Programs & Examples On #Finance

Finance relates to the management of assets over time under varying conditions, usually in order to make a profit.

Getting data from Yahoo Finance

As from the answer from BrianC use the YQL console. But after selecting the "Show Community Tables" go to the bottom of the tables list and expand yahoo where you find plenty of yahoo.finance tables:

Stock Quotes:

  • yahoo.finance.quotes
  • yahoo.finance.historicaldata

Fundamental analysis:

  • yahoo.finance.keystats
  • yahoo.finance.balancesheet
  • yahoo.finance.incomestatement
  • yahoo.finance.analystestimates
  • yahoo.finance.dividendhistory

Technical analysis:

  • yahoo.finance.historicaldata
  • yahoo.finance.quotes
  • yahoo.finance.quant
  • yahoo.finance.option*

General financial information:

  • yahoo.finance.industry
  • yahoo.finance.sectors
  • yahoo.finance.isin
  • yahoo.finance.quoteslist
  • yahoo.finance.xchange

2/Nov/2017: Yahoo finance has apparently killed this API, for more info and alternative resources see https://news.ycombinator.com/item?id=15616880

Download history stock prices automatically from yahoo finance in python

Short answer: Yes. Use Python's urllib to pull the historical data pages for the stocks you want. Go with Yahoo! Finance; Google is both less reliable, has less data coverage, and is more restrictive in how you can use it once you have it. Also, I believe Google specifically prohibits you from scraping the data in their ToS.

Longer answer: This is the script I use to pull all the historical data on a particular company. It pulls the historical data page for a particular ticker symbol, then saves it to a csv file named by that symbol. You'll have to provide your own list of ticker symbols that you want to pull.

import urllib

base_url = "http://ichart.finance.yahoo.com/table.csv?s="
def make_url(ticker_symbol):
    return base_url + ticker_symbol

output_path = "C:/path/to/output/directory"
def make_filename(ticker_symbol, directory="S&P"):
    return output_path + "/" + directory + "/" + ticker_symbol + ".csv"

def pull_historical_data(ticker_symbol, directory="S&P"):
    try:
        urllib.urlretrieve(make_url(ticker_symbol), make_filename(ticker_symbol, directory))
    except urllib.ContentTooShortError as e:
        outfile = open(make_filename(ticker_symbol, directory), "w")
        outfile.write(e.content)
        outfile.close()

Yahoo Finance All Currencies quote API Documentation

From the research that I've done, there doesn't appear to be any documentation available for the API you're using. Depending on the data you're trying to get, I'd recommend using Yahoo's YQL API for accessing Yahoo Finance (An example can be found here). Alternatively, you could try using this well documented way to get CSV data from Yahoo Finance.

EDIT:

There has been some discussion on the Yahoo developer forums and it looks like there is no documentation (emphasis mine):

The reason for the lack of documentation is that we don't have a Finance API. It appears some have reverse engineered an API that they use to pull Finance data, but they are breaking our Terms of Service (no redistribution of Finance data) in doing this so I would encourage you to avoid using these webservices.

At the same time, the URL you've listed can be accessed using the YQL console, though I'm not savvy enough to know how to extract URL parameters with it.

Bloomberg BDH function with ISIN

To download ISIN code data the only place I see this is on the ISIN organizations website, www.isin.org. try http://isin.org, they should have a function where you can easily download.

source of historical stock data

Let me add a source I just discovered, found here.

It has lots of historical stock data in csv format and was gathered by Andy Pavlo, who according to his homepage is an "Assistant Professor in the Computer Science Department at Carnegie Mellon University".

Download all stock symbol list of a market

There does not seem to be a straight-forward way provided by Google or Yahoo finance portals to download the full list of tickers. One possible 'brute force' way to get it is to query their APIs for every possible combinations of letters and save only those that return valid results. As silly as it may seem there are people who actually do it (ie. check this: http://investexcel.net/all-yahoo-finance-stock-tickers/).

