Programs & Examples On #Location aware

Passing by reference in C

No pass-by-reference in C, but p "refers" to i, and you pass p by value.

What does ON [PRIMARY] mean?

It refers to which filegroup the object you are creating resides on. So your Primary filegroup could reside on drive D:\ of your server. you could then create another filegroup called Indexes. This filegroup could reside on drive E:\ of your server.

How to convert local time string to UTC?

I found the best answer on another question here. It only uses python built-in libraries and does not require you to input your local timezone (a requirement in my case)

import time
import calendar

local_time = time.strptime("2018-12-13T09:32:00.000", "%Y-%m-%dT%H:%M:%S.%f")
local_seconds = time.mktime(local_time)
utc_time = time.gmtime(local_seconds)

I'm reposting the answer here since this question pops up in google instead of the linked question depending on the search keywords.

Body of Http.DELETE request in Angular2

Definition in http.js from the @angular/http:

delete(url, options)

The request doesn't accept a body so it seem your only option is to but your data in the URI.

I found another topic with references to correspond RFC, among other things: How to pass data in the ajax DELETE request other than headers

Httpd returning 503 Service Unavailable with mod_proxy for Tomcat 8

(Answered by the OP in a question edit. Converted to a community wiki answer. See Question with no answers, but issue solved in the comments (or extended in chat) )

The OP wrote:

The answer is here: http://sysadminsjourney.com/content/2010/02/01/apache-modproxy-error-13permission-denied-error-rhel/

Which is a link to a blog that explains:

SELinux on RHEL/CentOS by default ships so that httpd processes cannot initiate outbound connections, which is just what mod_proxy attempts to do.

If this is the problem, it can be solved by running:

 /usr/sbin/setsebool -P httpd_can_network_connect 1

And for a more definitive source of information, see https://wiki.apache.org/httpd/13PermissionDenied

How to use Bash to create a folder if it doesn't already exist?

Simply do:

mkdir /path/to/your/potentially/existing/folder

mkdir will throw an error if the folder already exists. To ignore the errors write:

mkdir -p /path/to/your/potentially/existing/folder

No need to do any checking or anything like that.


For reference:

-p, --parents no error if existing, make parent directories as needed http://man7.org/linux/man-pages/man1/mkdir.1.html

Comparing user-inputted characters in C

answer shouldn't be a pointer, the intent is obviously to hold a character. scanf takes the address of this character, so it should be called as

char answer;
scanf(" %c", &answer);

Next, your "or" statement is formed incorrectly.

if (answer == 'Y' || answer == 'y')

What you wrote originally asks to compare answer with the result of 'Y' || 'y', which I'm guessing isn't quite what you wanted to do.

How to send and receive JSON data from a restful webservice using Jersey API

For me, parameter (JSONObject inputJsonObj) was not working. I am using jersey 2.* Hence I feel this is the

java(Jax-rs) and Angular way

I hope it's helpful to someone using JAVA Rest and AngularJS like me.

@POST
@Consumes(MediaType.TEXT_PLAIN)
@Produces(MediaType.APPLICATION_JSON)
public Map<String, String> methodName(String data) throws Exception {
    JSONObject recoData = new JSONObject(data);
    //Do whatever with json object
}

Client side I used AngularJS

factory.update = function () {
data = {user:'Shreedhar Bhat',address:[{houseNo:105},{city:'Bengaluru'}]};
        data= JSON.stringify(data);//Convert object to string
        var d = $q.defer();
        $http({
            method: 'POST',
            url: 'REST/webApp/update',
            headers: {'Content-Type': 'text/plain'},
            data:data
        })
        .success(function (response) {
            d.resolve(response);
        })
        .error(function (response) {
            d.reject(response);
        });

        return d.promise;
    };

Best way to create a simple python web service

Look at the WSGI reference implementation. You already have it in your Python libraries. It's quite simple.

Zsh: Conda/Pip installs command not found

I simply added the anaconda3 path to $PATH in .zshrc which did the trick for.

My environment : Catalina / clean Anaconda install / iTerm / zsh / oh-my-zsh

First locate your conda installation:

> find ~/ -name 'conda' -print

(on my system: ~/opt/anaconda3/bin/conda)

Then add that path to PATH in the .zshrc file

export PATH="opt/anaconda3/bin":$PATH

TSQL: How to convert local time to UTC? (SQL Server 2008)

This works for dates that currently have the same UTC offset as SQL Server's host; it doesn't account for daylight savings changes. Replace YOUR_DATE with the local date to convert.

SELECT DATEADD(second, DATEDIFF(second, GETDATE(), GETUTCDATE()), YOUR_DATE);

Specifying content of an iframe instead of the src attribute to a page

iframe now supports srcdoc which can be used to specify the HTML content of the page to show in the inline frame.

how to get a list of dates between two dates in java

You can also look at the Date.getTime() API. That gives a long to which you can add your increment. Then create a new Date.

List<Date> dates = new ArrayList<Date>();
long interval = 1000 * 60 * 60; // 1 hour in millis
long endtime = ; // create your endtime here, possibly using Calendar or Date
long curTime = startDate.getTime();
while (curTime <= endTime) {
  dates.add(new Date(curTime));
  curTime += interval;
}

and maybe apache commons has something like this in DateUtils, or perhaps they have a CalendarUtils too :)

EDIT

including the start and enddate may not be possible if your interval is not perfect :)

How to check for file existence

Check out Pathname and in particular Pathname#exist?.

File and its FileTest module are perhaps simpler/more direct, but I find Pathname a nicer interface in general.

What is the T-SQL syntax to connect to another SQL Server?

Also, make sure when you write the query involving the linked server, you include brackets like this:

SELECT * FROM [LinkedServer].[RemoteDatabase].[User].[Table]

I've found that at least on 2000/2005 the [] brackets are necessary, at least around the server name.

Convert XmlDocument to String

" is shown as \" in the debugger, but the data is correct in the string, and you don't need to replace anything. Try to dump your string to a file and you will note that the string is correct.

fetch from origin with deleted remote branches?

Regarding git fetch -p, its behavior changed in Git 1.9, and only Git 2.9.x/2.10 reflects that.

See commit 9e70233 (13 Jun 2016) by Jeff King (peff).
(Merged by Junio C Hamano -- gitster -- in commit 1c22105, 06 Jul 2016)

fetch: document that pruning happens before fetching

This was changed in 10a6cc8 (fetch --prune: Run prune before fetching, 2014-01-02), but it seems that nobody in that discussion realized we were advertising the "after" explicitly.

So the documentation now states:

Before fetching, remove any remote-tracking references that no longer exist on the remote

That is because:

When we have a remote-tracking branch named "frotz/nitfol" from a previous fetch, and the upstream now has a branch named "frotz", fetch would fail to remove "frotz/nitfol" with a "git fetch --prune" from the upstream. git would inform the user to use "git remote prune" to fix the problem.

Change the way "fetch --prune" works by moving the pruning operation before the fetching operation. This way, instead of warning the user of a conflict, it automatically fixes it.

mysql stored-procedure: out parameter

You must have use correct signature for input parameter *IN is missing in the below code.

CREATE PROCEDURE my_sqrt(IN input_number INT, OUT out_number FLOAT)

Convert INT to VARCHAR SQL

You can use CAST function:

SELECT CAST(your_column_name AS varchar(10)) FROM your_table_name

Writing to a TextBox from another thread?

I would use BeginInvoke instead of Invoke as often as possible, unless you are really required to wait until your control has been updated (which in your example is not the case). BeginInvoke posts the delegate on the WinForms message queue and lets the calling code proceed immediately (in your case the for-loop in the SampleFunction). Invoke not only posts the delegate, but also waits until it has been completed.

So in the method AppendTextBox from your example you would replace Invoke with BeginInvoke like that:

public void AppendTextBox(string value)
{
    if (InvokeRequired)
    {
        this.BeginInvoke(new Action<string>(AppendTextBox), new object[] {value});
        return;
    }
    textBox1.Text += value;
}

Well and if you want to get even more fancy, there is also the SynchronizationContext class, which lets you basically do the same as Control.Invoke/Control.BeginInvoke, but with the advantage of not needing a WinForms control reference to be known. Here is a small tutorial on SynchronizationContext.

Do you recommend using semicolons after every statement in JavaScript?

No, only use semicolons when they're required.

How to implement a queue using two stacks?

You can even simulate a queue using only one stack. The second (temporary) stack can be simulated by the call stack of recursive calls to the insert method.

The principle stays the same when inserting a new element into the queue:

  • You need to transfer elements from one stack to another temporary stack, to reverse their order.
  • Then push the new element to be inserted, onto the temporary stack
  • Then transfer the elements back to the original stack
  • The new element will be on the bottom of the stack, and the oldest element is on top (first to be popped)

A Queue class using only one Stack, would be as follows:

public class SimulatedQueue<E> {
    private java.util.Stack<E> stack = new java.util.Stack<E>();

    public void insert(E elem) {
        if (!stack.empty()) {
            E topElem = stack.pop();
            insert(elem);
            stack.push(topElem);
        }
        else
            stack.push(elem);
    }

    public E remove() {
        return stack.pop();
    }
}

What does /p mean in set /p?

The /P switch allows you to set the value of a variable to a line of input entered by the user. Displays the specified promptString before reading the line of input. The promptString can be empty.

Two ways I've used it... first:

SET /P variable=

When batch file reaches this point (when left blank) it will halt and wait for user input. Input then becomes variable.

And second:

SET /P variable=<%temp%\filename.txt

Will set variable to contents (the first line) of the txt file. This method won't work unless the /P is included. Both tested on Windows 8.1 Pro, but it's the same on 7 and 10.

Unpacking a list / tuple of pairs into two lists / tuples

list1 = (x[0] for x in source_list)
list2 = (x[1] for x in source_list)

How to include a class in PHP

I suggest you also take a look at __autoload.
This will clean up the code of requires and includes.

Convert String into a Class Object

You can use the statement :-

Class c = s.getClass();

To get the class instance.

Combine a list of data frames into one data frame by row

Use bind_rows() from the dplyr package:

bind_rows(list_of_dataframes, .id = "column_label")

Notice: Undefined offset: 0 in

As you might have already about knew the error. This is due to trying to access the empty array or trying to access the value of empty key of array. In my project, I am dealing with this error with counting the array and displaying result.

You can do it like this:

if(count($votes) == '0'){

    echo 'Sorry, no votes are available at the moment.';
}
else{
    //do the stuff with votes
}

count($votes) counts the $votes array. If it is equal to zero (0), you can display your custom message or redirect to certain page else you can do stuff with $votes. In this way you can remove the Notice: Undefined offset: 0 in notice in PHP.

RESTful Authentication via Spring

You might consider Digest Access Authentication. Essentially the protocol is as follows:

  1. Request is made from client
  2. Server responds with a unique nonce string
  3. Client supplies a username and password (and some other values) md5 hashed with the nonce; this hash is known as HA1
  4. Server is then able to verify client's identity and serve up the requested materials
  5. Communication with the nonce can continue until the server supplies a new nonce (a counter is used to eliminate replay attacks)

All of this communication is made through headers, which, as jmort253 points out, is generally more secure than communicating sensitive material in the url parameters.

Digest Access Authentication is supported by Spring Security. Notice that, although the docs say that you must have access to your client's plain-text password, you can successfully authenticate if you have the HA1 hash for your client.

Bootstrap combining rows (rowspan)

Paul's answer seems to defeat the purpose of bootstrap; that of being responsive to the viewport / screen size.

By nesting rows and columns you can achieve the same result, while retaining responsiveness.

Here is an up-to-date response to this problem;

_x000D_
_x000D_
<div class="container-fluid">_x000D_
  <h1>  Responsive Nested Bootstrap </h1> _x000D_
  <div class="row">_x000D_
    <div class="col-md-5" style="background-color:red;">Span 5</div>_x000D_
    <div class="col-md-3" style="background-color:blue;">Span 3</div>_x000D_
    <div class="col-md-2">_x000D_
      <div class="row">_x000D_
        <div class="container" style="background-color:green;">Span 2</div>_x000D_
      </div>_x000D_
      <div class="row">_x000D_
        <div class="container" style="background-color:purple;">Span 2</div>_x000D_
      </div>_x000D_
    </div>_x000D_
    <div class="col-md-2" style="background-color:yellow;">Span 2</div>_x000D_
  </div>_x000D_
  _x000D_
  <div class="row">_x000D_
    <div class="col-md-6">_x000D_
      <div class="row">_x000D_
        <div class="container" style="background-color:yellow;">Span 6</div>_x000D_
      </div>_x000D_
      <div class="row">_x000D_
        <div class="container" style="background-color:green;">Span 6</div>_x000D_
      </div>_x000D_
    </div>_x000D_
    <div class="col-md-6" style="background-color:red;">Span 6</div>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

You can view the codepen here.

Python code to remove HTML tags from a string

global temp

temp =''

s = ' '

def remove_strings(text):

    global temp 

    if text == '':

        return temp

    start = text.find('<')

    end = text.find('>')

    if start == -1 and end == -1 :

        temp = temp + text

    return temp

newstring = text[end+1:]

fresh_start = newstring.find('<')

if newstring[:fresh_start] != '':

    temp += s+newstring[:fresh_start]

remove_strings(newstring[fresh_start:])

return temp

Adding POST parameters before submit

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

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

form = form.serializeArray();

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

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

HTML button opening link in new tab

Try using below code:

<button title="button title" class="action primary tocart" onclick=" window.open('http://www.google.com', '_blank'); return false;">Google</button>

Here, the window.open with _blank as second argument of window.open function will open the link in new tab.

And by the use of return false we can remove/cancel the default behavior of the button like submit.

For more detail and live example, click here

Difference between dates in JavaScript

You can also use it

export function diffDateAndToString(small: Date, big: Date) {


    // To calculate the time difference of two dates 
    const Difference_In_Time = big.getTime() - small.getTime()

    // To calculate the no. of days between two dates 
    const Days = Difference_In_Time / (1000 * 3600 * 24)
    const Mins = Difference_In_Time / (60 * 1000)
    const Hours = Mins / 60

    const diffDate = new Date(Difference_In_Time)

    console.log({ date: small, now: big, diffDate, Difference_In_Days: Days, Difference_In_Mins: Mins, Difference_In_Hours: Hours })

    var result = ''

    if (Mins < 60) {
        result = Mins + 'm'
    } else if (Hours < 24) result = diffDate.getMinutes() + 'h'
    else result = Days + 'd'
    return { result, Days, Mins, Hours }
}

results in { result: '30d', Days: 30, Mins: 43200, Hours: 720 }

Is there a decorator to simply cache function return values?

Try joblib http://pythonhosted.org/joblib/memory.html

from joblib import Memory
memory = Memory(cachedir=cachedir, verbose=0)
@memory.cache
    def f(x):
        print('Running f(%s)' % x)
        return x

Can clearInterval() be called inside setInterval()?

Yes you can. You can even test it:

_x000D_
_x000D_
var i = 0;_x000D_
var timer = setInterval(function() {_x000D_
  console.log(++i);_x000D_
  if (i === 5) clearInterval(timer);_x000D_
  console.log('post-interval'); //this will still run after clearing_x000D_
}, 200);
_x000D_
_x000D_
_x000D_

In this example, this timer clears when i reaches 5.

VT-x is disabled in the BIOS for both all CPU modes (VERR_VMX_MSR_ALL_VMX_DISABLED)

For Ubuntu on HP (Intel processors),

Press F10 on booting the system, it will enter into system setup mode.

You will find tabs on top like Main, Security, Advanced.

Go into Advanced >> and click on System settings.

Mark the check boxes on Enable Virtualization Technology (VTx) and Virtualization Technology Directed I/O (VTd).

