your image path")
                       .transform(
                               new MultiTransformation<>(
                                       new CenterCrop(),
                                       new RoundedCorners(
                                               holder.imgCompanyLogo.getResources()
                                                       .getDimensionPixelSize(R.dimen._2sdp)
                                       )
                               )
                       )
                       .error(R.drawable.ic_nfs_default)
                       .into(holder.imgCompanyLogo);
           }

How to vertically align a html radio button to it's label?

I know I'd selected the anwer by menuka devinda but looking at the comments below it I concurred and tried to come up with a better solution. I managed to come up with this and in my opinion it's a much more elegant solution:

input[type='radio'], label{   
    vertical-align: baseline;
    padding: 10px;
    margin: 10px;
 }

Thanks to everyone who offered an answer, your answer didn't go unnoticed. If you still got any other ideas feel free to add your own answer to this question.

keytool error Keystore was tampered with, or password was incorrect

For me I solved it by changing passwords from Arabic letter to English letter, but first I went to the folder and deleted the generated key then it works.

how to have two headings on the same line in html

You'd need to wrap the two headings in a div tag, and have that div tag use a style that does clear: both. e.g:

<div style="clear: both">
    <h2 style="float: left">Heading 1</h2>
    <h3 style="float: right">Heading 2</h3>
</div>
<hr />

Having the hr after the div tag will ensure that it is pushed beneath both headers.

Or something very similar to that. Hope this helps.

How to run a stored procedure in oracle sql developer?

Consider you've created a procedure like below.

CREATE OR REPLACE PROCEDURE GET_FULL_NAME like
(
  FIRST_NAME IN VARCHAR2, 
  LAST_NAME IN VARCHAR2,
  FULL_NAME OUT VARCHAR2 
) IS 
BEGIN
  FULL_NAME:= FIRST_NAME || ' ' || LAST_NAME;
END GET_FULL_NAME;

In Oracle SQL Developer, you can run this procedure in two ways.

1. Using SQL Worksheet

Create a SQL Worksheet and write PL/SQL anonymous block like this and hit f5

DECLARE
  FULL_NAME Varchar2(50);
BEGIN
  GET_FULL_NAME('Foo', 'Bar', FULL_NAME);
  Dbms_Output.Put_Line('Full name is: ' || FULL_NAME);
END;

2. Using GUI Controls

  • Expand Procedures

  • Right click on the procudure you've created and Click Run

  • In the pop-up window, Fill the parameters and Click OK.

Cheers!

Is there a way to split a widescreen monitor in to two or more virtual monitors?

What about just using virtual desktops? You can spread your windows around among multiple workspaces. Something like Virtual Dimension should give you most of that functionality. I use virtual desktops all the time on Linux, and it's the next best thing to multiple monitors.

I'm getting favicon.ico error

I have had this error for some time as well. It might be some kind of netbeans bug that has to do with netbeans connector. I can't find any mention of favicon.ico in my code or in the project settings.

I was able to fix it by putting the following line in the head section of my html file

<link rel="shortcut icon" href="#">

I am currently using this in my testing environment, but I would remove it for any production environment.

What is the difference between MOV and LEA?

LEA (Load Effective Address) is a shift-and-add instruction. It was added to 8086 because hardware is there to decode and calculate adressing modes.

POSTing JsonObject With HttpClient From Web API

the code over it in vbnet:

dim FeToSend as new (object--> define class)

Dim client As New HttpClient
Dim content = New StringContent(FeToSend.ToString(), Encoding.UTF8,"application/json")
content.Headers.ContentType = New MediaTypeHeaderValue( "application/json" )
Dim risp = client.PostAsync(Chiamata, content).Result

msgbox(risp.tostring)

Hope this help

How can I run Tensorboard on a remote server?

For anyone who must use the ssh keys (for a corporate server).

Just add -i /.ssh/id_rsa at the end.

$ ssh -N -f -L localhost:8211:localhost:6007 myname@servername -i /.ssh/id_rsa

SQL Not Like Statement not working

mattgcon,

Should work, do you get more rows if you run the same SQL with the "NOT LIKE" line commented out? If not, check the data. I know you mentioned in your question, but check that the actual SQL statement is using that clause. The other answers with NULL are also a good idea.

Correct way to populate an Array with a Range in Ruby

This works for me in irb:

irb> (1..4).to_a
=> [1, 2, 3, 4]

I notice that:

irb> 1..4.to_a
(irb):1: warning: default `to_a' will be obsolete
ArgumentError: bad value for range
        from (irb):1

So perhaps you are missing the parentheses?

(I am running Ruby 1.8.6 patchlevel 114)

How can I listen for keypress event on the whole page?

Be aware "document:keypress" is deprecated. We should use document:keydown instead.

Link: https://developer.mozilla.org/fr/docs/Web/API/Document/keypress_event

Temporary tables in stored procedures

Not really and I am talking about SQL Server. The temp table (with single #) exists and is visible within the scope it is created (scope-bound). Each time you call your stored procedure it creates a new scope and therefore that temp table exists only in that scope. I believe the temp tables are also visible to stored procedures and udfs that're called within that scope as well. If you however use double pound (##) then they become global within your session and therefore visible to other executing processes as part of the session that the temp table is created in and you will have to think if the possibility of temp table being accessed concurrently is desirable or not.

How do I use Maven through a proxy?

To set Maven Proxy :

Edit the proxies session in your ~/.m2/settings.xml file. If you cant find the file, create one.

<settings>
<proxies>
    <proxy>
        <id>httpproxy</id>
        <active>true</active>
        <protocol>http</protocol>
        <host>your-proxy-host</host>
        <port>your-proxy-port</port>
        <nonProxyHosts>local.net|some.host.com</nonProxyHosts>
    </proxy>
<proxy>
        <id>httpsproxy</id>
        <active>true</active>
        <protocol>https</protocol>
        <host>your-proxy-host</host>
        <port>your-proxy-port</port>
        <nonProxyHosts>local.net|some.host.com</nonProxyHosts>
    </proxy>

</proxies>
</settings>

or

Edit the proxies session in your {M2_HOME}/conf/settings.xml

Hope it Helps.. :)

Running Python from Atom

Download and Install package here: https://atom.io/packages/script

To execute the python command in atom use the below shortcuts:

For Windows/Linux, it's SHIFT + Ctrl + B OR Ctrl + SHIFT + B

If you're on Mac, press ? + I

Remove all child elements of a DOM node in JavaScript

If you want to put something back into that div, the innerHTML is probably better.

My example:

<ul><div id="result"></div></ul>

<script>
  function displayHTML(result){
    var movieLink = document.createElement("li");
    var t = document.createTextNode(result.Title);
    movieLink.appendChild(t);
    outputDiv.appendChild(movieLink);
  }
</script>

If I use the .firstChild or .lastChild method the displayHTML() function doesnt work afterwards, but no problem with the .innerHTML method.

codes for ADD,EDIT,DELETE,SEARCH in vb2010

A good resource start off point would be MSDN as your looking into a microsoft product

Get the IP Address of local computer

I suggest my code.

DllExport void get_local_ips(boost::container::vector<wstring>& ips)
{
   IP_ADAPTER_ADDRESSES*       adapters  = NULL;
   IP_ADAPTER_ADDRESSES*       adapter       = NULL;
   IP_ADAPTER_UNICAST_ADDRESS* adr           = NULL;
   ULONG                       adapter_size = 0;
   ULONG                       err           = 0;
   SOCKADDR_IN*                sockaddr  = NULL;

   err = ::GetAdaptersAddresses(AF_UNSPEC, GAA_FLAG_SKIP_ANYCAST | GAA_FLAG_SKIP_MULTICAST | GAA_FLAG_SKIP_DNS_SERVER | GAA_FLAG_SKIP_FRIENDLY_NAME, NULL, NULL, &adapter_size);
   adapters = (IP_ADAPTER_ADDRESSES*)malloc(adapter_size);
   err = ::GetAdaptersAddresses(AF_UNSPEC, GAA_FLAG_SKIP_ANYCAST | GAA_FLAG_SKIP_MULTICAST | GAA_FLAG_SKIP_DNS_SERVER | GAA_FLAG_SKIP_FRIENDLY_NAME, NULL, adapters, &adapter_size);

   for (adapter = adapters; NULL != adapter; adapter = adapter->Next)
   {
       if (adapter->IfType     == IF_TYPE_SOFTWARE_LOOPBACK) continue; // Skip Loopback
       if (adapter->OperStatus != IfOperStatusUp) continue;            // Live connection only  

       for (adr = adapter->FirstUnicastAddress;adr != NULL; adr = adr->Next)
       {
           sockaddr = (SOCKADDR_IN*)(adr->Address.lpSockaddr);
           char    ipstr [INET6_ADDRSTRLEN] = { 0 };
           wchar_t ipwstr[INET6_ADDRSTRLEN] = { 0 };
           inet_ntop(AF_INET, &(sockaddr->sin_addr), ipstr, INET_ADDRSTRLEN);
           mbstowcs(ipwstr, ipstr, INET6_ADDRSTRLEN);
           wstring wstr(ipwstr);
           if (wstr != "0.0.0.0") ips.push_back(wstr);                      
       }
   }

   free(adapters);
   adapters = NULL; }

Convert A String (like testing123) To Binary In Java

This is my implementation.

public class Test {
    public String toBinary(String text) {
        StringBuilder sb = new StringBuilder();

        for (char character : text.toCharArray()) {
            sb.append(Integer.toBinaryString(character) + "\n");
        }

        return sb.toString();

    }
}

how to download file using AngularJS and calling MVC API?

using FileSaver.js solved my issue thanks for help, below code helped me

'$'

 DownloadClaimForm: function (claim) 
{
 url = baseAddress + "DownLoadFile";
 return  $http.post(baseAddress + "DownLoadFile", claim, {responseType: 'arraybuffer' })
                            .success(function (data) {
                                var file = new Blob([data], { type: 'application/pdf' });
                                saveAs(file, 'Claims.pdf');
                            });


    }

How to post an array of complex objects with JSON, jQuery to ASP.NET MVC Controller?

Towards the second half of Create REST API using ASP.NET MVC that speaks both JSON and plain XML, to quote:

Now we need to accept JSON and XML payload, delivered via HTTP POST. Sometimes your client might want to upload a collection of objects in one shot for batch processing. So, they can upload objects using either JSON or XML format. There's no native support in ASP.NET MVC to automatically parse posted JSON or XML and automatically map to Action parameters. So, I wrote a filter that does it."

He then implements an action filter that maps the JSON to C# objects with code shown.

Node.js create folder or use existing

Raugaral's answer but with -p functionality. Ugly, but it works:

function mkdirp(dir) {
    let dirs = dir.split(/\\/).filter(asdf => !asdf.match(/^\s*$/))
    let fullpath = ''

    // Production directory will begin \\, test is on my local drive.
    if (dirs[0].match(/C:/i)) {
        fullpath = dirs[0] + '\\'
    }
    else {
        fullpath = '\\\\' + dirs[0] + '\\'
    }

    // Start from root directory + 1, build out one level at a time.
    dirs.slice(1).map(asdf => {
        fullpath += asdf + '\\'
        if (!fs.existsSync(fullpath)) {
            fs.mkdirSync(fullpath)
        }
    })
}//mkdirp

How do I perform HTML decoding/encoding using Python/Django?

Given the Django use case, there are two answers to this. Here is its django.utils.html.escape function, for reference:

def escape(html):
    """Returns the given HTML with ampersands, quotes and carets encoded."""
    return mark_safe(force_unicode(html).replace('&', '&amp;').replace('<', '&l
t;').replace('>', '&gt;').replace('"', '&quot;').replace("'", '&#39;'))

To reverse this, the Cheetah function described in Jake's answer should work, but is missing the single-quote. This version includes an updated tuple, with the order of replacement reversed to avoid symmetric problems:

def html_decode(s):
    """
    Returns the ASCII decoded version of the given HTML string. This does
    NOT remove normal HTML tags like <p>.
    """
    htmlCodes = (
            ("'", '&#39;'),
            ('"', '&quot;'),
            ('>', '&gt;'),
            ('<', '&lt;'),
            ('&', '&amp;')
        )
    for code in htmlCodes:
        s = s.replace(code[1], code[0])
    return s

unescaped = html_decode(my_string)

This, however, is not a general solution; it is only appropriate for strings encoded with django.utils.html.escape. More generally, it is a good idea to stick with the standard library:

# Python 2.x:
import HTMLParser
html_parser = HTMLParser.HTMLParser()
unescaped = html_parser.unescape(my_string)

# Python 3.x:
import html.parser
html_parser = html.parser.HTMLParser()
unescaped = html_parser.unescape(my_string)

# >= Python 3.5:
from html import unescape
unescaped = unescape(my_string)

As a suggestion: it may make more sense to store the HTML unescaped in your database. It'd be worth looking into getting unescaped results back from BeautifulSoup if possible, and avoiding this process altogether.

With Django, escaping only occurs during template rendering; so to prevent escaping you just tell the templating engine not to escape your string. To do that, use one of these options in your template:

{{ context_var|safe }}
{% autoescape off %}
    {{ context_var }}
{% endautoescape %}

How to clone ArrayList and also clone its contents?

Some other alternatives for copying ArrayList as a Deep Copy

Alernative 1 - Use of external package commons-lang3, method SerializationUtils.clone():

SerializationUtils.clone()

Let's say we have a class dog where the fields of the class are mutable and at least one field is an object of type String and mutable - not a primitive data type (otherwise shallow copy would be enough).

Example of shallow copy:

List<Dog> dogs = getDogs(); // We assume it returns a list of Dogs
List<Dog> clonedDogs = new ArrayList<>(dogs);

Now back to deep copy of dogs.

The Dog class does only have mutable fields.