You can download lists of symbols from exchanges directly or 3rd party websites as suggested by @Eugene S and @Capn Sparrow, however if you intend to use it to fetch data from Google or Yahoo, you have to sometimes use prefixes or suffixes to make sure that you're getting the correct data. This is because some symbols may repeat between exchanges, so Google and Yahoo prepend or append exchange codes to the tickers in order to distinguish between them. Here's an example:

Company:  Vodafone
------------------
LSE symbol:    VOD
 in Google:    LON:VOD
 in Yahoo:     VOD.L
NASDAQ symbol: VOD
 in Google:    NASDAQ:VOD
 in Yahoo:     VOD

How to get a matplotlib Axes instance to plot to?

Use the gca ("get current axes") helper function:

ax = plt.gca()

Example:

import matplotlib.pyplot as plt
import matplotlib.finance
quotes = [(1, 5, 6, 7, 4), (2, 6, 9, 9, 6), (3, 9, 8, 10, 8), (4, 8, 8, 9, 8), (5, 8, 11, 13, 7)]
ax = plt.gca()
h = matplotlib.finance.candlestick(ax, quotes)
plt.show()

enter image description here

Best/Most Comprehensive API for Stocks/Financial Data

Some of the brokerage firms like TDAmeritrade have APIs you can use to get streaming data from their servers:

http://www.tdameritrade.com/tradingtools/partnertools/api_dev.html

How to avoid .pyc files?

You can set sys.dont_write_bytecode = True in your source, but that would have to be in the first python file loaded. If you execute python somefile.py then you will not get somefile.pyc.

When you install a utility using setup.py and entry_points= you will have set sys.dont_write_bytecode in the startup script. So you cannot rely on the "default" startup script generated by setuptools.

If you start Python with python file as argument yourself you can specify -B:

python -B somefile.py

somefile.pyc would not be generated anyway, but no .pyc files for other files imported too.

If you have some utility myutil and you cannot change that, it will not pass -B to the python interpreter. Just start it by setting the environment variable PYTHONDONTWRITEBYTECODE:

PYTHONDONTWRITEBYTECODE=x myutil

When to use 'raise NotImplementedError'?

One could also do a raise NotImplementedError() inside the child method of an @abstractmethod-decorated base class method.


Imagine writing a control script for a family of measurement modules (physical devices). The functionality of each module is narrowly-defined, implementing just one dedicated function: one could be an array of relays, another a multi-channel DAC or ADC, another an ammeter etc.

Much of the low-level commands in use would be shared between the modules for example to read their ID numbers or to send a command to them. Let's see what we have at this point:

Base Class

from abc import ABC, abstractmethod  #< we'll make use of these later

class Generic(ABC):
    ''' Base class for all measurement modules. '''

    # Shared functions
    def __init__(self):
        # do what you must...

    def _read_ID(self):
        # same for all the modules

    def _send_command(self, value):
        # same for all the modules

Shared Verbs

We then realise that much of the module-specific command verbs and, therefore, the logic of their interfaces is also shared. Here are 3 different verbs whose meaning would be self-explanatory considering a number of target modules.

  • get(channel)

  • relay: get the on/off status of the relay on channel

  • DAC: get the output voltage on channel

  • ADC: get the input voltage on channel

  • enable(channel)

  • relay: enable the use of the relay on channel

  • DAC: enable the use of the output channel on channel

  • ADC: enable the use of the input channel on channel

  • set(channel)

  • relay: set the relay on channel on/off

  • DAC: set the output voltage on channel

  • ADC: hmm... nothing logical comes to mind.