Back to Main, click on save changes and exit.

Add a linebreak in an HTML text area

You could use \r\n, or System.Environment.NewLine.

Testing web application on Mac/Safari when I don't own a Mac

For my case (a small, personal project) https://www.lambdatest.com/ was very helpful. Free tier allows for 6 sessions per month.

How do I move a redis database from one server to another?

I also want to do the same thing: migrate a db from a standalone redis instance to a another redis instances(redis sentinel).

Because the data is not critical(session data), i will give https://github.com/yaauie/redis-copy a try.

importing external ".txt" file in python

Import gives you access to other modules in your program. You can't decide to import a text file. If you want to read from a file that's in the same directory, you can look at this. Here's another StackOverflow post about it.

What is the symbol for whitespace in C?

#include <stdio.h>
main()
{
int c,sp,tb,nl;
sp = 0;
tb = 0;
nl = 0;
while((c = getchar()) != EOF)
{
   switch( c )
{
   case ' ':
        ++sp;
     printf("space:%d\n", sp);
     break;
   case  '\t':
        ++tb;
     printf("tab:%d\n", tb);
     break;
   case '\n':
        ++nl;
     printf("new line:%d\n", nl);
     break;
  }
 }
}

Caesar Cipher Function in Python

This is an improved version of the code in the answer of @amillerrhodes that works with different alphabets, not just lowercase:

def caesar(text, step, alphabets):

    def shift(alphabet):
        return alphabet[step:] + alphabet[:step]

    shifted_alphabets = tuple(map(shift, alphabets))
    joined_aphabets = ''.join(alphabets)
    joined_shifted_alphabets = ''.join(shifted_alphabets)
    table = str.maketrans(joined_aphabets, joined_shifted_alphabets)
    return text.translate(table)

Example of usage:

>>> import string
>>> alphabets = (string.ascii_lowercase, string.ascii_uppercase, string.digits)
>>> caesar('Abc-xyZ.012:789??ñç', step=4, alphabets=alphabets)
'Efg-bcD.456:123??ñç'

References:
Docs on str.maketrans.
Docs on str.translate.
Docs on the string library

Java SE 6 vs. JRE 1.6 vs. JDK 1.6 - What do these mean?

  • JDK - Java Development Kit
  • JRE - Java Runtime Environment
  • Java SE - Java Standard Edition

SE defines a set of capabilities and functionalities; there are more complex editions (Enterprise Edition – EE) and simpler ones (Micro Edition – ME – for mobile environments).

The JDK includes the compiler and other tools needed to develop Java applications; JRE does not. So, to run a Java application someone else provides, you need JRE; to develop a Java application, you need JDK.

Edited: As Chris Marasti-Georg pointed out in a comment, you can find out lots of information at Sun's Java web site, and in particular from the Java SE section, (2nd option, Java SE Development Kit (JDK) 6 Update 10).


Edited 2011-04-06: The world turns, and Java is now managed by Oracle, which bought Sun. Later this year, the sun.com domain is supposed to go dark. The new page (based on a redirect) is this Java page at the Oracle Tech Network. (See also java.com.)


Edited 2013-01-11: And the world keeps on turning (2012-12-21 notwithstanding), and lo and behold, JRE 6 is about to reach its end of support. Oracle says no more public updates to Java 6 after February 2013.

Within a given version of Java, this answer remains valid. JDK is the Java Development Kit, JRE is the Java Runtime Environment, Java SE is the standard edition, and so on. But the version 6 (1.6) is becoming antiquated.

Edited 2015-04-29: And with another couple of revolutions around the sun, the time has come for the end of support for Java SE 7, too. In April 2015, Oracle affirmed that it was no longer providing public updates to Java SE 7. The tentative end of public updates for Java SE 8 is March 2017, but that end date is subject to change (later, not earlier).

angular 2 ngIf and CSS transition/animation

According to the latest angular 2 documentation you can animate "Entering and Leaving" elements (like in angular 1).

Example of simple fade animation:

In relevant @Component add:

animations: [
  trigger('fadeInOut', [
    transition(':enter', [   // :enter is alias to 'void => *'
      style({opacity:0}),
      animate(500, style({opacity:1})) 
    ]),
    transition(':leave', [   // :leave is alias to '* => void'
      animate(500, style({opacity:0})) 
    ])
  ])
]

Do not forget to add imports

import {style, state, animate, transition, trigger} from '@angular/animations';

The relevant component's html's element should look like:

<div *ngIf="toggle" [@fadeInOut]>element</div>

I built example of slide and fade animation here.

Explanation on 'void' and '*':

  • void is the state when ngIf is set to false (it applies when the element is not attached to a view).
  • * - There can be many animation states (read more in docs). The * state takes precedence over all of them as a "wildcard" (in my example this is the state when ngIf is set to true).

Notice (taken from angular docs):

Extra declare inside the app module, import { BrowserAnimationsModule } from '@angular/platform-browser/animations';

Angular animations are built on top of the standard Web Animations API and run natively on browsers that support it. For other browsers, a polyfill is required. Grab web-animations.min.js from GitHub and add it to your page.

error: RPC failed; curl transfer closed with outstanding read data remaining

After few days, today I just resolved this problem. Generate ssh key, follow this article:

https://help.github.com/articles/generating-a-new-ssh-key-and-adding-it-to-the-ssh-agent/

Declare it to

  1. Git provider (GitLab what I am using, GitHub).
  2. Add this to local identity.

Then clone by command:

git clone [email protected]:my_group/my_repository.git

And no error happen.

The above problem

error: RPC failed; curl 18 transfer closed with outstanding read data remaining

because have error when clone by HTTP protocol (curl command).

And, you should increment buffer size:

git config --global http.postBuffer 524288000

Java 8 Distinct by property

You can use groupingBy collector:

persons.collect(Collectors.groupingBy(p -> p.getName())).values().forEach(t -> System.out.println(t.get(0).getId()));

If you want to have another stream you can use this:

persons.collect(Collectors.groupingBy(p -> p.getName())).values().stream().map(l -> (l.get(0)));

Convert string to date then format the date

enter image description here

String myFormat= "yyyy-MM-dd";
String finalString = "";
try {
DateFormat formatter = new SimpleDateFormat("yyyy MMM dd");
Date date = (Date) formatter .parse("2015 Oct 09");
SimpleDateFormat newFormat = new SimpleDateFormat(myFormat);
finalString= newFormat .format(date );
newDate.setText(finalString);
} catch (Exception e) {

}

@POST in RESTful web service

REST webservice: (http://localhost:8080/your-app/rest/data/post)

package com.yourorg.rest;

import javax.ws.rs.Consumes;
import javax.ws.rs.POST; 
import javax.ws.rs.Path; 
import javax.ws.rs.Produces; 
import javax.ws.rs.core.MediaType; 
import javax.ws.rs.core.Response;

    @Path("/data")
public class JSONService {

    @POST
    @Path("/post")
    @Consumes(MediaType.APPLICATION_JSON)
    public Response createDataInJSON(String data) { 

        String result = "Data post: "+data;

        return Response.status(201).entity(result).build(); 
    }

Client send a post:

package com.yourorg.client;

import com.sun.jersey.api.client.Client;
import com.sun.jersey.api.client.ClientResponse;
import com.sun.jersey.api.client.WebResource;

public class JerseyClientPost {

  public static void main(String[] args) {

    try {

        Client client = Client.create();

        WebResource webResource = client.resource("http://localhost:8080/your-app/rest/data/post");

        String input = "{\"message\":\"Hello\"}";

        ClientResponse response = webResource.type("application/json")
           .post(ClientResponse.class, input);

        if (response.getStatus() != 201) {
            throw new RuntimeException("Failed : HTTP error code : "
                 + response.getStatus());
        }

        System.out.println("Output from Server .... \n");
        String output = response.getEntity(String.class);
        System.out.println(output);

      } catch (Exception e) {

        e.printStackTrace();

      }

    }
}

How do you get a directory listing in C?

Directory listing varies greatly according to the OS/platform under consideration. This is because, various Operating systems using their own internal system calls to achieve this.

A solution to this problem would be to look for a library which masks this problem and portable. Unfortunately, there is no solution that works on all platforms flawlessly.

On POSIX compatible systems, you could use the library to achieve this using the code posted by Clayton (which is referenced originally from the Advanced Programming under UNIX book by W. Richard Stevens). this solution will work under *NIX systems and would also work on Windows if you have Cygwin installed.

Alternatively, you could write a code to detect the underlying OS and then call the appropriate directory listing function which would hold the 'proper' way of listing the directory structure under that OS.

Replace HTML Table with Divs

This ought to do the trick.

<style>
div.block{
  overflow:hidden;
}
div.block label{
  width:160px;
  display:block;
  float:left;
  text-align:left;
}
div.block .input{
  margin-left:4px;
  float:left;
}
</style>

<div class="block">
  <label>First field</label>
  <input class="input" type="text" id="txtFirstName"/>
</div>
<div class="block">
  <label>Second field</label>
  <input class="input" type="text" id="txtLastName"/>
</div>

I hope you get the concept.

run program in Python shell

If you're wanting to run the script and end at a prompt (so you can inspect variables, etc), then use:

python -i test.py

That will run the script and then drop you into a Python interpreter.

How does the Spring @ResponseBody annotation work?

The first basic thing to understand is the difference in architectures.

One end you have the MVC architecture, which is based on your normal web app, using web pages, and the browser makes a request for a page:

Browser <---> Controller <---> Model
               |      |
               +-View-+

The browser makes a request, the controller (@Controller) gets the model (@Entity), and creates the view (JSP) from the model and the view is returned back to the client. This is the basic web app architecture.

On the other end, you have a RESTful architecture. In this case, there is no View. The Controller only sends back the model (or resource representation, in more RESTful terms). The client can be a JavaScript application, a Java server application, any application in which we expose our REST API to. With this architecture, the client decides what to do with this model. Take for instance Twitter. Twitter as the Web (REST) API, that allows our applications to use its API to get such things as status updates, so that we can use it to put that data in our application. That data will come in some format like JSON.

That being said, when working with Spring MVC, it was first built to handle the basic web application architecture. There are may different method signature flavors that allow a view to be produced from our methods. The method could return a ModelAndView where we explicitly create it, or there are implicit ways where we can return some arbitrary object that gets set into model attributes. But either way, somewhere along the request-response cycle, there will be a view produced.

But when we use @ResponseBody, we are saying that we do not want a view produced. We just want to send the return object as the body, in whatever format we specify. We wouldn't want it to be a serialized Java object (though possible). So yes, it needs to be converted to some other common type (this type is normally dealt with through content negotiation - see link below). Honestly, I don't work much with Spring, though I dabble with it here and there. Normally, I use

@RequestMapping(..., produces = MediaType.APPLICATION_JSON_VALUE)

to set the content type, but maybe JSON is the default. Don't quote me, but if you are getting JSON, and you haven't specified the produces, then maybe it is the default. JSON is not the only format. For instance, the above could easily be sent in XML, but you would need to have the produces to MediaType.APPLICATION_XML_VALUE and I believe you need to configure the HttpMessageConverter for JAXB. As for the JSON MappingJacksonHttpMessageConverter configured, when we have Jackson on the classpath.

I would take some time to learn about Content Negotiation. It's a very important part of REST. It'll help you learn about the different response formats and how to map them to your methods.

addClass - can add multiple classes on same div?

$('.page-address-edit').addClass('test1 test2 test3');

Ref- jQuery

pandas GroupBy columns with NaN (missing) values

pandas >= 1.1

From pandas 1.1 you have better control over this behavior, NA values are now allowed in the grouper using dropna=False:

pd.__version__
# '1.1.0.dev0+2004.g8d10bfb6f'

# Example from the docs
df

   a    b  c
0  1  2.0  3
1  1  NaN  4
2  2  1.0  3
3  1  2.0  2

# without NA (the default)
df.groupby('b').sum()

     a  c
b        
1.0  2  3
2.0  2  5
# with NA
df.groupby('b', dropna=False).sum()

     a  c
b        
1.0  2  3
2.0  2  5
NaN  1  4

Check free disk space for current partition in bash

I think this should be a comment or an edit to ThinkingMedia's answer on this very question (Check free disk space for current partition in bash), but I am not allowed to comment (not enough rep) and my edit has been rejected (reason: "this should be a comment or an answer"). So please, powers of the SO universe, don't damn me for repeating and fixing someone else's "answer". But someone on the internet was wrong!™ and they wouldn't let me fix it.

The code

  df --output=avail -h "$PWD" | sed '1d;s/[^0-9]//g'

has a substantial flaw: Yes, it will output 50G free as 50 -- but it will also output 5.0M free as 50 or 3.4G free as 34 or 15K free as 15.

To create a script with the purpose of checking for a certain amount of free disk space you have to know the unit you're checking against. Remove it (as sed does in the example above) the numbers don't make sense anymore.

If you actually want it to work, you will have to do something like:

FREE=`df -k --output=avail "$PWD" | tail -n1`   # df -k not df -h
if [[ $FREE -lt 10485760 ]]; then               # 10G = 10*1024*1024k
     # less than 10GBs free!
fi;

Also for an installer to df -k $INSTALL_TARGET_DIRECTORY might make more sense than df -k "$PWD". Finally, please note that the --output flag is not available in every version of df / linux.

Background position, margin-top?

#div-name

{

  background-image: url('../images/background-art-main.jpg');
  background-position: top right 50px;
  background-repeat: no-repeat;
}

Redirecting output to $null in PowerShell, but ensuring the variable remains set

using a function:

function run_command ($command)
{
    invoke-expression "$command *>$null"
    return $_
}

if (!(run_command "dir *.txt"))
{
    if (!(run_command "dir *.doc"))
    {
        run_command "dir *.*"
    }
}

or if you like one-liners:

function run_command ($command) { invoke-expression "$command  "|out-null; return $_ }

if (!(run_command "dir *.txt")) { if (!(run_command "dir *.doc")) { run_command "dir *.*" } }

How to check whether a pandas DataFrame is empty?

I use the len function. It's much faster than empty. len(df.index) is even faster.

import pandas as pd
import numpy as np

df = pd.DataFrame(np.random.randn(10000, 4), columns=list('ABCD'))

def empty(df):
    return df.empty

def lenz(df):
    return len(df) == 0

def lenzi(df):
    return len(df.index) == 0

'''
%timeit empty(df)
%timeit lenz(df)
%timeit lenzi(df)

10000 loops, best of 3: 13.9 µs per loop
100000 loops, best of 3: 2.34 µs per loop
1000000 loops, best of 3: 695 ns per loop

len on index seems to be faster
'''

Putting GridView data in a DataTable

user this full solution to convert gridview to datatable

 public DataTable gridviewToDataTable(GridView gv)
        {

            DataTable dtCalculate = new DataTable("TableCalculator");

            // Create Column 1: Date
            DataColumn dateColumn = new DataColumn();
            dateColumn.DataType = Type.GetType("System.DateTime");
            dateColumn.ColumnName = "date";

            // Create Column 3: TotalSales
            DataColumn loanBalanceColumn = new DataColumn();
            loanBalanceColumn.DataType = Type.GetType("System.Double");
            loanBalanceColumn.ColumnName = "loanbalance";


            DataColumn offsetBalanceColumn = new DataColumn();
            offsetBalanceColumn.DataType = Type.GetType("System.Double");
            offsetBalanceColumn.ColumnName = "offsetbalance";


            DataColumn netloanColumn = new DataColumn();
            netloanColumn.DataType = Type.GetType("System.Double");
            netloanColumn.ColumnName = "netloan";


            DataColumn interestratecolumn = new DataColumn();
            interestratecolumn.DataType = Type.GetType("System.Double");
            interestratecolumn.ColumnName = "interestrate";

            DataColumn interestrateperdaycolumn = new DataColumn();
            interestrateperdaycolumn.DataType = Type.GetType("System.Double");
            interestrateperdaycolumn.ColumnName = "interestrateperday";

            // Add the columns to the ProductSalesData DataTable
            dtCalculate.Columns.Add(dateColumn);
            dtCalculate.Columns.Add(loanBalanceColumn);
            dtCalculate.Columns.Add(offsetBalanceColumn);
            dtCalculate.Columns.Add(netloanColumn);
            dtCalculate.Columns.Add(interestratecolumn);
            dtCalculate.Columns.Add(interestrateperdaycolumn);

            foreach (GridViewRow row in gv.Rows)
            {
                DataRow dr;
                dr = dtCalculate.NewRow();

                dr["date"] = DateTime.Parse(row.Cells[0].Text);
                dr["loanbalance"] = double.Parse(row.Cells[1].Text);
                dr["offsetbalance"] = double.Parse(row.Cells[2].Text);
                dr["netloan"] = double.Parse(row.Cells[3].Text);
                dr["interestrate"] = double.Parse(row.Cells[4].Text);
                dr["interestrateperday"] = double.Parse(row.Cells[5].Text);


                dtCalculate.Rows.Add(dr);
            }



            return dtCalculate;
        }

GitHub: invalid username or password

Instead of git pull also try git pull origin master

I changed password, and the first command gave error:

$ git pull
remote: Invalid username or password.
fatal: Authentication failed for ...

