Programs & Examples On #Ripping

Numpy Resize/Rescale Image

import cv2
import numpy as np

image_read = cv2.imread('filename.jpg',0) 
original_image = np.asarray(image_read)
width , height = 452,452
resize_image = np.zeros(shape=(width,height))

for W in range(width):
    for H in range(height):
        new_width = int( W * original_image.shape[0] / width )
        new_height = int( H * original_image.shape[1] / height )
        resize_image[W][H] = original_image[new_width][new_height]

print("Resized image size : " , resize_image.shape)

cv2.imshow(resize_image)
cv2.waitKey(0)

Error in data frame undefined columns selected

Are you meaning?

data2 <- data1[good,]

With

data1[good]

you're selecting columns in a wrong way (using a logical vector of complete rows).

Consider that parameter pollutant is not used; is it a column name that you want to extract? if so it should be something like

data2 <- data1[good, pollutant]

Furthermore consider that you have to rbind the data.frames inside the for loop, otherwise you get only the last data.frame (its completed.cases)

And last but not least, i'd prefer generating filenames eg with

id <- 1:322
paste0( directory, "/", gsub(" ", "0", sprintf("%3d",id)), ".csv")

A little modified chunk of ?sprintf

The string fmt (in our case "%3d") contains normal characters, which are passed through to the output string, and also conversion specifications which operate on the arguments provided through .... The allowed conversion specifications start with a % and end with one of the letters in the set aAdifeEgGosxX%. These letters denote the following types:

  • d: integer

Eg a more general example

    sprintf("I am %10d years old", 25)
[1] "I am         25 years old"
          ^^^^^^^^^^
          |        |
          1       10

Python, remove all non-alphabet chars from string

If you prefer not to use regex, you might try

''.join([i for i in s if i.isalpha()])

Replace non-ASCII characters with a single space

What about this one?

def replace_trash(unicode_string):
     for i in range(0, len(unicode_string)):
         try:
             unicode_string[i].encode("ascii")
         except:
              #means it's non-ASCII
              unicode_string=unicode_string[i].replace(" ") #replacing it with a single space
     return unicode_string

Web API Put Request generates an Http 405 Method Not Allowed error

Your client application and server application must be under same domain, for example :

client - localhost

server - localhost

and not :

client - localhost:21234

server - localhost

Regular expression to remove HTML tags from a string

A trivial approach would be to replace

<[^>]*>

with nothing. But depending on how ill-structured your input is that may well fail.

Filename timestamp in Windows CMD batch script getting truncated

The first four lines of this code will give you reliable YY DD MM YYYY HH Min Sec variables in XP Pro and higher, using WMIC.

@echo off
for /f "tokens=2 delims==" %%a in ('wmic OS Get localdatetime /value') do set "dt=%%a"
set "YY=%dt:~2,2%" & set "YYYY=%dt:~0,4%" & set "MM=%dt:~4,2%" & set "DD=%dt:~6,2%"
set "HH=%dt:~8,2%" & set "Min=%dt:~10,2%" & set "Sec=%dt:~12,2%"

set "datestamp=%YYYY%%MM%%DD%" & set "timestamp=%HH%%Min%%Sec%"
set "fullstamp=%YYYY%-%MM%-%DD%_%HH%-%Min%-%Sec%"
echo datestamp: "%datestamp%"
echo timestamp: "%timestamp%"
echo fullstamp: "%fullstamp%"
pause

Output example:

datestamp: "20200828"
timestamp: "085513"
fullstamp: "2020-08-28_08-55-13"
Press any key to continue . . .

Breaking up long strings on multiple lines in Ruby without stripping newlines

I modified Zack's answer since I wanted spaces and interpolation but not newlines and used:

%W[
  It's a nice day "#{name}"
  for a walk!
].join(' ')

where name = 'fred' this produces It's a nice day "fred" for a walk!

How can I remove non-ASCII characters but leave periods and spaces using Python?

If you want printable ascii characters you probably should correct your code to:

if ord(char) < 32 or ord(char) > 126: return ''

this is equivalent, to string.printable (answer from @jterrace), except for the absence of returns and tabs ('\t','\n','\x0b','\x0c' and '\r') but doesnt correspond to the range on your question

Customizing Bootstrap CSS template

you can start with this tool, https://themestr.app/theme , seeing how it overwrites the scss variables, you would get an idea what variable impacts what. its the simplest way I think.

example scss genearation:

@import url(https://fonts.googleapis.com/css?family=Montserrat:200,300,400,700);
$font-family-base:Montserrat;
@import url(https://fonts.googleapis.com/css?family=Open+Sans:200,300,400,700);
$headings-font-family:Open Sans;

$enable-grid-classes:false;
$primary:#222222;
$secondary:#666666;
$success:#333333;
$danger:#434343;
$info:#515151;
$warning:#5f5f5f;
$light:#eceeec;
$dark:#111111;
@import "bootstrap";

Function to return only alpha-numeric characters from string?

Rather than preg_replace, you could always use PHP's filter functions using the filter_var() function with FILTER_SANITIZE_STRING.

How to import a .cer certificate into a java keystore?

Here is the code I've been using for programatically importing .cer files into a new KeyStore.

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
//VERY IMPORTANT.  SOME OF THESE EXIST IN MORE THAN ONE PACKAGE!
import java.security.GeneralSecurityException;
import java.security.KeyStore;
import java.security.cert.Certificate;
import java.security.cert.CertificateFactory;

//Put everything after here in your function.
KeyStore trustStore  = KeyStore.getInstance(KeyStore.getDefaultType());
trustStore.load(null);//Make an empty store
InputStream fis = /* insert your file path here */;
BufferedInputStream bis = new BufferedInputStream(fis);

CertificateFactory cf = CertificateFactory.getInstance("X.509");

while (bis.available() > 0) {
    Certificate cert = cf.generateCertificate(bis);
    trustStore.setCertificateEntry("fiddler"+bis.available(), cert);
}

Restful API service

I would highly recommend the REST client Retrofit.

I have found this well written blog post extremely helpful, it also contains simple example code. The author uses Retrofit to make the network calls and Otto to implement a data bus pattern:

http://www.mdswanson.com/blog/2014/04/07/durable-android-rest-clients.html

How can I remove "\r\n" from a string in C#? Can I use a regular expression?

The .Trim() function will do all the work for you!

I was trying the code above, but after the "trim" function, and I noticed it's all "clean" even before it reaches the replace code!

String input:       "This is an example string.\r\n\r\n"
Trim method result: "This is an example string."

Source: http://www.dotnetperls.com/trim

How to Replace Multiple Characters in SQL?

Here are the steps

  1. Create a CLR function

See following code:

public partial class UserDefinedFunctions 
{

[Microsoft.SqlServer.Server.SqlFunction]
public static SqlString Replace2(SqlString inputtext, SqlString filter,SqlString      replacewith)
{

    string str = inputtext.ToString();
    try
    {
        string pattern = (string)filter;
        string replacement = (string)replacewith;
        Regex rgx = new Regex(pattern);
        string result = rgx.Replace(str, replacement);
        return (SqlString)result;

    }
    catch (Exception s)
    {
        return (SqlString)s.Message;
    }
}
}
  1. Deploy your CLR function

  2. Now Test it

See following code:

create table dbo.test(dummydata varchar(255))
Go
INSERT INTO dbo.test values('P@ssw1rd'),('This 12is @test')
Go
Update dbo.test
set dummydata=dbo.Replace2(dummydata,'[0-9@]','')

select * from dbo.test
dummydata, Psswrd, This is test booom!!!!!!!!!!!!!

Stripping everything but alphanumeric chars from a string in Python

Timing with random strings of ASCII printables:

from inspect import getsource
from random import sample
import re
from string import printable
from timeit import timeit

pattern_single = re.compile(r'[\W]')
pattern_repeat = re.compile(r'[\W]+')
translation_tb = str.maketrans('', '', ''.join(c for c in map(chr, range(256)) if not c.isalnum()))


def generate_test_string(length):
    return ''.join(sample(printable, length))


def main():
    for i in range(0, 60, 10):
        for test in [
            lambda: ''.join(c for c in generate_test_string(i) if c.isalnum()),
            lambda: ''.join(filter(str.isalnum, generate_test_string(i))),
            lambda: re.sub(r'[\W]', '', generate_test_string(i)),
            lambda: re.sub(r'[\W]+', '', generate_test_string(i)),
            lambda: pattern_single.sub('', generate_test_string(i)),
            lambda: pattern_repeat.sub('', generate_test_string(i)),
            lambda: generate_test_string(i).translate(translation_tb),

        ]:
            print(timeit(test), i, getsource(test).lstrip('            lambda: ').rstrip(',\n'), sep='\t')


if __name__ == '__main__':
    main()

Result (Python 3.7):

       Time       Length                           Code                           
6.3716264850008880  00  ''.join(c for c in generate_test_string(i) if c.isalnum())
5.7285426190064750  00  ''.join(filter(str.isalnum, generate_test_string(i)))
8.1875841680011940  00  re.sub(r'[\W]', '', generate_test_string(i))
8.0002205439959650  00  re.sub(r'[\W]+', '', generate_test_string(i))
5.5290945199958510  00  pattern_single.sub('', generate_test_string(i))
5.4417179649972240  00  pattern_repeat.sub('', generate_test_string(i))
4.6772285089973590  00  generate_test_string(i).translate(translation_tb)
23.574712151996210  10  ''.join(c for c in generate_test_string(i) if c.isalnum())
22.829975890002970  10  ''.join(filter(str.isalnum, generate_test_string(i)))
27.210196289997840  10  re.sub(r'[\W]', '', generate_test_string(i))
27.203713296003116  10  re.sub(r'[\W]+', '', generate_test_string(i))
24.008979928999906  10  pattern_single.sub('', generate_test_string(i))
23.945240008994006  10  pattern_repeat.sub('', generate_test_string(i))
21.830899796994345  10  generate_test_string(i).translate(translation_tb)
38.731336012999236  20  ''.join(c for c in generate_test_string(i) if c.isalnum())
37.942474347000825  20  ''.join(filter(str.isalnum, generate_test_string(i)))
42.169366310001350  20  re.sub(r'[\W]', '', generate_test_string(i))
41.933375883003464  20  re.sub(r'[\W]+', '', generate_test_string(i))
38.899814646996674  20  pattern_single.sub('', generate_test_string(i))
38.636144253003295  20  pattern_repeat.sub('', generate_test_string(i))
36.201238164998360  20  generate_test_string(i).translate(translation_tb)
49.377356811004574  30  ''.join(c for c in generate_test_string(i) if c.isalnum())
48.408927293996385  30  ''.join(filter(str.isalnum, generate_test_string(i)))
53.901889764994850  30  re.sub(r'[\W]', '', generate_test_string(i))
52.130339455994545  30  re.sub(r'[\W]+', '', generate_test_string(i))
50.061149017004940  30  pattern_single.sub('', generate_test_string(i))
49.366573111998150  30  pattern_repeat.sub('', generate_test_string(i))
46.649754120997386  30  generate_test_string(i).translate(translation_tb)
63.107938601999194  40  ''.join(c for c in generate_test_string(i) if c.isalnum())
65.116287978999030  40  ''.join(filter(str.isalnum, generate_test_string(i)))
71.477421126997800  40  re.sub(r'[\W]', '', generate_test_string(i))
66.027950693998720  40  re.sub(r'[\W]+', '', generate_test_string(i))
63.315361931003280  40  pattern_single.sub('', generate_test_string(i))
62.342320287003530  40  pattern_repeat.sub('', generate_test_string(i))
58.249303059004890  40  generate_test_string(i).translate(translation_tb)
73.810345625002810  50  ''.join(c for c in generate_test_string(i) if c.isalnum())
72.593953348005020  50  ''.join(filter(str.isalnum, generate_test_string(i)))
76.048324580995540  50  re.sub(r'[\W]', '', generate_test_string(i))
75.106637657001560  50  re.sub(r'[\W]+', '', generate_test_string(i))
74.681338128997600  50  pattern_single.sub('', generate_test_string(i))
72.430461594005460  50  pattern_repeat.sub('', generate_test_string(i))
69.394243567003290  50  generate_test_string(i).translate(translation_tb)

str.maketrans & str.translate is fastest, but includes all non-ASCII characters. re.compile & pattern.sub is slower, but is somehow faster than ''.join & filter.

What is the purpose of using WHERE 1=1 in SQL statements?

People use it because they're inherently lazy when building dynamic SQL queries. If you start with a "where 1 = 1" then all your extra clauses just start with "and" and you don't have to figure out.

Not that there's anything wrong with being inherently lazy. I've seen doubly-linked lists where an "empty" list consists of two sentinel nodes and you start processing at the first->next up until last->prev inclusive.

This actually removed all the special handling code for deleting first and last nodes. In this set-up, every node was a middle node since you weren't able to delete first or last. Two nodes were wasted but the code was simpler and (ever so slightly) faster.

The only other place I've ever seen the "1 = 1" construct is in BIRT. Reports often use positional parameters and are modified with Javascript to allow all values. So the query:

select * from tbl where col = ?

when the user selects "*" for the parameter being used for col is modified to read:

select * from tbl where ((col = ?) or (1 = 1))

This allows the new query to be used without fiddling around with the positional parameter details. There's still exactly one such parameter. Any decent DBMS (e.g., DB2/z) will optimize that query to basically remove the clause entirely before trying to construct an execution plan, so there's no trade-off.

How can I Convert HTML to Text in C#?

What you are looking for is a text-mode DOM renderer that outputs text, much like Lynx or other Text browsers...This is much harder to do than you would expect.

Getting a list of files in a directory with a glob

This works quite nicely for IOS, but should also work for cocoa.