Dog class:

public class Dog implements Serializable {
    private String name;
    private int age;

    public Dog() {
        // Class with only mutable fields!
        this.name = "NO_NAME";
        this.age = -1;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "Dog{" +
                "name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}

Note that the class Dog implements Serializable! This makes it possible to utilize method "SerializationUtils.clone(dog)"

Read the comments in the main method to understand the outcome. It shows that we have successfully made a deep copy of ArrayList(). See below "SerializationUtils.clone(dog)" in context:

public static void main(String[] args) {
    Dog dog1 = new Dog();
    dog1.setName("Buddy");
    dog1.setAge(1);

    Dog dog2 = new Dog();
    dog2.setName("Milo");
    dog2.setAge(2);

    List<Dog> dogs = new ArrayList<>(Arrays.asList(dog1,dog2));

    // Output: 'List dogs: [Dog{name='Buddy', age=1}, Dog{name='Milo', age=2}]'
    System.out.println("List dogs: " + dogs);

    // Let's clone and make a deep copy of the dogs' ArrayList with external package commons-lang3:
    List<Dog> clonedDogs = dogs.stream().map(dog -> SerializationUtils.clone(dog)).collect(Collectors.toList());
    // Output: 'Now list dogs are deep copied into list clonedDogs.'
    System.out.println("Now list dogs are deep copied into list clonedDogs.");

    // A change on dog1 or dog2 can not impact a deep copy.
    // Let's make a change on dog1 and dog2, and test this
    // statement.
    dog1.setName("Bella");
    dog1.setAge(3);
    dog2.setName("Molly");
    dog2.setAge(4);

    // The change is made on list dogs!
    // Output: 'List dogs after change: [Dog{name='Bella', age=3}, Dog{name='Molly', age=4}]'
    System.out.println("List dogs after change: " + dogs);

    // There is no impact on list clonedDogs's inner objects after the deep copy.
    // The deep copy of list clonedDogs was successful!
    // If clonedDogs would be a shallow copy we would see the change on the field
    // "private String name", the change made in list dogs, when setting the names
    // Bella and Molly.
    // Output clonedDogs:
    // 'After change in list dogs, no impact/change in list clonedDogs:\n'
    // '[Dog{name='Buddy', age=1}, Dog{name='Milo', age=2}]\n'
    System.out.println("After change in list dogs, no impact/change in list clonedDogs: \n" + clonedDogs);
}

Output:

List dogs: [Dog{name='Buddy', age=1}, Dog{name='Milo', age=2}]
Now list dogs are deep copied into list clonedDogs.
List dogs after change: [Dog{name='Bella', age=3}, Dog{name='Molly', age=4}]
After change in list dogs, no impact/change in list clonedDogs:
[Dog{name='Buddy', age=1}, Dog{name='Milo', age=2}]

Comment: Since there is no impact/change on list clonedDogs after changing list dogs, then deep copy of ArrayList is successful!

Alernative 2 - Use of no external packages:

A new method "clone()" is introduced in the Dog class and "implements Serializable" is removed compare to alternative 1.

clone()

Dog class:

public class Dog {
    private String name;
    private int age;

    public Dog() {
        // Class with only mutable fields!
        this.name = "NO_NAME";
        this.age = -1;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    /**
     * Returns a deep copy of the Dog
     * @return new instance of {@link Dog}
     */
    public Dog clone() {
        Dog newDog = new Dog();
        newDog.setName(this.name);
        newDog.setAge(this.age);
        return newDog;
    }

    @Override
    public String toString() {
        return "Dog{" +
                "name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}

Read the comments in the main method below to understand the outcome. It shows that we have successfully made a deep copy of ArrayList(). See below "clone()" method in context:

public static void main(String[] args) {
    Dog dog1 = new Dog();
    dog1.setName("Buddy");
    dog1.setAge(1);

    Dog dog2 = new Dog();
    dog2.setName("Milo");
    dog2.setAge(2);

    List<Dog> dogs = new ArrayList<>(Arrays.asList(dog1,dog2));

    // Output: 'List dogs: [Dog{name='Buddy', age=1}, Dog{name='Milo', age=2}]'
    System.out.println("List dogs: " + dogs);

    // Let's clone and make a deep copy of the dogs' ArrayList:
    List<Dog> clonedDogs = dogs.stream().map(dog -> dog.clone()).collect(Collectors.toList());
    // Output: 'Now list dogs are deep copied into list clonedDogs.'
    System.out.println("Now list dogs are deep copied into list clonedDogs.");

    // A change on dog1 or dog2 can not impact a deep copy.
    // Let's make a change on dog1 and dog2, and test this
    // statement.
    dog1.setName("Bella");
    dog1.setAge(3);
    dog2.setName("Molly");
    dog2.setAge(4);

    // The change is made on list dogs!
    // Output: 'List dogs after change: [Dog{name='Bella', age=3}, Dog{name='Molly', age=4}]'
    System.out.println("List dogs after change: " + dogs);

    // There is no impact on list clonedDogs's inner objects after the deep copy.
    // The deep copy of list clonedDogs was successful!
    // If clonedDogs would be a shallow copy we would see the change on the field
    // "private String name", the change made in list dogs, when setting the names
    // Bella and Molly.
    // Output clonedDogs:
    // 'After change in list dogs, no impact/change in list clonedDogs:\n'
    // '[Dog{name='Buddy', age=1}, Dog{name='Milo', age=2}]\n'
    System.out.println("After change in list dogs, no impact/change in list clonedDogs: \n" + clonedDogs);
}

Output:

List dogs: [Dog{name='Buddy', age=1}, Dog{name='Milo', age=2}]
Now list dogs are deep copied into list clonedDogs.
List dogs after change: [Dog{name='Bella', age=3}, Dog{name='Molly', age=4}]
After change in list dogs, no impact/change in list clonedDogs:
[Dog{name='Buddy', age=1}, Dog{name='Milo', age=2}]

Comment: Since there is no impact/change on list clonedDogs after changing list dogs, then deep copy of ArrayList is successful!

Note1: Alternative 1 is much slower than Alternative 2, but easier to mainatain since you do not need to upadate any methods like clone().

Note2: For alternative 1 the following maven dependency was used for method "SerializationUtils.clone()":

<!-- https://mvnrepository.com/artifact/org.apache.commons/commons-lang3 -->
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.9</version>
</dependency>

Find more releases of common-lang3 at:

https://mvnrepository.com/artifact/org.apache.commons/commons-lang3

Generate insert script for selected records?

You could create a view with your criteria and then export the view?

Fatal error: Call to a member function query() on null

First, you declared $db outside the function. If you want to use it inside the function, you should put this at the begining of your function code:

global $db;

And I guess, when you wrote:

if($result->num_rows){
        return (mysqli_result($query, 0) == 1) ? true : false;

what you really wanted was:

if ($result->num_rows==1) { return true; } else { return false; }

How do I compare strings in Java?

== tests object references, .equals() tests the string values.

Sometimes it looks as if == compares values, because Java does some behind-the-scenes stuff to make sure identical in-line strings are actually the same object.

For example:

String fooString1 = new String("foo");
String fooString2 = new String("foo");

// Evaluates to false
fooString1 == fooString2;

// Evaluates to true
fooString1.equals(fooString2);

// Evaluates to true, because Java uses the same object
"bar" == "bar";

But beware of nulls!

== handles null strings fine, but calling .equals() from a null string will cause an exception:

String nullString1 = null;
String nullString2 = null;

// Evaluates to true
System.out.print(nullString1 == nullString2);

// Throws a NullPointerException
System.out.print(nullString1.equals(nullString2));

So if you know that fooString1 may be null, tell the reader that by writing

System.out.print(fooString1 != null && fooString1.equals("bar"));

The following are shorter, but it’s less obvious that it checks for null:

System.out.print("bar".equals(fooString1));  // "bar" is never null
System.out.print(Objects.equals(fooString1, "bar"));  // Java 7 required

Enable UTF-8 encoding for JavaScript

just add your script like this:

<script src="/js/intlTelInput.min.js" charset="utf-8"></script>

How to call a REST web service API from JavaScript?

Your Javascript:

function UserAction() {
    var xhttp = new XMLHttpRequest();
    xhttp.onreadystatechange = function() {
         if (this.readyState == 4 && this.status == 200) {
             alert(this.responseText);
         }
    };
    xhttp.open("POST", "Your Rest URL Here", true);
    xhttp.setRequestHeader("Content-type", "application/json");
    xhttp.send("Your JSON Data Here");
}

Your Button action::

<button type="submit" onclick="UserAction()">Search</button>

For more info go through the following link (Updated 2017/01/11)

How do I copy a version of a single file from one git branch to another?

Run this from the branch where you want the file to end up:

git checkout otherbranch myfile.txt

General formulas:

git checkout <commit_hash> <relative_path_to_file_or_dir>
git checkout <remote_name>/<branch_name> <file_or_dir>

Some notes (from comments):

  • Using the commit hash you can pull files from any commit
  • This works for files and directories
  • overwrites the file myfile.txt and mydir
  • Wildcards don't work, but relative paths do
  • Multiple paths can be specified

an alternative:

git show commit_id:path/to/file > path/to/file

Is it possible to run .php files on my local computer?

Sure you just need to setup a local web server. Check out XAMPP: http://www.apachefriends.org/en/xampp.html

That will get you up and running in about 10 minutes.

There is now a way to run php locally without installing a server: https://stackoverflow.com/a/21872484/672229


Yes but the files need to be processed. For example you can install test servers like mamp / lamp / wamp depending on your plateform.

Basically you need apache / php running.

onclick event pass <li> id or value

I prefer to use the HTML5 data API, check this documentation:

A example

_x000D_
_x000D_
$('#some-list li').click(function() {_x000D_
  var textLoaded = 'Loading element with id='_x000D_
         + $(this).data('id');_x000D_
   $('#loading-content').text(textLoaded);_x000D_
});
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>_x000D_
<ul id='some-list'>_x000D_
  <li data-id='1'>One </li>_x000D_
  <li data-id='2'>Two </li>_x000D_
  <!-- ... more li -->_x000D_
  <li data-id='n'>Other</li>_x000D_
</ul>_x000D_
_x000D_
<h1 id='loading-content'></h1>
_x000D_
_x000D_
_x000D_

Reading a date using DataReader

This may seem slightly off topic but this was the post I came across when wondering what happens when you read a column as a dateTime in c#. The post reflects the information I would have liked to be able to find about this mechanism. If you worry about utc and timezones then read on

I did a little more research as I'm always very wary of DateTime as a class because of its automatic assumptions about what timezone you are using and because it is way too easy to confuse local times and utc times.

What I'm trying to avoid here is DateTime going 'oh look the computer I'm being run on is in timezone x, therefore this time must also be in timezone x, when I get asked for my values I'll reply as if I'm in that timezone'

I was trying to read a datetime2 column.

The date time you will get back from sql server will end up being of Kind.Unspecified this seems to mean it gets treated like UTC, which is what I wanted.

When reading a date column you also have to read it as a DateTime even though it has no time and is even more prone to screwing up by timezones (as it is on midnight).

I'd certainly consider this to be safer way of reading the DateTime as I suspect it can probably be modified by either settings in sql server or static settings in your c#:

var time = reader.GetDateTime(1);
var utcTime = new DateTime(time.Ticks, DateTimeKind.Utc);

From there you can get the components (Day, Month, Year) etc and format how you like.

If what you have is actually a date + a time then Utc might not be what you want there - since you are mucking around on the client you may need to convert it to a local time first (depending on what the meaning of the time is). However that opens up a whole can of worms.. If you need to do that I'd recommend using a library like noda time. There is TimeZoneInfo in the standard library but after briefly investigating it, it doesn't seem to have a proper set of timezones. You can see the list provided by TimeZoneInfo by using the method TimeZoneInfo.GetSystemTimeZones();

I also discovered sql server management studio doesn't convert times to local time before displaying them. Which is a relief!

jQuery change event on dropdown

You should've kept that DOM ready function

$(function() {
    $("#projectKey").change(function() {
        alert( $('option:selected', this).text() );
    });
});

The document isn't ready if you added the javascript before the elements in the DOM, you have to either use a DOM ready function or add the javascript after the elements, the usual place is right before the </body> tag

How do you delete a column by name in data.table?

For a data.table, assigning the column to NULL removes it:

DT[,c("col1", "col1", "col2", "col2")] <- NULL
^
|---- Notice the extra comma if DT is a data.table

... which is the equivalent of:

DT$col1 <- NULL
DT$col2 <- NULL
DT$col3 <- NULL
DT$col4 <- NULL

The equivalent for a data.frame is:

DF[c("col1", "col1", "col2", "col2")] <- NULL
      ^
      |---- Notice the missing comma if DF is a data.frame

Q. Why is there a comma in the version for data.table, and no comma in the version for data.frame?

A. As data.frames are stored as a list of columns, you can skip the comma. You could also add it in, however then you will need to assign them to a list of NULLs, DF[, c("col1", "col2", "col3")] <- list(NULL).

Warning: "continue" targeting switch is equivalent to "break". Did you mean to use "continue 2"?

Or download composer.phar from site: "https://getcomposer.org/download/" (manual download), and use command:

php composer.phar require your/package

Why does MSBuild look in C:\ for Microsoft.Cpp.Default.props instead of c:\Program Files (x86)\MSBuild? ( error MSB4019)

MSBuild in an independent build tool that is frequently bundled with other tools. It may have been installed on your computer with .NET (older versions), Visual Studio (newer versions), or even Team Foundation Build.

MSBuild needs configuration files, compilers, etc (a ToolSet) that matches the version of Visual Studio or TFS that will use it, as well as the version of .NET against which source code will be compiled.

Depending on how MSBuild was installed, the configuration files may be in one or more of these paths.

  • C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\
  • C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V120\
  • C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V140\

As described in other answers, a registry item and/or environmental variable point must to the ToolSet path.

  • The VCTargetsPath key under HKLM\SOFTWARE\Microsoft\MSBuild\ToolsVersions\4.0
  • The VCTargetsPath environmental variable.

Occasionally, an operation like installing a tool will leave the registry and/or environmental variable set incorrectly. The other answers are all variations on fixing them.

The only thing I have to add is the environmental variable didn't work for me when I left off the trailing \

How to recompile with -fPIC

Before compiling make sure that "rules.mk" file is included properly in Makefile or include it explicitly by:

"source rules.mk"

MySQL Creating tables with Foreign Keys giving errno: 150

MySQL Workbench 6.3 for Mac OS.

Problem: errno 150 on table X when trying to do Forward Engineering on a DB diagram, 20 out of 21 succeeded, 1 failed. If FKs on table X were deleted, the error moved to a different table that wasn't failing before.

Changed all tables engine to myISAM and it worked just fine.

enter image description here

git replacing LF with CRLF

I had this problem too.

SVN doesn't do any line ending conversion, so files are committed with CRLF line endings intact. If you then use git-svn to put the project into git then the CRLF endings persist across into the git repository, which is not the state git expects to find itself in - the default being to only have unix/linux (LF) line endings checked in.

When you then check out the files on windows, the autocrlf conversion leaves the files intact (as they already have the correct endings for the current platform), however the process that decides whether there is a difference with the checked in files performs the reverse conversion before comparing, resulting in comparing what it thinks is an LF in the checked out file with an unexpected CRLF in the repository.