After git pull origin master, it asked for password and seemed to update itself

Check if not nil and not empty in Rails shortcut?

There's a method that does this for you:

def show
  @city = @user.city.present?
end

The present? method tests for not-nil plus has content. Empty strings, strings consisting of spaces or tabs, are considered not present.

Since this pattern is so common there's even a shortcut in ActiveRecord:

def show
  @city = @user.city?
end

This is roughly equivalent.

As a note, testing vs nil is almost always redundant. There are only two logically false values in Ruby: nil and false. Unless it's possible for a variable to be literal false, this would be sufficient:

if (variable)
  # ...
end

This is preferable to the usual if (!variable.nil?) or if (variable != nil) stuff that shows up occasionally. Ruby tends to wards a more reductionist type of expression.

One reason you'd want to compare vs. nil is if you have a tri-state variable that can be true, false or nil and you need to distinguish between the last two states.

Select first 4 rows of a data.frame in R

For at DataFrame one can simply type

head(data, num=10L)

to get the first 10 for example.

For a data.frame one can simply type

head(data, 10)

to get the first 10.

How to open the second form?

On any click event (or other one):

Form2 frm2 = new Form2();
frm2.Show();

POSTing JSON to URL via WebClient in C#

The question is already answered but I think I've found the solution that is simpler and more relevant to the question title, here it is:

var cli = new WebClient();
cli.Headers[HttpRequestHeader.ContentType] = "application/json";
string response = cli.UploadString("http://some/address", "{some:\"json data\"}");

PS: In the most of .net implementations, but not in all WebClient is IDisposable, so of cource it is better to do 'using' or 'Dispose' on it. However in this particular case it is not really necessary.

Auto logout with Angularjs based on idle user

I think Buu's digest cycle watch is genius. Thanks for sharing. As others have noted $interval also causes the digest cycle to run. We could for the purpose of auto logging the user out use setInterval which will not cause a digest loop.

app.run(function($rootScope) {
    var lastDigestRun = new Date();
    setInterval(function () {
        var now = Date.now();
        if (now - lastDigestRun > 10 * 60 * 1000) {
          //logout
        }
    }, 60 * 1000);

    $rootScope.$watch(function() {
        lastDigestRun = new Date();
    });
});

JAX-WS and BASIC authentication, when user names and passwords are in a database

BindingProvider.USERNAME_PROPERTY and BindingProvider.PASSWORD_PROPERTY are matching HTTP Basic Authentication mechanism that enable authentication process at the HTTP level and not at the application nor servlet level.

Basically, only the HTTP server will know the username and the password (and eventually application according to HTTP/application server specification, such with Apache/PHP). With Tomcat/Java, add a login config BASIC in your web.xml and appropriate security-constraint/security-roles (roles that will be later associated to users/groups of real users).

<login-config>
    <auth-method>BASIC</auth-method>
    <realm-name>YourRealm</realm-name>
</login-config>

Then, connect the realm at the HTTP server (or application server) level with the appropriate user repository. For tomcat you may look at JAASRealm, JDBCRealm or DataSourceRealm that may suit your needs.

http://tomcat.apache.org/tomcat-6.0-doc/realm-howto.html

jQuery events .load(), .ready(), .unload()

If both "document.ready" variants are used they will both fire, in the order of appearance

$(function(){
    alert('shorthand document.ready');
});

//try changing places
$(document).ready(function(){
    alert('document.ready');
});

Sending arrays with Intent.putExtra

You are setting the extra with an array. You are then trying to get a single int.

Your code should be:

int[] arrayB = extras.getIntArray("numbers");

Matrix multiplication using arrays

You can try this code:

public class MyMatrix {
    Double[][] A = { { 4.00, 3.00 }, { 2.00, 1.00 } };
    Double[][] B = { { -0.500, 1.500 }, { 1.000, -2.0000 } };

    public static Double[][] multiplicar(Double[][] A, Double[][] B) {

        int aRows = A.length;
        int aColumns = A[0].length;
        int bRows = B.length;
        int bColumns = B[0].length;

        if (aColumns != bRows) {
            throw new IllegalArgumentException("A:Rows: " + aColumns + " did not match B:Columns " + bRows + ".");
        }

        Double[][] C = new Double[aRows][bColumns];
        for (int i = 0; i < aRows; i++) {
            for (int j = 0; j < bColumns; j++) {
                C[i][j] = 0.00000;
            }
        }

        for (int i = 0; i < aRows; i++) { // aRow
            for (int j = 0; j < bColumns; j++) { // bColumn
                for (int k = 0; k < aColumns; k++) { // aColumn
                    C[i][j] += A[i][k] * B[k][j];
                }
            }
        }

        return C;
    }

    public static void main(String[] args) {

        MyMatrix matrix = new MyMatrix();
        Double[][] result = multiplicar(matrix.A, matrix.B);

        for (int i = 0; i < 2; i++) {
            for (int j = 0; j < 2; j++)
                System.out.print(result[i][j] + " ");
            System.out.println();
        }
    }
}

Maximum and Minimum values for ints

sys.maxsize is not the actually the maximum integer value which is supported. You can double maxsize and multiply it by itself and it stays a valid and correct value.

However, if you try sys.maxsize ** sys.maxsize, it will hang your machine for a significant amount of time. As many have pointed out, the byte and bit size does not seem to be relevant because it practically doesn't exist. I guess python just happily expands it's integers when it needs more memory space. So in general there is no limit.

Now, if you're talking about packing or storing integers in a safe way where they can later be retrieved with integrity then of course that is relevant. I'm really not sure about packing but I know python's pickle module handles those things well. String representations obviously have no practical limit.

So really, the bottom line is: what is your applications limit? What does it require for numeric data? Use that limit instead of python's fairly nonexistent integer limit.

How to get the nth occurrence in a string?

I was playing around with the following code for another question on StackOverflow and thought that it might be appropriate for here. The function printList2 allows the use of a regex and lists all the occurrences in order. (printList was an attempt at an earlier solution, but it failed in a number of cases.)

_x000D_
_x000D_
<html>_x000D_
<head>_x000D_
<title>Checking regex</title>_x000D_
<script>_x000D_
var string1 = "123xxx5yyy1234ABCxxxabc";_x000D_
var search1 = /\d+/;_x000D_
var search2 = /\d/;_x000D_
var search3 = /abc/;_x000D_
function printList(search) {_x000D_
   document.writeln("<p>Searching using regex: " + search + " (printList)</p>");_x000D_
   var list = string1.match(search);_x000D_
   if (list == null) {_x000D_
      document.writeln("<p>No matches</p>");_x000D_
      return;_x000D_
   }_x000D_
   // document.writeln("<p>" + list.toString() + "</p>");_x000D_
   // document.writeln("<p>" + typeof(list1) + "</p>");_x000D_
   // document.writeln("<p>" + Array.isArray(list1) + "</p>");_x000D_
   // document.writeln("<p>" + list1 + "</p>");_x000D_
   var count = list.length;_x000D_
   document.writeln("<ul>");_x000D_
   for (i = 0; i < count; i++) {_x000D_
      document.writeln("<li>" +  "  " + list[i] + "   length=" + list[i].length + _x000D_
          " first position=" + string1.indexOf(list[i]) + "</li>");_x000D_
   }_x000D_
   document.writeln("</ul>");_x000D_
}_x000D_
function printList2(search) {_x000D_
   document.writeln("<p>Searching using regex: " + search + " (printList2)</p>");_x000D_
   var index = 0;_x000D_
   var partial = string1;_x000D_
   document.writeln("<ol>");_x000D_
   for (j = 0; j < 100; j++) {_x000D_
       var found = partial.match(search);_x000D_
       if (found == null) {_x000D_
          // document.writeln("<p>not found</p>");_x000D_
          break;_x000D_
       }_x000D_
       var size = found[0].length;_x000D_
       var loc = partial.search(search);_x000D_
       var actloc = loc + index;_x000D_
       document.writeln("<li>" + found[0] + "  length=" + size + "  first position=" + actloc);_x000D_
       // document.writeln("  " + partial + "  " + loc);_x000D_
       partial = partial.substring(loc + size);_x000D_
       index = index + loc + size;_x000D_
       document.writeln("</li>");_x000D_
   }_x000D_
   document.writeln("</ol>");_x000D_
_x000D_
}_x000D_
</script>_x000D_
</head>_x000D_
<body>_x000D_
<p>Original string is <script>document.writeln(string1);</script></p>_x000D_
<script>_x000D_
   printList(/\d+/g);_x000D_
   printList2(/\d+/);_x000D_
   printList(/\d/g);_x000D_
   printList2(/\d/);_x000D_
   printList(/abc/g);_x000D_
   printList2(/abc/);_x000D_
   printList(/ABC/gi);_x000D_
   printList2(/ABC/i);_x000D_
</script>_x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

Java - Convert int to Byte Array of 4 Bytes?

This should work:

public static final byte[] intToByteArray(int value) {
    return new byte[] {
            (byte)(value >>> 24),
            (byte)(value >>> 16),
            (byte)(value >>> 8),
            (byte)value};
}

Code taken from here.

Edit An even simpler solution is given in this thread.

How to center a button within a div?

Updated Answer

Updating because I noticed it's an active answer, however Flexbox would be the correct approach now.

Live Demo

Vertical and horizontal alignment.

#wrapper {
  display: flex;
  align-items: center;
  justify-content: center;
}

Just horizontal (as long as the main flex axis is horizontal which is default)

#wrapper {
  display: flex;
  justify-content: center;
}

Original Answer using a fixed width and no flexbox

If the original poster wants vertical and center alignment its quite easy for fixed width and height of the button, try the following

Live Demo

CSS

button{
    height:20px; 
    width:100px; 
    margin: -20px -50px; 
    position:relative;
    top:50%; 
    left:50%;
}

for just horizontal alignment use either

button{
    margin: 0 auto;
}

or

div{
    text-align:center;
}

Expected response code 220 but got code "", with message "" in Laravel

In my case I had to set the

MAIL_DRIVER=smtp
MAIL_HOST=smtp.gmail.com
MAIL_PORT=465           <<<<<<<------------------------- (FOCUS THIS)
MAIL_USERNAME=<<your email address>>
MAIL_PASSWORD=<<app password>>

MAIL_ENCRYPTION= ssl    <<<<<<<------------------------- (FOCUS THIS)

to work it.. Might be useful. Rest of the code was same as @Sid said.

And I think that editing both environment file and app/config/mail.php is unnecessary. Just use one method.

Edit as per the comment by @Zan

If you need to enable tls protection use following settings.

MAIL_PORT=587
MAIL_ENCRYPTION= tls  

See here for some other gmail settings

Mosaic Grid gallery with dynamic sized images

I think you can try "Google Grid Gallery", it based on aforementioned Masonry with some additions, like styles and viewer.

Excel VBA Code: Compile Error in x64 Version ('PtrSafe' attribute required)

I think all you need to do for your function is just add PtrSafe: i.e. the first line of your first function should look like this:

Private Declare PtrSafe Function swe_azalt Lib "swedll32.dll" ......

How to use if, else condition in jsf to display image

It is illegal to nest EL expressions: you should inline them. Using JSTL is perfectly valid in your situation. Correcting the mistake, you'll make the code working:

<html xmlns="http://www.w3.org/1999/xhtml" xmlns:c="http://java.sun.com/jstl/core">
    <c:if test="#{not empty user or user.userId eq 0}">
        <a href="Images/thumb_02.jpg" target="_blank" ></a>
        <img src="Images/thumb_02.jpg" />
    </c:if>
    <c:if test="#{empty user or user.userId eq 0}">
        <a href="/DisplayBlobExample?userId=#{user.userId}" target="_blank"></a>
        <img src="/DisplayBlobExample?userId=#{user.userId}" />
    </c:if>
</html>

Another solution is to specify all the conditions you want inside an EL of one element. Though it could be heavier and less readable, here it is:

<a href="#{not empty user or user.userId eq 0 ? '/Images/thumb_02.jpg' : '/DisplayBlobExample?userId='}#{not empty user or user.userId eq 0 ? '' : user.userId}" target="_blank"></a>
<img src="#{not empty user or user.userId eq 0 ? '/Images/thumb_02.jpg' : '/DisplayBlobExample?userId='}#{not empty user or user.userId eq 0 ? '' : user.userId}" target="_blank"></img>

Accidentally committed .idea directory files into git

Add .idea directory to the list of ignored files

First, add it to .gitignore, so it is not accidentally committed by you (or someone else) again:

.idea

Remove it from repository

Second, remove the directory only from the repository, but do not delete it locally. To achieve that, do what is listed here:

Remove a file from a Git repository without deleting it from the local filesystem

Send the change to others

Third, commit the .gitignore file and the removal of .idea from the repository. After that push it to the remote(s).

Summary

The full process would look like this:

$ echo '.idea' >> .gitignore
$ git rm -r --cached .idea
$ git add .gitignore
$ git commit -m '(some message stating you added .idea to ignored entries)'
$ git push

(optionally you can replace last line with git push some_remote, where some_remote is the name of the remote you want to push to)

What is the fastest way to send 100,000 HTTP requests in Python?

I found that using the tornado package to be the fastest and simplest way to achieve this:

from tornado import ioloop, httpclient, gen


def main(urls):
    """
    Asynchronously download the HTML contents of a list of URLs.
    :param urls: A list of URLs to download.
    :return: List of response objects, one for each URL.
    """

    @gen.coroutine
    def fetch_and_handle():
        httpclient.AsyncHTTPClient.configure(None, defaults=dict(user_agent='MyUserAgent'))
        http_client = httpclient.AsyncHTTPClient()
        waiter = gen.WaitIterator(*[http_client.fetch(url, raise_error=False, method='HEAD')
                                    for url in urls])
        results = []
        # Wait for the jobs to complete
        while not waiter.done():
            try:
                response = yield waiter.next()
            except httpclient.HTTPError as e:
                print(f'Non-200 HTTP response returned: {e}')
                continue
            except Exception as e:
                print(f'An unexpected error occurred querying: {e}')
                continue
            else:
                print(f'URL \'{response.request.url}\' has status code <{response.code}>')
                results.append(response)
        return results

    loop = ioloop.IOLoop.current()
    web_pages = loop.run_sync(fetch_and_handle)

    return web_pages

my_urls = ['url1.com', 'url2.com', 'url100000.com']
responses = main(my_urls)
print(responses[0])

How to destroy Fragment?