NSString *bundleRoot = [[NSBundle mainBundle] bundlePath];
NSFileManager *manager = [NSFileManager defaultManager];
NSDirectoryEnumerator *direnum = [manager enumeratorAtPath:bundleRoot];
NSString *filename;

while ((filename = [direnum nextObject] )) {

    //change the suffix to what you are looking for
    if ([filename hasSuffix:@".data"]) {   

        // Do work here
        NSLog(@"Files in resource folder: %@", filename);            
    }       
}

base64 encode in MySQL

create table encrypt(username varchar(20),password varbinary(200))

insert into encrypt values('raju',aes_encrypt('kumar','key')) select *,cast(aes_decrypt(password,'key') as char(40)) from encrypt where username='raju';

Stripping non printable characters from a string in python

Iterating over strings is unfortunately rather slow in Python. Regular expressions are over an order of magnitude faster for this kind of thing. You just have to build the character class yourself. The unicodedata module is quite helpful for this, especially the unicodedata.category() function. See Unicode Character Database for descriptions of the categories.

import unicodedata, re, itertools, sys

all_chars = (chr(i) for i in range(sys.maxunicode))
categories = {'Cc'}
control_chars = ''.join(c for c in all_chars if unicodedata.category(c) in categories)
# or equivalently and much more efficiently
control_chars = ''.join(map(chr, itertools.chain(range(0x00,0x20), range(0x7f,0xa0))))

control_char_re = re.compile('[%s]' % re.escape(control_chars))

def remove_control_chars(s):
    return control_char_re.sub('', s)

For Python2

import unicodedata, re, sys

all_chars = (unichr(i) for i in xrange(sys.maxunicode))
categories = {'Cc'}
control_chars = ''.join(c for c in all_chars if unicodedata.category(c) in categories)
# or equivalently and much more efficiently
control_chars = ''.join(map(unichr, range(0x00,0x20) + range(0x7f,0xa0)))

control_char_re = re.compile('[%s]' % re.escape(control_chars))

def remove_control_chars(s):
    return control_char_re.sub('', s)

For some use-cases, additional categories (e.g. all from the control group might be preferable, although this might slow down the processing time and increase memory usage significantly. Number of characters per category:

  • Cc (control): 65
  • Cf (format): 161
  • Cs (surrogate): 2048
  • Co (private-use): 137468
  • Cn (unassigned): 836601

Edit Adding suggestions from the comments.

Counting words in string

There may be a more efficient way to do this, but this is what has worked for me.

function countWords(passedString){
  passedString = passedString.replace(/(^\s*)|(\s*$)/gi, '');
  passedString = passedString.replace(/\s\s+/g, ' '); 
  passedString = passedString.replace(/,/g, ' ');  
  passedString = passedString.replace(/;/g, ' ');
  passedString = passedString.replace(/\//g, ' ');  
  passedString = passedString.replace(/\\/g, ' ');  
  passedString = passedString.replace(/{/g, ' ');
  passedString = passedString.replace(/}/g, ' ');
  passedString = passedString.replace(/\n/g, ' ');  
  passedString = passedString.replace(/\./g, ' '); 
  passedString = passedString.replace(/[\{\}]/g, ' ');
  passedString = passedString.replace(/[\(\)]/g, ' ');
  passedString = passedString.replace(/[[\]]/g, ' ');
  passedString = passedString.replace(/[ ]{2,}/gi, ' ');
  var countWordsBySpaces = passedString.split(' ').length; 
  return countWordsBySpaces;

}

its able to recognise all of the following as separate words:

abc,abc = 2 words,
abc/abc/abc = 3 words (works with forward and backward slashes),
abc.abc = 2 words,
abc[abc]abc = 3 words,
abc;abc = 2 words,

(some other suggestions I've tried count each example above as only 1 x word) it also:

  • ignores all leading and trailing white spaces

  • counts a single-letter followed by a new line, as a word - which I've found some of the suggestions given on this page don't count, for example:
    a
    a
    a
    a
    a
    sometimes gets counted as 0 x words, and other functions only count it as 1 x word, instead of 5 x words)

if anyone has any ideas on how to improve it, or cleaner / more efficient - then please add you 2 cents! Hope This Helps Someone out.

Why does git status show branch is up-to-date when changes exist upstream?

Let look into a sample git repo to verify if your branch (master) is up to date with origin/master.

Verify that local master is tracking origin/master:

$ git branch -vv
* master a357df1eb [origin/master] This is a commit message

More info about local master branch:

$ git show --summary
commit a357df1eb941beb5cac3601153f063dae7faf5a8 (HEAD -> master, tag: 2.8.0, origin/master, origin/HEAD)
Author: ...
Date:   Tue Dec 11 14:25:52 2018 +0100

    Another commit message

Verify if origin/master is on the same commit:

$ cat .git/packed-refs | grep origin/master
a357df1eb941beb5cac3601153f063dae7faf5a8 refs/remotes/origin/master

We can see the same hash around, and safe to say the branch is in consistency with the remote one, at least in the current git repo.

Argument list too long error for rm, cp, mv commands

The below option seems simple to this problem. I got this info from some other thread but it helped me.

for file in /usr/op/data/Software/temp/application/openpages-storage/*; do
    cp "$file" /opt/sw/op-storage/
done

Just run the above one command and it will do the task.

Adding a right click menu to an item

Having just messed around with this, it's useful to kjnow that the e.X / e.Y points are relative to the control, so if (as I was) you are adding a context menu to a listview or something similar, you will want to adjust it with the form's origin. In the example below I've added 20 to the x/y so that the menu appears slightly to the right and under the cursor.

cmDelete.Show(this, new Point(e.X + ((Control)sender).Left+20, e.Y + ((Control)sender).Top+20));

Angularjs $http.get().then and binding to a list

Promise returned from $http can not be binded directly (I dont exactly know why). I'm using wrapping service that works perfectly for me:

.factory('DocumentsList', function($http, $q){
    var d = $q.defer();
    $http.get('/DocumentsList').success(function(data){
        d.resolve(data);
    });
    return d.promise;
});

and bind to it in controller:

function Ctrl($scope, DocumentsList) {
    $scope.Documents = DocumentsList;
    ...
}

UPDATE!:

In Angular 1.2 auto-unwrap promises was removed. See http://docs.angularjs.org/guide/migration#templates-no-longer-automatically-unwrap-promises

Find and replace strings in vim on multiple lines

We don't need to bother entering the current line number.

If you would like to change each foo to bar for current line (.) and the two next lines (+2), simply do:

:.,+2s/foo/bar/g

If you want to confirm before changes are made, replace g with gc:

:.,+2s/foo/bar/gc

In a unix shell, how to get yesterday's date into a variable?

If your HP-UX installation has Tcl installed, you might find it's date arithmetic very readable (unfortunately the Tcl shell does not have a nice "-e" option like perl):

dt=$(echo 'puts [clock format [clock scan yesterday] -format "%a %d/%m/%Y"]' | tclsh)
echo "yesterday was $dt"

This will handle all the daylight savings bother.

WPF button click in C# code

I don't think WPF supports what you are trying to achieve i.e. assigning method to a button using method's name or btn1.Click = "btn1_Click". You will have to use approach suggested in above answers i.e. register button click event with appropriate method btn1.Click += btn1_Click;

How to update Xcode from command line

I encountered the same issue when I uninstalled the complete version of Xcode to reinstall the CLI version. My fix was:

sudo xcode-select -s /Library/Developer/CommandLineTools

Excel VBA - Delete empty rows

How about

sub foo()
  dim r As Range, rows As Long, i As Long
  Set r = ActiveSheet.Range("A1:Z50")
  rows = r.rows.Count
  For i = rows To 1 Step (-1)
    If WorksheetFunction.CountA(r.rows(i)) = 0 Then r.rows(i).Delete
  Next
End Sub

Try this

Option Explicit

Sub Sample()
    Dim i As Long
    Dim DelRange As Range

    On Error GoTo Whoa

    Application.ScreenUpdating = False

    For i = 1 To 50
        If Application.WorksheetFunction.CountA(Range("A" & i & ":" & "Z" & i)) = 0 Then
            If DelRange Is Nothing Then
                Set DelRange = Range("A" & i & ":" & "Z" & i)
            Else
                Set DelRange = Union(DelRange, Range("A" & i & ":" & "Z" & i))
            End If
        End If
    Next i

    If Not DelRange Is Nothing Then DelRange.Delete shift:=xlUp
LetsContinue:
    Application.ScreenUpdating = True

    Exit Sub
Whoa:
    MsgBox Err.Description
    Resume LetsContinue
End Sub

IF you want to delete the entire row then use this code

Option Explicit

Sub Sample()
    Dim i As Long
    Dim DelRange As Range

    On Error GoTo Whoa

    Application.ScreenUpdating = False

    For i = 1 To 50
        If Application.WorksheetFunction.CountA(Range("A" & i & ":" & "Z" & i)) = 0 Then
            If DelRange Is Nothing Then
                Set DelRange = Rows(i)
            Else
                Set DelRange = Union(DelRange, Rows(i))
            End If
        End If
    Next i

    If Not DelRange Is Nothing Then DelRange.Delete shift:=xlUp
LetsContinue:
    Application.ScreenUpdating = True

    Exit Sub
Whoa:
    MsgBox Err.Description
    Resume LetsContinue
End Sub

What are some ways of accessing Microsoft SQL Server from Linux?

FreeTDS + unixODBC or iODBC

Install first FreeTDS, then configure one of the two ODBC engines to use FreeTDS as its ODBC driver. Then use the commandline interface of the ODBC engine.

unixODBC has isql, iODBC has iodbctest

You can also use your favorite programming language (I've successfully used Perl, C, Python and Ruby to connect to MSSQL)

I'm personally using FreeTDS + iODBC:

$more /etc/freetds/freetds.conf
[10.0.1.251]
    host = 10.0.1.251
    port = 1433
    tds version = 8.0

$ more /etc/odbc.ini
[ACCT]
Driver = /usr/local/freetds/lib/libtdsodbc.so
Description = ODBC to SQLServer via FreeTDS
Trace = No
Servername = 10.0.1.251
Database = accounts_ver8

Does C# have a String Tokenizer like Java's?

_words = new List<string>(YourText.ToLower().Trim('\n', '\r').Split(' ').
            Select(x => new string(x.Where(Char.IsLetter).ToArray()))); 

Or

_words = new List<string>(YourText.Trim('\n', '\r').Split(' ').
            Select(x => new string(x.Where(Char.IsLetterOrDigit).ToArray()))); 

How to remove "rows" with a NA value?

dat <- data.frame(x1 = c(1,2,3, NA, 5), x2 = c(100, NA, 300, 400, 500))

na.omit(dat)
  x1  x2
1  1 100
3  3 300
5  5 500

How to get the first line of a file in a bash script?

to read first line using bash, use read statement. eg

read -r firstline<file

firstline will be your variable (No need to assign to another)

Python regex to match dates

Well, from my understanding, simply for matching this format in a given string, I prefer this regular expression:

pattern='[0-9|/]+'

to match the format in a more strict way, the following works:

pattern='(?:[0-9]{2}/){2}[0-9]{2}'

Personally, I cannot agree with unutbu's answer since sometimes we use regular expression for "finding" and "extract", not only "validating".

How to create an integer array in Python?

import random

def random_zeroes(max_size):
  "Create a list of zeros for a random size (up to max_size)."
  a = []
  for i in xrange(random.randrange(max_size)):
    a += [0]

Use range instead if you are using Python 3.x.

Python read JSON file and modify

Set item using data['id'] = ....

import json

with open('data.json', 'r+') as f:
    data = json.load(f)
    data['id'] = 134 # <--- add `id` value.
    f.seek(0)        # <--- should reset file position to the beginning.
    json.dump(data, f, indent=4)
    f.truncate()     # remove remaining part

Bootstrap carousel width and height

I had the same problem.

My height changed to its original height while my slide was animating to the left, ( in a responsive website )

so I fixed it with CSS only :

.carousel .item.left img{
    width: 100% !important;
}

Angular2 - Input Field To Accept Only Numbers

You can create this Validator and import it in your component.
Basically validates the form input string:

  • check there is no dot
  • converts string to number
  • check is an integer
  • check is greater than zero

To implement it in your project:

  1. suggested path in your app folder: src/app/validators/number.validator.ts
  2. import in your component

    import { NumberValidator } from '../../validators/number.validator';

  3. add it to the form control
    inputNumber: ['', [NumberValidator.isInteger]],
  4. if you dont want to show the invalid char, bind a (change)="deleteCharIfInvalid()" to the input, if form.get('inputNumber').hasError('isInteger') is true, delete the last char inserted.
// FILE: src/app/validators/number.validator.ts

import { FormControl } from '@angular/forms';

export interface ValidationResult {
    [key: string]: boolean;
}

export class NumberValidator {

    public static isInteger(control: FormControl): ValidationResult {
        // check if string has a dot
        let hasDot:boolean = control.value.indexOf('.') >= 0 ? true : false;
        // convert string to number
        let number:number = Math.floor(control.value);
        // get result of isInteger()
        let integer:boolean = Number.isInteger(number);
        // validate conditions 
        let valid:boolean = !hasDot && integer && number>0;
        console.log('isInteger > valid', hasDot, number, valid);
        if (!valid) {
            return { isInteger: true };
        }
        return null;
    }        
}

Spring can you autowire inside an abstract class?

What if you need any database operation in SuperGirl you would inject it again into SuperGirl.

I think the main idea is using the same object reference in different classes. So what about this:

//There is no annotation about Spring in the abstract part.
abstract class SuperMan {


    private final DatabaseService databaseService;

    public SuperMan(DatabaseService databaseService) {
     this.databaseService = databaseService;
    }

    abstract void Fly();

    protected void doSuperPowerAction(Thing thing) {

        //busy code

        databaseService.save(thing);

    }
}

@Component
public class SuperGirl extends SuperMan {

private final DatabaseService databaseService;

@Autowired
public SuperGirl (DatabaseService databaseService) {
     super(databaseService);
     this.databaseService = databaseService;
    }

@Override
public void Fly() {
    //busy code
}

public doSomethingSuperGirlDoes() {

    //busy code

    doSuperPowerAction(thing)

}

In my opinion, inject once run everywhere :)

SQL get the last date time record

select max(dates)
from yourTable
group by dates
having count(status) > 1

How to edit HTML input value colour?

You can add color in the style rule of your input: color:#ccc;

How can I compile LaTeX in UTF8?

You needed to iconv your source.

That said, the TEX-based compiler invoked by latex doesn't really support variable-length encodings; it needs big libraries that tell it that certain bytes go together. Xelatex is Unicode-aware and works much better.

How to extract or unpack an .ab file (Android Backup file)

As per https://android.stackexchange.com/a/78183/239063 you can run a one line command in Linux to add in an appropriate tar header to extract it.

( printf "\x1f\x8b\x08\x00\x00\x00\x00\x00" ; tail -c +25 backup.ab ) | tar xfvz -

Replace backup.ab with the path to your file.

How do I solve this error, "error while trying to deserialize parameter"

I found the actual solution...There is a problem in invoking your service from the client.. check the following things.

  1. Make sure all [datacontract], [datamember] attribute are placed properly i.e. make sure WCF is error free

  2. The WCF client, either web.config or any window app config, make sure config entries are properly pointing to the right ones.. binding info, url of the service..etc..etc

Then above problem : tempuri issue is resolved.. it has nothing to do with namespace.. though you are sure you lived with default,

Hope it saves your number of hours!

Please help me convert this script to a simple image slider

Problems only surface when I am I trying to give the first loaded content an active state

Does this mean that you want to add a class to the first button?