Shared Verbs Become Enforced Verbs

I'd argue that there is a strong case for the above verbs to be shared across the modules as we saw that their meaning is evident for each one of them. I'd continue writing my base class Generic like so:

class Generic(ABC):  # ...continued
    
    @abstractmethod
    def get(self, channel):
        pass

    @abstractmethod
    def enable(self, channel):
        pass

    @abstractmethod
    def set(self, channel):
        pass

Subclasses

We now know that our subclasses will all have to define these methods. Let's see what it could look like for the ADC module:

class ADC(Generic):

    def __init__(self):
        super().__init__()  #< applies to all modules
        # more init code specific to the ADC module
    
    def get(self, channel):
        # returns the input voltage measured on the given 'channel'

    def enable(self, channel):
        # enables accessing the given 'channel'

You may now be wondering:

But this won't work for the ADC module as set makes no sense there as we've just seen this above!

You're right: not implementing set is not an option as Python would then fire the error below when you tried to instantiate your ADC object.

TypeError: Can't instantiate abstract class 'ADC' with abstract methods 'set'

So you must implement something, because we made set an enforced verb (aka '@abstractmethod'), which is shared by two other modules but, at the same time, you must also not implement anything as set does not make sense for this particular module.

NotImplementedError to the Rescue

By completing the ADC class like this:

class ADC(Generic): # ...continued

    def set(self, channel):
        raise NotImplementedError("Can't use 'set' on an ADC!")

You are doing three very good things at once:

  1. You are protecting a user from erroneously issuing a command ('set') that is not (and shouldn't!) be implemented for this module.
  2. You are telling them explicitly what the problem is (see TemporalWolf's link about 'Bare exceptions' for why this is important)
  3. You are protecting the implementation of all the other modules for which the enforced verbs do make sense. I.e. you ensure that those modules for which these verbs do make sense will implement these methods and that they will do so using exactly these verbs and not some other ad-hoc names.

How do I check to see if my array includes an object?

This ...

horse = Horse.find(:first,:offset=>rand(Horse.count))
unless @suggested_horses.exists?(horse.id)
   @suggested_horses<< horse
end

Should probably be this ...

horse = Horse.find(:first,:offset=>rand(Horse.count))
unless @suggested_horses.include?(horse)
   @suggested_horses<< horse
end

How do I create variable variables?

Whenever you want to use variable variables, it's probably better to use a dictionary. So instead of writing

$foo = "bar"
$$foo = "baz"

you write

mydict = {}
foo = "bar"
mydict[foo] = "baz"

This way you won't accidentally overwrite previously existing variables (which is the security aspect) and you can have different "namespaces".

Clearing NSUserDefaults

NSDictionary *defaultsDictionary = [[NSUserDefaults standardUserDefaults] dictionaryRepresentation];
for (NSString *key in [defaultsDictionary allKeys]) {
                    [[NSUserDefaults standardUserDefaults] removeObjectForKey:key];
}

How do I convert NSInteger to NSString datatype?

Easy way to do:

NSInteger value = x;
NSString *string = [@(value) stringValue];

Here the @(value) converts the given NSInteger to an NSNumber object for which you can call the required function, stringValue.

How to turn off gcc compiler optimization to enable buffer overflow

On newer distros (as of 2016), it seems that PIE is enabled by default so you will need to disable it explicitly when compiling.

Here's a little summary of commands which can be helpful when playing locally with buffer overflow exercises in general:

Disable canary:

gcc vuln.c -o vuln_disable_canary -fno-stack-protector

Disable DEP:

gcc vuln.c -o vuln_disable_dep -z execstack

Disable PIE:

gcc vuln.c -o vuln_disable_pie -no-pie

Disable all of protection mechanisms listed above (warning: for local testing only):

gcc vuln.c -o vuln_disable_all -fno-stack-protector -z execstack -no-pie

For 32-bit machines, you'll need to add the -m32 parameter as well.

What is the Windows equivalent of the diff command?

I've found a lightweight graphical software for windows that seems to be useful in lack of diff command. It could solve all of my problems.