Give a try to this

@Override
public void destroyItem(ViewGroup container, int position, Object object) {
    // TODO Auto-generated method stub

    FragmentManager manager = ((Fragment) object).getFragmentManager();
    FragmentTransaction trans = manager.beginTransaction();
    trans.remove((Fragment) object);
    trans.commit();

    super.destroyItem(container, position, object);
}

Android - Start service on boot

Just to make searching easier, as mentioned in comments, this is not possible since 3.1 https://stackoverflow.com/a/19856367/6505257

How to get DateTime.Now() in YYYY-MM-DDThh:mm:ssTZD format using C#

Use the zzz format specifier to get the timezone offset as hours and minutes. You also want to use the HH format specifier to get the hours in 24 hour format.

DateTime.Now.ToString("yyyy-MM-ddTHH:mm:sszzz")

Result:

2011-08-09T23:49:58+02:00

Some culture settings uses periods instead of colons for time, so you might want to use literal colons instead of time separators:

DateTime.Now.ToString("yyyy-MM-ddTHH':'mm':'sszzz")

Custom Date and Time Format Strings

How to remove square brackets in string using regex?

Use this regular expression to match square brackets or single quotes:

/[\[\]']+/g

Replace with the empty string.

_x000D_
_x000D_
console.log("['abc','xyz']".replace(/[\[\]']+/g,''));
_x000D_
_x000D_
_x000D_

Rollback transaction after @Test

Just add @Transactional annotation on top of your test:

@RunWith(SpringJUnit4ClassRunner.class)  
@ContextConfiguration(locations = {"testContext.xml"})
@Transactional
public class StudentSystemTest {

By default Spring will start a new transaction surrounding your test method and @Before/@After callbacks, rolling back at the end. It works by default, it's enough to have some transaction manager in the context.

From: 10.3.5.4 Transaction management (bold mine):

In the TestContext framework, transactions are managed by the TransactionalTestExecutionListener. Note that TransactionalTestExecutionListener is configured by default, even if you do not explicitly declare @TestExecutionListeners on your test class. To enable support for transactions, however, you must provide a PlatformTransactionManager bean in the application context loaded by @ContextConfiguration semantics. In addition, you must declare @Transactional either at the class or method level for your tests.

How do I create delegates in Objective-C?

To create your own delegate, first you need to create a protocol and declare the necessary methods, without implementing. And then implement this protocol into your header class where you want to implement the delegate or delegate methods.

A protocol must be declared as below:

@protocol ServiceResponceDelegate <NSObject>

- (void) serviceDidFailWithRequestType:(NSString*)error;
- (void) serviceDidFinishedSucessfully:(NSString*)success;

@end

This is the service class where some task should be done. It shows how to define delegate and how to set the delegate. In the implementation class after the task is completed the delegate's the methods are called.

@interface ServiceClass : NSObject
{
id <ServiceResponceDelegate> _delegate;
}

- (void) setDelegate:(id)delegate;
- (void) someTask;

@end

@implementation ServiceClass

- (void) setDelegate:(id)delegate
{
_delegate = delegate;
}

- (void) someTask
{
/*

   perform task

*/
if (!success)
{
[_delegate serviceDidFailWithRequestType:@”task failed”];
}
else
{
[_delegate serviceDidFinishedSucessfully:@”task success”];
}
}
@end

This is the main view class from where the service class is called by setting the delegate to itself. And also the protocol is implemented in the header class.

@interface viewController: UIViewController <ServiceResponceDelegate>
{
ServiceClass* _service;
}

- (void) go;

@end

@implementation viewController

//
//some methods
//

- (void) go
{
_service = [[ServiceClass alloc] init];
[_service setDelegate:self];
[_service someTask];
}

That's it, and by implementing delegate methods in this class, control will come back once the operation/task is done.

C++ Compare char array with string

your thinking about this program below

#include <stdio.h>
#include <string.h>

int main ()
{
char str[][5] = { "R2D2" , "C3PO" , "R2A6" };
int n;
puts ("Looking for R2 astromech droids...");
for (n=0 ; n<3 ; n++)
if (strncmp (str[n],"R2xx",2) == 0)
{
  printf ("found %s\n",str[n]);
}
return 0;
}
//outputs:
//
//Looking for R2 astromech droids...
//found R2D2
//found R2A6

when you should be thinking about inputting something into an array & then use strcmp functions like the program above ... check out a modified program below

#include <iostream>
#include<cctype>
#include <string.h>
#include <string>
using namespace std;

int main()
{
int Students=2;
int Projects=3, Avg2=0, Sum2=0, SumT2=0, AvgT2=0, i=0, j=0;
int Grades[Students][Projects];

for(int j=0; j<=Projects-1; j++){
  for(int i=0; i<=Students; i++) {
 cout <<"Please give grade of student "<< j <<"in project "<< i  <<  ":";
  cin >> Grades[j][i];

  }
  Sum2 = Sum2 + Grades[i][j];
     Avg2 = Sum2/Students;
}
SumT2 = SumT2 + Avg2;
AvgT2 = SumT2/Projects;
cout << "avg is  : " << AvgT2 << " and sum : " << SumT2 << ":";
return 0;
}

change to string except it only reads 1 input and throws the rest out maybe need two for loops and two pointers

#include <cstring>
#include <iostream>
#include <string>
#include <stdio.h>
using namespace std;
int main()
{
char name[100];
//string userInput[26];
int i=0, n=0, m=0;
cout<<"your name? ";
cin>>name;
cout<<"Hello "<<name<< endl;

char *ptr=name;
for (i = 0; i < 20; i++)
{
cout<<i<<" "<<ptr[i]<<" "<<(int)ptr[i]<<endl;
}   
int length = 0;
while(name[length] != '\0')
{
length++;
}
                    for(n=0; n<4; n++)
                {
                            if (strncmp(ptr, "snit", 4) == 0)
                            {
            cout << "you found the snitch "    <<        ptr[i];
                            }
                }
cout<<name <<"is"<<length<<"chars long";
}

How to change UIButton image in Swift

From your Obc-C code I think you want to set an Image for button so try this way:

let playButton  = UIButton(type: .Custom)
if let image = UIImage(named: "play.png") {
    playButton.setImage(image, forState: .Normal)
}

In Short:

playButton.setImage(UIImage(named: "play.png"), forState: UIControlState.Normal)

For Swift 3:

let playButton  = UIButton(type: .custom)
playButton.setImage(UIImage(named: "play.png"), for: .normal)

Angular JS Uncaught Error: [$injector:modulerr]

I had exactly the same problem and what resolved it was to remove the closure:

$(function(){
    var app = angular.module("myApp", []); 
    app.controller('myController', function(){
        ...
    });
});

becomes:

var app = angular.module("myApp", []); 
app.controller('myController', function(){
    ...
});

Apply global variable to Vuejs

you can use Vuex to handle all your global data

identifier "string" undefined?

You forgot the namespace you're referring to. Add

using namespace std;

to avoid std::string all the time.

mysql datetime comparison

I know its pretty old but I just encounter the problem and there is what I saw in the SQL doc :

[For best results when using BETWEEN with date or time values,] use CAST() to explicitly convert the values to the desired data type. Examples: If you compare a DATETIME to two DATE values, convert the DATE values to DATETIME values. If you use a string constant such as '2001-1-1' in a comparison to a DATE, cast the string to a DATE.

I assume it's better to use STR_TO_DATE since they took the time to make a function just for that and also the fact that i found this in the BETWEEN doc...

jQuery to loop through elements with the same class

I may be missing part of the question, but I believe you can simply do this:

$('.testimonial').each((index, element) => {
    if (/* Condition */) {
        // Do Something
    }
});

This uses jQuery's each method: https://learn.jquery.com/using-jquery-core/iterating/

How to generate an MD5 file hash in JavaScript?

If you don't want to use libraries or other things, you can use this native javascript approach:

_x000D_
_x000D_
var MD5 = function(d){var r = M(V(Y(X(d),8*d.length)));return r.toLowerCase()};function M(d){for(var _,m="0123456789ABCDEF",f="",r=0;r<d.length;r++)_=d.charCodeAt(r),f+=m.charAt(_>>>4&15)+m.charAt(15&_);return f}function X(d){for(var _=Array(d.length>>2),m=0;m<_.length;m++)_[m]=0;for(m=0;m<8*d.length;m+=8)_[m>>5]|=(255&d.charCodeAt(m/8))<<m%32;return _}function V(d){for(var _="",m=0;m<32*d.length;m+=8)_+=String.fromCharCode(d[m>>5]>>>m%32&255);return _}function Y(d,_){d[_>>5]|=128<<_%32,d[14+(_+64>>>9<<4)]=_;for(var m=1732584193,f=-271733879,r=-1732584194,i=271733878,n=0;n<d.length;n+=16){var h=m,t=f,g=r,e=i;f=md5_ii(f=md5_ii(f=md5_ii(f=md5_ii(f=md5_hh(f=md5_hh(f=md5_hh(f=md5_hh(f=md5_gg(f=md5_gg(f=md5_gg(f=md5_gg(f=md5_ff(f=md5_ff(f=md5_ff(f=md5_ff(f,r=md5_ff(r,i=md5_ff(i,m=md5_ff(m,f,r,i,d[n+0],7,-680876936),f,r,d[n+1],12,-389564586),m,f,d[n+2],17,606105819),i,m,d[n+3],22,-1044525330),r=md5_ff(r,i=md5_ff(i,m=md5_ff(m,f,r,i,d[n+4],7,-176418897),f,r,d[n+5],12,1200080426),m,f,d[n+6],17,-1473231341),i,m,d[n+7],22,-45705983),r=md5_ff(r,i=md5_ff(i,m=md5_ff(m,f,r,i,d[n+8],7,1770035416),f,r,d[n+9],12,-1958414417),m,f,d[n+10],17,-42063),i,m,d[n+11],22,-1990404162),r=md5_ff(r,i=md5_ff(i,m=md5_ff(m,f,r,i,d[n+12],7,1804603682),f,r,d[n+13],12,-40341101),m,f,d[n+14],17,-1502002290),i,m,d[n+15],22,1236535329),r=md5_gg(r,i=md5_gg(i,m=md5_gg(m,f,r,i,d[n+1],5,-165796510),f,r,d[n+6],9,-1069501632),m,f,d[n+11],14,643717713),i,m,d[n+0],20,-373897302),r=md5_gg(r,i=md5_gg(i,m=md5_gg(m,f,r,i,d[n+5],5,-701558691),f,r,d[n+10],9,38016083),m,f,d[n+15],14,-660478335),i,m,d[n+4],20,-405537848),r=md5_gg(r,i=md5_gg(i,m=md5_gg(m,f,r,i,d[n+9],5,568446438),f,r,d[n+14],9,-1019803690),m,f,d[n+3],14,-187363961),i,m,d[n+8],20,1163531501),r=md5_gg(r,i=md5_gg(i,m=md5_gg(m,f,r,i,d[n+13],5,-1444681467),f,r,d[n+2],9,-51403784),m,f,d[n+7],14,1735328473),i,m,d[n+12],20,-1926607734),r=md5_hh(r,i=md5_hh(i,m=md5_hh(m,f,r,i,d[n+5],4,-378558),f,r,d[n+8],11,-2022574463),m,f,d[n+11],16,1839030562),i,m,d[n+14],23,-35309556),r=md5_hh(r,i=md5_hh(i,m=md5_hh(m,f,r,i,d[n+1],4,-1530992060),f,r,d[n+4],11,1272893353),m,f,d[n+7],16,-155497632),i,m,d[n+10],23,-1094730640),r=md5_hh(r,i=md5_hh(i,m=md5_hh(m,f,r,i,d[n+13],4,681279174),f,r,d[n+0],11,-358537222),m,f,d[n+3],16,-722521979),i,m,d[n+6],23,76029189),r=md5_hh(r,i=md5_hh(i,m=md5_hh(m,f,r,i,d[n+9],4,-640364487),f,r,d[n+12],11,-421815835),m,f,d[n+15],16,530742520),i,m,d[n+2],23,-995338651),r=md5_ii(r,i=md5_ii(i,m=md5_ii(m,f,r,i,d[n+0],6,-198630844),f,r,d[n+7],10,1126891415),m,f,d[n+14],15,-1416354905),i,m,d[n+5],21,-57434055),r=md5_ii(r,i=md5_ii(i,m=md5_ii(m,f,r,i,d[n+12],6,1700485571),f,r,d[n+3],10,-1894986606),m,f,d[n+10],15,-1051523),i,m,d[n+1],21,-2054922799),r=md5_ii(r,i=md5_ii(i,m=md5_ii(m,f,r,i,d[n+8],6,1873313359),f,r,d[n+15],10,-30611744),m,f,d[n+6],15,-1560198380),i,m,d[n+13],21,1309151649),r=md5_ii(r,i=md5_ii(i,m=md5_ii(m,f,r,i,d[n+4],6,-145523070),f,r,d[n+11],10,-1120210379),m,f,d[n+2],15,718787259),i,m,d[n+9],21,-343485551),m=safe_add(m,h),f=safe_add(f,t),r=safe_add(r,g),i=safe_add(i,e)}return Array(m,f,r,i)}function md5_cmn(d,_,m,f,r,i){return safe_add(bit_rol(safe_add(safe_add(_,d),safe_add(f,i)),r),m)}function md5_ff(d,_,m,f,r,i,n){return md5_cmn(_&m|~_&f,d,_,r,i,n)}function md5_gg(d,_,m,f,r,i,n){return md5_cmn(_&f|m&~f,d,_,r,i,n)}function md5_hh(d,_,m,f,r,i,n){return md5_cmn(_^m^f,d,_,r,i,n)}function md5_ii(d,_,m,f,r,i,n){return md5_cmn(m^(_|~f),d,_,r,i,n)}function safe_add(d,_){var m=(65535&d)+(65535&_);return(d>>16)+(_>>16)+(m>>16)<<16|65535&m}function bit_rol(d,_){return d<<_|d>>>32-_}_x000D_
_x000D_
/** NORMAL words**/_x000D_
var value = 'test';_x000D_
_x000D_
var result = MD5(value);_x000D_
 _x000D_
document.body.innerHTML = 'hash -  normal words: ' + result;_x000D_
_x000D_
/** NON ENGLISH words**/_x000D_
value = '????'_x000D_
_x000D_
//unescape() can be deprecated for the new browser versions_x000D_
result = MD5(unescape(encodeURIComponent(value)));_x000D_
_x000D_
document.body.innerHTML += '<br><br>hash - non english words: ' + result;_x000D_
 
_x000D_
_x000D_
_x000D_

For non english words you may need to use unescape() and the encodeURIComponent() methods.

Object Library Not Registered When Adding Windows Common Controls 6.0

On 32-bit machines:

cd C:\Windows\System32
regsvr32 mscomctl.ocx
regtlib msdatsrc.tlb

or on 64 bit machines:

cd C:\Windows\SysWOW64
regsvr32 mscomctl.ocx
regtlib msdatsrc.tlb

These need to be run as administrator.

What do the return values of Comparable.compareTo mean in Java?

Official Definition

From the reference docs of Comparable.compareTo(T):

Compares this object with the specified object for order. Returns a negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the specified object.

The implementor must ensure sgn(x.compareTo(y)) == -sgn(y.compareTo(x)) for all x and y. (This implies that x.compareTo(y) must throw an exception iff y.compareTo(x) throws an exception.)

The implementor must also ensure that the relation is transitive: (x.compareTo(y)>0 && y.compareTo(z)>0) implies x.compareTo(z)>0.

Finally, the implementor must ensure that x.compareTo(y)==0 implies that sgn(x.compareTo(z)) == sgn(y.compareTo(z)), for all z.