$('.o-links').click(function(e) {   // ... }).first().addClass('O_Nav_Current'); 

instead of using IDs for the slider's items and resetting html contents you can use classes and indexes:

CSS:

.image-area {     width: 100%;     height: auto;     display: none; }  .image-area:first-of-type {     display: block; } 

JavaScript:

var $slides = $('.image-area'),     $btns = $('a.o-links');  $btns.on('click', function (e) {     var i = $btns.removeClass('O_Nav_Current').index(this);     $(this).addClass('O_Nav_Current');      $slides.filter(':visible').fadeOut(1000, function () {         $slides.eq(i).fadeIn(1000);     });      e.preventDefault();  }).first().addClass('O_Nav_Current'); 

http://jsfiddle.net/RmF57/

R apply function with multiple parameters

To further generalize @Alexander's example, outer is relevant in cases where a function must compute itself on each pair of vector values:

vars1<-c(1,2,3)
vars2<-c(10,20,30)
mult_one<-function(var1,var2)
{
   var1*var2
}
outer(vars1,vars2,mult_one)

gives:

> outer(vars1, vars2, mult_one)
     [,1] [,2] [,3]
[1,]   10   20   30
[2,]   20   40   60
[3,]   30   60   90

How to convert unsigned long to string

char buffer [50];

unsigned long a = 5;

int n=sprintf (buffer, "%lu", a);

Get line number while using grep

grep -A20 -B20 pattern file.txt

Search pattern and show 20 lines after and before pattern

How to open .mov format video in HTML video Tag?

in the video source change the type to "video/quicktime"

<video width="400" controls Autoplay=autoplay>
  <source src="D:/mov1.mov" type="video/quicktime">
</video>

unable to remove file that really exists - fatal: pathspec ... did not match any files

Your file .idea/workspace.xml is not under git version control. You have either not added it yet (check git status/Untracked files) or ignored it (using .gitignore or .git/info/exclude files)

You can verify it using following git command, that lists all ignored files:

git ls-files --others -i --exclude-standard

How to detect a route change in Angular?

Location works...

import {Component, OnInit} from '@angular/core';
import {Location} from '@angular/common';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.scss']
})

export class AppComponent implements OnInit {

    constructor(private location: Location) {
        this.location.onUrlChange(x => this.urlChange(x));
    }

    ngOnInit(): void {}

    urlChange(x) {
        console.log(x);
    }
}

Get Cell Value from a DataTable in C#

You probably need to reference it from the Rowsrather than as a cell:

var cellValue = dt.Rows[i][j];

Best way to repeat a character in C#

Fill the screen with 6,435 z's $str = [System.Linq.Enumerable]::Repeat([string]::new("z", 143), 45)

$str

How do I disable the resizable property of a textarea?

In reactjs, you can disable the resize widget using style props.

<textarea id={"multiline-id"} ref={'my-ref'} style={{resize: "none"}} className="text-area-additional-styles" />

Open links in new window using AngularJS

Here's a directive that will add target="_blank" to all <a> tags with an href attribute. That means they will all open in a new window. Remember that directives are used in Angular for any dom manipulation/behavior. Live demo (click).

app.directive('href', function() {
  return {
    compile: function(element) {
      element.attr('target', '_blank');
    }
  };
});

Here's the same concept made less invasive (so it won't affect all links) and more adaptable. You can use it on a parent element to have it affect all children links. Live demo (click).

app.directive('targetBlank', function() {
  return {
    compile: function(element) {
      var elems = (element.prop("tagName") === 'A') ? element : element.find('a');
      elems.attr("target", "_blank");
    }
  };
});

Old Answer

It seems like you would just use "target="_blank" on your <a> tag. Here are two ways to go:

<a href="//facebook.com" target="_blank">Facebook</a>
<button ng-click="foo()">Facebook</button>

JavaScript:

var app = angular.module('myApp', []);

app.controller('myCtrl', function($scope, $window) {
  $scope.foo = function() {
    $window.open('//facebook.com');
  };
});

Live demo here (click).

Here are the docs for $window: http://docs.angularjs.org/api/ng.$window

You could just use window, but it is better to use dependency injection, passing in angular's $window for testing purposes.

Jackson Vs. Gson

Gson 1.6 now includes a low-level streaming API and a new parser which is actually faster than Jackson.

How to set JAVA_HOME environment variable on Mac OS X 10.9?

Set $JAVA_HOME environment variable on latest or older Mac OSX.

Download & Install install JDK

  1. First, install JDK
  2. Open terminal check java version

$ java -version

Set JAVA_HOME environment variable

  1. Open .zprofile file

$ open -t .zprofile

Or create . zprofile file

$ open -t .zprofile

  1. write in .zprofile

export JAVA_HOME=$(/usr/libexec/java_home)

Save .zprofile and close the bash file & then write in the terminal for work perfectly.

$ source .zprofile

Setup test in terminal

$ echo $JAVA_HOME  
/Library/Java/JavaVirtualMachines/jdk-13.0.1.jdk/Contents/Home

Error:(9, 5) error: resource android:attr/dialogCornerRadius not found

The dependencies must be applied as shown below to solve this issue :

dependencies {
implementation fileTree(include: ['*.jar'], dir: 'libs')
implementation 'com.android.support.constraint:constraint-layout:1.0.2'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.1'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
implementation 'com.android.support:support-v4:27.1.0'
implementation 'com.android.support:appcompat-v7:27.1.0'
implementation 'com.android.support:recyclerview-v7:27.1.0'
}

Please do not use the version of :

v7:28.0.0-alpha1

Get all dates between two dates in SQL Server

DECLARE @FirstDate DATE = '2018-01-01'
DECLARE @LastDate Date = '2018-12-31'
DECLARE @tbl TABLE(ID INT IDENTITY(1,1) PRIMARY KEY,CurrDate date)
INSERT @tbl VALUES( @FirstDate)
WHILE @FirstDate < @LastDate
BEGIN
SET @FirstDate = DATEADD( day,1, @FirstDate)
INSERT @tbl VALUES( @FirstDate)
END
INSERT @tbl VALUES( @LastDate) 

SELECT * FROM @tbl

Install npm (Node.js Package Manager) on Windows (w/o using Node.js MSI)

I also needed to install npm in Windows and got it through the Chocolatey pacakage manager. For those who haven't heard about it, Chocolatey is a package manager for Windows, that gives you the convenience of an apt-get in Windows environments. To get it go to https://chocolatey.org/ where there's a PowerShell script to download it and install it. After that you can run:

chocolatey install npm

and you're good to go.

Note that the standalone npm is no longer being updated and the last version that is out there is known to have problems on Windows. Another option you can look at is extracting npm from the MSI using LessMSI.

How to recover Git objects damaged by hard disk failure?

Here are two functions that may help if your backup is corrupted, or you have a few partially corrupted backups as well (this may happen if you backup the corrupted objects).

Run both in the repo you're trying to recover.

Standard warning: only use if you're really desperate and you have backed up your (corrupted) repo. This might not resolve anything, but at least should highlight the level of corruption.

fsck_rm_corrupted() {
    corrupted='a'
    while [ "$corrupted" ]; do
        corrupted=$(                                  \
        git fsck --full --no-dangling 2>&1 >/dev/null \
            | grep 'stored in'                          \
            | sed -r 's:.*(\.git/.*)\).*:\1:'           \
        )
        echo "$corrupted"
        rm -f "$corrupted"
    done
}

if [ -z "$1" ]  || [ ! -d "$1" ]; then
    echo "'$1' is not a directory. Please provide the directory of the git repo"
    exit 1
fi

pushd "$1" >/dev/null
fsck_rm_corrupted
popd >/dev/null

and

unpack_rm_corrupted() {
    corrupted='a'
    while [ "$corrupted" ]; do
        corrupted=$(                                  \
        git unpack-objects -r < "$1" 2>&1 >/dev/null \
            | grep 'stored in'                          \
            | sed -r 's:.*(\.git/.*)\).*:\1:'           \
        )
        echo "$corrupted"
        rm -f "$corrupted"
    done
}

if [ -z "$1" ]  || [ ! -d "$1" ]; then
    echo "'$1' is not a directory. Please provide the directory of the git repo"
    exit 1
fi

for p in $1/objects/pack/pack-*.pack; do
    echo "$p"
    unpack_rm_corrupted "$p"
done

NSAttributedString add text alignment

[averagRatioArray addObject:[NSString stringWithFormat:@"When you respond Yes to %@ the average response to    %@ was %0.02f",QString1,QString2,M1]];
[averagRatioArray addObject:[NSString stringWithFormat:@"When you respond No  to %@ the average response to    %@ was %0.02f",QString1,QString2,M0]];

UIFont *font2 = [UIFont fontWithName:@"Helvetica-Bold" size:15];
UIFont *font = [UIFont fontWithName:@"Helvetica-Bold" size:12];

NSMutableAttributedString *str=[[NSMutableAttributedString alloc] initWithString:[NSString stringWithFormat:@"When you respond Yes to %@ the average response to %@ was",QString1,QString2]];
[str addAttribute:NSFontAttributeName value:font range:NSMakeRange(0,[@"When you respond Yes to " length])];
[str addAttribute:NSFontAttributeName value:font2 range:NSMakeRange([@"When you respond Yes to " length],[QString1 length])];
[str addAttribute:NSFontAttributeName value:font range:NSMakeRange([QString1 length],[@" the average response to " length])];
[str addAttribute:NSFontAttributeName value:font2 range:NSMakeRange([@" the average response to " length],[QString2 length])];
[str addAttribute:NSFontAttributeName value:font range:NSMakeRange([QString2 length] ,[@" was" length])];
// [str addAttribute:NSFontAttributeName value:font2 range:NSMakeRange(49+[QString1 length]+[QString2 length] ,8)];
[averagRatioArray addObject:[NSString stringWithFormat:@"%@",str]];

Ruby on Rails. How do I use the Active Record .build method in a :belongs to relationship?

@article = user.articles.build(:title => "MainTitle")
@article.save

How to convert a string into double and vice versa?

convert text entered in textfield to integer

double mydouble=[_myTextfield.text doubleValue];

rounding to the nearest double

mydouble=(round(mydouble));

rounding to the nearest int(considering only positive values)

int myint=(int)(mydouble);

converting from double to string

myLabel.text=[NSString stringWithFormat:@"%f",mydouble];

or

NSString *mystring=[NSString stringWithFormat:@"%f",mydouble];

converting from int to string

myLabel.text=[NSString stringWithFormat:@"%d",myint];

or

NSString *mystring=[NSString stringWithFormat:@"%f",mydouble];

Cannot read property 'style' of undefined -- Uncaught Type Error

Add your <script> to the bottom of your <body>, or add an event listener for DOMContentLoaded following this StackOverflow question.

If that script executes in the <head> section of the code, document.getElementsByClassName(...) will return an empty array because the DOM is not loaded yet.

You're getting the Type Error because you're referencing search_span[0], but search_span[0] is undefined.

This works when you execute it in Dev Tools because the DOM is already loaded.

How to create a link to a directory

Symbolic or soft link (files or directories, more flexible and self documenting)

#     Source                             Link
ln -s /home/jake/doc/test/2000/something /home/jake/xxx

Hard link (files only, less flexible and not self documenting)

#   Source                             Link
ln /home/jake/doc/test/2000/something /home/jake/xxx

More information: man ln


/home/jake/xxx is like a new directory. To avoid "is not a directory: No such file or directory" error, as @trlkly comment, use relative path in the target, that is, using the example:

  1. cd /home/jake/
  2. ln -s /home/jake/doc/test/2000/something xxx

Deserializing JSON to .NET object using Newtonsoft (or LINQ to JSON maybe?)

Deserializing using JsonConvert.DeserializeObject() function

public class ApiValues
    {
        [JsonProperty("Address")]
        public string Address { get; set; }

        [JsonProperty("BaseUrl")]
        public string BaseUrl{ get; set; }
    }

var json = 
{ 
    "Address":"some-address",
    "BaseUrl":"some-url-value"
}


var values = JsonConvert.DeserializeObject<ApiValues>(json);

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

According to Mozilla MDN: "The X-Forwarded-For (XFF) header is a de-facto standard header for identifying the originating IP address of a client."
They publish clear information in their X-Forwarded-For article.

How to call a JavaScript function, declared in <head>, in the body when I want to call it

I'm not sure what you mean by "myself".

Any JavaScript function can be called by an event, but you must have some sort of event to trigger it.

e.g. On page load:

<body onload="myfunction();">

Or on mouseover:

<table onmouseover="myfunction();">

As a result the first question is, "What do you want to do to cause the function to execute?"

After you determine that it will be much easier to give you a direct answer.

How to create nested directories using Mkdir in Golang?

os.Mkdir is used to create a single directory. To create a folder path, instead try using:

os.MkdirAll(folderPath, os.ModePerm)

Go documentation

func MkdirAll(path string, perm FileMode) error

MkdirAll creates a directory named path, along with any necessary parents, and returns nil, or else returns an error. The permission bits perm are used for all directories that MkdirAll creates. If path is already a directory, MkdirAll does nothing and returns nil.

Edit:

Updated to correctly use os.ModePerm instead.
For concatenation of file paths, use package path/filepath as described in @Chris' answer.

Update rows in one table with data from another table based on one column in each being equal

If you want to update matching rows in t1 with data from t2 then:

update t1
set (c1, c2, c3) = 
(select c1, c2, c3 from t2
 where t2.user_id = t1.user_id)
where exists
(select * from t2
 where t2.user_id = t1.user_id)

The "where exists" part it to prevent updating the t1 columns to null where no match exists.

Select distinct values from a list using LINQ in C#

You can try with this code

var result =  (from  item in List
              select new 
              {
                 EmpLoc = item.empLoc,
                 EmpPL= item.empPL,
                 EmpShift= item.empShift
              })
              .ToList()
              .Distinct();

How to get file creation date/time in Bash/Debian?

Another trick to add to your arsenal is the following:

$ grep -r "Copyright" /<path-to-source-files>/src

Generally speaking, if one changes a file they should claim credit in the “Copyright”. Examine the results for dates, file names, contributors and contact email.

example grep result:

/<path>/src/someobject.h: * Copyright 2007-2012 <creator's name> <creator's email>(at)<some URL>>

Disable and enable buttons in C#

Change this

button2.Enabled == true

to

button2.Enabled = true;

Placing a textview on top of imageview in android

As you mentioned in OP, you need to overlay Text on ImageView programmatically way. You can get ImageView drawable and write on it with the help of putting it on Canvas and Paint.

 private BitmapDrawable writeTextOnDrawable(int drawableId, String text) 
 {
 Bitmap bm = BitmapFactory.decodeResource(getResources(), drawableId).copy(Bitmap.Config.ARGB_8888, true);
 Typeface tf = Typeface.create("Helvetica", Typeface.BOLD);
 Paint paint = new Paint();
 paint.setStyle(Style.FILL);
 paint.setColor(Color.WHITE);
 paint.setTypeface(tf);
 paint.setTextAlign(Align.CENTER);
 paint.setTextSize(11);
 Rect textRect = new Rect();
 paint.getTextBounds(text, 0, text.length(), textRect);
 Canvas canvas = new Canvas(bm);
 canvas.drawText(text, xPos, yPos, paint);
 return new BitmapDrawable(getResources(), bm);
 }

How to draw a standard normal distribution in R

Something like this perhaps?

x<-rnorm(100000,mean=10, sd=2)
hist(x,breaks=150,xlim=c(0,20),freq=FALSE)
abline(v=10, lwd=5)
abline(v=c(4,6,8,12,14,16), lwd=3,lty=3)

How do I URl encode something in Node.js?