As far as I can see your choices are:

  1. Re-import your code into a new git repository without using git-svn, this will mean line endings are converted in the intial git commit --all
  2. Set autocrlf to false, and ignore the fact that the line endings are not in git's preferred style
  3. Check out your files with autocrlf off, fix all the line endings, check everything back in, and turn it back on again.
  4. Rewrite your repository's history so that the original commit no longer contains the CRLF that git wasn't expecting. (The usual caveats about history rewriting apply)

Footnote: if you choose option #2 then my experience is that some of the ancillary tools (rebase, patch etc) do not cope with CRLF files and you will end up sooner or later with files with a mix of CRLF and LF (inconsistent line endings). I know of no way of getting the best of both.

Android: show/hide a view using an animation

If you only want to animate the height of a view (from say 0 to a certain number) you could implement your own animation:

final View v = getTheViewToAnimateHere();
Animation anim=new Animation(){
    protected void applyTransformation(float interpolatedTime, Transformation t) {
        super.applyTransformation(interpolatedTime, t);
        // Do relevant calculations here using the interpolatedTime that runs from 0 to 1
        v.setLayoutParams(new LinearLayout.LayoutParams(LayoutParams.FILL_PARENT, (int)(30*interpolatedTime)));
    }};
anim.setDuration(500);
v.startAnimation(anim);

MySQL - force not to use cache for testing speed of query

Try using the SQL_NO_CACHE (MySQL 5.7) option in your query. (MySQL 5.6 users click HERE )

eg.

SELECT SQL_NO_CACHE * FROM TABLE

This will stop MySQL caching the results, however be aware that other OS and disk caches may also impact performance. These are harder to get around.

jQuery counter to count up to a target number

You can use jquery animate function for that.

$({ countNum: $('.code').html() }).animate({ countNum: 4000 }, {
        duration: 8000,
        easing: 'linear',
        step: function () {
        $('.code').html(Math.floor(this.countNum) );
        },
        complete: function () {
        $('.code').html(this.countNum);
        //alert('finished');
        }
    });

Here's the original article

What's the Linq to SQL equivalent to TOP or LIMIT/OFFSET?

I had to use Take(n) method, then transform to list, Worked like a charm:

    var listTest = (from x in table1
                     join y in table2
                     on x.field1 equals y.field1
                     orderby x.id descending
                     select new tempList()
                     {
                         field1 = y.field1,
                         active = x.active
                     }).Take(10).ToList();

Create a batch file to run an .exe with an additional parameter

in batch file abc.bat

cd c:\user\ben_dchost\documents\
executible.exe -flag1 -flag2 -flag3 

I am assuming that your executible.exe is present in c:\user\ben_dchost\documents\ I am also assuming that the parameters it takes are -flag1 -flag2 -flag3

Edited:

For the command you say you want to execute, do:

cd C:\Users\Ben\Desktop\BGInfo\
bginfo.exe dc_bginfo.bgi
pause

Hope this helps

Javascript ES6 export const vs export let

I think that once you've imported it, the behaviour is the same (in the place your variable will be used outside source file).

The only difference would be if you try to reassign it before the end of this very file.

How to copy data from one HDFS to another HDFS?

It's also useful to note that you can run the underlying MapReduce jobs with either the source or target cluster like so:

hadoop --config /path/to/hadoop/config distcp <src> <dst>

How to iterate over array of objects in Handlebars?

You can pass this to each block. See here: http://jsfiddle.net/yR7TZ/1/

{{#each this}}
    <div class="row"></div>
{{/each}}

android ellipsize multiline textview

Got this problem to, and finaly, I build myself a short solution. You just have to ellipsize manually the line you want, your maxLine attribute will cut your text.

This example cut your text for 3 lines max

        final TextView title = (TextView)findViewById(R.id.text);
        title.setText("A really long text");
        ViewTreeObserver vto = title.getViewTreeObserver();
        vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {

            @Override
            public void onGlobalLayout() {
                ViewTreeObserver obs = title.getViewTreeObserver();
                obs.removeGlobalOnLayoutListener(this);
                if(title.getLineCount() > 3){
                    Log.d("","Line["+title.getLineCount()+"]"+title.getText());
                    int lineEndIndex = title.getLayout().getLineEnd(2);
                    String text = title.getText().subSequence(0, lineEndIndex-3)+"...";
                    title.setText(text);
                    Log.d("","NewText:"+text);
                }

            }
        });

How to rotate x-axis tick labels in Pandas barplot

You can use set_xticklabels()

ax.set_xticklabels(df['Names'], rotation=90, ha='right')

Create a .tar.bz2 file Linux

You are not indicating what to include in the archive.

Go one level outside your folder and try:

sudo tar -cvjSf folder.tar.bz2 folder

Or from the same folder try

sudo tar -cvjSf folder.tar.bz2 *

Cheers!

Find max and second max salary for a employee table MySQL

Try below Query, was working for me to find Nth highest number salary. Just replace your number with nth_No

Select DISTINCT TOP 1 salary
from 
(Select DISTINCT TOP *nth_No* salary
from Employee
ORDER BY Salary DESC)
Result
ORDER BY Salary

Change CSS class properties with jQuery

$(document)[0].styleSheets[styleSheetIndex].insertRule(rule, lineIndex);


styleSheetIndex is the index value that corresponds to which order you loaded the file in the <head> (e.g. 0 is the first file, 1 is the next, etc. if there is only one CSS file, use 0).

rule is a text string CSS rule. Like this: "body { display:none; }".

lineIndex is the line number in that file. To get the last line number, use $(document)[0].styleSheets[styleSheetIndex].cssRules.length. Just console.log that styleSheet object, it's got some interesting properties/methods.

Because CSS is a "cascade", whatever rule you're trying to insert for that selector you can just append to the bottom of the CSS file and it will overwrite anything that was styled at page load.

In some browsers, after manipulating the CSS file, you have to force CSS to "redraw" by calling some pointless method in DOM JS like document.offsetHeight (it's abstracted up as a DOM property, not method, so don't use "()") -- simply adding that after your CSSOM manipulation forces the page to redraw in older browsers.


So here's an example:

var stylesheet = $(document)[0].styleSheets[0]; stylesheet.insertRule('body { display:none; }', stylesheet.cssRules.length);

Singletons vs. Application Context in Android?

From the proverbial horse's mouth...

When developing your app, you may find it necessary to share data, context or services globally across your app. For example, if your app has session data, such as the currently logged-in user, you will likely want to expose this information. In Android, the pattern for solving this problem is to have your android.app.Application instance own all global data, and then treat your Application instance as a singleton with static accessors to the various data and services.

When writing an Android app, you're guaranteed to only have one instance of the android.app.Application class, and so it's safe (and recommended by Google Android team) to treat it as a singleton. That is, you can safely add a static getInstance() method to your Application implementation. Like so:

public class AndroidApplication extends Application {

    private static AndroidApplication sInstance;

    public static AndroidApplication getInstance(){
        return sInstance;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        sInstance = this;
    }
}

browser sessionStorage. share between tabs?

My solution to not having sessionStorage transferable over tabs was to create a localProfile and bang off this variable. If this variable is set but my sessionStorage variables arent go ahead and reinitialize them. When user logs out window closes destroy this localStorage variable

Recursively counting files in a Linux directory

This should work:

find DIR_NAME -type f | wc -l

Explanation:

  • -type f to include only files.
  • | (and not ¦) redirects find command's standard output to wc command's standard input.
  • wc (short for word count) counts newlines, words and bytes on its input (docs).
  • -l to count just newlines.

Notes:

  • Replace DIR_NAME with . to execute the command in the current folder.
  • You can also remove the -type f to include directories (and symlinks) in the count.
  • It's possible this command will overcount if filenames can contain newline characters.

Explanation of why your example does not work:

In the command you showed, you do not use the "Pipe" (|) to kind-of connect two commands, but the broken bar (¦) which the shell does not recognize as a command or something similar. That's why you get that error message.

add a string prefix to each value in a string column using Pandas

If you load you table file with dtype=str
or convert column type to string df['a'] = df['a'].astype(str)
then you can use such approach:

df['a']= 'col' + df['a'].str[:]

This approach allows prepend, append, and subset string of df.
Works on Pandas v0.23.4, v0.24.1. Don't know about earlier versions.

SQLAlchemy insert or update example

I try lots of ways and finally try this:

def db_persist(func):
    def persist(*args, **kwargs):
        func(*args, **kwargs)
        try:
            session.commit()
            logger.info("success calling db func: " + func.__name__)
            return True
        except SQLAlchemyError as e:
            logger.error(e.args)
            session.rollback()
            return False

    return persist

and :

@db_persist
def insert_or_update(table_object):
    return session.merge(table_object)

How can I hash a password in Java?

You can actually use a facility built in to the Java runtime to do this. The SunJCE in Java 6 supports PBKDF2, which is a good algorithm to use for password hashing.

byte[] salt = new byte[16];
random.nextBytes(salt);
KeySpec spec = new PBEKeySpec("password".toCharArray(), salt, 65536, 128);
SecretKeyFactory f = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
byte[] hash = f.generateSecret(spec).getEncoded();
Base64.Encoder enc = Base64.getEncoder();
System.out.printf("salt: %s%n", enc.encodeToString(salt));
System.out.printf("hash: %s%n", enc.encodeToString(hash));

Here's a utility class that you can use for PBKDF2 password authentication:

import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.KeySpec;
import java.util.Arrays;
import java.util.Base64;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;

/**
 * Hash passwords for storage, and test passwords against password tokens.
 * 
 * Instances of this class can be used concurrently by multiple threads.
 *  
 * @author erickson
 * @see <a href="http://stackoverflow.com/a/2861125/3474">StackOverflow</a>
 */
public final class PasswordAuthentication
{

  /**
   * Each token produced by this class uses this identifier as a prefix.
   */
  public static final String ID = "$31$";

  /**
   * The minimum recommended cost, used by default
   */
  public static final int DEFAULT_COST = 16;

  private static final String ALGORITHM = "PBKDF2WithHmacSHA1";

  private static final int SIZE = 128;

  private static final Pattern layout = Pattern.compile("\\$31\\$(\\d\\d?)\\$(.{43})");

  private final SecureRandom random;

  private final int cost;

  public PasswordAuthentication()
  {
    this(DEFAULT_COST);
  }

  /**
   * Create a password manager with a specified cost
   * 
   * @param cost the exponential computational cost of hashing a password, 0 to 30
   */
  public PasswordAuthentication(int cost)
  {
    iterations(cost); /* Validate cost */
    this.cost = cost;
    this.random = new SecureRandom();
  }

  private static int iterations(int cost)
  {
    if ((cost < 0) || (cost > 30))
      throw new IllegalArgumentException("cost: " + cost);
    return 1 << cost;
  }

  /**
   * Hash a password for storage.
   * 
   * @return a secure authentication token to be stored for later authentication 
   */
  public String hash(char[] password)
  {
    byte[] salt = new byte[SIZE / 8];
    random.nextBytes(salt);
    byte[] dk = pbkdf2(password, salt, 1 << cost);
    byte[] hash = new byte[salt.length + dk.length];
    System.arraycopy(salt, 0, hash, 0, salt.length);
    System.arraycopy(dk, 0, hash, salt.length, dk.length);
    Base64.Encoder enc = Base64.getUrlEncoder().withoutPadding();
    return ID + cost + '$' + enc.encodeToString(hash);
  }

  /**
   * Authenticate with a password and a stored password token.
   * 
   * @return true if the password and token match
   */
  public boolean authenticate(char[] password, String token)
  {
    Matcher m = layout.matcher(token);
    if (!m.matches())
      throw new IllegalArgumentException("Invalid token format");
    int iterations = iterations(Integer.parseInt(m.group(1)));
    byte[] hash = Base64.getUrlDecoder().decode(m.group(2));
    byte[] salt = Arrays.copyOfRange(hash, 0, SIZE / 8);
    byte[] check = pbkdf2(password, salt, iterations);
    int zero = 0;
    for (int idx = 0; idx < check.length; ++idx)
      zero |= hash[salt.length + idx] ^ check[idx];
    return zero == 0;
  }

  private static byte[] pbkdf2(char[] password, byte[] salt, int iterations)
  {
    KeySpec spec = new PBEKeySpec(password, salt, iterations, SIZE);
    try {
      SecretKeyFactory f = SecretKeyFactory.getInstance(ALGORITHM);
      return f.generateSecret(spec).getEncoded();
    }
    catch (NoSuchAlgorithmException ex) {
      throw new IllegalStateException("Missing algorithm: " + ALGORITHM, ex);
    }
    catch (InvalidKeySpecException ex) {
      throw new IllegalStateException("Invalid SecretKeyFactory", ex);
    }
  }

  /**
   * Hash a password in an immutable {@code String}. 
   * 
   * <p>Passwords should be stored in a {@code char[]} so that it can be filled 
   * with zeros after use instead of lingering on the heap and elsewhere.
   * 
   * @deprecated Use {@link #hash(char[])} instead
   */
  @Deprecated
  public String hash(String password)
  {
    return hash(password.toCharArray());
  }

  /**
   * Authenticate with a password in an immutable {@code String} and a stored 
   * password token. 
   * 
   * @deprecated Use {@link #authenticate(char[],String)} instead.
   * @see #hash(String)
   */
  @Deprecated
  public boolean authenticate(String password, String token)
  {
    return authenticate(password.toCharArray(), token);
  }

}

Create sequence of repeated values, in sequence?

For your example, Dirk's answer is perfect. If you instead had a data frame and wanted to add that sort of sequence as a column, you could also use group from groupdata2 (disclaimer: my package) to greedily divide the datapoints into groups.

# Attach groupdata2
library(groupdata2)
# Create a random data frame
df <- data.frame("x" = rnorm(27))
# Create groups with 5 members each (except last group)
group(df, n = 5, method = "greedy")
         x .groups
     <dbl> <fct>  
 1  0.891  1      
 2 -1.13   1      
 3 -0.500  1      
 4 -1.12   1      
 5 -0.0187 1      
 6  0.420  2      
 7 -0.449  2      
 8  0.365  2      
 9  0.526  2      
10  0.466  2      
# … with 17 more rows

There's a whole range of methods for creating this kind of grouping factor. E.g. by number of groups, a list of group sizes, or by having groups start when the value in some column differs from the value in the previous row (e.g. if a column is c("x","x","y","z","z") the grouping factor would be c(1,1,2,3,3).

How to install Java SDK on CentOS?

To install OpenJDK 8 JRE using yum with non root user, run this command:

sudo yum install java-1.8.0-openjdk

to verify java -version

Ruby: Easiest Way to Filter Hash Keys?