WinDiff http://www.grigsoft.com/download-windiff.htm

C# loop - break vs. continue

break causes the program counter to jump out of the scope of the innermost loop

for(i = 0; i < 10; i++)
{
    if(i == 2)
        break;
}

Works like this

for(i = 0; i < 10; i++)
{
    if(i == 2)
        goto BREAK;
}
BREAK:;

continue jumps to the end of the loop. In a for loop, continue jumps to the increment expression.

for(i = 0; i < 10; i++)
{
    if(i == 2)
        continue;

    printf("%d", i);
}

Works like this

for(i = 0; i < 10; i++)
{
    if(i == 2)
        goto CONTINUE;

    printf("%d", i);

    CONTINUE:;
}

How can I create an editable dropdownlist in HTML?

The <select> tag only allows the use of predefined entries. The typical solution to your problem is to have one entry labeled 'Other' and a disabled edit field (<input type="text"). Add some JavaScript to enable the edit field only when 'Other' is selected.

It may be possible to somehow create a dropdown that allows direct editing, but IMO that is not worth the effort. If it was, Amazon, Google or Microsoft would be doing it ;-) Just get the job done with the least complicated solution. It as faster (your boss may like that) and usually easier to maintain (you may like that).

How can I make a button redirect my page to another page?

you could do so:

<button onclick="location.href='page'">

you could change the action attribute of the form on click the button:

<button class="float-left submit-button" onclick='myFun()'>Home</button>

<script>
myFun(){
$('form').attr('action','new path');
}
</script>

How to uninstall/upgrade Angular CLI?

Run the following commands to get the very latest of angular

npm uninstall -g @angular/cli
npm cache verify
npm install -g @angular/cli@latest
npm install

The I/O operation has been aborted because of either a thread exit or an application request

995 is an error reported by the IO Completion Port. The error comes since you try to continue read from the socket when it has most likely been closed.

Receiving 0 bytes from EndRecieve means that the socket has been closed, as does most exceptions that EndRecieve will throw.

You need to start dealing with those situations.

Never ever ignore exceptions, they are thrown for a reason.

Update

There is nothing that says that the server does anything wrong. A connection can be lost for a lot of reasons such as idle connection being closed by a switch/router/firewall, shaky network, bad cables etc.

What I'm saying is that you MUST handle disconnections. The proper way of doing so is to dispose the socket and try to connect a new one at certain intervals.

As for the receive callback a more proper way of handling it is something like this (semi pseudo code):

public void OnDataReceived(IAsyncResult asyn)
{
    BLCommonFunctions.WriteLogger(0, "In :- OnDataReceived", ref swReceivedLogWriter, strLogPath, 0);

    try
    {
        SocketPacket client = (SocketPacket)asyn.AsyncState;

        int bytesReceived = client.thisSocket.EndReceive(asyn); //Here error is coming
        if (bytesReceived == 0)
        {
          HandleDisconnect(client);
          return;
        }
    }
    catch (Exception err)
    {
       HandleDisconnect(client);
    }

    try
    {
        string strHEX = BLCommonFunctions.ByteArrToHex(theSockId.dataBuffer);                    

        //do your handling here
    }
    catch (Exception err)
    {
        // Your logic threw an exception. handle it accordinhly
    }

    try
    {
       client.thisSocket.BeginRecieve(.. all parameters ..);
    }
    catch (Exception err)
    {
       HandleDisconnect(client);
    }
}

the reason to why I'm using three catch blocks is simply because the logic for the middle one is different from the other two. Exceptions from BeginReceive/EndReceive usually indicates socket disconnection while exceptions from your logic should not stop the socket receiving.

syntaxerror: unexpected character after line continuation character in python

Replace

f = open(D\\python\\HW\\2_1 - Copy.cp,"r");

by

f = open("D:\\python\\HW\\2_1 - Copy.cp", "r")

  1. File path needs to be a string (constant)
  2. need colon in Windows file path
  3. space after comma for better style
  4. ; after statement is allowed but fugly.