It is strongly recommended, but not strictly required that (x.compareTo(y)==0) == (x.equals(y)). Generally speaking, any class that implements the Comparable interface and violates this condition should clearly indicate this fact. The recommended language is "Note: this class has a natural ordering that is inconsistent with equals."

In the foregoing description, the notation sgn(expression) designates the mathematical signum function, which is defined to return one of -1, 0, or 1 according to whether the value of expression is negative, zero or positive.

My Version

In short:

this.compareTo(that)

returns

  • a negative int if this < that
  • 0 if this == that
  • a positive int if this > that

where the implementation of this method determines the actual semantics of < > and == (I don't mean == in the sense of java's object identity operator)

Examples

"abc".compareTo("def")

will yield something smaller than 0 as abc is alphabetically before def.

Integer.valueOf(2).compareTo(Integer.valueOf(1))

will yield something larger than 0 because 2 is larger than 1.

Some additional points

Note: It is good practice for a class that implements Comparable to declare the semantics of it's compareTo() method in the javadocs.

Note: you should read at least one of the following:

Warning: you should never rely on the return values of compareTo being -1, 0 and 1. You should always test for x < 0, x == 0, x > 0, respectively.

git is not installed or not in the PATH

while @vitocorleone is technically correct. If you have already installed, there is no need to reinstall. You just need to add it to your path. You will find yourself doing this for many of the tools for the mean stack so you should get used to doing it. You don't want to have to be in the folder that holds the executable to run it.

  • Control Panel --> System and Security --> System
  • click on Advanced System Settings on the left.
  • make sure you are on the advanced tab
  • click the Environment Variables button on the bottom
  • under system variables on the bottom find the Path variable
  • at the end of the line type (assuming this is where you installed it)

    ;C:\Program Files (x86)\git\cmd

  • click ok, ok, and ok to save

This essentially tells the OS.. if you don't find this executable in the folder I am typing in, look in Path to fide where it is.

When should I use Async Controllers in ASP.NET MVC?

is it good to use async action everywhere in ASP.NET MVC?

As usual in programming, it depends. There is always a trade-off when going down a certain path.

async-await shines in places where you know you'll receiving concurrent requests to your service and you want to be able to scale out well. How does async-await help with scaling out? In the fact that when you invoke a async IO call synchronously, such as a network call or hitting your database, the current thread which is responsible for the execution is blocked waiting for the request to finish. When you use async-await, you enable the framework to create a state machine for you which makes sure that after the IO call is complete, your method continues executing from where it left off.

A thing to note is that this state machine has a subtle overhead. Making a method asynchronous does not make it execute faster, and that is an important factor to understand and a misconception many people have.

Another thing to take under consideration when using async-await is the fact that it is async all the way, meaning that you'll see async penetrate your entire call stack, top to buttom. This means that if you want to expose synchronous API's, you'll often find yourself duplicating a certain amount of code, as async and sync don't mix very well.

Shall I use async/await keywords when I want to query database (via EF/NHibernate/other ORM)?

If you choose to go down the path of using async IO calls, then yes, async-await will be a good choice, as more and more modern database providers expose async method implementing the TAP (Task Asynchronous Pattern).

How many times I can use await keywords to query database asynchronously in ONE single action method?

As many as you want, as long as you follow the rules stated by your database provider. There is no limit to the amount of async calls you can make. If you have queries which are independent of each other and can be made concurrently, you can spin a new task for each and use await Task.WhenAll to wait for both to complete.

How to make a button redirect to another page using jQuery or just Javascript

From YT 2012 code.

<button href="/signin" onclick=";window.location.href=this.getAttribute('href');return false;">Sign In</button>

jQuery and TinyMCE: textarea value doesn't submit

When you run ajax on your form, you need to tell TinyMCE to update your textarea first:

// TinyMCE will now save the data into textarea
tinyMCE.triggerSave(); 
// now grap the data
var form_data = form.serialize(); 

Using mysql concat() in WHERE clause?

You can try this:

select * FROM table where (concat(first_name, ' ', last_name)) = $search_term;

What are the differences between ArrayList and Vector?

There are 2 major differentiation's between Vector and ArrayList.

  1. Vector is synchronized by default, and ArrayList is not. Note : you can make ArrayList also synchronized by passing arraylist object to Collections.synchronizedList() method. Synchronized means : it can be used with multiple threads with out any side effect.

  2. ArrayLists grow by 50% of the previous size when space is not sufficient for new element, where as Vector will grow by 100% of the previous size when there is no space for new incoming element.

Other than this, there are some practical differences between them, in terms of programming effort:

  1. To get the element at a particular location from Vector we use elementAt(int index) function. This function name is very lengthy. In place of this in ArrayList we have get(int index) which is very easy to remember and to use.
  2. Similarly to replace an existing element with a new element in Vector we use setElementAt() method, which is again very lengthy and may irritate the programmer to use repeatedly. In place of this ArrayList has add(int index, object) method which is easy to use and remember. Like this they have more programmer friendly and easy to use function names in ArrayList.

When to use which one?

  1. Try to avoid using Vectors completely. ArrayLists can do everything what a Vector can do. More over ArrayLists are by default not synchronized. If you want, you can synchronize it when ever you need by using Collections util class.
  2. ArrayList has easy to remember and use function names.

Note : even though arraylist grows by 100%, you can avoid this by ensurecapacity() method to make sure that you are allocating sufficient memory at the initial stages itself.

Hope it helps.

How to write to a file without overwriting current contents?

Instead of "w" use "a" (append) mode with open function:

with open("games.txt", "a") as text_file:

SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax — PHP — PDO

ALTER TABLE `{$installer->getTable('sales/quote_payment')}`
ADD `custom_field_one` VARCHAR( 255 ) NOT NULL,
    ADD `custom_field_two` VARCHAR( 255 ) NOT NULL;

Add backtick i.e. " ` " properly. Write your getTable name and column name between backtick.

Using the star sign in grep

The "star sign" is only meaningful if there is something in front of it. If there isn't the tool (grep in this case) may just treat it as an error. For example:

'*xyz'    is meaningless
'a*xyz'   means zero or more occurrences of 'a' followed by xyz

In Git, how do I figure out what my current revision is?

below will work with any previously pushed revision, not only HEAD

for abbreviated revision hash:

git log -1 --pretty=format:%h

for long revision hash:

git log -1 --pretty=format:%H

Xcode stops working after set "xcode-select -switch"

You should be pointing it towards the Developer directory, not the Xcode application bundle. Run this:

sudo xcode-select --switch /Applications/Xcode.app/Contents/Developer

With recent versions of Xcode, you can go to Xcode ? Preferences… ? Locations and pick one of the options for Command Line Tools to set the location.

git with IntelliJ IDEA: Could not read from remote repository

The only thing that helped in my case (switch SSH-executabe did not work) was to deactivate the git and git-flow plugin, restart intellij and reactivate those plugins again...

Invert colors of an image in CSS or JavaScript

You can apply the style via javascript. This is the Js code below that applies the filter to the image with the ID theImage.

function invert(){
document.getElementById("theImage").style.filter="invert(100%)";
}

And this is the

<img id="theImage" class="img-responsive" src="http://i.imgur.com/1H91A5Y.png"></img>

Now all you need to do is call invert() We do this when the image is clicked.

_x000D_
_x000D_
function invert(){_x000D_
document.getElementById("theImage").style.filter="invert(100%)";_x000D_
}
_x000D_
<h4> Click image to invert </h4>_x000D_
_x000D_
<img id="theImage" class="img-responsive" src="http://i.imgur.com/1H91A5Y.png" onClick="invert()" ></img>
_x000D_
_x000D_
_x000D_

We use this on our website

Escape dot in a regex range

On this web page, I see that:

"Remember that the dot is not a metacharacter inside a character class, so we do not need to escape it with a backslash."

So I guess the escaping of it is unnecessary...

How to manually include external aar package using new Gradle Android Build System

I've also had this problem. This issue report: https://code.google.com/p/android/issues/detail?id=55863 seems to suggest that directly referencing the .AAR file is not supported.

Perhaps the alternative for now is to define the actionbarsherlock library as a Gradle library under the parent directory of your project and reference accordingly.

The syntax is defined here http://tools.android.com/tech-docs/new-build-system/user-guide#TOC-Referencing-a-Library

HTTP redirect: 301 (permanent) vs. 302 (temporary)

Status 301 means that the resource (page) is moved permanently to a new location. The client/browser should not attempt to request the original location but use the new location from now on.

Status 302 means that the resource is temporarily located somewhere else, and the client/browser should continue requesting the original url.

No Such Element Exception?

I had run into the same issue while I was dealing with large dataset. One thing I've noticed was the NoSuchElementException is thrown when the Scanner reaches the endOfFile, where it is not going to affect our data.

Here, I've placed my code in try block and catch block handles the exception. You can also leave it empty, if you don't want to perform any task.

For the above question, because you are using file.next() both in the condition and in the while loop you can handle the exception as

while(!file.next().equals(treasure)){
    try{
        file.next(); //stack trace error here
       }catch(NoSuchElementException e) {  }
}

This worked perfectly for me, if there are any corner cases for my approach, do let me know through comments.

Vim clear last search highlighting

I added this to my vimrc file.

command! H let @/=""

After you do a search and want to clear the highlights from your search just do :H

Java Package Does Not Exist Error

If you are facing this issue while using Kotlin and have

kotlin.incremental=true
kapt.incremental.apt=true

in the gradle.properties, then you need to remove this temporarily to fix the build.

After the successful build, you can again add these properties to speed up the build time while using Kotlin.

Make A List Item Clickable (HTML/CSS)

HTML and CSS only.

_x000D_
_x000D_
#leftsideMenu ul li {_x000D_
  border-bottom: 1px dashed lightgray;_x000D_
  background-color: cadetblue;_x000D_
}_x000D_
_x000D_
#leftsideMenu ul li a {_x000D_
  padding: 8px 20px 8px 20px;_x000D_
  color: white;_x000D_
  display: block;_x000D_
}_x000D_
_x000D_
#leftsideMenu ul li a:hover {_x000D_
  background-color: lightgreen;_x000D_
  transition: 0.5s;_x000D_
  padding-left: 30px;_x000D_
  padding-right: 10px;_x000D_
}
_x000D_
<div id="leftsideMenu">_x000D_
  <ul style="list-style-type:none">_x000D_
    <li><a href="#">India</a></li>_x000D_
    <li><a href="#">USA</a></li>_x000D_
    <li><a href="#">Russia</a></li>_x000D_
    <li><a href="#">China</a></li>_x000D_
    <li><a href="#">Afganistan</a></li>_x000D_
    <li><a href="#">Landon</a></li>_x000D_
    <li><a href="#">Scotland</a></li>_x000D_
    <li><a href="#">Ireland</a></li>_x000D_
  </ul>_x000D_
</div>
_x000D_
_x000D_
_x000D_

clear form values after submission ajax

Simply

$('#cform')[0].reset();

How to append a newline to StringBuilder

you can use line.seperator for appending new line in

How to tune Tomcat 5.5 JVM Memory settings without using the configuration program

In my case there was a /etc/sysconfig/tomcat5.conf file overwriting all settings in /etc/tomcat5/tomcat5.conf

What is the difference between .text, .value, and .value2?

Out of curiosity, I wanted to see how Value performed against Value2. After about 12 trials of similar processes, I could not see any significant differences in speed so I would always recommend using Value. I used the below code to run some tests with various ranges.

If anyone sees anything contrary regarding performance, please post.

Sub Trial_RUN()
    For t = 0 To 5
        TestValueMethod (True)
        TestValueMethod (False)
    Next t

End Sub




Sub TestValueMethod(useValue2 As Boolean)
Dim beginTime As Date, aCell As Range, rngAddress As String, ResultsColumn As Long
ResultsColumn = 5

'have some values in your RngAddress. in my case i put =Rand() in the cells, and then set to values
rngAddress = "A2:A399999" 'I changed this around on my sets.



With ThisWorkbook.Sheets(1)
.Range(rngAddress).Offset(0, 1).ClearContents


beginTime = Now

For Each aCell In .Range(rngAddress).Cells
    If useValue2 Then
        aCell.Offset(0, 1).Value2 = aCell.Value2 + aCell.Offset(-1, 1).Value2
    Else
        aCell.Offset(0, 1).Value = aCell.Value + aCell.Offset(-1, 1).Value
    End If

Next aCell

Dim Answer As String
 If useValue2 Then Answer = " using Value2"

.Cells(Rows.Count, ResultsColumn).End(xlUp).Offset(1, 0) = DateDiff("S", beginTime, Now) & _
            " seconds. For " & .Range(rngAddress).Cells.Count & " cells, at " & Now & Answer


End With


End Sub

enter image description here

Remove carriage return in Unix

I made this shell-script to remove the \r character. It works in solaris and red-hat:

#!/bin/ksh

LOCALPATH=/Any_PATH

for File in `ls ${LOCALPATH}`
do
   ARCACT=${LOCALPATH}/${File}
   od -bc ${ARCACT}|sed -n 'p;n'|sed 's/015/012/g'|awk '{$1=""; print $0}'|sed 's/ /\\/g'|awk '{printf $0;}'>${ARCACT}.TMP
   printf "`cat ${ARCACT}.TMP`"|sed '/^$/d'>${ARCACT}
   rm ${ARCACT}.TMP
done

exit 0

Running stages in parallel with Jenkins workflow / pipeline

You may not place the deprecated non-block-scoped stage (as in the original question) inside parallel.

As of JENKINS-26107, stage takes a block argument. You may put parallel inside stage or stage inside parallel or stage inside stage etc. However visualizations of the build are not guaranteed to support all nestings; in particular

  • The built-in Pipeline Steps (a “tree table” listing every step run by the build) shows arbitrary stage nesting.
  • The Pipeline Stage View plugin will currently only display a linear list of stages, in the order they started, regardless of nesting structure.
  • Blue Ocean will display top-level stages, plus parallel branches inside a top-level stage, but currently no more.

JENKINS-27394, if implemented, would display arbitrarily nested stages.

Fundamental difference between Hashing and Encryption algorithms

  1. Use hashes when you only need to go one way. For example, for passwords in a system, you use hashing because you will only ever verify that the value a user entered, after hashing, matches the value in your repository. With encryption, you can go two ways.

  2. hashing algorithms and encryption algorithms are just mathematical algorithms. So in that respect they are not different -- its all just mathematical formulas. Semantics wise, though, there is the very big distinction between hashing (one-way) and encryption(two-way). Why are hashes irreversible? Because they are designed to be that way, because sometimes you want a one-way operation.

Getting path of captured image in Android using camera intent

There is a solution to create file (on external cache dir or anywhere else) and put this file's uri as output extra to camera intent - this will define path where taken picture will be stored.

Here is an example:

File file;
Uri fileUri;
final int RC_TAKE_PHOTO = 1;

    private void takePhoto() {
        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        file = new File(getActivity().getExternalCacheDir(), 
                String.valueOf(System.currentTimeMillis()) + ".jpg");
        fileUri = Uri.fromFile(file);
        intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);
        getActivity().startActivityForResult(intent, RC_TAKE_PHOTO);

    }


    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        if (requestCode == RC_TAKE_PHOTO && resultCode == RESULT_OK) {

                //do whatever you need with taken photo using file or fileUri

            }
        }
    }

Then if you don't need the file anymore, you can delete it using file.delete();

By the way, files from cache dir will be removed when user clears app's cache from apps settings.

Example to use shared_ptr?