In Ruby, the Hash#select is a right option. If you work with Rails, you can use Hash#slice and Hash#slice!. e.g. (rails 3.2.13)

h1 = {:a => 1, :b => 2, :c => 3, :d => 4}

h1.slice(:a, :b)         # return {:a=>1, :b=>2}, but h1 is not changed

h2 = h1.slice!(:a, :b)   # h1 = {:a=>1, :b=>2}, h2 = {:c => 3, :d => 4}

Can someone explain the dollar sign in Javascript?

"Using the dollar sign is not very common in JavaScript, but professional programmers often use it as an alias for the main function in a JavaScript library.

In the JavaScript library jQuery, for instance, the main function $ is used to select HTML elements. In jQuery $("p"); means "select all p elements". "

via https://www.w3schools.com/js/js_variables.asp

Objective-C : BOOL vs bool

I go against convention here. I don't like typedef's to base types. I think it's a useless indirection that removes value.

  1. When I see the base type in your source I will instantly understand it. If it's a typedef I have to look it up to see what I'm really dealing with.
  2. When porting to another compiler or adding another library their set of typedefs may conflict and cause issues that are difficult to debug. I just got done dealing with this in fact. In one library boolean was typedef'ed to int, and in mingw/gcc it's typedef'ed to a char.

Adding a Time to a DateTime in C#

You can use the DateTime.Add() method to add the time to the date.

DateTime date = DateTime.Now;
TimeSpan time = new TimeSpan(36, 0, 0, 0);
DateTime combined = date.Add(time);
Console.WriteLine("{0:dddd}", combined);

You can also create your timespan by parsing a String, if that is what you need to do.

Alternatively, you could look at using other controls. You didn't mention if you are using winforms, wpf or asp.net, but there are various date and time picker controls that support selection of both date and time.

How can I unstage my files again after making a local commit?

Use:

git reset HEAD^

That does a "mixed" reset by default, which will do what you asked; put foo.java in unstaged, removing the most recent commit.

What is the standard Python docstring format?

It's Python; anything goes. Consider how to publish your documentation. Docstrings are invisible except to readers of your source code.

People really like to browse and search documentation on the web. To achieve that, use the documentation tool Sphinx. It's the de-facto standard for documenting Python projects. The product is beautiful - take a look at https://python-guide.readthedocs.org/en/latest/ . The website Read the Docs will host your docs for free.

More than 1 row in <Input type="textarea" />

As said by Sparky in comments on many answers to this question, there is NOT any textarea value for the type attribute of the input tag.

On other terms, the following markup is not valid :

<input type="textarea" />

And the browser replaces it by the default :

<input type="text" />

To define a multi-lines text input, use :

<textarea></textarea>

See the textarea element documentation for more details.

How to stop event bubbling on checkbox click

In angularjs this should works:

event.preventDefault(); 
event.stopPropagation();

Fake "click" to activate an onclick method

Once you have selected an element you can call click()

document.getElementById('link').click();

see: https://developer.mozilla.org/En/DOM/Element.click

I don't remember if this works on IE, but it should. I don't have a windows machine nearby.

What's the scope of a variable initialized in an if statement?

Yes, they're in the same "local scope", and actually code like this is common in Python:

if condition:
  x = 'something'
else:
  x = 'something else'

use(x)

Note that x isn't declared or initialized before the condition, like it would be in C or Java, for example.

In other words, Python does not have block-level scopes. Be careful, though, with examples such as

if False:
    x = 3
print(x)

which would clearly raise a NameError exception.

Best way to reset an Oracle sequence to the next value in an existing column?

If you can count on having a period of time where the table is in a stable state with no new inserts going on, this should do it (untested):

DECLARE
  last_used  NUMBER;
  curr_seq   NUMBER;
BEGIN
  SELECT MAX(pk_val) INTO last_used FROM your_table;

  LOOP
    SELECT your_seq.NEXTVAL INTO curr_seq FROM dual;
    IF curr_seq >= last_used THEN EXIT;
    END IF;
  END LOOP;
END;

This enables you to get the sequence back in sync with the table, without dropping/recreating/re-granting the sequence. It also uses no DDL, so no implicit commits are performed. Of course, you're going to have to hunt down and slap the folks who insist on not using the sequence to populate the column...

How to increase the max upload file size in ASP.NET?

I have a blog post on how to increase the file size for asp upload control.

From the post:

By default, the FileUpload control allows a maximum of 4MB file to be uploaded and the execution timeout is 110 seconds. These properties can be changed from within the web.config file’s httpRuntime section. The maxRequestLength property determines the maximum file size that can be uploaded. The executionTimeout property determines the maximum time for execution.

Embedding Windows Media Player for all browsers

December 2020 :

  • We have now Firefox 83.0 and Chrome 87.0
  • Internet Explorer is dead, it has been replaced by the new Chromium-based Edge 87.0
  • Silverlight is dead
  • Windows XP is dead
  • WMV is not a standard : https://www.w3schools.com/html/html_media.asp

To answer the question :

  • You have to convert your WMV file to another format : MP4, WebM or Ogg video.
  • Then embed it in your page with the HTML 5 <video> element.

I think this question should be closed.

How can I get a List from some class properties with Java 8 Stream?

You can use map :

List<String> names = 
    personList.stream()
              .map(Person::getName)
              .collect(Collectors.toList());

EDIT :

In order to combine the Lists of friend names, you need to use flatMap :

List<String> friendNames = 
    personList.stream()
              .flatMap(e->e.getFriends().stream())
              .collect(Collectors.toList());

Create a custom event in Java

What you want is an implementation of the observer pattern. You can do it yourself completely, or use java classes like java.util.Observer and java.util.Observable

DLL and LIB files - what and why?

One other difference lies in the performance.

As the DLL is loaded at runtime by the .exe(s), the .exe(s) and the DLL work with shared memory concept and hence the performance is low relatively to static linking.

On the other hand, a .lib is code that is linked statically at compile time into every process that requests. Hence the .exe(s) will have single memory, thus increasing the performance of the process.

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

ord() will not work because your end string is two characters long.

Returns the ASCII value of the first character of string.

Watch it break.

From my testing, you need to check that the end string doesn't get "stepped over". The perl-style character incrementation is a cool method, but it is a single-stepping method. For this reason, an inner loop helps it along when necessary. This is actually not a bother, in fact, it is useful because we need to check if the loop(s) should be broken on each single step.

Code: (Demo)

function excelCols($letter,$end,$step=1){  // function doesn't check that $end is "later" than $letter
    if($step==0)return [];  // prevent infinite loop
    do{
        $letters[]=$letter;  // store letter
        for($x=0; $x<$step; ++$x){  // increment in accordance with $step declaration
            if($letter===$end)break(2);  // break if end is "stepped on"
            ++$letter;
        }
    }while(true);
    return $letters;    
}
echo implode(' ',excelCols('A','JJ',4));
echo "\n --- \n";
echo implode(' ',excelCols('A','BB',3));
echo "\n --- \n";
echo implode(' ',excelCols('A','ZZ',1));
echo "\n --- \n";
echo implode(' ',excelCols('A','ZZ',3));

Output:

A E I M Q U Y AC AG AK AO AS AW BA BE BI BM BQ BU BY CC CG CK CO CS CW DA DE DI DM DQ DU DY EC EG EK EO ES EW FA FE FI FM FQ FU FY GC GG GK GO GS GW HA HE HI HM HQ HU HY IC IG IK IO IS IW JA JE JI
 --- 
A D G J M P S V Y AB AE AH AK AN AQ AT AW AZ
 --- 
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z AA AB AC AD AE AF AG AH AI AJ AK AL AM AN AO AP AQ AR AS AT AU AV AW AX AY AZ BA BB BC BD BE BF BG BH BI BJ BK BL BM BN BO BP BQ BR BS BT BU BV BW BX BY BZ CA CB CC CD CE CF CG CH CI CJ CK CL CM CN CO CP CQ CR CS CT CU CV CW CX CY CZ DA DB DC DD DE DF DG DH DI DJ DK DL DM DN DO DP DQ DR DS DT DU DV DW DX DY DZ EA EB EC ED EE EF EG EH EI EJ EK EL EM EN EO EP EQ ER ES ET EU EV EW EX EY EZ FA FB FC FD FE FF FG FH FI FJ FK FL FM FN FO FP FQ FR FS FT FU FV FW FX FY FZ GA GB GC GD GE GF GG GH GI GJ GK GL GM GN GO GP GQ GR GS GT GU GV GW GX GY GZ HA HB HC HD HE HF HG HH HI HJ HK HL HM HN HO HP HQ HR HS HT HU HV HW HX HY HZ IA IB IC ID IE IF IG IH II IJ IK IL IM IN IO IP IQ IR IS IT IU IV IW IX IY IZ JA JB JC JD JE JF JG JH JI JJ JK JL JM JN JO JP JQ JR JS JT JU JV JW JX JY JZ KA KB KC KD KE KF KG KH KI KJ KK KL KM KN KO KP KQ KR KS KT KU KV KW KX KY KZ LA LB LC LD LE LF LG LH LI LJ LK LL LM LN LO LP LQ LR LS LT LU LV LW LX LY LZ MA MB MC MD ME MF MG MH MI MJ MK ML MM MN MO MP MQ MR MS MT MU MV MW MX MY MZ NA NB NC ND NE NF NG NH NI NJ NK NL NM NN NO NP NQ NR NS NT NU NV NW NX NY NZ OA OB OC OD OE OF OG OH OI OJ OK OL OM ON OO OP OQ OR OS OT OU OV OW OX OY OZ PA PB PC PD PE PF PG PH PI PJ PK PL PM PN PO PP PQ PR PS PT PU PV PW PX PY PZ QA QB QC QD QE QF QG QH QI QJ QK QL QM QN QO QP QQ QR QS QT QU QV QW QX QY QZ RA RB RC RD RE RF RG RH RI RJ RK RL RM RN RO RP RQ RR RS RT RU RV RW RX RY RZ SA SB SC SD SE SF SG SH SI SJ SK SL SM SN SO SP SQ SR SS ST SU SV SW SX SY SZ TA TB TC TD TE TF TG TH TI TJ TK TL TM TN TO TP TQ TR TS TT TU TV TW TX TY TZ UA UB UC UD UE UF UG UH UI UJ UK UL UM UN UO UP UQ UR US UT UU UV UW UX UY UZ VA VB VC VD VE VF VG VH VI VJ VK VL VM VN VO VP VQ VR VS VT VU VV VW VX VY VZ WA WB WC WD WE WF WG WH WI WJ WK WL WM WN WO WP WQ WR WS WT WU WV WW WX WY WZ XA XB XC XD XE XF XG XH XI XJ XK XL XM XN XO XP XQ XR XS XT XU XV XW XX XY XZ YA YB YC YD YE YF YG YH YI YJ YK YL YM YN YO YP YQ YR YS YT YU YV YW YX YY YZ ZA ZB ZC ZD ZE ZF ZG ZH ZI ZJ ZK ZL ZM ZN ZO ZP ZQ ZR ZS ZT ZU ZV ZW ZX ZY ZZ
 --- 
A D G J M P S V Y AB AE AH AK AN AQ AT AW AZ BC BF BI BL BO BR BU BX CA CD CG CJ CM CP CS CV CY DB DE DH DK DN DQ DT DW DZ EC EF EI EL EO ER EU EX FA FD FG FJ FM FP FS FV FY GB GE GH GK GN GQ GT GW GZ HC HF HI HL HO HR HU HX IA ID IG IJ IM IP IS IV IY JB JE JH JK JN JQ JT JW JZ KC KF KI KL KO KR KU KX LA LD LG LJ LM LP LS LV LY MB ME MH MK MN MQ MT MW MZ NC NF NI NL NO NR NU NX OA OD OG OJ OM OP OS OV OY PB PE PH PK PN PQ PT PW PZ QC QF QI QL QO QR QU QX RA RD RG RJ RM RP RS RV RY SB SE SH SK SN SQ ST SW SZ TC TF TI TL TO TR TU TX UA UD UG UJ UM UP US UV UY VB VE VH VK VN VQ VT VW VZ WC WF WI WL WO WR WU WX XA XD XG XJ XM XP XS XV XY YB YE YH YK YN YQ YT YW YZ ZC ZF ZI ZL ZO ZR ZU ZX

Here is an array-functions approach:

Code: (Demo)

$start='C';
$end='DD';
$step=4;

// generate and store more than we need (this is an obvious method disadvantage)
$result=$array=range('A','Z',1);  // store A - Z as $array and $result
foreach($array as $a){
    foreach($array as $b){
        $result[]="$a$b";  // store double letter combinations
        if(in_array($end,$result)){break(2);}  // stop asap
    }
}
//echo implode(' ',$result),"\n\n";

// slice away from the front of the array
$result=array_slice($result,array_search($start,$result));  // reindex keys
//echo implode(' ',$result),"\n\n";

 // punch out elements that are not "stepped on"
$result=array_filter($result,function($k)use($step){return $k%$step==0;},ARRAY_FILTER_USE_KEY); // use modulo

// result is ready
echo implode(' ',$result);

Output:

C G K O S W AA AE AI AM AQ AU AY BC BG BK BO BS BW CA CE CI CM CQ CU CY DC

How to get memory available or used in C#

Look here for details.

private PerformanceCounter cpuCounter;
private PerformanceCounter ramCounter;
public Form1()
{
    InitializeComponent();
    InitialiseCPUCounter();
    InitializeRAMCounter();
    updateTimer.Start();
}

private void updateTimer_Tick(object sender, EventArgs e)
{
    this.textBox1.Text = "CPU Usage: " +
    Convert.ToInt32(cpuCounter.NextValue()).ToString() +
    "%";

    this.textBox2.Text = Convert.ToInt32(ramCounter.NextValue()).ToString()+"Mb";
}

private void Form1_Load(object sender, EventArgs e)
{
}

private void InitialiseCPUCounter()
{
    cpuCounter = new PerformanceCounter(
    "Processor",
    "% Processor Time",
    "_Total",
    true
    );
}

private void InitializeRAMCounter()
{
    ramCounter = new PerformanceCounter("Memory", "Available MBytes", true);

}

If you get value as 0 it need to call NextValue() twice. Then it gives the actual value of CPU usage. See more details here.

Batch files - number of command line arguments

Avoids using either shift or a for cycle at the cost of size and readability.