Note that URI encoding is good for the query part, it's not good for the domain. The domain gets encoded using punycode. You need a library like URI.js to convert between a URI and IRI (Internationalized Resource Identifier).

This is correct if you plan on using the string later as a query string:

> encodeURIComponent("http://examplé.org/rosé?rosé=rosé")
'http%3A%2F%2Fexampl%C3%A9.org%2Fros%C3%A9%3Fros%C3%A9%3Dros%C3%A9'

If you don't want ASCII characters like /, : and ? to be escaped, use encodeURI instead:

> encodeURI("http://examplé.org/rosé?rosé=rosé")
'http://exampl%C3%A9.org/ros%C3%A9?ros%C3%A9=ros%C3%A9'

However, for other use-cases, you might need uri-js instead:

> var URI = require("uri-js");
undefined
> URI.serialize(URI.parse("http://examplé.org/rosé?rosé=rosé"))
'http://xn--exampl-gva.org/ros%C3%A9?ros%C3%A9=ros%C3%A9'

No converter found capable of converting from type to type

Simple Solution::

use {nativeQuery=true} in your query.

for example

  @Query(value = "select d.id,d.name,d.breed,d.origin from Dog d",nativeQuery = true)
        
    List<Dog> findALL();

Java count occurrence of each item in an array

With , you can do it like this:

String[] array = {"name1","name2","name3","name4", "name5", "name2"};
Arrays.stream(array)
      .collect(Collectors.groupingBy(s -> s))
      .forEach((k, v) -> System.out.println(k+" "+v.size()));

Output:

name5 1
name4 1
name3 1
name2 2
name1 1

What it does is:

  • Create a Stream<String> from the original array
  • Group each element by identity, resulting in a Map<String, List<String>>
  • For each key value pair, print the key and the size of the list

If you want to get a Map that contains the number of occurences for each word, it can be done doing:

Map<String, Long> map = Arrays.stream(array)
    .collect(Collectors.groupingBy(s -> s, Collectors.counting()));

For more informations:

Hope it helps! :)

How to add a line break within echo in PHP?

The new line character is \n, like so:

echo __("Thanks for your email.\n<br />\n<br />Your order's details are below:", 'jigoshop');

How to display the first few characters of a string in Python?

If you want first 2 letters and last 2 letters of a string then you can use the following code: name = "India" name[0:2]="In" names[-2:]="ia"

adding child nodes in treeview

May i add to Stormenet example some KISS (Keep It Simple & Stupid):

If you already have a treeView or just created an instance of it: Let's populate with some data - Ex. One parent two child's :

            treeView1.Nodes.Add("ParentKey","Parent Text");
            treeView1.Nodes["ParentKey"].Nodes.Add("Child-1 Text");
            treeView1.Nodes["ParentKey"].Nodes.Add("Child-2 Text");

Another Ex. two parent's first have two child's second one child:

            treeView1.Nodes.Add("ParentKey1","Parent-1  Text");
            treeView1.Nodes.Add("ParentKey2","Parent-2 Text");
            treeView1.Nodes["ParentKey1"].Nodes.Add("Child-1 Text");
            treeView1.Nodes["ParentKey1"].Nodes.Add("Child-2 Text");
            treeView1.Nodes["ParentKey2"].Nodes.Add("Child-3 Text");

Take if farther - sub child of child 2:

            treeView1.Nodes.Add("ParentKey1","Parent-1  Text");
            treeView1.Nodes["ParentKey1"].Nodes.Add("Child-1 Text");
            treeView1.Nodes["ParentKey1"].Nodes.Add("ChildKey2","Child-2 Text");
            treeView1.Nodes["ParentKey1"].Nodes["ChildKey2"].Nodes.Add("Child-3 Text");

As you see you can have as many child's and parent's as you want and those can have sub child's of child's and so on.... Hope i help!

How do I display a MySQL error in PHP for a long query that depends on the user input?

One useful line of code for you would be:

$sql = "Your SQL statement here";
$result = mysqli_query($this->db_link, $sql) or trigger_error("Query Failed! SQL: $sql - Error: ".mysqli_error($this->db_link), E_USER_ERROR);

This method is better than die, because you can use it for development AND production. It's the permanent solution.

What's the better (cleaner) way to ignore output in PowerShell?

I would consider using something like:

function GetList
{
  . {
     $a = new-object Collections.ArrayList
     $a.Add(5)
     $a.Add('next 5')
  } | Out-Null
  $a
}
$x = GetList

Output from $a.Add is not returned -- that holds for all $a.Add method calls. Otherwise you would need to prepend [void] before each the call.

In simple cases I would go with [void]$a.Add because it is quite clear that output will not be used and is discarded.

How to copy directory recursively in python and overwrite all?

In Python 3.8 the dirs_exist_ok keyword argument was added to shutil.copytree():

dirs_exist_ok dictates whether to raise an exception in case dst or any missing parent directory already exists.

So, the following will work in recent versions of Python, even if the destination directory already exists:

shutil.copytree(src, dest, dirs_exist_ok=True)  # 3.8+ only!

One major benefit is that it's more flexible than distutils.dir_util.copy_tree() as it takes additional arguments on files to ignore, etc. There is also a draft PEP (PEP 632, associated discussion), which suggests that distutils may be deprecated and then removed in future versions of Python 3.

Insert into C# with SQLCommand

You can use dapper library:

conn2.Execute(@"INSERT INTO klant(klant_id,naam,voornaam) VALUES (@p1,@p2,@p3)", 
                new { p1 = klantId, p2 = klantNaam, p3 = klantVoornaam });

BTW Dapper is a Stack Overflow project :)

UPDATE: I believe you can't do it simpler without something like EF. Also try to use using statements when you are working with database connections. This will close connection automatically, even in case of exception. And connection will be returned to connections pool.

private readonly string _spionshopConnectionString;

private void Form1_Load(object sender, EventArgs e)
{            
    _spionshopConnectionString = ConfigurationManager
          .ConnectionStrings["connSpionshopString"].ConnectionString;
}

private void button4_Click(object sender, EventArgs e)
{
    using(var connection = new SqlConnection(_spionshopConnectionString))
    {
         connection.Execute(@"INSERT INTO klant(klant_id,naam,voornaam) 
                              VALUES (@klantId,@klantNaam,@klantVoornaam)",
                              new { 
                                      klantId = Convert.ToInt32(textBox1.Text), 
                                      klantNaam = textBox2.Text, 
                                      klantVoornaam = textBox3.Text 
                                  });
    }
}

How to stop Python closing immediately when executed in Microsoft Windows

The reason why it is closing is because the program is not running anymore, simply add any sort of loop or input to fix this (or you could just run it through idle.)

Accessing a Dictionary.Keys Key through a numeric index

Why don't you just extend the dictionary class to add in a last key inserted property. Something like the following maybe?

public class ExtendedDictionary : Dictionary<string, int>
{
    private int lastKeyInserted = -1;

    public int LastKeyInserted
    {
        get { return lastKeyInserted; }
        set { lastKeyInserted = value; }
    }

    public void AddNew(string s, int i)
    {
        lastKeyInserted = i;

        base.Add(s, i);
    }
}

Bind service to activity in Android

There is a method called unbindService that will take a ServiceConnection which you will have created upon calling bindService. This will allow you to disconnect from the service while still leaving it running.

This may pose a problem when you connect to it again, since you probably don't know whether it's running or not when you start the activity again, so you'll have to consider that in your activity code.

Good luck!

Removing App ID from Developer Connection

App IDs cannot be removed because once allocated they need to stay alive so that another App ID doesn't accidentally collide with a previously existing App ID.

Apple should however support hiding unwanted App IDs (instead of completely deleting them) to reduce clutter.

How to read the post request parameters using JavaScript

POST variables are only available to the browser if that same browser sent them in the first place. If another website form submits via POST to another URL, the browser will not see the POST data come in.

SITE A: has a form submit to an external URL (site B) using POST SITE B: will receive the visitor but with only GET variables

Using .otf fonts on web browsers

From the Google Font Directory examples:

@font-face {
  font-family: 'Tangerine';
  font-style: normal;
  font-weight: normal;
  src: local('Tangerine'), url('http://example.com/tangerine.ttf') format('truetype');
}
body {
  font-family: 'Tangerine', serif;
  font-size: 48px;
}

This works cross browser with .ttf, I believe it may work with .otf. (Wikipedia says .otf is mostly backwards compatible with .ttf) If not, you can convert the .otf to .ttf

Here are some good sites:

How to access single elements in a table in R

?"[" pretty much covers the various ways of accessing elements of things.

Under usage it lists these:

x[i]
x[i, j, ... , drop = TRUE]
x[[i, exact = TRUE]]
x[[i, j, ..., exact = TRUE]]
x$name
getElement(object, name)

x[i] <- value
x[i, j, ...] <- value
x[[i]] <- value
x$i <- value

The second item is sufficient for your purpose

Under Arguments it points out that with [ the arguments i and j can be numeric, character or logical

So these work:

data[1,1]
data[1,"V1"]

As does this:

data$V1[1]

and keeping in mind a data frame is a list of vectors:

data[[1]][1]
data[["V1"]][1]

will also both work.

So that's a few things to be going on with. I suggest you type in the examples at the bottom of the help page one line at a time (yes, actually type the whole thing in one line at a time and see what they all do, you'll pick up stuff very quickly and the typing rather than copypasting is an important part of helping to commit it to memory.)

UIButton title text color

I created a custom class MyButton extended from UIButton. Then added this inside the Identity Inspector:

enter image description here

After this, change the button type to Custom:

enter image description here

Then you can set attributes like textColor and UIFont for your UIButton for the different states:

enter image description here

Then I also created two methods inside MyButton class which I have to call inside my code when I want a UIButton to be displayed as highlighted:

- (void)changeColorAsUnselection{
    [self setTitleColor:[UIColor colorFromHexString:acColorGreyDark] 
               forState:UIControlStateNormal & 
                        UIControlStateSelected & 
                        UIControlStateHighlighted];
}

- (void)changeColorAsSelection{
    [self setTitleColor:[UIColor colorFromHexString:acColorYellow] 
               forState:UIControlStateNormal & 
                        UIControlStateHighlighted & 
                        UIControlStateSelected];
}

You have to set the titleColor for normal, highlight and selected UIControlState because there can be more than one state at a time according to the documentation of UIControlState. If you don't create these methods, the UIButton will display selection or highlighting but they won't stay in the UIColor you setup inside the UIInterface Builder because they are just available for a short display of a selection, not for displaying selection itself.

Generating a UUID in Postgres for Insert statement?

The answer by Craig Ringer is correct. Here's a little more info for Postgres 9.1 and later…

Is Extension Available?

You can only install an extension if it has already been built for your Postgres installation (your cluster in Postgres lingo). For example, I found the uuid-ossp extension included as part of the installer for Mac OS X kindly provided by EnterpriseDB.com. Any of a few dozen extensions may be available.

To see if the uuid-ossp extension is available in your Postgres cluster, run this SQL to query the pg_available_extensions system catalog:

SELECT * FROM pg_available_extensions;

Install Extension

To install that UUID-related extension, use the CREATE EXTENSION command as seen in this this SQL:

CREATE EXTENSION IF NOT EXISTS "uuid-ossp";

Beware: I found the QUOTATION MARK characters around extension name to be required, despite documentation to the contrary.

The SQL standards committee or Postgres team chose an odd name for that command. To my mind, they should have chosen something like "INSTALL EXTENSION" or "USE EXTENSION".

Verify Installation

You can verify the extension was successfully installed in the desired database by running this SQL to query the pg_extension system catalog:

SELECT * FROM pg_extension;

UUID as default value

For more info, see the Question: Default value for UUID column in Postgres

The Old Way

The information above uses the new Extensions feature added to Postgres 9.1. In previous versions, we had to find and run a script in a .sql file. The Extensions feature was added to make installation easier, trading a bit more work for the creator of an extension for less work on the part of the user/consumer of the extension. See my blog post for more discussion.

Types of UUIDs

By the way, the code in the Question calls the function uuid_generate_v4(). This generates a type known as Version 4 where nearly all of the 128 bits are randomly generated. While this is fine for limited use on smaller set of rows, if you want to virtually eliminate any possibility of collision, use another "version" of UUID.

For example, the original Version 1 combines the MAC address of the host computer with the current date-time and an arbitrary number, the chance of collisions is practically nil.

For more discussion, see my Answer on related Question.

Wireshark localhost traffic capture

You cannot capture loopback on Solaris, HP-UX, or Windows, however you can very easily work around this limitation by using a tool like RawCap.

RawCap can capture raw packets on any ip including 127.0.0.1 (localhost/loopback). Rawcap can also generate a pcap file. You can open and analyze the pcap file with Wireshark.

See here for full details on how to monitor localhost using RawCap and Wireshark.

Are multiple `.gitignore`s frowned on?

As a tangential note, one case where the ability to have multiple .gitignore files is very useful is if you want an extra directory in your working copy that you never intend to commit. Just put a 1-byte .gitignore (containing just a single asterisk) in that directory and it will never show up in git status etc.

Using Python's list index() method on a list of tuples or objects?

I would place this as a comment to Triptych, but I can't comment yet due to lack of rating:

Using the enumerator method to match on sub-indices in a list of tuples. e.g.

li = [(1,2,3,4), (11,22,33,44), (111,222,333,444), ('a','b','c','d'),
        ('aa','bb','cc','dd'), ('aaa','bbb','ccc','ddd')]

# want pos of item having [22,44] in positions 1 and 3:

def getIndexOfTupleWithIndices(li, indices, vals):

    # if index is a tuple of subindices to match against:
    for pos,k in enumerate(li):
        match = True
        for i in indices:
            if k[i] != vals[i]:
                match = False
                break;
        if (match):
            return pos

    # Matches behavior of list.index
    raise ValueError("list.index(x): x not in list")

idx = [1,3]
vals = [22,44]
print getIndexOfTupleWithIndices(li,idx,vals)    # = 1
idx = [0,1]
vals = ['a','b']
print getIndexOfTupleWithIndices(li,idx,vals)    # = 3
idx = [2,1]
vals = ['cc','bb']
print getIndexOfTupleWithIndices(li,idx,vals)    # = 4

How to get MD5 sum of a string using python?

Have you tried using the MD5 implementation in hashlib? Note that hashing algorithms typically act on binary data rather than text data, so you may want to be careful about which character encoding is used to convert from text to binary data before hashing.