Through Boost you can do it >

std::vector<boost::any> vecobj;
    boost::shared_ptr<string> sharedString1(new string("abcdxyz!"));    
    boost::shared_ptr<int> sharedint1(new int(10));
    vecobj.push_back(sharedString1);
    vecobj.push_back(sharedint1);

> for inserting different object type in your vector container. while for accessing you have to use any_cast, which works like dynamic_cast, hopes it will work for your need.

cat, grep and cut - translated to python

For Translating the command to python refer below:-

1)Alternative of cat command is open refer this. Below is the sample

>>> f = open('workfile', 'r')
>>> print f

2)Alternative of grep command refer this

3)Alternative of Cut command refer this

Match everything except for specified strings

Depends on the language, but there are generally negative-assertions you can put in like so:

(?!red|green|blue)

(Thanks for the syntax fix, the above is valid Java and Perl, YMMV)

What is the right way to populate a DropDownList from a database?

You could bind the DropDownList to a data source (DataTable, List, DataSet, SqlDataSource, etc).

For example, if you wanted to use a DataTable:

ddlSubject.DataSource = subjectsTable;
ddlSubject.DataTextField = "SubjectNamne";
ddlSubject.DataValueField = "SubjectID";
ddlSubject.DataBind();

EDIT - More complete example

private void LoadSubjects()
{

    DataTable subjects = new DataTable();

    using (SqlConnection con = new SqlConnection(connectionString))
    {

        try
        {
            SqlDataAdapter adapter = new SqlDataAdapter("SELECT SubjectID, SubjectName FROM Students.dbo.Subjects", con);
            adapter.Fill(subjects);

            ddlSubject.DataSource = subjects;
            ddlSubject.DataTextField = "SubjectNamne";
            ddlSubject.DataValueField = "SubjectID";
            ddlSubject.DataBind();
        }
        catch (Exception ex)
        {
            // Handle the error
        }

    }

    // Add the initial item - you can add this even if the options from the
    // db were not successfully loaded
    ddlSubject.Items.Insert(0, new ListItem("<Select Subject>", "0"));

}

To set an initial value via the markup, rather than code-behind, specify the option(s) and set the AppendDataBoundItems attribute to true:

<asp:DropDownList ID="ddlSubject" runat="server" AppendDataBoundItems="true">
    <asp:ListItem Text="<Select Subject>" Value="0" />
</asp:DropDownList>

You could then bind the DropDownList to a DataSource in the code-behind (just remember to remove:

ddlSubject.Items.Insert(0, new ListItem("<Select Subject>", "0"));

from the code-behind, or you'll have two "" items.

Fatal error compiling: invalid target release: 1.8 -> [Help 1]

For eclipse here is how I solved my problem:

  1. Preferences --> Compiler --> Compiler Complainer Level (Change to 1.8) enter image description here

  2. Perferences --> Installed JREs --> select JAVA SE 8 1.8 enter image description here

  3. Rebuild via maven using Run as maven build.

It shouldn't show you the invalid target error anymore.
Note: I didn't have to set or change any other variables in my terminal. Hope this helps.

Printing column separated by comma using Awk command line

Try:

awk -F',' '{print $3}' myfile.txt

Here in -F you are saying to awk that use "," as field separator.

Mocking methods of local scope objects with Mockito

You can do this by creating a factory method in MyObject:

class MyObject {
    public static MyObject create() {
      return new MyObject();
    }
}

then mock that with PowerMock.

However, by mocking the methods of a local scope object, you are depending on that part of the implementation of the method staying the same. So you lose the ability to refactor that part of the method without breaking the test. In addition, if you are stubbing return values in the mock, then your unit test may pass, but the method may behave unexpectedly when using the real object.

In sum, you should probably not try to do this. Rather, letting the test drive your code (aka TDD), you would arrive at a solution like:

void method1(MyObject obj1) {
   obj1.method1();
}

passing in the dependency, which you can easily mock for the unit test.

Floating point exception

It's caused by n % x, when x is 0. You should have x start at 2 instead. You should not use floating point here at all, since you only need integer operations.

General notes:

  1. Try to format your code better. Focus on using a consistent style. E.g. you have one else that starts immediately after a if brace (not even a space), and another with a newline in between.
  2. Don't use globals unless necessary. There is no reason for q to be global.
  3. Don't return without a value in a non-void (int) function.

LIMIT 10..20 in SQL Server

The equivalent of LIMIT is SET ROWCOUNT, but if you want generic pagination it's better to write a query like this:

;WITH Results_CTE AS
(
    SELECT
        Col1, Col2, ...,
        ROW_NUMBER() OVER (ORDER BY SortCol1, SortCol2, ...) AS RowNum
    FROM Table
    WHERE <whatever>
)
SELECT *
FROM Results_CTE
WHERE RowNum >= @Offset
AND RowNum < @Offset + @Limit

Convert string to integer type in Go?

Here are three ways to parse strings into integers, from fastest runtime to slowest:

  1. strconv.ParseInt(...) fastest
  2. strconv.Atoi(...) still very fast
  3. fmt.Sscanf(...) not terribly fast but most flexible

Here's a benchmark that shows usage and example timing for each function:

package main

import "fmt"
import "strconv"
import "testing"

var num = 123456
var numstr = "123456"

func BenchmarkStrconvParseInt(b *testing.B) {
  num64 := int64(num)
  for i := 0; i < b.N; i++ {
    x, err := strconv.ParseInt(numstr, 10, 64)
    if x != num64 || err != nil {
      b.Error(err)
    }
  }
}

func BenchmarkAtoi(b *testing.B) {
  for i := 0; i < b.N; i++ {
    x, err := strconv.Atoi(numstr)
    if x != num || err != nil {
      b.Error(err)
    }
  }
}

func BenchmarkFmtSscan(b *testing.B) {
  for i := 0; i < b.N; i++ {
    var x int
    n, err := fmt.Sscanf(numstr, "%d", &x)
    if n != 1 || x != num || err != nil {
      b.Error(err)
    }
  }
}

You can run it by saving as atoi_test.go and running go test -bench=. atoi_test.go.

goos: darwin
goarch: amd64
BenchmarkStrconvParseInt-8      100000000           17.1 ns/op
BenchmarkAtoi-8                 100000000           19.4 ns/op
BenchmarkFmtSscan-8               2000000          693   ns/op
PASS
ok      command-line-arguments  5.797s

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

If you use C# 2010 or newer, you can use dynamic type:

dynamic json = Newtonsoft.Json.JsonConvert.DeserializeObject(jsonstring);

Then you can access attributes and arrays in dynamic object using dot notation:

string nemo = json.response[0].images[0].report.nemo;

Windows equivalent of 'touch' (i.e. the node.js way to create an index.html)

Windows does not natively include a touch command.

You can use any of the available public versions or you can use your own version. Save this code as touch.cmd and place it somewhere in your path

@echo off
    setlocal enableextensions disabledelayedexpansion

    (for %%a in (%*) do if exist "%%~a" (
        pushd "%%~dpa" && ( copy /b "%%~nxa"+,, & popd )
    ) else (
        type nul > "%%~fa"
    )) >nul 2>&1

It will iterate over it argument list, and for each element if it exists, update the file timestamp, else, create it.

Adding ASP.NET MVC5 Identity Authentication to an existing project

This is what I did to integrate Identity with an existing database.

  1. Create a sample MVC project with MVC template. This has all the code needed for Identity implementation - Startup.Auth.cs, IdentityConfig.cs, Account Controller code, Manage Controller, Models and related views.

  2. Install the necessary nuget packages for Identity and OWIN. You will get an idea by seeing the references in the sample Project and the answer by @Sam

  3. Copy all these code to your existing project. Please note don't forget to add the "DefaultConnection" connection string for Identity to map to your database. Please check the ApplicationDBContext class in IdentityModel.cs where you will find the reference to "DefaultConnection" connection string.

  4. This is the SQL script I ran on my existing database to create necessary tables:

    USE ["YourDatabse"]
    GO
    /****** Object:  Table [dbo].[AspNetRoles]    Script Date: 16-Aug-15 6:52:25 PM ******/
    SET ANSI_NULLS ON
    GO
    SET QUOTED_IDENTIFIER ON
    GO
    CREATE TABLE [dbo].[AspNetRoles](
    [Id] [nvarchar](128) NOT NULL,
    [Name] [nvarchar](256) NOT NULL,
    CONSTRAINT [PK_dbo.AspNetRoles] PRIMARY KEY CLUSTERED 
    (
      [Id] ASC
    )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
    ) ON [PRIMARY]
    
    GO
    /****** Object:  Table [dbo].[AspNetUserClaims]    Script Date: 16-Aug-15 6:52:25 PM ******/
    SET ANSI_NULLS ON
    GO
    SET QUOTED_IDENTIFIER ON
    GO
    CREATE TABLE [dbo].[AspNetUserClaims](
       [Id] [int] IDENTITY(1,1) NOT NULL,
       [UserId] [nvarchar](128) NOT NULL,
       [ClaimType] [nvarchar](max) NULL,
       [ClaimValue] [nvarchar](max) NULL,
    CONSTRAINT [PK_dbo.AspNetUserClaims] PRIMARY KEY CLUSTERED 
    (
       [Id] ASC
    )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
    ) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
    
    GO
    /****** Object:  Table [dbo].[AspNetUserLogins]    Script Date: 16-Aug-15 6:52:25 PM ******/
    SET ANSI_NULLS ON
    GO
    SET QUOTED_IDENTIFIER ON
    GO
    CREATE TABLE [dbo].[AspNetUserLogins](
        [LoginProvider] [nvarchar](128) NOT NULL,
        [ProviderKey] [nvarchar](128) NOT NULL,
        [UserId] [nvarchar](128) NOT NULL,
    CONSTRAINT [PK_dbo.AspNetUserLogins] PRIMARY KEY CLUSTERED 
    (
        [LoginProvider] ASC,
        [ProviderKey] ASC,
        [UserId] ASC
    )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
    ) ON [PRIMARY]
    
    GO
    /****** Object:  Table [dbo].[AspNetUserRoles]    Script Date: 16-Aug-15 6:52:25 PM ******/
    SET ANSI_NULLS ON
    GO
    SET QUOTED_IDENTIFIER ON
    GO
    CREATE TABLE [dbo].[AspNetUserRoles](
       [UserId] [nvarchar](128) NOT NULL,
       [RoleId] [nvarchar](128) NOT NULL,
    CONSTRAINT [PK_dbo.AspNetUserRoles] PRIMARY KEY CLUSTERED 
    (
        [UserId] ASC,
        [RoleId] ASC
    )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
    ) ON [PRIMARY]
    
    GO
    /****** Object:  Table [dbo].[AspNetUsers]    Script Date: 16-Aug-15 6:52:25 PM ******/
    SET ANSI_NULLS ON
    GO
    SET QUOTED_IDENTIFIER ON
    GO
    CREATE TABLE [dbo].[AspNetUsers](
        [Id] [nvarchar](128) NOT NULL,
        [Email] [nvarchar](256) NULL,
        [EmailConfirmed] [bit] NOT NULL,
        [PasswordHash] [nvarchar](max) NULL,
        [SecurityStamp] [nvarchar](max) NULL,
        [PhoneNumber] [nvarchar](max) NULL,
        [PhoneNumberConfirmed] [bit] NOT NULL,
        [TwoFactorEnabled] [bit] NOT NULL,
        [LockoutEndDateUtc] [datetime] NULL,
        [LockoutEnabled] [bit] NOT NULL,
        [AccessFailedCount] [int] NOT NULL,
        [UserName] [nvarchar](256) NOT NULL,
    CONSTRAINT [PK_dbo.AspNetUsers] PRIMARY KEY CLUSTERED 
    (
        [Id] ASC
    )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
    ) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
    
     GO
     ALTER TABLE [dbo].[AspNetUserClaims]  WITH CHECK ADD  CONSTRAINT [FK_dbo.AspNetUserClaims_dbo.AspNetUsers_UserId] FOREIGN KEY([UserId])
     REFERENCES [dbo].[AspNetUsers] ([Id])
     ON DELETE CASCADE
     GO
     ALTER TABLE [dbo].[AspNetUserClaims] CHECK CONSTRAINT [FK_dbo.AspNetUserClaims_dbo.AspNetUsers_UserId]
     GO
     ALTER TABLE [dbo].[AspNetUserLogins]  WITH CHECK ADD  CONSTRAINT [FK_dbo.AspNetUserLogins_dbo.AspNetUsers_UserId] FOREIGN KEY([UserId])
     REFERENCES [dbo].[AspNetUsers] ([Id])
     ON DELETE CASCADE
     GO
     ALTER TABLE [dbo].[AspNetUserLogins] CHECK CONSTRAINT [FK_dbo.AspNetUserLogins_dbo.AspNetUsers_UserId]
     GO
     ALTER TABLE [dbo].[AspNetUserRoles]  WITH CHECK ADD  CONSTRAINT [FK_dbo.AspNetUserRoles_dbo.AspNetRoles_RoleId] FOREIGN KEY([RoleId])
     REFERENCES [dbo].[AspNetRoles] ([Id])
     ON DELETE CASCADE
     GO
     ALTER TABLE [dbo].[AspNetUserRoles] CHECK CONSTRAINT [FK_dbo.AspNetUserRoles_dbo.AspNetRoles_RoleId]
     GO
     ALTER TABLE [dbo].[AspNetUserRoles]  WITH CHECK ADD  CONSTRAINT [FK_dbo.AspNetUserRoles_dbo.AspNetUsers_UserId] FOREIGN KEY([UserId])
     REFERENCES [dbo].[AspNetUsers] ([Id])
     ON DELETE CASCADE
     GO
     ALTER TABLE [dbo].[AspNetUserRoles] CHECK CONSTRAINT [FK_dbo.AspNetUserRoles_dbo.AspNetUsers_UserId]
     GO
    
  5. Check and solve any remaining errors and you are done. Identity will handle the rest :)

JPA or JDBC, how are they different?

JDBC is a much lower-level (and older) specification than JPA. In it's bare essentials, JDBC is an API for interacting with a database using pure SQL - sending queries and retrieving results. It has no notion of objects or hierarchies. When using JDBC, it's up to you to translate a result set (essentially a row/column matrix of values from one or more database tables, returned by your SQL query) into Java objects.

Now, to understand and use JDBC it's essential that you have some understanding and working knowledge of SQL. With that also comes a required insight into what a relational database is, how you work with it and concepts such as tables, columns, keys and relationships. Unless you have at least a basic understanding of databases, SQL and data modelling you will not be able to make much use of JDBC since it's really only a thin abstraction on top of these things.

Creating a triangle with for loops

First of all, you need to make sure you're producing the correct number of * symbols. We need to produce 1, 3, 5 et cetera instead of 1, 2, 3. This can be fixed by modifying the counter variables:

for (int i=1; i<10; i += 2)
{
    for (int j=0; j<i; j++)
    {
        System.out.print("*");
    }
    System.out.println("");
}

As you can see, this causes i to start at 1 and increase by 2 at each step as long is it is smaller than 10 (i.e., 1, 3, 5, 7, 9). This gives us the correct number of * symbols. We then need to fix the indentation level per line. This can be done as follows:

for (int i=1; i<10; i += 2)
{
    for (int k=0; k < (4 - i / 2); k++)
    {
        System.out.print(" ");
    }
    for (int j=0; j<i; j++)
    {
        System.out.print("*");
    }
    System.out.println("");
}

Before printing the * symbols we print some spaces and the number of spaces varies depending on the line that we are on. That is what the for loop with the k variable is for. We can see that k iterates over the values 4, 3, 2, 1 and 0 when ì is 1,3, 5, 7 and 9. This is what we want because the higher in the triangle we are, the more spaces we need to place. The further we get down the triangle, we less spaces we need and the last line of the triangle does not even need spaces at all.

DROP IF EXISTS VS DROP?