@echo off
setlocal EnableExtensions EnableDelayedExpansion
set /a arg_idx=1
set "curr_arg_value="
:loop1
if !arg_idx! GTR 9 goto :done
set curr_arg_label=%%!arg_idx!
call :get_value curr_arg_value !curr_arg_label!
if defined curr_arg_value (
  echo/!curr_arg_label!: !curr_arg_value!
  set /a arg_idx+=1
  goto :loop1
)
:done
set /a cnt=!arg_idx!-1
echo/argument count: !cnt!
endlocal
goto :eof

:get_value
(
  set %1=%2
)

Output:

count_cmdline_args.bat testing more_testing arg3 another_arg

%1: testing
%2: more_testing
%3: arg3
%4: another_arg
argument count: 4

EDIT: The "trick" used here involves:

  1. Constructing a string that represents a currently evaluated command-line argument variable (i.e. "%1", "%2" etc.) using a string that contains a percent character (%%) and a counter variable arg_idx on each loop iteration.

  2. Storing that string into a variable curr_arg_label.

  3. Passing both that string (!curr_arg_label!) and a return variable's name (curr_arg_value) to a primitive subprogram get_value.

  4. In the subprogram its first argument's (%1) value is used on the left side of assignment (set) and its second argument's (%2) value on the right. However, when the second subprogram's argument is passed it is resolved into value of the main program's command-line argument by the command interpreter. That is, what is passed is not, for example, "%4" but whatever value the fourth command-line argument variable holds ("another_arg" in the sample usage).

  5. Then the variable given to the subprogram as return variable (curr_arg_value) is tested for being undefined, which would happen if currently evaluated command-line argument is absent. Initially this was a comparison of the return variable's value wrapped in square brackets to empty square brackets (which is the only way I know of testing program or subprogram arguments which may contain quotes and was an overlooked leftover from trial-and-error phase) but was since fixed to how it is now.

Shortest way to check for null and assign another value if not

I use extention method SelfChk

static class MyExt {
//Self Check 
 public static void SC(this string you,ref string me)
    {
        me = me ?? you;
    }
}

Then use like

string a = null;
"A".SC(ref a);

Get domain name from given url

try this one : java.net.URL;
JOptionPane.showMessageDialog(null, getDomainName(new URL("https://en.wikipedia.org/wiki/List_of_Internet_top-level_domains")));

public String getDomainName(URL url){
String strDomain;
String[] strhost = url.getHost().split(Pattern.quote("."));
String[] strTLD = {"com","org","net","int","edu","gov","mil","arpa"};

if(Arrays.asList(strTLD).indexOf(strhost[strhost.length-1])>=0)
    strDomain = strhost[strhost.length-2]+"."+strhost[strhost.length-1];
else if(strhost.length>2)
    strDomain = strhost[strhost.length-3]+"."+strhost[strhost.length-2]+"."+strhost[strhost.length-1];
else
    strDomain = strhost[strhost.length-2]+"."+strhost[strhost.length-1];
return strDomain;}

Maven: add a dependency to a jar by relative path

Using the system scope. ${basedir} is the directory of your pom.

<dependency>
    <artifactId>..</artifactId>
    <groupId>..</groupId>
    <scope>system</scope>
    <systemPath>${basedir}/lib/dependency.jar</systemPath>
</dependency>

However it is advisable that you install your jar in the repository, and not commit it to the SCM - after all that's what maven tries to eliminate.

How can I conditionally import an ES6 module?

Looks like the answer is that, as of now, you can't.

http://exploringjs.com/es6/ch_modules.html#sec_module-loader-api

I think the intent is to enable static analysis as much as possible, and conditionally imported modules break that. Also worth mentioning -- I'm using Babel, and I'm guessing that System is not supported by Babel because the module loader API didn't become an ES6 standard.

How to filter in NaN (pandas)?

Pandas uses numpy's NaN value. Use numpy.isnan to obtain a Boolean vector from a pandas series.

Exception 'open failed: EACCES (Permission denied)' on Android

after adding permission solved my problem

<uses-permission android:name="android.permission.INTERNET"/>

Reverse order of foreach list items

If you don't mind destroying the array (or a temp copy of it) you can do:

$stack = array("orange", "banana", "apple", "raspberry");

while ($fruit = array_pop($stack)){
    echo $fruit . "\n<br>"; 
}

produces:

raspberry 
apple 
banana 
orange 

I think this solution reads cleaner than fiddling with an index and you are less likely to introduce index handling mistakes, but the problem with it is that your code will likely take slightly longer to run if you have to create a temporary copy of the array first. Fiddling with an index is likely to run faster, and it may also come in handy if you actually need to reference the index, as in:

$stack = array("orange", "banana", "apple", "raspberry");
$index = count($stack) - 1;
while($index > -1){
    echo $stack[$index] ." is in position ". $index . "\n<br>";
    $index--;
} 

But as you can see, you have to be very careful with the index...

Cannot download Docker images behind a proxy

To configure Docker to work with a proxy you need to add the HTTPS_PROXY / HTTP_PROXY environment variable to the Docker sysconfig file (/etc/sysconfig/docker).

Depending on if you use init.d or the services tool you need to add the "export" statement (due to Debian Bug report logs - #767441. Examples in /etc/default/docker are misleading regarding the supported syntax):

HTTPS_PROXY="https://<user>:<password>@<proxy-host>:<proxy-port>"
HTTP_PROXY="https://<user>:<password>@<proxy-host>:<proxy-port>"
export HTTP_PROXY="https://<user>:<password>@<proxy-host>:<proxy-port>"
export HTTPS_PROXY="https://<user>:<password>@<proxy-host>:<proxy-port>"

The Docker repository (Docker Hub) only supports HTTPS. To get Docker working with SSL intercepting proxies you have to add the proxy root certificate to the systems trust store.

For CentOS, copy the file to /etc/pki/ca-trust/source/anchors/ and update the CA trust store and restart the Docker service.

If your proxy uses NTLMv2 authentication - you need to use intermediate proxies like Cntlm to bridge the authentication. This blog post explains it in detail.

Can you recommend a free light-weight MySQL GUI for Linux?

i suggest using phpmyadmin

it’s definitely the best free tool out there and it works on every system with php+mysql

PreparedStatement with list of parameters in a IN clause

Currently, MySQL doesn't allow to set multiple values in one method call. So you have to have it under your own control. I usually create one prepared statement for predefined number of parameters, then I add as many batches as I need.

    int paramSizeInClause = 10; // required to be greater than 0!
    String color = "FF0000"; // red
    String name = "Nathan"; 
    Date now = new Date();
    String[] ids = "15,21,45,48,77,145,158,321,325,326,327,328,329,330,331,332,333,334,335,336,337,338,339,340,341,342,343,344,345,346,347,348,349,350,351,358,1284,1587".split(",");

    // Build sql query 
    StringBuilder sql = new StringBuilder();
    sql.append("UPDATE book SET color=? update_by=?, update_date=? WHERE book_id in (");
    // number of max params in IN clause can be modified 
    // to get most efficient combination of number of batches
    // and number of parameters in each batch
    for (int n = 0; n < paramSizeInClause; n++) {
        sql.append("?,");
    }
    if (sql.length() > 0) {
        sql.deleteCharAt(sql.lastIndexOf(","));
    }
    sql.append(")");

    PreparedStatement pstm = null;
    try {
        pstm = connection.prepareStatement(sql.toString());
        int totalIdsToProcess = ids.length;
        int batchLoops = totalIdsToProcess / paramSizeInClause + (totalIdsToProcess % paramSizeInClause > 0 ? 1 : 0);
        for (int l = 0; l < batchLoops; l++) {
            int i = 1;
            pstm.setString(i++, color);
            pstm.setString(i++, name);
            pstm.setTimestamp(i++, new Timestamp(now.getTime()));
            for (int count = 0; count < paramSizeInClause; count++) {
                int param = (l * paramSizeInClause + count);
                if (param < totalIdsToProcess) {
                    pstm.setString(i++, ids[param]);
                } else {
                    pstm.setNull(i++, Types.VARCHAR);
                }
            }
            pstm.addBatch();
        }
    } catch (SQLException e) {
    } finally {
        //close statement(s)
    }

If you don't like to set NULL when no more parameters left, you can modify code to build two queries and two prepared statements. First one is the same, but second statement for the remainder (modulus). In this particular example that would be one query for 10 params and one for 8 params. You will have to add 3 batches for the first query (first 30 params) then one batch for the second query (8 params).

How to download Google Play Services in an Android emulator?

To the latest setup and information if you have installed the Android Studio (i.e. 1.5) and trying to target SDK 4.0 then you may not be able to locate and setup the and AVD Emulator with SDK-vX.XX (with Google API's).

See following steps in order to download the required library and start with that. AVD Emulator setup -setting up Emulator for SDK4.0 with GoogleAPI so Map application can work- In Android Studio

But unfortunately above method did not work well on my side. And was not able to created Emulator with API Level 17 (SDK 4.2). So I followed this post that worked on my side well. The reason seems that the Android Studio Emulator creation window has limited options/features.

Google Play Services in emulator, implementing Google Plus login button etc

Date ticks and rotation in matplotlib

Simply use

ax.set_xticklabels(label_list, rotation=45)

Is Laravel really this slow?

I faced 1.40s while working with a pure laravel in development area!

the problem was using: php artisan serve to run the webserver

when I used apache webserver (or NGINX) instead for the same code I got it down to 153ms

Search and replace part of string in database

update VersionedFields
set Value = replace(replace(value,'<iframe','<a>iframe'), '> </iframe>','</a>')

and you do it in a single pass.

Android view layout_width - how to change programmatically?

try using

View view_instance = (View)findViewById(R.id.nutrition_bar_filled);
view_instance.setWidth(10);

use Layoutparams to do so where you can set width and height like below.

LayoutParams lp = new LayoutParams(10,LayoutParams.wrap_content);
View_instance.setLayoutParams(lp);

ImportError: No Module Named bs4 (BeautifulSoup)

pip3 install BeautifulSoup4

Try this. It works for me. The reason is well explained here..

How can I get customer details from an order in WooCommerce?

Although, this may not be advisable.

If you want to get customer details, even when the user doesn’t create an account, but only makes an order, you could just query it, directly from the database.

Although, there may be performance issues, querying directly. But this surely works 100%.

You can search by post_id and meta_keys.

 global $wpdb; // Get the global $wpdb
 $order_id = {Your Order Id}

 $table = $wpdb->prefix . 'postmeta';
 $sql = 'SELECT * FROM `'. $table . '` WHERE post_id = '. $order_id;

        $result = $wpdb->get_results($sql);
        foreach($result as $res) {
            if( $res->meta_key == 'billing_phone'){
                   $phone = $res->meta_value;      // get billing phone
            }
            if( $res->meta_key == 'billing_first_name'){
                   $firstname = $res->meta_value;   // get billing first name
            }

            // You can get other values
            // billing_last_name
            // billing_email
            // billing_country
            // billing_address_1
            // billing_address_2
            // billing_postcode
            // billing_state

            // customer_ip_address
            // customer_user_agent

            // order_currency
            // order_key
            // order_total
            // order_shipping_tax
            // order_tax

            // payment_method_title
            // payment_method

            // shipping_first_name
            // shipping_last_name
            // shipping_postcode
            // shipping_state
            // shipping_city
            // shipping_address_1
            // shipping_address_2
            // shipping_company
            // shipping_country
        }

Cannot resolve symbol 'AppCompatActivity'

After trying literally every solution, I realised that the project I had been working on was previously using the latest Android Studio which was 3.2 at the time and the current pc I was using was running 2.2 after updating android studio this seemed to fix the issue completely for me.

Solution: Android Studio -> Check For Updates and then install latest build

How to declare variable and use it in the same Oracle SQL script?

Here's your answer:

DEFINE num := 1;       -- The semi-colon is needed for default values.
SELECT &num FROM dual;

Freezing Row 1 and Column A at the same time

Select cell B2 and click "Freeze Panes" this will freeze Row 1 and Column A.

For future reference, selecting Freeze Panes in Excel will freeze the rows above your selected cell and the columns to the left of your selected cell. For example, to freeze rows 1 and 2 and column A, you could select cell B3 and click Freeze Panes. You could also freeze columns A and B and row 1, by selecting cell C2 and clicking "Freeze Panes".

Visual Aid on Freeze Panes in Excel 2010 - http://www.dummies.com/how-to/content/how-to-freeze-panes-in-an-excel-2010-worksheet.html

Microsoft Reference Guide (More Complicated, but resourceful none the less) - http://office.microsoft.com/en-us/excel-help/freeze-or-lock-rows-and-columns-HP010342542.aspx

Convert Set to List without creating new List

Use constructor to convert it:

List<?> list = new ArrayList<?>(set);

Error: [$resource:badcfg] Error in resource configuration. Expected response to contain an array but got an object?

Also, if your service is sending an object instead of an array add isArray:false to its declaration.

'query': {method: 'GET', isArray: false }

How to filter by object property in angularJS

You simply have to use the filter filter (see the documentation) :

<div id="totalPos">{{(tweets | filter:{polarity:'Positive'}).length}}</div>
<div id="totalNeut">{{(tweets | filter:{polarity:'Neutral'}).length}}</div>
<div id="totalNeg">{{(tweets | filter:{polarity:'Negative'}).length}}</div>

Fiddle

How to set cellpadding and cellspacing in table with CSS?

Use padding on the cells and border-spacing on the table. The former will give you cellpadding while the latter will give you cellspacing.

table { border-spacing: 5px; } /* cellspacing */

th, td { padding: 5px; } /* cellpadding */

jsFiddle Demo

Setting timezone in Python

It's not an answer, but...

To get datetime components individually, better use datetime.timetuple:

time = datetime.now()
time.timetuple()
#-> time.struct_time(
#    tm_year=2014, tm_mon=9, tm_mday=7, 
#    tm_hour=2, tm_min=38, tm_sec=5, 
#    tm_wday=6, tm_yday=250, tm_isdst=-1
#)

It's now easy to get the parts:

ts = time.timetuple()
ts.tm_year
ts.tm_mon
ts.tm_mday
ts.tm_hour
ts.tm_min
ts.tm_sec

Java maximum memory on Windows XP

First, using a page-file when you have 4 GB of RAM is useless. Windows can't access more than 4GB (actually, less because of memory holes) so the page file is not used.

Second, the address space is split in 2, half for kernel, half for user mode. If you need more RAM for your applications use the /3GB option in boot.ini (make sure java.exe is marked as "large address aware" (google for more info).

Third, I think you can't allocate the full 2 GB of address space because java wastes some memory internally (for threads, JIT compiler, VM initialization, etc). Use the /3GB switch for more.

psql: command not found Mac

You have got the PATH slightly wrong. You need the PATH to "the containing directory", not the actual executable itself.