The result of a hash is also binary data - it looks like Flickr's example has then been converted into text using hex encoding. Use the hexdigest function in hashlib to get this.

Convert DOS line endings to Linux line endings in Vim

Convert directory of files from DOS to Unix

Using command line and sed, find all files in current directory with the extension ".ext" and remove all "^M"

@ https://gist.github.com/sparkida/7773170

find $(pwd) -type f -name "*.ext" | while read file; do sed -e 's/^M//g' -i "$file"; done;

Also, as mentioned in a previous answer, ^M = Ctrl+V + Ctrl+M (don't just type the caret "^" symbol and M).

DataColumn Name from DataRow (not DataTable)

You need something like this:

foreach(DataColumn c in dr.Table.Columns)
{
  MessageBox.Show(c.ColumnName);
}

Convert ASCII number to ASCII Character in C

You can assign int to char directly.

int a = 65;
char c = a;
printf("%c", c);

In fact this will also work.

printf("%c", a);  // assuming a is in valid range

Find all controls in WPF Window by type

I found it easier without Visual Tree Helpers:

foreach (UIElement element in MainWindow.Children) {
    if (element is TextBox) { 
        if ((element as TextBox).Text != "")
        {
            //Do something
        }
    }
};

Can't access RabbitMQ web management interface after fresh install

If you are in Mac OS, you need to open the /usr/local/etc/rabbitmq/rabbitmq-env.conf and set NODE_IP_ADDRESS=, it used to be 127.0.0.1. Then add another user as the accepted answer suggested. After that, restart rabbitMQ, brew services restart rabbitmq

Are these methods thread safe?

The only problem with threads is accessing the same object from different threads without synchronization.

If each function only uses parameters for reading and local variables, they don't need any synchronization to be thread-safe.

How do you build a Singleton in Dart?

After reading all the alternatives I came up with this, which reminds me a "classic singleton":

class AccountService {
  static final _instance = AccountService._internal();

  AccountService._internal();

  static AccountService getInstance() {
    return _instance;
  }
}

How can I override Bootstrap CSS styles?

If you are planning to make any rather big changes, it might be a good idea to make them directly in bootstrap itself and rebuild it. Then, you could reduce the amount of data loaded.

Please refer to Bootstrap on GitHub for the build guide.

How do I import CSV file into a MySQL table?

You can fix this by listing the columns in you LOAD DATA statement. From the manual:

LOAD DATA INFILE 'persondata.txt' INTO TABLE persondata (col1,col2,...);

...so in your case you need to list the 99 columns in the order in which they appear in the csv file.

How to print float to n decimal places including trailing 0s?

Floating point numbers lack precision to accurately represent "1.6" out to that many decimal places. The rounding errors are real. Your number is not actually 1.6.

Check out: http://docs.python.org/library/decimal.html

"NoClassDefFoundError: Could not initialize class" error

I had this:

 class Util {
  static boolean isNeverAsync = System.getenv().get("asyncc_exclude_redundancy").equals("yes");
}

you can probably see the problem, the env var might return null instead of string. So just to test my theory, I changed it to:

 class Util {
  static boolean isNeverAsync = false;
}

and the problem went away. Too bad that Java can't give you the exact stack trace of the error though, kinda weird.

jQuery AJAX cross domain

It is true that the same-origin policy prevents JavaScript from making requests across domains, but the CORS specification allows just the sort of API access you are looking for, and is supported by the current batch of major browsers.

See how to enable cross-origin resource sharing for client and server:

http://enable-cors.org/

"Cross-Origin Resource Sharing (CORS) is a specification that enables truly open access across domain-boundaries. If you serve public content, please consider using CORS to open it up for universal JavaScript/browser access."

With CSS, use "..." for overflowed block of multi-lines

Just want to add to this question for completeness sake.

Python - Count elements in list

just do len(MyList)

This also works for strings, tuples, dict objects.

React Native - Image Require Module using Dynamic Names

 <StyledInput text="NAME" imgUri={require('../assets/userIcon.png')} ></StyledInput> 

<Image
            source={this.props.imgUri}
            style={{
              height: 30,
              width: 30,
              resizeMode: 'contain',
            }}
          />   

in my case i tried so much but finally it work StyledInput component name image inside the StyledInput if you still not understand let me know

Html table with button on each row

Put a single listener on the table. When it gets a click from an input with a button that has a name of "edit" and value "edit", change its value to "modify". Get rid of the input's id (they aren't used for anything here), or make them all unique.

<script type="text/javascript">

function handleClick(evt) {
  var node = evt.target || evt.srcElement;
  if (node.name == 'edit') {
    node.value = "Modify";
  }
}

</script>

<table id="table1" border="1" onclick="handleClick(event);">
    <thead>
      <tr>
          <th>Select
    </thead>
    <tbody>
       <tr> 
           <td>
               <form name="f1" action="#" >
                <input id="edit1" type="submit" name="edit" value="Edit">
               </form>
       <tr> 
           <td>
               <form name="f2" action="#" >
                <input id="edit2" type="submit" name="edit" value="Edit">
               </form>
       <tr> 
           <td>
               <form name="f3" action="#" >
                <input id="edit3" type="submit" name="edit" value="Edit">
               </form>

   </tbody>
</table>

How can I use grep to find a word inside a folder?

The answer you selected is fine, and it works, but it isn't the correct way to do it, because:

grep -nr yourString* .

This actually searches the string "yourStrin" and "g" 0 or many times.

So the proper way to do it is:

grep -nr \w*yourString\w* .

This command searches the string with any character before and after on the current folder.

How to count the number of observations in R like Stata command count

The with function will let you use shorthand column references and sum will count TRUE results from the expression(s).

sum(with(aaa, sex==1 & group1==2))
## [1] 3

sum(with(aaa, sex==1 & group2=="A"))
## [1] 2

As @mnel pointed out, you can also do:

nrow(aaa[aaa$sex==1 & aaa$group1==2,])
## [1] 3

nrow(aaa[aaa$sex==1 & aaa$group2=="A",])
## [1] 2

The benefit of that is that you can do:

nrow(aaa)
## [1] 6

And, the behaviour matches Stata's count almost exactly (syntax notwithstanding).

How to change plot background color?

The easiest thing is probably to provide the color when you create the plot :

fig1 = plt.figure(facecolor=(1, 1, 1))

or

fig1, (ax1, ax2) = plt.subplots(nrows=1, ncols=2, facecolor=(1, 1, 1))

Proper way to handle multiple forms on one page in Django

Wanted to share my solution where Django Forms are not being used. I have multiple form elements on a single page and I want to use a single view to manage all the POST requests from all the forms.

What I've done is I have introduced an invisible input tag so that I can pass a parameter to the views to check which form has been submitted.

<form method="post" id="formOne">
    {% csrf_token %}
   <input type="hidden" name="form_type" value="formOne">

    .....
</form>

.....

<form method="post" id="formTwo">
    {% csrf_token %}
    <input type="hidden" name="form_type" value="formTwo">
   ....
</form>

views.py

def handlemultipleforms(request, template="handle/multiple_forms.html"):
    """
    Handle Multiple <form></form> elements
    """
    if request.method == 'POST':
        if request.POST.get("form_type") == 'formOne':
            #Handle Elements from first Form
        elif request.POST.get("form_type") == 'formTwo':
            #Handle Elements from second Form

Is a Python list guaranteed to have its elements stay in the order they are inserted in?

In short, yes, the order is preserved. In long:

In general the following definitions will always apply to objects like lists:

A list is a collection of elements that can contain duplicate elements and has a defined order that generally does not change unless explicitly made to do so. stacks and queues are both types of lists that provide specific (often limited) behavior for adding and removing elements (stacks being LIFO, queues being FIFO). Lists are practical representations of, well, lists of things. A string can be thought of as a list of characters, as the order is important ("abc" != "bca") and duplicates in the content of the string are certainly permitted ("aaa" can exist and != "a").

A set is a collection of elements that cannot contain duplicates and has a non-definite order that may or may not change over time. Sets do not represent lists of things so much as they describe the extent of a certain selection of things. The internal structure of set, how its elements are stored relative to each other, is usually not meant to convey useful information. In some implementations, sets are always internally sorted; in others the ordering is simply undefined (usually depending on a hash function).

Collection is a generic term referring to any object used to store a (usually variable) number of other objects. Both lists and sets are a type of collection. Tuples and Arrays are normally not considered to be collections. Some languages consider maps (containers that describe associations between different objects) to be a type of collection as well.

This naming scheme holds true for all programming languages that I know of, including Python, C++, Java, C#, and Lisp (in which lists not keeping their order would be particularly catastrophic). If anyone knows of any where this is not the case, please just say so and I'll edit my answer. Note that specific implementations may use other names for these objects, such as vector in C++ and flex in ALGOL 68 (both lists; flex is technically just a re-sizable array).

If there is any confusion left in your case due to the specifics of how the + sign works here, just know that order is important for lists and unless there is very good reason to believe otherwise you can pretty much always safely assume that list operations preserve order. In this case, the + sign behaves much like it does for strings (which are really just lists of characters anyway): it takes the content of a list and places it behind the content of another.

If we have

list1 = [0, 1, 2, 3, 4]
list2 = [5, 6, 7, 8, 9]

Then

list1 + list2

Is the same as

[0, 1, 2, 3, 4] + [5, 6, 7, 8, 9]

Which evaluates to

[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

Much like

"abdcde" + "fghijk"

Produces

"abdcdefghijk"

How to check whether a string contains a substring in Ruby

You can also do this...

my_string = "Hello world"

if my_string["Hello"]
  puts 'It has "Hello"'
else
  puts 'No "Hello" found'
end

# => 'It has "Hello"'

This example uses Ruby's String #[] method.

PermissionError: [WinError 5] Access is denied python using moviepy to write gif

If you're encountering this in Jupyter/Jupyerlab while trying to pip install foo, you can sometimes work around it by using !python -m pip install foo instead.

Python IndentationError: unexpected indent

You can't mix tab and spaces for identation. Best practice is to convert all tabs to spaces.

How to fix this? Well just delete all the spaces/tabs before each line and convert them uniformly either to tabs OR spaces, but don't mix. Best solution: enable in your Editor the option to convert automagically any tabs to spaces.

Also be aware that your actual problem may lie in the lines before this block, and python throws the error here, because of a leading invalid indentation which doesn't match the following identations!

Javascript: Extend a Function

There are several ways to go about this, it depends what your purpose is, if you just want to execute the function as well and in the same context, you can use .apply():

function init(){
  doSomething();
}
function myFunc(){
  init.apply(this, arguments);
  doSomethingHereToo();
}

If you want to replace it with a newer init, it'd look like this:

function init(){
  doSomething();
}
//anytime later
var old_init = init;
init = function() {
  old_init.apply(this, arguments);
  doSomethingHereToo();
};

PHP String to Float

$rootbeer = (float) $InvoicedUnits;

Should do it for you. Check out Type-Juggling. You should also read String conversion to Numbers.

How do I set up a private Git repository on GitHub? Is it even possible?

Since January 7th, 2019, it is possible: unlimited free private repositories on GitHub!
... But for up to three collaborators per private repository.

Nat Friedman just announced it by twitter:

Today(!) we’re thrilled to announce unlimited free private repos for all GitHub users, and a new simplified Enterprise offering:

"New year, new GitHub: Announcing unlimited free private repos and unified Enterprise offering"

For the first time, developers can use GitHub for their private projects with up to three collaborators per repository for free.

Many developers want to use private repos to apply for a job, work on a side project, or try something out in private before releasing it publicly.
Starting today, those scenarios, and many more, are possible on GitHub at no cost.

Public repositories are still free (of course—no changes there) and include unlimited collaborators.

Sort rows in data.table in decreasing order on string key `order(-x,v)` gives error on data.table 1.9.4 or earlier

You can only use - on the numeric entries, so you can use decreasing and negate the ones you want in increasing order:

DT[order(x,-v,decreasing=TRUE),]
      x y v
 [1,] c 1 7
 [2,] c 3 8
 [3,] c 6 9
 [4,] b 1 1
 [5,] b 3 2
 [6,] b 6 3
 [7,] a 1 4
 [8,] a 3 5
 [9,] a 6 6

Reading an image file into bitmap from sdcard, why am I getting a NullPointerException?

The MediaStore API is probably throwing away the alpha channel (i.e. decoding to RGB565). If you have a file path, just use BitmapFactory directly, but tell it to use a format that preserves alpha:

BitmapFactory.Options options = new BitmapFactory.Options();
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
Bitmap bitmap = BitmapFactory.decodeFile(photoPath, options);
selected_photo.setImageBitmap(bitmap);

or

http://mihaifonoage.blogspot.com/2009/09/displaying-images-from-sd-card-in.html

Right way to convert data.frame to a numeric matrix, when df also contains strings?

Edit 2: See @flodel's answer. Much better.

Try:

# assuming SFI is your data.frame
as.matrix(sapply(SFI, as.numeric))  

Edit: or as @ CarlWitthoft suggested in the comments:

matrix(as.numeric(unlist(SFI)),nrow=nrow(SFI))

Set the layout weight of a TextView programmatically

TextView txtview = new TextView(v.getContext());
LayoutParams params = new LinearLayout.LayoutParams(0, LayoutParams.WRAP_CONTENT, 1f);
txtview.setLayoutParams(params);

1f is denotes as weight=1; you can give 2f or 3f, views will move accoding to the space

Convert SVG to PNG in Python

Install Inkscape and call it as command line:

${INKSCAPE_PATH} -z -f ${source_svg} -w ${width} -j -e ${dest_png}

You can also snap specific rectangular area only using parameter -j, e.g. co-ordinate "0:125:451:217"

${INKSCAPE_PATH} -z -f ${source_svg} -w ${width} -j -a ${coordinates} -e ${dest_png}

If you want to show only one object in the SVG file, you can specify the parameter -i with the object id that you have setup in the SVG. It hides everything else.

${INKSCAPE_PATH} -z -f ${source_svg} -w ${width} -i ${object} -j -a ${coordinates} -e ${dest_png}

Rules for C++ string literals escape character

ascii is a package on linux you could download. for example sudo apt-get install ascii ascii

Usage: ascii [-dxohv] [-t] [char-alias...]
-t = one-line output  -d = Decimal table  -o = octal table  -x = hex table
-h = This help screen -v = version information
Prints all aliases of an ASCII character. Args may be chars, C \-escapes,
English names, ^-escapes, ASCII mnemonics, or numerics in decimal/octal/hex.`

This code can help you with C/C++ escape codes like \x0A

REST API - Use the "Accept: application/json" HTTP Header

Here's a handy site to test out your headers. You can see your browser headers and also use cURL to reflect back whatever headers you send.

For example, you can validate the content negotiation like this.