DROP TABLE IF EXISTS [table_name]

it first checks if the table exists, if it does it deletes the table while

DROP TABLE [table_name]

it deletes without checking, so if it doesn't exist it exits with an error

.attr("disabled", "disabled") issue

Try

$(bla).click(function(){        
  if (something) {
     console.log("A:"+$target.prev("input")) // gives out the right object
     $target.toggleClass("open").prev("input").attr("disabled", "disabled");
  }else{
     console.log("A:"+$target.prev("input")) // any thing from there for a single click?
     $target.toggleClass("open").prev("input").removeAttr("disabled"); //this works
  }
});

Serving favicon.ico in ASP.NET MVC

Placing favicon.ico in the root of your domain only really affects IE5, IIRC. For more modern browsers you should be able to include a link tag to point to another directory:

<link rel="SHORTCUT ICON" href="http://www.mydomain.com/content/favicon.ico"/>

You can also use non-ico files for browsers other than IE, for which I'd maybe use the following conditional statement to serve a PNG to FF,etc, and an ICO to IE:

<link rel="icon" type="image/png" href="http://www.mydomain.com/content/favicon.png" />
<!--[if IE]>
<link rel="shortcut icon" href="http://www.mydomain.com/content/favicon.ico" type="image/vnd.microsoft.icon" />
<![endif]-->

React - How to force a function component to render?

None of these gave me a satisfactory answer so in the end I got what I wanted with the key prop, useRef and some random id generator like shortid.

Basically, I wanted some chat application to play itself out the first time someone opens the app. So, I needed full control over when and what the answers are updated with the ease of async await.

Example code:

function sleep(ms) {
    return new Promise(resolve => setTimeout(resolve, ms));
}

// ... your JSX functional component, import shortid somewhere

const [render, rerender] = useState(shortid.generate())

const messageList = useRef([
    new Message({id: 1, message: "Hi, let's get started!"})
])

useEffect(()=>{
    await sleep(500)
    messageList.current.push(new Message({id: 1, message: "What's your name?"}))
    // ... more stuff
    // now trigger the update
    rerender(shortid.generate())
}, [])

// only the component with the right render key will update itself, the others will stay as is and won't rerender.
return <div key={render}>{messageList.current}</div> 

In fact this also allowed me to roll something like a chat message with a rolling .

const waitChat = async (ms) => {
    let text = "."
    for (let i = 0; i < ms; i += 200) {
        if (messageList.current[messageList.current.length - 1].id === 100) {
            messageList.current = messageList.current.filter(({id}) => id !== 100)
        }
        messageList.current.push(new Message({
            id: 100,
            message: text
        }))
        if (text.length === 3) {
            text = "."
        } else {
            text += "."
        }
        rerender(shortid.generate())
        await sleep(200)
    }
    if (messageList.current[messageList.current.length - 1].id === 100) {
        messageList.current = messageList.current.filter(({id}) => id !== 100)
    }
}

How do I configure Notepad++ to use spaces instead of tabs?

Go to the Preferences menu command under menu Settings, and select Language Menu/Tab Settings, depending on your version. Earlier versions use Tab Settings. Later versions use Language. Click the Replace with space check box. Set the size to 4.

Enter image description here

See documentation: http://docs.notepad-plus-plus.org/index.php/Built-in_Languages#Tab_settings

Checking for a null object in C++

As everyone said, references can't be null. That is because, a reference refers to an object. In your code:

// this compiles, but doesn't work, and does this even mean anything?
if (&str == NULL)

you are taking the address of the object str. By definition, str exists, so it has an address. So, it cannot be NULL. So, syntactically, the above is correct, but logically, the if condition is always going to be false.

About your questions: it depends upon what you want to do. Do you want the function to be able to modify the argument? If yes, pass a reference. If not, don't (or pass reference to const). See this C++ FAQ for some good details.

In general, in C++, passing by reference is preferred by most people over passing a pointer. One of the reasons is exactly what you discovered: a reference can't be NULL, thus avoiding you the headache of checking for it in the function.

How to capitalize first letter of each word, like a 2-word city?

You can use CSS:

p.capitalize {text-transform:capitalize;}

Update (JS Solution):

Based on Kamal Reddy's comment:

document.getElementById("myP").style.textTransform = "capitalize";

How to convert a string to JSON object in PHP

To convert a valid JSON string back, you can use the json_decode() method.

To convert it back to an object use this method:

$jObj = json_decode($jsonString);

And to convert it to a associative array, set the second parameter to true:

$jArr = json_decode($jsonString, true);

By the way to convert your mentioned string back to either of those, you should have a valid JSON string. To achieve it, you should do the following:

  1. In the Coords array, remove the two " (double quote marks) from the start and end of the object.
  2. The objects in an array are comma seprated (,), so add commas between the objects in the Coords array..

And you will have a valid JSON String..

Here is your JSON String I converted to a valid one: http://pastebin.com/R16NVerw

Visual Studio Code Search and Replace with Regular Expressions

If you want ex. change all country codes in .json file from uppercase to lowercase:

ctrl+h
alt+r
alt+c

Find: ([A-Z]{2,})
Replace: $1

alt+enter
F1
type: lower -> select toLoweCase
ctrl+alt+enter

ex file:

[
 {"id": "PL", "name": "Poland"},
 {"id": "NZ", "name": "New Zealand"},
 ...
]

tr:hover not working

Works fine for me... The tr:hover should work. Probably it won't work because:

  1. The background color you have set is very light. You don't happen to use this on a white background, do you?

  2. Your <td> tags are not closed properly.

Please note that hovering a <tr> will not work in older browsers.

Working Copy Locked

I have experienced the same issues as you described. It appears to be a bug on Tortoise 1.7.3. I have reverted back to 1.7.2, executed a cleanup and an update. Now my SVN/Tortoise is working fine again

Vim delete blank lines

This worked for me:

:%s/^[^a-zA-Z0-9]$\n//ig

It basically deletes all the lines that don't have a number or letter. Since all the items in my list had letters, it deleted all the blank lines.

How to get the PYTHONPATH in shell?

Python, at startup, loads a bunch of values into sys.path (which is "implemented" via a list of strings), including:

  • various hardcoded places
  • the value of $PYTHONPATH
  • probably some stuff from startup files (I'm not sure if Python has rcfiles)

$PYTHONPATH is only one part of the eventual value of sys.path.

If you're after the value of sys.path, the best way would be to ask Python (thanks @Codemonkey):

python -c "import sys; print sys.path"

How to specify an alternate location for the .m2 folder or settings.xml permanently?

You need to add this line into your settings.xml (or uncomment if it's already there).

<localRepository>C:\Users\me\.m2\repo</localRepository>

Also it's possible to run your commands with mvn clean install -gs C:\Users\me\.m2\settings.xml - this parameter will force maven to use different settings.xml then the default one (which is in $HOME/.m2/settings.xml)

C++ IDE for Linux?

If you like Eclipse for Java, I suggest Eclipse CDT. Despite C/C++ support isn't so powerful as is for Java, it still offers most of the features. It has a nice feature named Managed Project that makes working with C/C++ projects easier if you don't have experience with Makefiles. But you can still use Makefiles. I do C and Java coding and I'm really happy with CDT. I'm developing the firmware for a embedded device in C and a application in Java that talks to this device, and is really nice to use the same environment for both. I guess it probably makes me more productive.

Converting Date and Time To Unix Timestamp

Seems like getTime is not function on above answer.

Date.parse(currentDate)/1000

Int to byte array

Marc's answer is of course the right answer. But since he mentioned the shift operators and unsafe code as an alternative. I would like to share a less common alternative. Using a struct with Explicit layout. This is similar in principal to a C/C++ union.

Here is an example of a struct that can be used to get to the component bytes of the Int32 data type and the nice thing is that it is two way, you can manipulate the byte values and see the effect on the Int.

  using System.Runtime.InteropServices;

  [StructLayout(LayoutKind.Explicit)]
  struct Int32Converter
  {
    [FieldOffset(0)] public int Value;
    [FieldOffset(0)] public byte Byte1;
    [FieldOffset(1)] public byte Byte2;
    [FieldOffset(2)] public byte Byte3;
    [FieldOffset(3)] public byte Byte4;

    public Int32Converter(int value)
    {
      Byte1 = Byte2 = Byte3 = Byte4 = 0;
      Value = value;
    }

    public static implicit operator Int32(Int32Converter value)
    {
      return value.Value;
    }

    public static implicit operator Int32Converter(int value)
    {
      return new Int32Converter(value);
    }
  }

The above can now be used as follows

 Int32Converter i32 = 256;
 Console.WriteLine(i32.Byte1);
 Console.WriteLine(i32.Byte2);
 Console.WriteLine(i32.Byte3);
 Console.WriteLine(i32.Byte4);

 i32.Byte2 = 2;
 Console.WriteLine(i32.Value);

Of course the immutability police may not be excited about the last possiblity :)

Simple java program of pyramid

public static void printPyramid(int number) {
    int size = 5;
    for (int k = 1; k <= size; k++) {
        for (int i = (size+2); i > k; i--) {
            System.out.print(" ");
        }
        for (int j = 1; j <= k; j++) {
            System.out.print(" *");
        }
        System.out.println();
    }
}

How do I output text without a newline in PowerShell?

Yes, as other answers have states, it cannot be done with Write-Output. Where PowerShell fails, turn to .NET, there are even a couple of .NET answers here but they are more complex than they need to be.

Just use:

[Console]::Write("Enabling feature XYZ.......")
Enable-SPFeature...
Write-Output "Done"

It is not purest PowerShell, but it works.

Converting an int to a binary string representation in Java?

Using bit shift is a little quicker...

public static String convertDecimalToBinary(int N) {

    StringBuilder binary = new StringBuilder(32);

    while (N > 0 ) {
        binary.append( N % 2 );
        N >>= 1;
     }

    return binary.reverse().toString();

}

Get HTML code using JavaScript with a URL

For an external (cross-site) solution, you can use: Get contents of a link tag with JavaScript - not CSS

It uses $.ajax() function, so it includes jquery.

How do I extract the contents of an rpm?

In OpenSuse at least, the unrpm command comes with the build package.

In a suitable directory (because this is an archive bomb):

unrpm file.rpm

android: changing option menu items programmatically

menu.xml

  <item 
    android:id="@+id/item1"
    android:title="your Item">
  </item>

put in your java file

  public void onPrepareOptionsMenu(Menu menu) {

    menu.removeItem(R.id.item1);
}

Objective C - Assign, Copy, Retain

NSMutableArray *array = [[NSMutableArray alloc] initWithObjects:@"First",@"Second", nil];
NSMutableArray *copiedArray = [array mutableCopy];
NSMutableArray *retainedArray = [array retain];

[retainedArray addObject:@"Retained Third"];
[copiedArray addObject:@"Copied Third"];

NSLog(@"array = %@",array);
NSLog(@"Retained Array = %@",retainedArray);
NSLog(@"Copied Array = %@",copiedArray);

array = (
    First,
    Second,
    "Retained Third"
)
Retained Array = (
    First,
    Second,
    "Retained Third"
)
Copied Array = (
    First,
    Second,
    "Copied Third"
)

'profile name is not valid' error when executing the sp_send_dbmail command

profile name is not valid [SQLSTATE 42000] (Error 14607)

This happened to me after I copied job script from old SQL server to new SQL server. In SSMS, under Management, the Database Mail profile name was different in the new SQL Server. All I had to do was update the name in job script.

Downloading MySQL dump from command line

Don't go inside mysql, just open Command prompt and directly type this:

mysqldump -u [uname] -p[pass] db_name > db_backup.sql

How do I concatenate a boolean to a string in Python?

answer = True
myvar = "the answer is " + str(answer)

Python does not do implicit casting, as implicit casting can mask critical logic errors. Just cast answer to a string itself to get its string representation ("True"), or use string formatting like so:

myvar = "the answer is %s" % answer

Note that answer must be set to True (capitalization is important).

How do you serialize a model instance in Django?

how about this way:

def ins2dic(obj):
    SubDic = obj.__dict__
    del SubDic['id']
    del SubDic['_state']
return SubDic

or exclude anything you don't want.

Tensorflow set CUDA_VISIBLE_DEVICES within jupyter

You can do it faster without any imports just by using magics:

%env CUDA_DEVICE_ORDER=PCI_BUS_ID
%env CUDA_VISIBLE_DEVICES=0

Notice that all env variable are strings, so no need to use ". You can verify that env-variable is set up by running: %env <name_of_var>. Or check all of them with %env.

How to process each output line in a loop?

Iterate over the grep results with a while/read loop. Like:

grep pattern filename.txt | while read -r line ; do
    echo "Matched Line:  $line"
    # your code goes here
done

How to increase the gap between text and underlining in CSS

I was able to Do it using the U (Underline Tag)

u {
    text-decoration: none;
    position: relative;
}
u:after {
    content: '';
    width: 100%;
    position: absolute;
    left: 0;
    bottom: 1px;
    border-width: 0 0 1px;
    border-style: solid;
}


<a href="" style="text-decoration:none">
    <div style="text-align: right; color: Red;">
        <u> Shop Now</u>
    </div>
</a>

Failed linking file resources

If anyone reading this has the same problem, this happened to me recently, and it was due to having the xml header written twice by mistake:

<?xml version="1.0" encoding="utf-8"?>
<?xml version="1.0" encoding="utf-8"?> <!-- Remove this one -->
<shape xmlns:android="http://schemas.android.com/apk/res/android">
     <solid android:color="@color/mug_blue"/>
     <corners android:radius="@dimen/featured_radius" />
</shape>

The error I was getting was completely unrelated to this file so it was a tough one to find. Just make sure all your new xml files don't have some kind of mistake like this (as it doesn't show up as an error). EDIT It seems like it shows up as an error now, make sure to check your error logs.

Unexpected token < in first line of HTML

For me this was a case that the Script path wouldn't load - I had incorrectly linked it. Check your script files - even if no path error is reported - actually load.

Create a rounded button / button with border-radius in Flutter

You can use ButtonTheme() also

enter image description here

Here is a example code -

ButtonTheme(
              minWidth: 200.0,
              shape: RoundedRectangleBorder(
                  borderRadius: BorderRadius.circular(18.0),
                  side: BorderSide(color: Colors.green)),
              child: RaisedButton(
                elevation: 5.0,
                hoverColor: Colors.green,
                color: Colors.amber,
                child: Text(
                  "Place Order",
                  style: TextStyle(
                      color: Colors.white, fontWeight: FontWeight.bold),
                ),
                onPressed: () {},
              ),
            ),

When to use pthread_exit() and when to use pthread_join() in Linux?

pthread_exit() will terminate the calling thread and exit from that(but resources used by calling thread is not released to operating system if it is not detached from main thread.)

pthrade_join() will wait or block the calling thread until target thread is not terminated. In simple word it will wait for to exit the target thread.

In your code, if you put sleep(or delay) in PrintHello function before pthread_exit(), then main thread may be exit and terminate full process, Although your PrintHello function is not completed it will terminate. If you use pthrade_join() function in main before calling pthread_exit() from main it will block main thread and wait to complete your calling thread (PrintHello).

How to match all occurrences of a regex

if you have a regexp with groups:

str="A 54mpl3 string w1th 7 numbers scatter3r ar0und"
re=/(\d+)[m-t]/

you can use String's scan method to find matching groups:

str.scan re
#> [["54"], ["1"], ["3"]]

To find the matching pattern:

str.to_enum(:scan,re).map {$&}
#> ["54m", "1t", "3r"]

/usr/bin/ld: cannot find

When you make the call to gcc it should say

g++ -Wall -I/home/alwin/Development/Calculator/ -L/opt/lib main.cpp -lcalc -o calculator

not -libcalc.so 

I have a similar problem with auto-generated makes.