Your PATH should be set like this:

export PATH=/Library/PostgreSQL/9.5/bin:$PATH

without the extra sql part in it. Also, you must remove the spaces around the equals sign.

Keywords: Postgresql, PATH, macOS, OSX, psql

Using scp to copy a file to Amazon EC2 instance?

I had exactly same problem, my solution was to

scp -i /path/pem -r /path/file/ ec2-user@public aws dns name: (leave it blank here)

once you done this part, get into ssh server and mv file to desired location

Assign format of DateTime with data annotations?

If your data field is already a DateTime datatype, you don't need to use [DataType(DataType.Date)] for the annotation; just use:

[DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:MM/dd/yyyy}")]

on the jQuery, use datepicker for you calendar

    $(document).ready(function () {
        $('#StartDate').datepicker();
    });

on your HTML, use EditorFor helper:

    @Html.EditorFor(model => model.StartDate)

Python convert decimal to hex

If you want to code this yourself instead of using the built-in function hex(), you can simply do the recursive call before you print the current digit:

def ChangeHex(n):
    if (n < 0):
        print(0)
    elif (n<=1):
        print n,
    else:
        ChangeHex( n / 16 )
        x =(n%16)
        if (x < 10):
            print(x), 
        if (x == 10):
            print("A"),
        if (x == 11):
            print("B"),
        if (x == 12):
            print("C"),
        if (x == 13):
            print("D"),
        if (x == 14):
            print("E"),
        if (x == 15):
            print ("F"),

How to get the element clicked (for the whole document)?

You need to use the event.target which is the element which originally triggered the event. The this in your example code refers to document.

In jQuery, that's...

$(document).click(function(event) {
    var text = $(event.target).text();
});

Without jQuery...

document.addEventListener('click', function(e) {
    e = e || window.event;
    var target = e.target || e.srcElement,
        text = target.textContent || target.innerText;   
}, false);

Also, ensure if you need to support < IE9 that you use attachEvent() instead of addEventListener().

Explicit Return Type of Lambda

You can have more than one statement when still return:

[]() -> your_type {return (
        your_statement,
        even_more_statement = just_add_comma,
        return_value);}

http://www.cplusplus.com/doc/tutorial/operators/#comma

How do I use Assert to verify that an exception has been thrown?

If you're using MSTest, which originally didn't have an ExpectedException attribute, you could do this:

try 
{
    SomeExceptionThrowingMethod()
    Assert.Fail("no exception thrown");
}
catch (Exception ex)
{
    Assert.IsTrue(ex is SpecificExceptionType);
}

How can I read an input string of unknown length?

i also have a solution with standard inputs and outputs

#include<stdio.h>
#include<malloc.h>
int main()
{
    char *str,ch;
    int size=10,len=0;
    str=realloc(NULL,sizeof(char)*size);
    if(!str)return str;
    while(EOF!=scanf("%c",&ch) && ch!="\n")
    {
        str[len++]=ch;
        if(len==size)
        {
            str = realloc(str,sizeof(char)*(size+=10));
            if(!str)return str;
        }
    }
    str[len++]='\0';
    printf("%s\n",str);
    free(str);
}

How to print VARCHAR(MAX) using Print Statement?

My PrintMax version for prevent bad line breaks on output:


    CREATE PROCEDURE [dbo].[PrintMax](@iInput NVARCHAR(MAX))
    AS
    BEGIN
      Declare @i int;
      Declare @NEWLINE char(1) = CHAR(13) + CHAR(10);
      While LEN(@iInput)>0 BEGIN
        Set @i = CHARINDEX(@NEWLINE, @iInput)
        if @i>8000 OR @i=0 Set @i=8000
        Print SUBSTRING(@iInput, 0, @i)
        Set @iInput = SUBSTRING(@iInput, @i+1, LEN(@iInput))
      END
    END

Resource interpreted as stylesheet but transferred with MIME type text/html (seems not related with web server)

Using Angular?

This is a very important caveat to remember.

The base tag needs to not only be in the head but in the right location.

I had my base tag in the wrong place in the head, it should come before any tags with url requests. Basically placing it as the second tag underneath the title solved it for me.

<base href="/">

I wrote a little post on it here

How can I customize the tab-to-space conversion factor?

If the accepted answer on this post doesn't work, give this a try:

I had EditorConfig for Visual Studio Code installed in my editor, and it kept overriding my user settings which were set to indent files using spaces. Every time I switched between editor tabs, my file would automatically get indented with tabs even if I had converted indentation to spaces!!!

Right after I uninstalled this extension, indentation no longer changes between switching editor tabs, and I can work more comfortably rather than having to manually convert tabs to spaces every time I switch files - that is painful.

Image encryption/decryption using AES256 symmetric block ciphers

Simple API to perform AES encryption on Android. This is the Android counterpart to the AESCrypt library Ruby and Obj-C (with the same defaults):

https://github.com/scottyab/AESCrypt-Android

How can I check if a string contains ANY letters from the alphabet?

Regex should be a fast approach:

re.search('[a-zA-Z]', the_string)

Oracle client ORA-12541: TNS:no listener

According to oracle online documentation

ORA-12541: TNS:no listener

Cause: The connection request could not be completed because the listener is not running.

Action: Ensure that the supplied destination address matches one of the addresses used by 
the listener - compare the TNSNAMES.ORA entry with the appropriate LISTENER.ORA file (or  
TNSNAV.ORA if the connection is to go by way of an Interchange). Start the listener on 
the remote machine.

How to fire an event on class change using jQuery?

you can use something like this:

$(this).addClass('someClass');

$(Selector).trigger('ClassChanged')

$(otherSelector).bind('ClassChanged', data, function(){//stuff });

but otherwise, no, there's no predefined function to fire an event when a class changes.

Read more about triggers here

Case Statement Equivalent in R

I see no proposal for 'switch'. Code example (run it):

x <- "three"
y <- 0
switch(x,
       one = {y <- 5},
       two = {y <- 12},
       three = {y <- 432})
y

laravel Eloquent ORM delete() method

At first,

You should know that destroy() is correct method for removing an entity directly via object or model and delete() can only be called in query builder.

In your case, You have not checked if record exists in database or not. Record can only be deleted if exists.

So, You can do it like follows.

$user = User::find($id);
    if($user){
        $destroy = User::destroy(2);
    }

The value or $destroy above will be 0 or 1 on fail or success respectively. So, you can alter the $data array like:

if ($destroy){

    $data=[
        'status'=>'1',
        'msg'=>'success'
    ];

}else{

    $data=[
        'status'=>'0',
        'msg'=>'fail'
    ];

}

Hope, you understand.

What is a Java String's default initial value?

That depends. Is it just a variable (in a method)? Or a class-member?

If it's just a variable you'll get an error that no value has been set when trying to read from it without first assinging it a value.

If it's a class-member it will be initialized to null by the VM.

Bash if statement with multiple conditions throws an error

You can get some inspiration by reading an entrypoint.sh script written by the contributors from MySQL that checks whether the specified variables were set.

As the script shows, you can pipe them with -a, e.g.:

if [ -z "$MYSQL_ROOT_PASSWORD" -a -z "$MYSQL_ALLOW_EMPTY_PASSWORD" -a -z "$MYSQL_RANDOM_ROOT_PASSWORD" ]; then
    ...
fi

UIImageView - How to get the file name of the image assigned?

if ([imageForCheckMark.image isEqual:[UIImage imageNamed:@"crossCheckMark.png"]]||[imageForCheckMark.image isEqual:[UIImage imageNamed:@"checkMark.png"]])
{

}

What is 0x10 in decimal?

The simple version is 0x is a prefix denoting a hexadecimal number, source.

So the value you're computing is after the prefix, in this case 10.

But that is not the number 10. The most significant bit 1 denotes the hex value while 0 denotes the units.

So the simple math you would do is

0x10

1 * 16 + 0 = 16

Note - you use 16 because hex is base 16.

Another example:

0xF7

15 * 16 + 7 = 247

You can get a list of values by searching for a hex table. For instance in this chart notice F corresponds with 15.

Algorithm to convert RGB to HSV and HSV to RGB in range 0-255 for both

I created a possibly faster implementation by using 0-1 range for RGBS and V and 0-6 range for Hue (avoiding the division), and grouping the cases into two categories:

#include <math.h>
#include <float.h>

void fromRGBtoHSV(float rgb[], float hsv[])
{
//    for(int i=0; i<3; ++i)
//        rgb[i] = max(0.0f, min(1.0f, rgb[i]));

     hsv[0] = 0.0f;
     hsv[2] = max(rgb[0], max(rgb[1], rgb[2]));
     const float delta = hsv[2] - min(rgb[0], min(rgb[1], rgb[2]));

     if (delta < FLT_MIN)
         hsv[1] = 0.0f;
     else
     {
         hsv[1] = delta / hsv[2];
         if (rgb[0] >= hsv[2])
         {
             hsv[0] = (rgb[1] - rgb[2]) / delta;
             if (hsv[0] < 0.0f)
                 hsv[0] += 6.0f;
         }
         else if (rgb[1] >= hsv[2])
             hsv[0] = 2.0f + (rgb[2] - rgb[0]) / delta;
         else
             hsv[0] = 4.0f + (rgb[0] - rgb[1]) / delta;
     }    
}

void fromHSVtoRGB(const float hsv[], float rgb[])
{
    if(hsv[1] < FLT_MIN)
        rgb[0] = rgb[1] = rgb[2] = hsv[2];
    else
    {
        const float h = hsv[0];
        const int i = (int)h;
        const float f = h - i;
        const float p = hsv[2] * (1.0f - hsv[1]);

        if (i & 1) {
            const float q = hsv[2] * (1.0f - (hsv[1] * f));
            switch(i) {
            case 1:
                rgb[0] = q;
                rgb[1] = hsv[2];
                rgb[2] = p;
                break;
            case 3:
                rgb[0] = p;
                rgb[1] = q;
                rgb[2] = hsv[2];
                break;
            default:
                rgb[0] = hsv[2];
                rgb[1] = p;
                rgb[2] = q;
                break;
            }
        }
        else
        {
            const float t = hsv[2] * (1.0f - (hsv[1] * (1.0f - f)));
            switch(i) {
            case 0:
                rgb[0] = hsv[2];
                rgb[1] = t;
                rgb[2] = p;
                break;
            case 2:
                rgb[0] = p;
                rgb[1] = hsv[2];
                rgb[2] = t;
                break;
            default:
                rgb[0] = t;
                rgb[1] = p;
                rgb[2] = hsv[2];
                break;
            }
        }
    }
}

For 0-255 range just * 255.0f + 0.5f and assign it to an unsigned char (or divide by 255.0 to get the opposite).

What's the difference between tilde(~) and caret(^) in package.json?

Tilde ~ matches minor version, if you have installed a package that has 1.4.2 and after your installation, versions 1.4.3 and 1.4.4 are also available if in your package.json it is used as ~1.4.2 then npm install in your project after upgrade will install 1.4.4 in your project. But there is 1.5.0 available for that package then it will not be installed by ~. It is called minor version.

Caret ^ matches major version, if 1.4.2 package is installed in your project and after your installation 1.5.0 is released then ^ will install major version. It will not allow to install 2.1.0 if you have ^1.4.2.

Fixed version if you don't want to change version of package on each installation then used fixed version with out any special character e.g "1.4.2"

Latest Version * If you want to install latest version then only use * in front of package name.

Pod install is staying on "Setting up CocoaPods Master repo"

May be this information will be helpful:

Official answer: http://blog.cocoapods.org/Master-Spec-Repo-Rate-Limiting-Post-Mortem/

As a result of this discussion https://github.com/CocoaPods/CocoaPods/issues/4989

Briefly: CocoaPods repository experiences a huge volume of fetches from GitHub and it was the problem. Changes have been available since version 1.0.0.beta.6.

Tips from this document:

If for whatever reason you cannot upgrade to version 1.0.0 just yet, you can perform the following steps to convert your clone of the Master spec-repo from a shallow to a full clone:

$ cd ~/.cocoapods/repos/master
$ git fetch --unshallow

My hack to first installation:

1. pod setup
2. Ctrl+C
After that I could find ~/.cocoapods/repos/ empty directory 
3. Download  https://github.com/CocoaPods/Specs/archive/master.zip
4. unpack it to ~/.cocoapods/repos/
5. Move to project folder
6. pod install --no-repo-update

Today it takes near 15 minutes

What is Mocking?

If your mock involves a network request, another alternative is to have a real test server to hit. You can use a service to generate a request and response for your testing.

How to read a Parquet file into Pandas DataFrame?

Update: since the time I answered this there has been a lot of work on this look at Apache Arrow for a better read and write of parquet. Also: http://wesmckinney.com/blog/python-parquet-multithreading/

There is a python parquet reader that works relatively well: https://github.com/jcrobak/parquet-python

It will create python objects and then you will have to move them to a Pandas DataFrame so the process will be slower than pd.read_csv for example.

How to use an image for the background in tkinter?

A simple tkinter code for Python 3 for setting background image .

from tkinter import *
from tkinter import messagebox
top = Tk()

C = Canvas(top, bg="blue", height=250, width=300)
filename = PhotoImage(file = "C:\\Users\\location\\imageName.png")
background_label = Label(top, image=filename)
background_label.place(x=0, y=0, relwidth=1, relheight=1)

C.pack()
top.mainloop

Get month name from date in Oracle

Try this

select to_char(SYSDATE,'Month') from dual;

for full name and try this

select to_char(SYSDATE,'Mon') from dual;

for abbreviation

you can find more option here:

https://www.techonthenet.com/oracle/functions/to_char.php

how to delete a specific row in codeigniter?

a simple way:

in view(pass the id value):

<td><?php echo anchor('textarea/delete_row?id='.$row->id, 'DELETE', 'id="$row->id"'); ?></td>

in controller(receive the id):

$id = $this->input->get('id');
$this->load->model('mod1');
$this->mod1->row_delete($id);

in model(get the passed args):

function row_delete($id){}

Actually, you should use the ajax to POST the id value to controller and delete the row, not the GET.