This Accept header prefers plain text so returns in that format:-

$ curl -H "Accept: application/json;q=0.9,text/plain" http://gethttp.info/Accept
application/json;q=0.9,text/plain

Whereas this one prefers JSON and so returns in that format:-

$ curl -H "Accept: application/json,text/*;q=0.99" http://gethttp.info/Accept
{
   "Accept": "application/json,text/*;q=0.99"
}

How to catch exception output from Python subprocess.check_output()?

As mentioned by @Sebastian the default solution should aim to use run(): https://docs.python.org/3/library/subprocess.html#subprocess.run

Here a convenient implementation (feel free to change the log class with print statements or what ever other logging functionality you are using):

import subprocess

def _run_command(command):
    log.debug("Command: {}".format(command))
    result = subprocess.run(command, shell=True, capture_output=True)
    if result.stderr:
        raise subprocess.CalledProcessError(
                returncode = result.returncode,
                cmd = result.args,
                stderr = result.stderr
                )
    if result.stdout:
        log.debug("Command Result: {}".format(result.stdout.decode('utf-8')))
    return result

And sample usage (code is unrelated, but I think it serves as example of how readable and easy to work with errors it is with this simple implementation):

try:
    # Unlock PIN Card
    _run_command(
        "sudo qmicli --device=/dev/cdc-wdm0 -p --uim-verify-pin=PIN1,{}"
        .format(pin)
    )

except subprocess.CalledProcessError as error:
    if "couldn't verify PIN" in error.stderr.decode("utf-8"):
        log.error(
                "SIM card could not be unlocked. "
                "Either the PIN is wrong or the card is not properly connected. "
                "Resetting module..."
                )
        _reset_4g_hat()
        return

What is the difference between int, Int16, Int32 and Int64?

According to Jeffrey Richter(one of the contributors of .NET framework development)'s book 'CLR via C#':

int is a primitive type allowed by the C# compiler, whereas Int32 is the Framework Class Library type (available across languages that abide by CLS). In fact, int translates to Int32 during compilation.

Also,

In C#, long maps to System.Int64, but in a different programming language, long could map to Int16 or Int32. In fact, C++/CLI does treat long as Int32.

In fact, most (.NET) languages won't even treat long as a keyword and won't compile code that uses it.

I have seen this author, and many standard literature on .NET preferring FCL types(i.e., Int32) to the language-specific primitive types(i.e., int), mainly on such interoperability concerns.

Connect to docker container as user other than root

As an updated answer from 2020. --user , -u option is Username or UID (format: <name|uid>[:<group|gid>]).

Then, it works for me like this,

docker exec -it -u root:root container /bin/bash

Reference: https://docs.docker.com/engine/reference/commandline/exec/

Where in an Eclipse workspace is the list of projects stored?

In Eclipse 3.3:

It's installed under your Eclipse workspace. Something like:

.metadata\.plugins\org.eclipse.core.resources\.projects\

within your workspace folder.

Under that folder is one folder per project. There's a file in there called .location, but it's binary.

So it looks like you can't do what you want, without interacting w/ Eclipse programmatically.

How to go up a level in the src path of a URL in HTML?

Supposing you have the following file structure:

-css
  --index.css
-images
  --image1.png
  --image2.png
  --image3.png

In CSS you can access image1, for example, using the line ../images/image1.png.

NOTE: If you are using Chrome, it may doesn't work and you will get an error that the file could not be found. I had the same problem, so I just deleted the entire cache history from chrome and it worked.

Getting "The remote certificate is invalid according to the validation procedure" when SMTP server has a valid certificate

Old post, but I thought I would share my solution because there aren't many solutions out there for this issue.

If you're running an old Windows Server 2003 machine, you likely need to install a hotfix (KB938397).

This problem occurs because the Cryptography API 2 (CAPI2) in Windows Server 2003 does not support the SHA2 family of hashing algorithms. CAPI2 is the part of the Cryptography API that handles certificates.

https://support.microsoft.com/en-us/kb/938397

For whatever reason, Microsoft wants to email you this hotfix instead of allowing you to download directly. Here's a direct link to the hotfix from the email:

http://hotfixv4.microsoft.com/Windows Server 2003/sp3/Fix200653/3790/free/315159_ENU_x64_zip.exe

Entity Framework: One Database, Multiple DbContexts. Is this a bad idea?

Reminder: If you do combine multiple contexts make sure you cut n paste all the functionality in your various RealContexts.OnModelCreating() into your single CombinedContext.OnModelCreating().

I just wasted time hunting down why my cascade delete relationships weren't being preserved only to discover that I hadn't ported the modelBuilder.Entity<T>()....WillCascadeOnDelete(); code from my real context into my combined context.

The source was not found, but some or all event logs could not be searched. Inaccessible logs: Security

Use NetworkService as Identity value in the application pool advanced settings when you are debugging in Visual Studio. ApplicationPoolIdentity is working if you open the site directly from the browser (or go to virtual directory in IIS and use Browse option at right).

Javascript ES6/ES5 find in array and change

One-liner using spread operator.

 const updatedData = originalData.map(x => (x.id === id ? { ...x, updatedField: 1 } : x));

long long int vs. long int vs. int64_t in C++

You don't need to go to 64-bit to see something like this. Consider int32_t on common 32-bit platforms. It might be typedef'ed as int or as a long, but obviously only one of the two at a time. int and long are of course distinct types.

It's not hard to see that there is no workaround which makes int == int32_t == long on 32-bit systems. For the same reason, there's no way to make long == int64_t == long long on 64-bit systems.

If you could, the possible consequences would be rather painful for code that overloaded foo(int), foo(long) and foo(long long) - suddenly they'd have two definitions for the same overload?!

The correct solution is that your template code usually should not be relying on a precise type, but on the properties of that type. The whole same_type logic could still be OK for specific cases:

long foo(long x);
std::tr1::disable_if(same_type(int64_t, long), int64_t)::type foo(int64_t);

I.e., the overload foo(int64_t) is not defined when it's exactly the same as foo(long).

[edit] With C++11, we now have a standard way to write this:

long foo(long x);
std::enable_if<!std::is_same<int64_t, long>::value, int64_t>::type foo(int64_t);

[edit] Or C++20

long foo(long x);
int64_t foo(int64_t) requires (!std::is_same_v<int64_t, long>);

Easiest way to copy a table from one database to another?

Use MySql Workbench's Export and Import functionality. Steps:
1. Select the values you want

E.g. select * from table1; 
  1. Click on the Export button and save it as CSV.
  2. create a new table using similar columns as the first one

    E.g. create table table2 like table1; 
    
  3. select all from the new table

    E.g. select * from table2;  
    
  4. Click on Import and select the CSV file you exported in step 2

Sample of the Export and Import buttons in MySql Workbench

Java2D: Increase the line width

You should use setStroke to set a stroke of the Graphics2D object.

The example at http://www.java2s.com gives you some code examples.

The following code produces the image below:

import java.awt.*;
import java.awt.geom.Line2D;
import javax.swing.*;

public class FrameTest {
    public static void main(String[] args) {
        JFrame jf = new JFrame("Demo");
        Container cp = jf.getContentPane();
        cp.add(new JComponent() {
            public void paintComponent(Graphics g) {
                Graphics2D g2 = (Graphics2D) g;
                g2.setStroke(new BasicStroke(10));
                g2.draw(new Line2D.Float(30, 20, 80, 90));
            }
        });
        jf.setSize(300, 200);
        jf.setVisible(true);
    }
}

enter image description here

(Note that the setStroke method is not available in the Graphics object. You have to cast it to a Graphics2D object.)


This post has been rewritten as an article here.

Can I run multiple programs in a Docker container?

Docker provides a couple of examples on how to do it. The lightweight option is to:

Put all of your commands in a wrapper script, complete with testing and debugging information. Run the wrapper script as your CMD. This is a very naive example. First, the wrapper script:

#!/bin/bash

# Start the first process
./my_first_process -D
status=$?
if [ $status -ne 0 ]; then
  echo "Failed to start my_first_process: $status"
  exit $status
fi

# Start the second process
./my_second_process -D
status=$?
if [ $status -ne 0 ]; then
  echo "Failed to start my_second_process: $status"
  exit $status
fi

# Naive check runs checks once a minute to see if either of the processes exited.
# This illustrates part of the heavy lifting you need to do if you want to run
# more than one service in a container. The container will exit with an error
# if it detects that either of the processes has exited.
# Otherwise it will loop forever, waking up every 60 seconds

while /bin/true; do
  ps aux |grep my_first_process |grep -q -v grep
  PROCESS_1_STATUS=$?
  ps aux |grep my_second_process |grep -q -v grep
  PROCESS_2_STATUS=$?
  # If the greps above find anything, they will exit with 0 status
  # If they are not both 0, then something is wrong
  if [ $PROCESS_1_STATUS -ne 0 -o $PROCESS_2_STATUS -ne 0 ]; then
    echo "One of the processes has already exited."
    exit -1
  fi
  sleep 60
done

Next, the Dockerfile:

FROM ubuntu:latest
COPY my_first_process my_first_process
COPY my_second_process my_second_process
COPY my_wrapper_script.sh my_wrapper_script.sh
CMD ./my_wrapper_script.sh

Control cannot fall through from one case label

You missed some breaks there:

switch (searchType)
{
    case "SearchBooks":
        Selenium.Type("//*[@id='SearchBooks_TextInput']", searchText);
        Selenium.Click("//*[@id='SearchBooks_SearchBtn']");
        break;

    case "SearchAuthors":
        Selenium.Type("//*[@id='SearchAuthors_TextInput']", searchText);
        Selenium.Click("//*[@id='SearchAuthors_SearchBtn']");
        break;
}

Without them, the compiler thinks you're trying to execute the lines below case "SearchAuthors": immediately after the lines under case "SearchBooks": have been executed, which isn't allowed in C#.

By adding the break statements at the end of each case, the program exits each case after it's done, for whichever value of searchType.

#1071 - Specified key was too long; max key length is 1000 bytes

This error means that length of index index is more then 1000 bytes. MySQL and storage engines may have this restriction. I have got similar error on MySQL 5.5 - 'Specified key was too long; max key length is 3072 bytes' when ran this script:

CREATE TABLE IF NOT EXISTS test_table1 (
  column1 varchar(500) NOT NULL,
  column2 varchar(500) NOT NULL,
  column3 varchar(500) NOT NULL,
  column4 varchar(500) NOT NULL,
  column5 varchar(500) NOT NULL,
  column6 varchar(500) NOT NULL,
  KEY `index` (column1, column2, column3, column4, column5, column6)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

UTF8 is multi-bytes, and key length is calculated in this way - 500 * 3 * 6 = 9000 bytes.

But note, next query works!

CREATE TABLE IF NOT EXISTS test_table1 (
  column1 varchar(500) NOT NULL,
  column2 varchar(500) NOT NULL,
  column3 varchar(500) NOT NULL,
  column4 varchar(500) NOT NULL,
  column5 varchar(500) NOT NULL,
  column6 varchar(500) NOT NULL,
  KEY `index` (column1, column2, column3, column4, column5, column6)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

...because I used CHARSET=latin1, in this case key length is 500 * 6 = 3000 bytes.

printf not printing on console

As others have pointed out, output can be buffered within your program before a console or shell has a chance to see it.

On unix-like systems, including macs, stdout has line-based buffering by default. This means that your program empties its stdout buffer as soon as it sees a newline.

However, on windows, newlines are no longer special, and full buffering is used. Windows doesn't support line buffering at all; see the msdn page on setvbuf.

So on windows, a good approach is to completely shut off stdout buffering like so:

setvbuf (stdout, NULL, _IONBF, 0);

How to use the pass statement?

The pass statement in Python is used when a statement is required syntactically but you do not want any command or code to execute.

The pass statement is a null operation; nothing happens when it executes. The pass is also useful in places where your code will eventually go, but has not been written yet (e.g., in stubs for example):

`Example:

#!/usr/bin/python

for letter in 'Python': 
   if letter == 'h':
      pass
      print 'This is pass block'
   print 'Current Letter :', letter

print "Good bye!"

This will produce following result:

Current Letter : P
Current Letter : y
Current Letter : t
This is pass block
Current Letter : h
Current Letter : o
Current Letter : n
Good bye!

The preceding code does not execute any statement or code if the value of letter is 'h'. The pass statement is helpful when you have created a code block but it is no longer required.

You can then remove the statements inside the block but let the block remain with a pass statement so that it doesn't interfere with other parts of the code.

"Least Astonishment" and the Mutable Default Argument

I used to think that creating the objects at runtime would be the better approach. I'm less certain now, since you do lose some useful features, though it may be worth it regardless simply to prevent newbie confusion. The disadvantages of doing so are:

1. Performance

def foo(arg=something_expensive_to_compute())):
    ...

If call-time evaluation is used, then the expensive function is called every time your function is used without an argument. You'd either pay an expensive price on each call, or need to manually cache the value externally, polluting your namespace and adding verbosity.

2. Forcing bound parameters

A useful trick is to bind parameters of a lambda to the current binding of a variable when the lambda is created. For example:

funcs = [ lambda i=i: i for i in range(10)]

This returns a list of functions that return 0,1,2,3... respectively. If the behaviour is changed, they will instead bind i to the call-time value of i, so you would get a list of functions that all returned 9.

The only way to implement this otherwise would be to create a further closure with the i bound, ie:

def make_func(i): return lambda: i
funcs = [make_func(i) for i in range(10)]

3. Introspection

Consider the code:

def foo(a='test', b=100, c=[]):
   print a,b,c

We can get information about the arguments and defaults using the inspect module, which

>>> inspect.getargspec(foo)
(['a', 'b', 'c'], None, None, ('test', 100, []))

This information is very useful for things like document generation, metaprogramming, decorators etc.

Now, suppose the behaviour of defaults could be changed so that this is the equivalent of:

_undefined = object()  # sentinel value

def foo(a=_undefined, b=_undefined, c=_undefined)
    if a is _undefined: a='test'
    if b is _undefined: b=100
    if c is _undefined: c=[]

However, we've lost the ability to introspect, and see what the default arguments are. Because the objects haven't been constructed, we can't ever get hold of them without actually calling the function. The best we could do is to store off the source code and return that as a string.

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

I made https://github.com/ajwhite/render-if recently to safely render elements only if the predicate passes.

{renderIf(1 + 1 === 2)(
  <span>Hello!</span>
)}

or

const ifUniverseIsWorking = renderIf(1 + 1 === 2);

//...

{ifUniverseIsWorking(
  <span>Hello!</span>
)}

I can pass a variable from a JSP scriptlet to JSTL but not from JSTL to a JSP scriptlet without an error

Scripts are raw java embedded in the page code, and if you declare variables in your scripts, then they become local variables embedded in the page.