You can create a soft link from your compile directory to the library directory. Then the library becomes "local".

cd /compile/directory

ln -s  /path/to/libcalc.so libcalc.so

Adding a line break in MySQL INSERT INTO text

First of all, if you want it displayed on a PHP form, the medium is HTML and so a new line will be rendered with the <br /> tag. Check the source HTML of the page - you may possibly have the new line rendered just as a line break, in which case your problem is simply one of translating the text for output to a web browser.

In C#, how to check if a TCP port is available?

Be aware the time window between you make check and the moment you try to make connection some process may take the port - classical TOCTOU. Why don't you just try to connect? If it fails then you know the port is not available.

How to run wget inside Ubuntu Docker image?

You need to install it first. Create a new Dockerfile, and install wget in it:

FROM ubuntu:14.04
RUN  apt-get update \
  && apt-get install -y wget \
  && rm -rf /var/lib/apt/lists/*

Then, build that image:

docker build -t my-ubuntu .

Finally, run it:

docker run my-ubuntu wget https://downloads-packages.s3.amazonaws.com/ubuntu-14.04/gitlab_7.8.2-omnibus.1-1_amd64.deb

How to overcome TypeError: unhashable type: 'list'

You're trying to use k (which is a list) as a key for d. Lists are mutable and can't be used as dict keys.

Also, you're never initializing the lists in the dictionary, because of this line:

if k not in d == False:

Which should be:

if k not in d == True:

Which should actually be:

if k not in d:

How to do a join in linq to sql with method syntax?

Justin has correctly shown the expansion in the case where the join is just followed by a select. If you've got something else, it becomes more tricky due to transparent identifiers - the mechanism the C# compiler uses to propagate the scope of both halves of the join.

So to change Justin's example slightly:

var result = from sc in enumerableOfSomeClass
             join soc in enumerableOfSomeOtherClass
             on sc.Property1 equals soc.Property2
             where sc.X + sc.Y == 10
             select new { SomeClass = sc, SomeOtherClass = soc }

would be converted into something like this:

var result = enumerableOfSomeClass
    .Join(enumerableOfSomeOtherClass,
          sc => sc.Property1,
          soc => soc.Property2,
          (sc, soc) => new { sc, soc })
    .Where(z => z.sc.X + z.sc.Y == 10)
    .Select(z => new { SomeClass = z.sc, SomeOtherClass = z.soc });

The z here is the transparent identifier - but because it's transparent, you can't see it in the original query :)

How to use Greek symbols in ggplot2?

Here is a link to an excellent wiki that explains how to put greek symbols in ggplot2. In summary, here is what you do to obtain greek symbols

  1. Text Labels: Use parse = T inside geom_text or annotate.
  2. Axis Labels: Use expression(alpha) to get greek alpha.
  3. Facet Labels: Use labeller = label_parsed inside facet.
  4. Legend Labels: Use bquote(alpha == .(value)) in legend label.

You can see detailed usage of these options in the link

EDIT. The objective of using greek symbols along the tick marks can be achieved as follows

require(ggplot2);
data(tips);
p0 = qplot(sex, data = tips, geom = 'bar');
p1 = p0 + scale_x_discrete(labels = c('Female' = expression(alpha),
                                      'Male'   = expression(beta)));
print(p1);

For complete documentation on the various symbols that are available when doing this and how to use them, see ?plotmath.

Can someone explain __all__ in Python?

Explain __all__ in Python?

I keep seeing the variable __all__ set in different __init__.py files.

What does this do?

What does __all__ do?

It declares the semantically "public" names from a module. If there is a name in __all__, users are expected to use it, and they can have the expectation that it will not change.

It also will have programmatic affects:

import *

__all__ in a module, e.g. module.py:

__all__ = ['foo', 'Bar']

means that when you import * from the module, only those names in the __all__ are imported:

from module import *               # imports foo and Bar

Documentation tools

Documentation and code autocompletion tools may (in fact, should) also inspect the __all__ to determine what names to show as available from a module.

__init__.py makes a directory a Python package

From the docs:

The __init__.py files are required to make Python treat the directories as containing packages; this is done to prevent directories with a common name, such as string, from unintentionally hiding valid modules that occur later on the module search path.

In the simplest case, __init__.py can just be an empty file, but it can also execute initialization code for the package or set the __all__ variable.

So the __init__.py can declare the __all__ for a package.

Managing an API:

A package is typically made up of modules that may import one another, but that are necessarily tied together with an __init__.py file. That file is what makes the directory an actual Python package. For example, say you have the following files in a package:

package
+-- __init__.py
+-- module_1.py
+-- module_2.py

Let's create these files with Python so you can follow along - you could paste the following into a Python 3 shell:

from pathlib import Path

package = Path('package')
package.mkdir()

(package / '__init__.py').write_text("""
from .module_1 import *
from .module_2 import *
""")

package_module_1 = package / 'module_1.py'
package_module_1.write_text("""
__all__ = ['foo']
imp_detail1 = imp_detail2 = imp_detail3 = None
def foo(): pass
""")

package_module_2 = package / 'module_2.py'
package_module_2.write_text("""
__all__ = ['Bar']
imp_detail1 = imp_detail2 = imp_detail3 = None
class Bar: pass
""")

And now you have presented a complete api that someone else can use when they import your package, like so:

import package
package.foo()
package.Bar()

And the package won't have all the other implementation details you used when creating your modules cluttering up the package namespace.

__all__ in __init__.py

After more work, maybe you've decided that the modules are too big (like many thousands of lines?) and need to be split up. So you do the following:

package
+-- __init__.py
+-- module_1
¦   +-- foo_implementation.py
¦   +-- __init__.py
+-- module_2
    +-- Bar_implementation.py
    +-- __init__.py

First make the subpackage directories with the same names as the modules:

subpackage_1 = package / 'module_1'
subpackage_1.mkdir()
subpackage_2 = package / 'module_2'
subpackage_2.mkdir()

Move the implementations:

package_module_1.rename(subpackage_1 / 'foo_implementation.py')
package_module_2.rename(subpackage_2 / 'Bar_implementation.py')

create __init__.pys for the subpackages that declare the __all__ for each:

(subpackage_1 / '__init__.py').write_text("""
from .foo_implementation import *
__all__ = ['foo']
""")
(subpackage_2 / '__init__.py').write_text("""
from .Bar_implementation import *
__all__ = ['Bar']
""")

And now you still have the api provisioned at the package level:

>>> import package
>>> package.foo()
>>> package.Bar()
<package.module_2.Bar_implementation.Bar object at 0x7f0c2349d210>

And you can easily add things to your API that you can manage at the subpackage level instead of the subpackage's module level. If you want to add a new name to the API, you simply update the __init__.py, e.g. in module_2:

from .Bar_implementation import *
from .Baz_implementation import *
__all__ = ['Bar', 'Baz']

And if you're not ready to publish Baz in the top level API, in your top level __init__.py you could have:

from .module_1 import *       # also constrained by __all__'s
from .module_2 import *       # in the __init__.py's
__all__ = ['foo', 'Bar']     # further constraining the names advertised

and if your users are aware of the availability of Baz, they can use it:

import package
package.Baz()

but if they don't know about it, other tools (like pydoc) won't inform them.

You can later change that when Baz is ready for prime time:

from .module_1 import *
from .module_2 import *
__all__ = ['foo', 'Bar', 'Baz']

Prefixing _ versus __all__:

By default, Python will export all names that do not start with an _. You certainly could rely on this mechanism. Some packages in the Python standard library, in fact, do rely on this, but to do so, they alias their imports, for example, in ctypes/__init__.py:

import os as _os, sys as _sys

Using the _ convention can be more elegant because it removes the redundancy of naming the names again. But it adds the redundancy for imports (if you have a lot of them) and it is easy to forget to do this consistently - and the last thing you want is to have to indefinitely support something you intended to only be an implementation detail, just because you forgot to prefix an _ when naming a function.

I personally write an __all__ early in my development lifecycle for modules so that others who might use my code know what they should use and not use.

Most packages in the standard library also use __all__.

When avoiding __all__ makes sense

It makes sense to stick to the _ prefix convention in lieu of __all__ when:

  • You're still in early development mode and have no users, and are constantly tweaking your API.
  • Maybe you do have users, but you have unittests that cover the API, and you're still actively adding to the API and tweaking in development.

An export decorator

The downside of using __all__ is that you have to write the names of functions and classes being exported twice - and the information is kept separate from the definitions. We could use a decorator to solve this problem.

I got the idea for such an export decorator from David Beazley's talk on packaging. This implementation seems to work well in CPython's traditional importer. If you have a special import hook or system, I do not guarantee it, but if you adopt it, it is fairly trivial to back out - you'll just need to manually add the names back into the __all__

So in, for example, a utility library, you would define the decorator:

import sys

def export(fn):
    mod = sys.modules[fn.__module__]
    if hasattr(mod, '__all__'):
        mod.__all__.append(fn.__name__)
    else:
        mod.__all__ = [fn.__name__]
    return fn

and then, where you would define an __all__, you do this:

$ cat > main.py
from lib import export
__all__ = [] # optional - we create a list if __all__ is not there.

@export
def foo(): pass

@export
def bar():
    'bar'

def main():
    print('main')

if __name__ == '__main__':
    main()

And this works fine whether run as main or imported by another function.

$ cat > run.py
import main
main.main()

$ python run.py
main

And API provisioning with import * will work too:

$ cat > run.py
from main import *
foo()
bar()
main() # expected to error here, not exported

$ python run.py
Traceback (most recent call last):
  File "run.py", line 4, in <module>
    main() # expected to error here, not exported
NameError: name 'main' is not defined

Is it possible to get a history of queries made in postgres

pgBadger is another option - also listed here: https://github.com/dhamaniasad/awesome-postgres#utilities

Requires some additional setup in advance to capture the necessary data in the postgres logs though, see the official website.

Is there any standard for JSON API response format?

Google JSON guide

Success response return data

{
  "data": {
    "id": 1001,
    "name": "Wing"
  }
}

Error response return error

{
  "error": {
    "code": 404,
    "message": "ID not found"
  }
}

and if your client is JS, you can use if ("error" in response) {} to check if there is an error.

Delete rows from multiple tables using a single query (SQL Express 2005) with a WHERE condition

You can use something like the following:

DECLARE db_cursor CURSOR FOR  
SELECT name 
FROM master.dbo.sysdatabases 
WHERE name IN ("TB2","TB1")  -- use these databases

OPEN db_cursor   
FETCH NEXT FROM db_cursor INTO @name   


WHILE @@FETCH_STATUS = 0   
BEGIN   

       DELETE FROM @name WHERE PersonID ='2'

       FETCH NEXT FROM db_cursor INTO @name   
END  

Why should a Java class implement comparable?

Comparable defines a natural ordering. What this means is that you're defining it when one object should be considered "less than" or "greater than".

Suppose you have a bunch of integers and you want to sort them. That's pretty easy, just put them in a sorted collection, right?

TreeSet<Integer> m = new TreeSet<Integer>(); 
m.add(1);
m.add(3);
m.add(2);
for (Integer i : m)
... // values will be sorted

But now suppose I have some custom object, where sorting makes sense to me, but is undefined. Let's say, I have data representing districts by zipcode with population density, and I want to sort them by density:

public class District {
  String zipcode; 
  Double populationDensity;
}

Now the easiest way to sort them is to define them with a natural ordering by implementing Comparable, which means there's a standard way these objects are defined to be ordered.:

public class District implements Comparable<District>{
  String zipcode; 
  Double populationDensity;
  public int compareTo(District other)
  {
    return populationDensity.compareTo(other.populationDensity);
  }
}

Note that you can do the equivalent thing by defining a comparator. The difference is that the comparator defines the ordering logic outside the object. Maybe in a separate process I need to order the same objects by zipcode - in that case the ordering isn't necessarily a property of the object, or differs from the objects natural ordering. You could use an external comparator to define a custom ordering on integers, for example by sorting them by their alphabetical value.

Basically the ordering logic has to exist somewhere. That can be -

  • in the object itself, if it's naturally comparable (extends Comparable -e.g. integers)

  • supplied in an external comparator, as in the example above.

mysql error 2005 - Unknown MySQL server host 'localhost'(11001)

ERROR 2005 (HY000): Unknown MySQL server host 'localhost' (0)

modify list of host names for your system:

C:\Windows\System32\drivers\etc\hosts

Make sure that you have the following entry:

127.0.0.1 localhost
In my case that entry was 0.0.0.0 localhost which caussed all problem

(you may need to change modify permission to modify this file)

This performs DNS resolution of host “localhost” to the IP address 127.0.0.1.

How to Import 1GB .sql file to WAMP/phpmyadmin

A phpMyAdmin feature called UploadDir permits to upload your file via another mechanism, then importing it from the server's file system. See http://docs.phpmyadmin.net/en/latest/faq.html#i-cannot-upload-big-dump-files-memory-http-or-timeout-problems.

Settings to Windows Firewall to allow Docker for Windows to share drive

None of the suggestions above worked for me, but uninstalling Docker Desktop (restart PC) and reinstalling Docked finally resolved the issue.

In Python, how do I loop through the dictionary and change the value if it equals something?

Comprehensions are usually faster, and this has the advantage of not editing mydict during the iteration:

mydict = dict((k, v if v else '') for k, v in mydict.items())

The model backing the <Database> context has changed since the database was created

Create custom context initializer:

public class MyDbContextInitializer : MigrateDatabaseToLatestVersion<MyDbContext, Migrations.Configuration>
{
    public override void InitializeDatabase(MyDbContext context)
    {
        bool exists = context.Database.Exists();

        base.InitializeDatabase(context);

        if (!exists)
        {         
            MyDbSeed.Seed(context);
        }
    }       
}

Note that Migrations.Configuration is a class generating by migration command line in Package Manager Console. You may need to change internal to public modifier of the Migrations.Configuration class.

And register it from your OmModelCreating:

public partial class MyDbContext : DbContext
{

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        Database.SetInitializer<MyDbContext>(new MyDbContextInitializer());

        //other code for creating model
    }
}

How to delete columns in pyspark dataframe

Reading the Spark documentation I found an easier solution.

Since version 1.4 of spark there is a function drop(col) which can be used in pyspark on a dataframe.

You can use it in two ways

  1. df.drop('age').collect()
  2. df.drop(df.age).collect()

Pyspark Documentation - Drop

SQL Server 2008 R2 can't connect to local database in Management Studio

If your instance is called SQLEXPRESS, then you need to use .\SQLEXPRESS or (local)\SQLEXPRESS or yourMachineName\SQLEXPRESS as your server name - if you have a named instance, you need to specify that name of the instance in your server name.

Javascript - Track mouse position

ES6 based code:

let handleMousemove = (event) => {
  console.log(`mouse position: ${event.x}:${event.y}`);
};

document.addEventListener('mousemove', handleMousemove);

If you need throttling for mousemoving, use this:

let handleMousemove = (event) => {
  console.warn(`${event.x}:${event.y}\n`);
};

let throttle = (func, delay) => {
  let prev = Date.now() - delay;
  return (...args) => {
    let current = Date.now();
    if (current - prev >= delay) {
      prev = current;
      func.apply(null, args);
    }
  }
};

// let's handle mousemoving every 500ms only
document.addEventListener('mousemove', throttle(handleMousemove, 500));

here is example

How do I keep CSS floats in one line?

Wrap your floating <div>s in a container <div> that uses this cross-browser min-width hack:

.minwidth { min-width:100px; width: auto !important; width: 100px; }

You may also need to set "overflow" but probably not.

This works because:

  • The !important declaration, combined with min-width cause everything to stay on the same line in IE7+
  • IE6 does not implement min-width, but it has a bug such that width: 100px overrides the !important declaration, causing the container width to be 100px.