Html Agility Pack get all elements by class

I used this extension method a lot in my project. Hope it will help one of you guys.

public static bool HasClass(this HtmlNode node, params string[] classValueArray)
    {
        var classValue = node.GetAttributeValue("class", "");
        var classValues = classValue.Split(' ');
        return classValueArray.All(c => classValues.Contains(c));
    }

How to make div background color transparent in CSS

It might be a little late to the discussion but inevitably someone will stumble onto this post like I did. I found the answer I was looking for and thought I'd post my own take on it. The following JSfiddle includes how to layer .PNG's with transparency. Jerska's mention of the transparency attribute for the div's CSS was the solution: http://jsfiddle.net/jyef3fqr/

HTML:

   <button id="toggle-box">toggle</button>
   <div id="box" style="display:none;" ><img src="x"></div>
   <button id="toggle-box2">toggle</button>
   <div id="box2" style="display:none;"><img src="xx"></div>
   <button id="toggle-box3">toggle</button>
   <div id="box3" style="display:none;" ><img src="xxx"></div>

CSS:

#box {
background-color: #ffffff;
height:400px;
width: 1200px;
position: absolute;
top:30px;
z-index:1;
}
#box2 {
background-color: #ffffff;
height:400px;
width: 1200px;
position: absolute;
top:30px;
z-index:2;
background-color : transparent;
      }
      #box3 {
background-color: #ffffff;
height:400px;
width: 1200px;
position: absolute;
top:30px;
z-index:2;
background-color : transparent;
      }
 body {background-color:#c0c0c0; }

JS:

$('#toggle-box').click().toggle(function() {
$('#box').animate({ width: 'show' });
}, function() {
$('#box').animate({ width: 'hide' });
});

$('#toggle-box2').click().toggle(function() {
$('#box2').animate({ width: 'show' });
}, function() {
$('#box2').animate({ width: 'hide' });
});
$('#toggle-box3').click().toggle(function() {
$('#box3').animate({ width: 'show' });
 }, function() {
$('#box3').animate({ width: 'hide' });
});

And my original inspiration:http://jsfiddle.net/5g1zwLe3/ I also used paint.net for creating the transparent PNG's, or rather the PNG's with transparent BG's.

Node / Express: EADDRINUSE, Address already in use - Kill server

server.close() takes a while to close the connection, thus we should make this an asynchronous call as such:

await server.close();

IMPORTANT: when using await, we must use the async keyword in our encapsulating function as such:

async () => {
  await server.close();
}

How to select last child element in jQuery?

You can also do this:

<ul id="example">
    <li>First</li>
    <li>Second</li>
    <li>Third</li>
    <li>Fourth</li>
</ul>

// possibility 1
$('#example li:last').val();
// possibility 2
$('#example').children().last()
// possibility 3
$('#example li:last-child').val();

:last

.children().last()

:last-child

How to remove files and directories quickly via terminal (bash shell)

rm -rf some_dir

-r "recursive" -f "force" (suppress confirmation messages)

Be careful!

Create table using Javascript

_x000D_
_x000D_
function addTable() {_x000D_
  var myTableDiv = document.getElementById("myDynamicTable");_x000D_
_x000D_
  var table = document.createElement('TABLE');_x000D_
  table.border = '1';_x000D_
_x000D_
  var tableBody = document.createElement('TBODY');_x000D_
  table.appendChild(tableBody);_x000D_
_x000D_
  for (var i = 0; i < 3; i++) {_x000D_
    var tr = document.createElement('TR');_x000D_
    tableBody.appendChild(tr);_x000D_
_x000D_
    for (var j = 0; j < 4; j++) {_x000D_
      var td = document.createElement('TD');_x000D_
      td.width = '75';_x000D_
      td.appendChild(document.createTextNode("Cell " + i + "," + j));_x000D_
      tr.appendChild(td);_x000D_
    }_x000D_
  }_x000D_
  myTableDiv.appendChild(table);_x000D_
}_x000D_
addTable();
_x000D_
<div id="myDynamicTable"></div>
_x000D_
_x000D_
_x000D_

Displaying a vector of strings in C++

You have to insert the elements using the insert method present in vectors STL, check the below program to add the elements to it, and you can use in the same way in your program.

#include <iostream>
#include <vector>
#include <string.h>

int main ()
{
  std::vector<std::string> myvector ;
  std::vector<std::string>::iterator it;

   it = myvector.begin();
  std::string myarray [] = { "Hi","hello","wassup" };
  myvector.insert (myvector.begin(), myarray, myarray+3);

  std::cout << "myvector contains:";
  for (it=myvector.begin(); it<myvector.end(); it++)
    std::cout << ' ' << *it;
    std::cout << '\n';

  return 0;
}

How to search for occurrences of more than one space between words in a line

This regex selects all spaces, you can use this and replace it with a single space

\s+

example in python

result = re.sub('\s+',' ', data))

Jaxb, Class has two properties of the same name

Your JAXB is looking at both the getTimeSeries() method and the member timeSeries. You don't say which JAXB implementation you're using, or its configuration, but the exception is fairly clear.

at public java.util.List testjaxp.ModeleREP.getTimeSeries()

and

at protected java.util.List testjaxp.ModeleREP.timeSeries

You need to configure you JAXB stuff to use annotations (as per your @XmlElement(name="TimeSeries")) and ignore public methods.

Passing an array by reference

Arrays are default passed by pointers. You can try modifying an array inside a function call for better understanding.

How to solve error: "Clock skew detected"?

One of the reason may be improper date/time of your PC.

In Ubuntu PC to check the date and time using:

date

Example, One of the ways to update date and time is:

date -s "23 MAR 2017 17:06:00"

Java: Check the date format of current string is according to required format or not

DateFormat formatter = new SimpleDateFormat("dd/MM/yyyy");
formatter.setLenient(false);
try {
    Date date= formatter.parse("02/03/2010");
} catch (ParseException e) {
    //If input date is in different format or invalid.
}

formatter.setLenient(false) will enforce strict matching.

If you are using Joda-Time -

private boolean isValidDate(String dateOfBirth) {
        boolean valid = true;
        try {
            DateTimeFormatter formatter = DateTimeFormat.forPattern("dd/MM/yyyy");
            DateTime dob = formatter.parseDateTime(dateOfBirth);
        } catch (Exception e) {
            valid = false;
        }
        return valid;
    }

How to redirect stderr to null in cmd.exe

Your DOS command 2> nul

Read page Using command redirection operators. Besides the "2>" construct mentioned by Tanuki Software, it lists some other useful combinations.

Checking length of dictionary object

var c = {'a':'A', 'b':'B', 'c':'C'};
var count = 0;
for (var i in c) {
   if (c.hasOwnProperty(i)) count++;
}

alert(count);

String to HashMap JAVA

try

 String s = "SALES:0,SALE_PRODUCTS:1,EXPENSES:2,EXPENSES_ITEMS:3";
    HashMap<String,Integer> hm =new HashMap<String,Integer>();
    for(String s1:s.split(",")){
       String[] s2 = s1.split(":");
        hm.put(s2[0], Integer.parseInt(s2[1]));
    }

What do raw.githubusercontent.com URLs represent?

raw.githubusercontent.com/username/repo-name/branch-name/path

Replace username with the username of the user that created the repo.

Replace repo-name with the name of the repo.

Replace branch-name with the name of the branch.

Replace path with the path to the file.

To reverse to go to GitHub.com:

GitHub.com/username/repo-name/directory-path/blob/branch-name/filename

Pass a datetime from javascript to c# (Controller)

The following format should work:

$.ajax({
    type: "POST",
    url: "@Url.Action("refresh", "group")",
    contentType: "application/json; charset=utf-8",
    data: JSON.stringify({ 
        myDate: '2011-04-02 17:15:45'
    }),
    success: function (result) {
        //do something
    },
    error: function (req, status, error) {
        //error                        
    }
});

How do I install PIL/Pillow for Python 3.6?

For python version 2.x you can simply use

  • pip install pillow

But for python version 3.X you need to specify

  • (sudo) pip3 install pillow

when you enter pip in bash hit tab and you will see what options you have

Fetch the row which has the Max value for a column

This should be as simple as:

SELECT UserId, Value
FROM Users u
WHERE Date = (SELECT MAX(Date) FROM Users WHERE UserID = u.UserID)

How to run python script with elevated privilege on windows

Thank you all for your reply. I have got my script working with the module/ script written by Preston Landers way back in 2010. After two days of browsing the internet I could find the script as it was was deeply hidden in pywin32 mailing list. With this script it is easier to check if the user is admin and if not then ask for UAC/ admin right. It does provide output in separate windows to find out what the code is doing. Example on how to use the code also included in the script. For the benefit of all who all are looking for UAC on windows have a look at this code. I hope it helps someone looking for same solution. It can be used something like this from your main script:-

import admin
if not admin.isUserAdmin():
        admin.runAsAdmin()

The actual code is:-

#!/usr/bin/env python
# -*- coding: utf-8; mode: python; py-indent-offset: 4; indent-tabs-mode: nil -*-
# vim: fileencoding=utf-8 tabstop=4 expandtab shiftwidth=4

# (C) COPYRIGHT © Preston Landers 2010
# Released under the same license as Python 2.6.5


import sys, os, traceback, types

def isUserAdmin():

    if os.name == 'nt':
        import ctypes
        # WARNING: requires Windows XP SP2 or higher!
        try:
            return ctypes.windll.shell32.IsUserAnAdmin()
        except:
            traceback.print_exc()
            print "Admin check failed, assuming not an admin."
            return False
    elif os.name == 'posix':
        # Check for root on Posix
        return os.getuid() == 0
    else:
        raise RuntimeError, "Unsupported operating system for this module: %s" % (os.name,)

def runAsAdmin(cmdLine=None, wait=True):

    if os.name != 'nt':
        raise RuntimeError, "This function is only implemented on Windows."

    import win32api, win32con, win32event, win32process
    from win32com.shell.shell import ShellExecuteEx
    from win32com.shell import shellcon

    python_exe = sys.executable

    if cmdLine is None:
        cmdLine = [python_exe] + sys.argv
    elif type(cmdLine) not in (types.TupleType,types.ListType):
        raise ValueError, "cmdLine is not a sequence."
    cmd = '"%s"' % (cmdLine[0],)
    # XXX TODO: isn't there a function or something we can call to massage command line params?
    params = " ".join(['"%s"' % (x,) for x in cmdLine[1:]])
    cmdDir = ''
    showCmd = win32con.SW_SHOWNORMAL
    #showCmd = win32con.SW_HIDE
    lpVerb = 'runas'  # causes UAC elevation prompt.

    # print "Running", cmd, params

    # ShellExecute() doesn't seem to allow us to fetch the PID or handle
    # of the process, so we can't get anything useful from it. Therefore
    # the more complex ShellExecuteEx() must be used.

    # procHandle = win32api.ShellExecute(0, lpVerb, cmd, params, cmdDir, showCmd)

    procInfo = ShellExecuteEx(nShow=showCmd,
                              fMask=shellcon.SEE_MASK_NOCLOSEPROCESS,
                              lpVerb=lpVerb,
                              lpFile=cmd,
                              lpParameters=params)

    if wait:
        procHandle = procInfo['hProcess']    
        obj = win32event.WaitForSingleObject(procHandle, win32event.INFINITE)
        rc = win32process.GetExitCodeProcess(procHandle)
        #print "Process handle %s returned code %s" % (procHandle, rc)
    else:
        rc = None

    return rc

def test():
    rc = 0
    if not isUserAdmin():
        print "You're not an admin.", os.getpid(), "params: ", sys.argv
        #rc = runAsAdmin(["c:\\Windows\\notepad.exe"])
        rc = runAsAdmin()
    else:
        print "You are an admin!", os.getpid(), "params: ", sys.argv
        rc = 0
    x = raw_input('Press Enter to exit.')
    return rc


if __name__ == "__main__":
    sys.exit(test())

How to calculate difference in hours (decimal) between two dates in SQL Server?

DATEDIFF but note it returns an integer so if you need fractions of hours use something like this:-

CAST(DATEDIFF(ss, startDate, endDate) AS decimal(precision, scale)) / 3600

Does HTML5 <video> playback support the .avi format?

The current HTML5 draft specification does not specify which video formats browsers should support in the video tag. User agents are free to support any video formats they feel are appropriate.

http://en.wikipedia.org/wiki/HTML5_video

How do I override nested NPM dependency versions?

NPM shrinkwrap offers a nice solution to this problem. It allows us to override that version of a particular dependency of a particular sub-module.

Essentially, when you run npm install, npm will first look in your root directory to see whether a npm-shrinkwrap.json file exists. If it does, it will use this first to determine package dependencies, and then falling back to the normal process of working through the package.json files.

To create an npm-shrinkwrap.json, all you need to do is

 npm shrinkwrap --dev

code:

{
  "dependencies": {
    "grunt-contrib-connect": {
      "version": "0.3.0",
      "from": "[email protected]",
      "dependencies": {
        "connect": {
          "version": "2.8.1",
          "from": "connect@~2.7.3"
        }
      }
    }
  }
}

Cannot run Eclipse; JVM terminated. Exit code=13

use the configuration below;

    -startup
    plugins/org.eclipse.equinox.launcher_1.3.0.v20130327-1440.jar
    --launcher.library
    plugins/org.eclipse.equinox.launcher.win32.win32.x86_64_1.1.200.v20130807-1835
    -product
    org.springsource.ggts.ide
    --launcher.defaultAction
    openFile
    --launcher.XXMaxPermSize
    256M
    -vm
    C:\Program Files\Java\jdk1.7.0_51\jre\bin\javaw.exe
    -vmargs
    -Dorg.eclipse.swt.browser.IEVersion=10001
    -Dgrails.console.enable.interactive=false
    -Dgrails.console.enable.terminal=false
    -Djline.terminal=jline.UnsupportedTerminal
    -Dgrails.console.class=grails.build.logging.GrailsEclipseConsole
    -Dosgi.requiredJavaVersion=1.6
    -Xms40m
    -Xmx768m
    -XX:MaxPermSize=256m
    -Dorg.eclipse.swt.browser.IEVersion=10001

Where to find free public Web Services?

https://www.programmableweb.com/ -- Great collection of all category API's across web. It not only show cases the API's , but also Developers who use those API's in their applications and code samples, rating of the API and much more. They have more than apis they also have sdk and libraries too.

How to set cursor to input box in Javascript?

You have not provided enough code to help You likely submit the form and reload the page OR you have an object on the page like an embedded PDF that steals the focus.

Here is the canonical plain javascript method of validating a form It can be improved with onubtrusive JS which will remove the inline script, but this is the starting point DEMO

function validate(formObj) {
  document.getElementById("errorMsg").innerHTML = "";    
  var quantity = formObj.quantity;
  if (isNaN(quantity)) {
    quantity.value="";
    quantity.focus();
    document.getElementById("errorMsg").innerHTML = "Only numeric value is allowed";
    return false;
  }
  return true; // allow submit
}   

Here is the HTML

<form onsubmit="return validate(this)">
    <input type="text" name="quantity" value="" />
    <input type="submit" />
</form>    
<span id="errorMsg"></span>

Git reset --hard and push to remote repository

To complement Jakub's answer, if you have access to the remote git server in ssh, you can go into the git remote directory and set:

user@remote$ git config receive.denyNonFastforwards false

Then go back to your local repo, try again to do your commit with --force:

user@local$ git push origin +master:master --force

And finally revert the server's setting in the original protected state:

user@remote$ git config receive.denyNonFastforwards true

Auto Resize Image in CSS FlexBox Layout and keeping Aspect Ratio?