In contrast, JSTL works entirely with scoped attributes, either at page, request or session scope. You need to rework your scriptlet to fish test out as an attribute:

<c:set var="test" value="test1"/>
<%
  String resp = "abc";
  String test = pageContext.getAttribute("test");
  resp = resp + test;
  pageContext.setAttribute("resp", resp);
%>
<c:out value="${resp}"/>

If you look at the docs for <c:set>, you'll see you can specify scope as page, request or session, and it defaults to page.

Better yet, don't use scriptlets at all: they make the baby jesus cry.

How to reset all checkboxes using jQuery or pure JS?

I have used this before:

$('input[type=checkbox]').prop('checked', false);

seems that .attr and .removeAttr doesn't work for some situations.

edit: Note that in jQuery v1.6 and higher, you should be using .prop('checked', false) instead for greater cross-browser compatibility - see https://api.jquery.com/prop

Comment here: How to reset all checkboxes using jQuery or pure JS?

Reading e-mails from Outlook with Python through MAPI

I have created my own iterator to iterate over Outlook objects via python. The issue is that python tries to iterates starting with Index[0], but outlook expects for first item Index[1]... To make it more Ruby simple, there is below a helper class Oli with following methods:

.items() - yields a tuple(index, Item)...

.prop() - helping to introspect outlook object exposing available properties (methods and attributes)

from win32com.client import constants
from win32com.client.gencache import EnsureDispatch as Dispatch

outlook = Dispatch("Outlook.Application")
mapi = outlook.GetNamespace("MAPI")

class Oli():
    def __init__(self, outlook_object):
        self._obj = outlook_object

    def items(self):
        array_size = self._obj.Count
        for item_index in xrange(1,array_size+1):
            yield (item_index, self._obj[item_index])

    def prop(self):
        return sorted( self._obj._prop_map_get_.keys() )

for inx, folder in Oli(mapi.Folders).items():
    # iterate all Outlook folders (top level)
    print "-"*70
    print folder.Name

    for inx,subfolder in Oli(folder.Folders).items():
        print "(%i)" % inx, subfolder.Name,"=> ", subfolder

What is Android keystore file, and what is it used for?

The whole idea of a keytool is to sign your apk with a unique identifier indicating the source of that apk. A keystore file (from what I understand) is used for debuging so your apk has the functionality of a keytool without signing your apk for production. So yes, for debugging purposes you should be able to sign multiple apk's with a single keystore. But understand that, upon pushing to production you'll need unique keytools as identifiers for each apk you create.

SQL - IF EXISTS UPDATE ELSE INSERT INTO

  1. Create a UNIQUE constraint on your subs_email column, if one does not already exist:

    ALTER TABLE subs ADD UNIQUE (subs_email)
    
  2. Use INSERT ... ON DUPLICATE KEY UPDATE:

    INSERT INTO subs
      (subs_name, subs_email, subs_birthday)
    VALUES
      (?, ?, ?)
    ON DUPLICATE KEY UPDATE
      subs_name     = VALUES(subs_name),
      subs_birthday = VALUES(subs_birthday)
    

You can use the VALUES(col_name) function in the UPDATE clause to refer to column values from the INSERT portion of the INSERT ... ON DUPLICATE KEY UPDATE - dev.mysql.com

  1. Note that I have used parameter placeholders in the place of string literals, as one really should be using parameterised statements to defend against SQL injection attacks.

How to round 0.745 to 0.75 using BigDecimal.ROUND_HALF_UP?

Use BigDecimal.valueOf(double d) instead of new BigDecimal(double d). The last one has precision errors by float and double.

wget can't download - 404 error

I had the same problem. Solved using single quotes like this:

$ wget 'http://www.icerts.com/images/logo.jpg'

wget version in use:

$ wget --version
GNU Wget 1.11.4 Red Hat modified

Scrollbar without fixed height/Dynamic height with scrollbar

Use this:

style="height: 150px; max-height: 300px; overflow: auto;" 

fixe a height, it will be the default height and then a scroll bar come to access to the entire height

How to vertically center an image inside of a div element in HTML using CSS?

If you want content to be what ever you need to have inside a div, this did the job for me:

<div style="
  display: table-cell;
  vertical-align: middle;
  background-color: blue;
  width: ...px;
  height: ...px;
">
    <div style="
      margin: auto;
      display: block;
      width: fit-content;
    ">
        <!-- CONTENT -->
        <img src="...">
        <p> some text </p>
    </div>
 </div>

How to install a certificate in Xcode (preparing for app store submission)

You can update your provisioning certificates in XCode at:

Organizer -> Devices -> LIBRARY -> Provisioning Profiles

There is a refresh button :) So if you have created the certificate manually in iTunes connect, then you need to press this button or download the certificate manually.

ADB Driver and Windows 8.1

Use the awesome "Universal ADB (Android Debug Bridge) Driver for Windows": https://plus.google.com/103583939320326217147/posts/BQ5iYJEaaEH https://github.com/koush/UniversalAdbDriver

  • Windows 8 compatible
  • comes signed, so does not require you to turn off windows driver signature checks

Tested under Win8.1.1 x64.

how to auto select an input field and the text in it on page load

To do it on page load:

_x000D_
_x000D_
window.onload = function () {_x000D_
  var input = document.getElementById('myTextInput');_x000D_
  input.focus();_x000D_
  input.select();_x000D_
}
_x000D_
<input id="myTextInput" value="Hello world!" />
_x000D_
_x000D_
_x000D_

Regular expression to detect semi-colon terminated C++ for & while loops

I wouldn't even pay attention to the contents of the parens.

Just match any line that starts with for and ends with semi-colon:

^\t*for.+;$

Unless you've got for statements split over multiple lines, that will work fine?

Javascript set img src

If you're using WinJS you can change the src through the Utilities functions.

WinJS.Utilities.id("pic1").setAttribute("src", searchPic.src);

Animate text change in UILabel

UILabel Extension Solution

extension UILabel{

  func animation(typing value:String,duration: Double){
    let characters = value.map { $0 }
    var index = 0
    Timer.scheduledTimer(withTimeInterval: duration, repeats: true, block: { [weak self] timer in
        if index < value.count {
            let char = characters[index]
            self?.text! += "\(char)"
            index += 1
        } else {
            timer.invalidate()
        }
    })
  }


  func textWithAnimation(text:String,duration:CFTimeInterval){
    fadeTransition(duration)
    self.text = text
  }

  //followed from @Chris and @winnie-ru
  func fadeTransition(_ duration:CFTimeInterval) {
    let animation = CATransition()
    animation.timingFunction = CAMediaTimingFunction(name:
        CAMediaTimingFunctionName.easeInEaseOut)
    animation.type = CATransitionType.fade
    animation.duration = duration
    layer.add(animation, forKey: CATransitionType.fade.rawValue)
  }

}

Simply Called function by

uiLabel.textWithAnimation(text: "text you want to replace", duration: 0.2)

Thanks for all the tips guys. Hope this will help in long term

Setting up a JavaScript variable from Spring model by using Thymeleaf

I've seen this kind of thing work in the wild:

<input type="button"  th:onclick="'javascript:getContactId(\'' + ${contact.id} + '\');'" />

Cannot send a content-body with this verb-type

Please set the request Content Type before you read the response stream;

 request.ContentType = "text/xml";

How do I install Java on Mac OSX allowing version switching?

If you have multiple versions installed on your machine, add the following in bash profile:

export JAVA_HOME_7=$(/usr/libexec/java_home -v1.7)

export JAVA_HOME_8=$(/usr/libexec/java_home -v1.8)

export JAVA_HOME_9=$(/usr/libexec/java_home -v9)

And add the following aliases:

alias java7='export JAVA_HOME=$JAVA_HOME_7'

alias java8='export JAVA_HOME=$JAVA_HOME_8'

alias java9='export JAVA_HOME=$JAVA_HOME_9'

And can switch to required version by using the alias:

In terminal:

~ >> java7 export JAVA_HOME=$JAVA_7_HOME

Using different Web.config in development and production environment

On one project where we had 4 environments (development, test, staging and production) we developed a system where the application selected the appropriate configuration based on the machine name it was deployed to.

This worked for us because:

  • administrators could deploy applications without involving developers (a requirement) and without having to fiddle with config files (which they hated);
  • machine names adhered to a convention. We matched names using a regular expression and deployed to multiple machines in an environment; and
  • we used integrated security for connection strings. This means we could keep account names in our config files at design time without revealing any passwords.

It worked well for us in this instance, but probably wouldn't work everywhere.

How to invoke a Linux shell command from Java

exec does not execute a command in your shell

try

Process p = Runtime.getRuntime().exec(new String[]{"csh","-c","cat /home/narek/pk.txt"});

instead.

EDIT:: I don't have csh on my system so I used bash instead. The following worked for me

Process p = Runtime.getRuntime().exec(new String[]{"bash","-c","ls /home/XXX"});

Difference between static, auto, global and local variable in the context of c and c++

static is a heavily overloaded word in C and C++. static variables in the context of a function are variables that hold their values between calls. They exist for the duration of the program.

local variables persist only for the lifetime of a function or whatever their enclosing scope is. For example:

void foo()
{
    int i, j, k;
    //initialize, do stuff
} //i, j, k fall out of scope, no longer exist

Sometimes this scoping is used on purpose with { } blocks:

{ 
   int i, j, k;
   //...
} //i, j, k now out of scope

global variables exist for the duration of the program.

auto is now different in C and C++. auto in C was a (superfluous) way of specifying a local variable. In C++11, auto is now used to automatically derive the type of a value/expression.

Detect Android phone via Javascript / jQuery

js version, catches iPad too:

var is_mobile = /mobile|android/i.test (navigator.userAgent);

UIView's frame, bounds, center, origin, when to use what?

They are related values, and kept consistent by the property setter/getter methods (and using the fact that frame is a purely synthesized value, not backed by an actual instance variable).

The main equations are:

frame.origin = center - bounds.size / 2

(which is the same as)

center = frame.origin + bounds.size / 2

(and there’s also)

frame.size = bounds.size

That's not code, just equations to express the invariant between the three properties. These equations also assume your view's transform is the identity, which it is by default. If it's not, then bounds and center keep the same meaning, but frame can change. Unless you're doing non-right-angle rotations, the frame will always be the transformed view in terms of the superview's coordinates.

This stuff is all explained in more detail with a useful mini-library here:

http://bynomial.com/blog/?p=24

Specified argument was out of the range of valid values. Parameter name: site

If you are okay with using the built in Visual Studio Development server or you don't want to or cannot install IIS, you can change the web server the project uses by going into

  1. Project Properties (right click project in solution explorer and select properties)

  2. select Web tab

  3. select "Use Visual Studio Development Server".

I don't know how it happened to me, but somehow this option was changed to "Use Local IIS Web Server" for one of my projects.

Change the location of an object programmatically

The Location property has type Point which is a struct.

Instead of trying to modify the existing Point, try assigning a new Point object:

 this.balancePanel.Location = new Point(
     this.optionsPanel.Location.X,
     this.balancePanel.Location.Y
 );

Good ways to sort a queryset? - Django

Here's a way that allows for ties for the cut-off score.

author_count = Author.objects.count()
cut_off_score = Author.objects.order_by('-score').values_list('score')[min(30, author_count)]
top_authors = Author.objects.filter(score__gte=cut_off_score).order_by('last_name')

You may get more than 30 authors in top_authors this way and the min(30,author_count) is there incase you have fewer than 30 authors.

Display exact matches only with grep

This may work for you

grep -E '(^|\s)OK($|\s)'

How to discard local commits in Git?

As an aside, apart from the answer by mipadi (which should work by the way), you should know that doing:

git branch -D master
git checkout master

also does exactly what you want without having to redownload everything (your quote paraphrased). That is because your local repo contains a copy of the remote repo (and that copy is not the same as your local directory, it is not even the same as your checked out branch).

Wiping out a branch is perfectly safe and reconstructing that branch is very fast and involves no network traffic. Remember, git is primarily a local repo by design. Even remote branches have a copy on the local. There's only a bit of metadata that tells git that a specific local copy is actually a remote branch. In git, all files are on your hard disk all the time.

If you don't have any branches other than master, you should:

git checkout -b 'temp'
git branch -D master
git checkout master
git branch -D temp

How to export all collections in MongoDB?

There are multiple options depending on what you want to do

1) If you want to export your database to another mongo database, you should use mongodump. This creates a folder of BSON files which have metadata that JSON wouldn't have.

mongodump
mongorestore --host mongodb1.example.net --port 37017 dump/

2) If you want to export your database into JSON you can use mongoexport except you have to do it one collection at a time (this is by design). However I think it's easiest to export the entire database with mongodump and then convert to JSON.

# -d is a valid option for both mongorestore and mongodump

mongodump -d <DATABASE_NAME>
for file in dump/*/*.bson; do bsondump $file > $file.json; done

Create a git patch from the uncommitted changes in the current working directory

We could also specify the files, to include just the files with relative changes, particularly when they span multiple directories e.x.

git diff ~/path1/file1.ext ~/path2/file2.ext...fileN.ext > ~/whatever_path/whatever_name.patch

I found this to be not specified in the answers or comments, which are all relevant and correct, so chose to add it. Explicit is better than implicit!

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.

Java Swing - how to show a panel on top of another panel?

JOptionPane.showInternalInputDialog probably does what you want. If not, it would be helpful to understand what it is missing.

How to add multiple classes to a ReactJS Component?

Concat

No need to be fancy I am using CSS modules and it's easy

import style from '/css/style.css';

<div className={style.style1+ ' ' + style.style2} />

This will result in:

<div class="src-client-css-pages-style1-selectionItem src-client-css-pages-style2">

In other words, both styles

Conditionals

It would be easy to use the same idea with if's

const class1 = doIHaveSomething ? style.style1 : 'backupClass';

<div className={class1 + ' ' + style.style2} />

ES6

For the last year or so I have been using the template literals, so I feel its worth mentioning, i find it very expressive and easy to read:

`${class1} anotherClass ${class1}`

javascript filter array of objects

You may use jQuery.grep():

var found_names = $.grep(names, function(v) {
    return v.name === "Joe" && v.age < 30;
});

DEMO: http://jsfiddle.net/ejPV4/

File opens instead of downloading in internet explorer in a href link

Zip your file (.zip) and IE will give the user the option to open or download the file.

Setting focus on an HTML input box on page load

This line:

<input type="password" name="PasswordInput"/>

should have an id attribute, like so:

<input type="password" name="PasswordInput" id="PasswordInput"/>

Create SQL script that create database and tables

Although Clayton's answer will get you there (eventually), in SQL2005/2008/R2/2012 you have a far easier option:

Right-click on the Database, select Tasks and then Generate Scripts, which will launch the Script Wizard. This allows you to generate a single script that can recreate the full database including table/indexes & constraints/stored procedures/functions/users/etc. There are a multitude of options that you can configure to customise the output, but most of it is self explanatory.

If you are happy with the default options, you can do the whole job in a matter of seconds.

If you want to recreate the data in the database (as a series of INSERTS) I'd also recommend SSMS Tools Pack (Free for SQL 2008 version, Paid for SQL 2012 version).

How to run Node.js as a background process and never die?

nohup will allow the program to continue even after the terminal dies. I have actually had situations where nohup prevents the SSH session from terminating correctly, so you should redirect input as well:

$ nohup node server.js </dev/null &

Depending on how nohup is configured, you may also need to redirect standard output and standard error to files.

How to debug Spring Boot application with Eclipse?

Run below command where pom.xml is placed:

mvn spring-boot:run -Drun.jvmArguments="-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=5005"

And start your remote java application with debugging option on port 5005

Check if table exists without using "select from"

This has been my 'go-to' EXISTS procedure that checks both temp and normal tables. This procedure works in MySQL version 5.6 and above. The @DEBUG parameter is optional. The default schema is assumed, but can be concatenated to the table in the @s statement.

drop procedure if exists `prcDoesTableExist`;
delimiter #
CREATE PROCEDURE `prcDoesTableExist`(IN pin_Table varchar(100), OUT pout_TableExists BOOL)
BEGIN
    DECLARE `boolTableExists` TINYINT(1) DEFAULT 1;
    DECLARE CONTINUE HANDLER FOR 1243, SQLSTATE VALUE '42S02' SET `boolTableExists` := 0;
        SET @s = concat('SELECT null FROM `', pin_Table, '` LIMIT 0 INTO @resultNm');
    PREPARE stmt1 FROM @s;
    EXECUTE stmt1;
    DEALLOCATE PREPARE stmt1;
    set pout_TableExists = `boolTableExists`; -- Set output variable
    IF @DEBUG then
        select IF(`boolTableExists`
            , CONCAT('TABLE `', pin_Table, '` exists: ', pout_TableExists)
            , CONCAT('TABLE `', pin_Table, '` does not exist: ', pout_TableExists)
        ) as result;
    END IF;
END #
delimiter ;

Here is the example call statement with @debug on:

set @DEBUG = true;
call prcDoesTableExist('tempTable', @tblExists);
select @tblExists as '@tblExists';

The variable @tblExists returns a boolean.

Find object by id in an array of JavaScript objects

myArray.filter(function(a){ return a.id == some_id_you_want })[0]

Format specifier %02x

You are actually getting the correct value out.

The way your x86 (compatible) processor stores data like this, is in Little Endian order, meaning that, the MSB is last in your output.

So, given your output:

10101010

the last two hex values 10 are the Most Significant Byte (2 hex digits = 1 byte = 8 bits (for (possibly unnecessary) clarification).

So, by reversing the memory storage order of the bytes, your value is actually: 01010101.

Hope that clears it up!

Java Refuses to Start - Could not reserve enough space for object heap

It seems that for 32-bit servers there is a JVM limitation that cannot be overcome (unless you find a special 32-bit JVM that does not impose a 2GB limit or less).

This thread on The Server Side has more details including several people who tested out various JVMs on 32-bit architectures. IBM's JVM seems to allow 100 more MB but that's not really going to get you what you want.

http://www.theserverside.com/discussions/thread.tss?thread_id=26347

The "real" solution is to use a 64-bit server with a 64-bit JVM to get heaps larger than 2GB per process. However, it's important to also consider the impact of increasing your address size (not just the addressable space) by using a 64-bit JVM. There will likely be performance and memory impacts for processing using less than 4GB of memory.

Food for thought: do each of these jobs really require 2GB of memory? Is there any way for the jobs to be modified to run within 1.8GB so this limit is not a problem?

The import org.apache.commons cannot be resolved in eclipse juno

expand "Java Resources" and then 'Libraries' (in eclipse project). make sure that "Apache Tomcat" present.

if not follow- right click on project -> "Build Path" -> "Java Build Path" -> "Add Library" -> select "Server Runtime" -> next -> select "Apache Tomcat -> click finish

Can I target all <H> tags with a single selector?

Stylus's selector interpolation

for n in 1..6
  h{n}
    font: 32px/42px trajan-pro-1,trajan-pro-2;

Windows command to get service status?

according to this http://www.computerhope.com/nethlp.htm it should be NET START /LIST but i can't get it to work on by XP box. I'm sure there's some WMI that will give you the list.

.htaccess redirect all pages to new domain

From the usability point of view it would be better, if you also send the path with the request (i.e., what you have at the moment) and let your new site deal with it:

You searched for "/products".

Unfortunately this page is gone. Would you like to visit "/new_products" instead?

(and better, still, doing this automatically.)

This is obviously a lot of coding and heuristics for a larger website, but in my opinion it would pay off in terms of user satisfaction (when your carefully saved bookmark of your dream product just leads you to the front page of newdomain.com, this is frustrating.)

Android - implementing startForeground for a service?

Solution for Oreo 8.1

I've encountered some problems such as RemoteServiceException because of invalid channel id with most recent versions of Android. This is how i solved it:

Activity:

override fun onCreate(savedInstanceState: Bundle?) {
    val intent = Intent(this, BackgroundService::class.java)

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        startForegroundService(intent)
    } else {
        startService(intent)
    }
}

BackgroundService:

override fun onCreate() {
    super.onCreate()
    startForeground()
}

private fun startForeground() {

    val service = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
    val channelId =
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                createNotificationChannel()
            } else {
                // If earlier version channel ID is not used
                // https://developer.android.com/reference/android/support/v4/app/NotificationCompat.Builder.html#NotificationCompat.Builder(android.content.Context)
                ""
            }

    val notificationBuilder = NotificationCompat.Builder(this, channelId )
    val notification = notificationBuilder.setOngoing(true)
            .setSmallIcon(R.mipmap.ic_launcher)
            .setPriority(PRIORITY_MIN)
            .setCategory(Notification.CATEGORY_SERVICE)
            .build()
    startForeground(101, notification)
}


@RequiresApi(Build.VERSION_CODES.O)
private fun createNotificationChannel(): String{
    val channelId = "my_service"
    val channelName = "My Background Service"
    val chan = NotificationChannel(channelId,
            channelName, NotificationManager.IMPORTANCE_HIGH)
    chan.lightColor = Color.BLUE
    chan.importance = NotificationManager.IMPORTANCE_NONE
    chan.lockscreenVisibility = Notification.VISIBILITY_PRIVATE
    val service = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
    service.createNotificationChannel(chan)
    return channelId
}

JAVA EQUIVALENT

public class YourService extends Service {

    // Constants
    private static final int ID_SERVICE = 101;

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        super.onStartCommand(intent, flags, startId);
        return START_STICKY;
    }

    @Override
    public void onCreate() {
        super.onCreate();

        // do stuff like register for BroadcastReceiver, etc.

        // Create the Foreground Service
        NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
        String channelId = Build.VERSION.SDK_INT >= Build.VERSION_CODES.O ? createNotificationChannel(notificationManager) : "";
        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this, channelId);
        Notification notification = notificationBuilder.setOngoing(true)
                .setSmallIcon(R.mipmap.ic_launcher)
                .setPriority(PRIORITY_MIN)
                .setCategory(NotificationCompat.CATEGORY_SERVICE)
                .build();

        startForeground(ID_SERVICE, notification);
    }

    @RequiresApi(Build.VERSION_CODES.O)
    private String createNotificationChannel(NotificationManager notificationManager){
        String channelId = "my_service_channelid";
        String channelName = "My Foreground Service";
        NotificationChannel channel = new NotificationChannel(channelId, channelName, NotificationManager.IMPORTANCE_HIGH);
        // omitted the LED color
        channel.setImportance(NotificationManager.IMPORTANCE_NONE);
        channel.setLockscreenVisibility(Notification.VISIBILITY_PRIVATE);
        notificationManager.createNotificationChannel(channel);
        return channelId;
    }
}

How to replace all double quotes to single quotes using jquery?

Use double quote to enclose the quote or escape it.

newTemp = mystring.replace(/"/g, "'");

or

newTemp = mystring.replace(/"/g, '\'');

jquery: how to get the value of id attribute?

You can also try this way

<option id="opt7" class='select_continent' data-value='7'>Antarctica</option>

jquery

$('.select_continent').click(function () {
alert($(this).data('value'));
});

Good luck !!!!

Solve error javax.mail.AuthenticationFailedException

You should change the port to 587, I tested your code and it's working fine

If error still happens, please change session variable to code below:

Session session = Session.getInstance(props, new javax.mail.Authenticator() {
    protected PasswordAuthentication getPasswordAuthentication() {
        return new PasswordAuthentication(userName, password);
    }
});

Where is shared_ptr?

There are at least three places where you may find shared_ptr:

  1. If your C++ implementation supports C++11 (or at least the C++11 shared_ptr), then std::shared_ptr will be defined in <memory>.

  2. If your C++ implementation supports the C++ TR1 library extensions, then std::tr1::shared_ptr will likely be in <memory> (Microsoft Visual C++) or <tr1/memory> (g++'s libstdc++). Boost also provides a TR1 implementation that you can use.

  3. Otherwise, you can obtain the Boost libraries and use boost::shared_ptr, which can be found in <boost/shared_ptr.hpp>.

How to send cookies in a post request with the Python Requests library?

Just to extend on the previous answer, if you are linking two requests together and want to send the cookies returned from the first one to the second one (for example, maintaining a session alive across requests) you can do:

import requests
r1 = requests.post('http://www.yourapp.com/login')
r2 = requests.post('http://www.yourapp.com/somepage',cookies=r1.cookies)

How do I format {{$timestamp}} as MM/DD/YYYY in Postman?

Use Pre-request script tab to write javascript to get and save the date into a variable:

const dateNow= new Date();
pm.environment.set('currentDate', dateNow.toISOString());

and then use it in the request body as follows:

"currentDate": "{{currentDate}}"

How to Remove the last char of String in C#?

var input = "12342";
var output = input.Substring(0, input.Length - 1); 

or

var output = input.Remove(input.Length - 1);

Best way to replace multiple characters in a string?

Using reduce which is available in python2.7 and python3.* you can easily replace mutiple substrings in a clean and pythonic way.

# Lets define a helper method to make it easy to use
def replacer(text, replacements):
    return reduce(
        lambda text, ptuple: text.replace(ptuple[0], ptuple[1]), 
        replacements, text
    )

if __name__ == '__main__':
    uncleaned_str = "abc&def#ghi"
    cleaned_str = replacer(uncleaned_str, [("&","\&"),("#","\#")])
    print(cleaned_str) # "abc\&def\#ghi"

In python2.7 you don't have to import reduce but in python3.* you have to import it from the functools module.

Programmatically Install Certificate into Mozilla

I have an update of this awesome answer (just not working any more with last Firefox updates), in this same thread, made by H.-Dirk Schmitt, also thanks to the answer in this other thread made by BecarioEstrella.

I just adapted the script to recent changes.

Tested in 2021 just in Firefox 85.0.1 (64bit) in Ubuntu 20.04 and 18.04.

#!/usr/bin/env bash

function usage {
  echo "Error: no certificate filename or name supplied."
  echo "Usage: $ ./installcerts.sh <certname>.pem <Cert-DB-Name>"
  exit 1

}

if [ -z "$1" ] || [ -z "$2" ]
  then
    usage
fi

certificate_file="$1"
certificate_name="$2"
for certDB in $(find  ~/.mozilla* ~/.thunderbird -name "cert9.db")
do
  cert_dir=$(dirname ${certDB});
  echo "Mozilla Firefox certificate" "install '${certificate_name}' in ${cert_dir}"
  certutil -A -n "${certificate_name}" -t "TCu,Cuw,Tuw" -i ${certificate_file} -d sql:"${cert_dir}"
done

If you want it just for Firefox, replace the line:

for certDB in $(find  ~/.mozilla* ~/.thunderbird -name "cert9.db")

By

for certDB in $(find  ~/.mozilla* -name "cert9.db")

Further readings:

What is the runtime performance cost of a Docker container?

An excellent 2014 IBM research paper “An Updated Performance Comparison of Virtual Machines and Linux Containers” by Felter et al. provides a comparison between bare metal, KVM, and Docker containers. The general result is: Docker is nearly identical to native performance and faster than KVM in every category.

The exception to this is Docker’s NAT — if you use port mapping (e.g., docker run -p 8080:8080), then you can expect a minor hit in latency, as shown below. However, you can now use the host network stack (e.g., docker run --net=host) when launching a Docker container, which will perform identically to the Native column (as shown in the Redis latency results lower down).

Docker NAT overhead

They also ran latency tests on a few specific services, such as Redis. You can see that above 20 client threads, highest latency overhead goes Docker NAT, then KVM, then a rough tie between Docker host/native.

Docker Redis Latency Overhead

Just because it’s a really useful paper, here are some other figures. Please download it for full access.

Taking a look at Disk I/O:

Docker vs. KVM vs. Native I/O Performance

Now looking at CPU overhead:

Docker CPU Overhead

Now some examples of memory (read the paper for details, memory can be extra tricky):

Docker Memory Comparison

How to fully delete a git repository created with init?

Windows cmd prompt: (You could try the below command directly in windows cmd if you are not comfortable with grep, rm -rf, find, xargs etc., commands in git bash )

Delete .git recursively inside the project folder by the following command in cmd:

FOR /F "tokens=*" %G IN ('DIR /B /AD /S .git') DO RMDIR /S /Q "%G"

Is there a way to have printf() properly print out an array (of floats, say)?

You have to loop through the array and printf() each element:

for(int i=0;i<10;++i) {
  printf("%.2f ", foo[i]);
}

printf("\n");

Where is GACUTIL for .net Framework 4.0 in windows 7?

There is no Gacutil included in the .net 4.0 standard installation. They have moved the GAC too, from %Windir%\assembly to %Windir%\Microsoft.NET\Assembly.

They havent' even bothered adding a "special view" for the folder in Windows explorer, as they have for the .net 1.0/2.0 GAC.

Gacutil is part of the Windows SDK, so if you want to use it on your developement machine, just install the Windows SDK for your current platform. Then you will find it somewhere like this (depending on your SDK version):

C:\Program Files\Microsoft SDKs\Windows\v7.0A\bin\NETFX 4.0 Tools

There is a discussion on the new GAC here: .NET 4.0 has a new GAC, why?

If you want to install something in GAC on a production machine, you need to do it the "proper" way (gacutil was never meant as a tool for installing stuff on production servers, only as a development tool), with a Windows Installer, or with other tools. You can e.g. do it with PowerShell and the System.EnterpriseServices dll.

On a general note, and coming from several years of experience, I would personally strongly recommend against using GAC at all. Your application will always work if you deploy the DLL with each application in its bin folder as well. Yes, you will get multiple copies of the DLL on your server if you have e.g. multiple web apps on one server, but it's definitely worth the flexibility of being able to upgrade one application without breaking the others (by introducing an incompatible version of the shared DLL in the GAC).