In the second image it looks like you want the image to fill the box, but the example you created DOES keep the aspect ratio (the pets look normal, not slim or fat).

I have no clue if you photoshopped those images as example or the second one is "how it should be" as well (you said IS, while the first example you said "should")

Anyway, I have to assume:

If "the images are not resized keeping the aspect ration" and you show me an image which DOES keep the aspect ratio of the pixels, I have to assume you are trying to accomplish the aspect ratio of the "cropping" area (the inner of the green) WILE keeping the aspect ratio of the pixels. I.e. you want to fill the cell with the image, by enlarging and cropping the image.

If that's your problem, the code you provided does NOT reflect "your problem", but your starting example.

Given the previous two assumptions, what you need can't be accomplished with actual images if the height of the box is dynamic, but with background images. Either by using "background-size: contain" or these techniques (smart paddings in percents that limit the cropping or max sizes anywhere you want): http://fofwebdesign.co.uk/template/_testing/scale-img/scale-img.htm

The only way this is possible with images is if we FORGET about your second iimage, and the cells have a fixed height, and FORTUNATELY, judging by your sample images, the height stays the same!

So if your container's height doesn't change, and you want to keep your images square, you just have to set the max-height of the images to that known value (minus paddings or borders, depending on the box-sizing property of the cells)

Like this:

<div class="content">
  <div class="row">    
      <div class="cell">    
          <img src="http://lorempixel.com/output/people-q-c-320-320-2.jpg"/>
      </div>
      <div class="cell">    
          <img src="http://lorempixel.com/output/people-q-c-320-320-7.jpg"/>
      </div>
    </div>
</div>

And the CSS:

.content {
    background-color: green;
}

.row {
    display: -webkit-box;
    display: -moz-box;
    display: -ms-flexbox;
    display: -webkit-flex;
    display: flex;

    -webkit-box-orient: horizontal; 
    -moz-box-orient: horizontal;
    box-orient: horizontal;
    flex-direction: row;

    -webkit-box-pack: center;
    -moz-box-pack: center;
    box-pack: center;
    justify-content: center;

    -webkit-box-align: center;
    -moz-box-align: center;
    box-align: center;  
    align-items: center;

}

.cell {
    -webkit-box-flex: 1;
    -moz-box-flex: 1;
    box-flex: 1;
    -webkit-flex: 1 1 auto;
    flex: 1 1 auto;
    padding: 10px;
    border: solid 10px red;
    text-align: center;
    height: 300px;
    display: flex;
    align-items: center;
    box-sizing: content-box;
}
img {
    margin: auto;
    width: 100%;
    max-width: 300px;
    max-height:100%
}

http://jsfiddle.net/z25heocL/

Your code is invalid (opening tags are instead of closing ones, so they output NESTED cells, not siblings, he used a SCREENSHOT of your images inside the faulty code, and the flex box is not holding the cells but both examples in a column (you setup "row" but the corrupt code nesting one cell inside the other resulted in a flex inside a flex, finally working as COLUMNS. I have no idea what you wanted to accomplish, and how you came up with that code, but I'm guessing what you want is this.

I added display: flex to the cells too, so the image gets centered (I think display: table could have been used here as well with all this markup)

How to change button background image on mouseOver?

I think something like this:

btn.BackgroundImage = Properties.Resources.*Image_Identifier*;

Where *Image_Identifier* is an identifier of the image in your resources.

How to set default value to all keys of a dict object in python?

You can use the following class. Just change zero to any default value you like. The solution was tested in Python 2.7.

class cDefaultDict(dict):
    # dictionary that returns zero for missing keys
    # keys with zero values are not stored

    def __missing__(self,key):
        return 0

    def __setitem__(self, key, value):
        if value==0:
            if key in self:  # returns zero anyway, so no need to store it
                del self[key]
        else:
            dict.__setitem__(self, key, value)

What's the syntax for mod in java

you should examine the specification before using 'remainder' operator % :

http://java.sun.com/docs/books/jls/third_edition/html/expressions.html#15.17.3

// bad enough implementation of isEven method, for fun. so any worse?
boolean isEven(int num)
{
    num %= 10;
    if(num == 1)
       return false;
    else if(num == 0)
       return true;
    else
       return isEven(num + 2);
}
isEven = isEven(a);

phpmyadmin "no data received to import" error, how to fix?

Check permissions for you upload directory. You can find its path inside /etc/phpmyadmin/apache.conf file.

In my case (Ubuntu 14.04) it was:

php_admin_value upload_tmp_dir /var/lib/phpmyadmin/tmp

So I checked permissions for /var/lib/phpmyadmin/tmp and it turns out that the directory wasn't writable for my Apache user (which is by default www-data). It could be the case especially if you changed your apache user like I do.

Using the slash character in Git branch name

just had the same issue, but i could not find the conflicting branch anymore.

in my case the repo had and "foo" branch before, but not anymore and i tried to create and checkout "foo/bar" from remote. As i said "foo" did not exist anymore, but the issue persisted.

In the end, the branch "foo" was still in the .git/config file, after deleting it everything was alright :)

Bubble Sort Homework

def bubble_sort(l):
    for i in range(len(l) -1):
        for j in range(len(l)-i-1):
            if l[j] > l[j+1]:
                l[j],l[j+1] = l[j+1], l[j]
    return l

Focusable EditText inside ListView

some times when you use android:windowSoftInputMode="stateAlwaysHidden"in manifest activity or xml, that time it will lose keyboard focus. So first check for that property in your xml and manifest,if it is there just remove it. After add these option to manifest file in side activity android:windowSoftInputMode="adjustPan"and add this property to listview in xml android:descendantFocusability="beforeDescendants"

How to connect Robomongo to MongoDB

Here's what we do:

  • Create a new connection, set the name, IP address and the appropriate port:

    Connection setup

  • Set up authentication, if required

    Authentication settings

  • Optionally set up other available settings for SSL, SSH, etc.

  • Save and connect

Git says remote ref does not exist when I delete remote branch

For me this worked $ ? git branch -D -r origin/mybranch

Details

$ ? git branch -a | grep mybranch remotes/origin/mybranch

$ ? git branch -r | grep mybranch origin/mybranch

$ ? git branch develop * feature/pre-deployment

$ ? git push origin --delete mybranch error: unable to delete 'mybranch': remote ref does not exist error: failed to push some refs to '[email protected]:config/myrepo.git'

$ ? git branch -D -r origin/mybranch Deleted remote branch origin/mybranch (was 62c7421).

$ ? git branch -a | grep mybranch

$ ? git branch -r | grep mybranch

how to fire event on file select

Use the change event on the file input.

$("#file").change(function(){
         //submit the form here
 });

How do I get the time difference between two DateTime objects using C#?

You want the TimeSpan struct:

TimeSpan diff = dateTime1 - dateTime2;

A TimeSpan object represents a time interval (duration of time or elapsed time) that is measured as a positive or negative number of days, hours, minutes, seconds, and fractions of a second. The TimeSpan structure can also be used to represent the time of day, but only if the time is unrelated to a particular date.

There are various methods for getting the days, hours, minutes, seconds and milliseconds back from this structure.

If you are just interested in the difference then:

TimeSpan diff = Math.Abs(dateTime1 - dateTime2);

will give you the positive difference between the times regardless of the order.

If you have just got the time component but the times could be split by midnight then you need to add 24 hours to the span to get the actual difference:

TimeSpan diff = dateTime1 - dateTime2;
if (diff < 0)
{
    diff = diff + TimeSpan.FromDays(1);
}

How to replace plain URLs with links?

Here's my solution:

var content = "Visit https://wwww.google.com or watch this video: https://www.youtube.com/watch?v=0T4DQYgsazo and news at http://www.bbc.com";
content = replaceUrlsWithLinks(content, "http://");
content = replaceUrlsWithLinks(content, "https://");

function replaceUrlsWithLinks(content, protocol) {
    var startPos = 0;
    var s = 0;

    while (s < content.length) {
        startPos = content.indexOf(protocol, s);

        if (startPos < 0)
            return content;

        let endPos = content.indexOf(" ", startPos + 1);

        if (endPos < 0)
            endPos = content.length;

        let url = content.substr(startPos, endPos - startPos);

        if (url.endsWith(".") || url.endsWith("?") || url.endsWith(",")) {
            url = url.substr(0, url.length - 1);
            endPos--;
        }

        if (ROOTNS.utils.stringsHelper.validUrl(url)) {
            let link = "<a href='" + url + "'>" + url + "</a>";
            content = content.substr(0, startPos) + link + content.substr(endPos);
            s = startPos + link.length;
        } else {
            s = endPos + 1;
        }
    }

    return content;
}

function validUrl(url) {
    try {
        new URL(url);
        return true;
    } catch (e) {
        return false;
    }
}

open_basedir restriction in effect. File(/) is not within the allowed path(s):

Modify the open_basedir settings in your PHP configuration (See Runtime Configuration).

The open_basedir setting is primarily used to prevent PHP scripts for a particular user from accessing files in another user's account. So usually, any files in your own account should be readable by your own scripts.

Example settings via .htaccess if PHP runs as Apache module on a Linux system:

<DirectoryMatch "/home/sites/site81/">
    php_admin_value open_basedir "/home/sites/site81/:/tmp/:/"
</DirectoryMatch>

A network-related or instance-specific error occurred while establishing a connection to SQL Server

Sql Server fire this error when your application don't have enough rights to access the database. there are several reason about this error . To fix this error you should follow the following instruction.

  1. Try to connect sql server from your server using management studio . if you use windows authentication to connect sql server then set your application pool identity to server administrator .

  2. if you use sql server authentication then check you connection string in web.config of your web application and set user id and password of sql server which allows you to log in .

  3. if your database in other server(access remote database) then first of enable remote access of sql server form sql server property from sql server management studio and enable TCP/IP form sql server configuration manager .

  4. after doing all these stuff and you still can't access the database then check firewall of server form where you are trying to access the database and add one rule in firewall to enable port of sql server(by default sql server use 1433 , to check port of sql server you need to check sql server configuration manager network protocol TCP/IP port).

  5. if your sql server is running on named instance then you need to write port number with sql serer name for example 117.312.21.21/nameofsqlserver,1433.

  6. If you are using cloud hosting like amazon aws or microsoft azure then server or instance will running behind cloud firewall so you need to enable 1433 port in cloud firewall if you have default instance or specific port for sql server for named instance.

  7. If you are using amazon RDS or SQL azure then you need to enable port from security group of that instance.

  8. If you are accessing sql server through sql server authentication mode them make sure you enabled "SQL Server and Windows Authentication Mode" sql server instance property. enter image description here

    1. Restart your sql server instance after making any changes in property as some changes will require restart.

if you further face any difficulty then you need to provide more information about your web site and sql server .

Why are only a few video games written in Java?

I'd guess that speed is still the issue. Cross platform is going to be an issue isn't it since you don't know what 3d card is available when you write the code? Does java have anything to support auto discovery of 3d capabilities? And I'd guess that there are tools to ease porting a game between the wii, xbox, and ps3, but expensive I'll bet.

The ps3 has java, via the blue ray support. Check the bd-j site.

Bash script error [: !=: unary operator expected

Or for what seems like rampant overkill, but is actually simplistic ... Pretty much covers all of your cases, and no empty string or unary concerns.

In the case the first arg is '-v', then do your conditional ps -ef, else in all other cases throw the usage.

#!/bin/sh
case $1 in
  '-v') if [ "$1" = -v ]; then
         echo "`ps -ef | grep -v '\['`"
        else
         echo "`ps -ef | grep '\[' | grep root`"
        fi;;
     *) echo "usage: $0 [-v]"
        exit 1;; #It is good practice to throw a code, hence allowing $? check
esac

If one cares not where the '-v' arg is, then simply drop the case inside a loop. The would allow walking all the args and finding '-v' anywhere (provided it exists). This means command line argument order is not important. Be forewarned, as presented, the variable arg_match is set, thus it is merely a flag. It allows for multiple occurrences of the '-v' arg. One could ignore all other occurrences of '-v' easy enough.

#!/bin/sh

usage ()
 {
  echo "usage: $0 [-v]"
  exit 1
 }

unset arg_match

for arg in $*
 do
  case $arg in
    '-v') if [ "$arg" = -v ]; then
           echo "`ps -ef | grep -v '\['`"
          else
           echo "`ps -ef | grep '\[' | grep root`"
          fi
          arg_match=1;; # this is set, but could increment.
       *) ;;
  esac
done

if [ ! $arg_match ]
 then
  usage
fi

But, allow multiple occurrences of an argument is convenient to use in situations such as:

$ adduser -u:sam -s -f -u:bob -trace -verbose

We care not about the order of the arguments, and even allow multiple -u arguments. Yes, it is a simple matter to also allow:

$ adduser -u sam -s -f -u bob -trace -verbose

PHP mail not working for some reason

The mail function do not guarantee the actual delivery of mail. All it do is to pass the message to external program (usually sendmail). You need a properly configured SMTP server in order for this to work. Also keep in mind it does not support SMTP authentication. You may check out the PEAR::Mail library of SwiftMailer, both of them give you more options.

GROUP BY without aggregate function

If you have some column in SELECT clause , how will it select it if there is several rows ? so yes , every column in SELECT clause should be in GROUP BY clause also , you can use aggregate functions in SELECT ...

you can have column in GROUP BY clause which is not in SELECT clause , but not otherwise

Why does range(start, end) not include end?

It works well in combination with zero-based indexing and len(). For example, if you have 10 items in a list x, they are numbered 0-9. range(len(x)) gives you 0-9.

Of course, people will tell you it's more Pythonic to do for item in x or for index, item in enumerate(x) rather than for i in range(len(x)).

Slicing works that way too: foo[1:4] is items 1-3 of foo (keeping in mind that item 1 is actually the second item due to the zero-based indexing). For consistency, they should both work the same way.

I think of it as: "the first number you want, followed by the first number you don't want." If you want 1-10, the first number you don't want is 11, so it's range(1, 11).

If it becomes cumbersome in a particular application, it's easy enough to write a little helper function that adds 1 to the ending index and calls range().