What tutorial are you using?

Parse Error: Adjacent JSX elements must be wrapped in an enclosing tag

React 16.0.0 we can return multiple components from render as an array.

return ([
    <Comp1 />,
    <Comp2 />
]);

React 16.4.0 we can return multiple components from render in a Fragment tag. Fragment

return (
<React.Fragment>
    <Comp1 />
    <Comp2 />
</React.Fragment>);

Future React you wil be able to use this shorthand syntax. (many tools don’t support it yet so you might want to explicitly write <Fragment> until the tooling catches up.)

return (
<>
    <Comp1 />
    <Comp2 />
</>)

How and where to use ::ng-deep?

Make sure not to miss the explanation of :host-context which is directly above ::ng-deep in the angular guide : https://angular.io/guide/component-styles. I missed it up until now and wish I'd seen it sooner.

::ng-deep is often necessary when you didn't write the component and don't have access to its source, but :host-context can be a very useful option when you do.

For example I have a black <h1> header inside a component I designed, and I want the ability to change it to white when it's displayed on a dark themed background.

If I didn't have access to the source I may have to do this in the css for the parent:

.theme-dark widget-box ::ng-deep h1 { color: white; }

But instead with :host-context you can do this inside the component.

 h1 
 {
     color: black;       // default color

     :host-context(.theme-dark) &
     {
         color: white;   // color for dark-theme
     }

     // OR set an attribute 'outside' with [attr.theme]="'dark'"

     :host-context([theme='dark']) &
     {
         color: white;   // color for dark-theme
     }
 }

This will look anywhere in the component chain for .theme-dark and apply the css to the h1 if found. This is a good alternative to relying too much on ::ng-deep which while often necessary is somewhat of an anti-pattern.

In this case the & is replaced by the h1 (that's how sass/scss works) so you can define your 'normal' and themed/alternative css right next to each other which is very handy.

Be careful to get the correct number of :. For ::ng-deep there are two and for :host-context only one.

How to make a launcher

They're examples provided by the Android team, if you've already loaded Samples, you can import Home screen replacement sample by following these steps.

File > New > Other >Android > Android Sample Project > Android x.x > Home > Finish

But if you do not have samples loaded, then download it using the below steps

Windows > Android SDK Manager > chooses "Sample for SDK" for SDK you need it > Install package > Accept License > Install

How to Position a table HTML?

As BalausC mentioned in a comment, you are probably looking for CSS (Cascading Style Sheets) not HTML attributes.

To position an element, a <table> in your case you want to use either padding or margins.

the difference between margins and paddings can be seen as the "box model":

box model image

Image from HTML Dog article on margins and padding http://www.htmldog.com/guides/cssbeginner/margins/.

I highly recommend the article above if you need to learn how to use CSS.

To move the table down and right I would use margins like so:

table{
    margin:25px 0 0 25px;
}

This is in shorthand so the margins are as follows:

margin: top right bottom left;

Skip download if files exist in wget?

Try the following parameter:

-nc, --no-clobber: skip downloads that would download to existing files.

Sample usage:

wget -nc http://example.com/pic.png

Why am I seeing "TypeError: string indices must be integers"?

The variable item is a string. An index looks like this:

>>> mystring = 'helloworld'
>>> print mystring[0]
'h'

The above example uses the 0 index of the string to refer to the first character.

Strings can't have string indices (like dictionaries can). So this won't work:

>>> mystring = 'helloworld'
>>> print mystring['stringindex']
TypeError: string indices must be integers

How do I add a new sourceset to Gradle?

If you're using

To get IntelliJ to recognize custom sourceset as test sources root:

plugin {
    idea
}

idea {
    module {
        testSourceDirs = testSourceDirs + sourceSets["intTest"].allJava.srcDirs
        testResourceDirs = testResourceDirs + sourceSets["intTest"].resources.srcDirs
    }
}

Get AVG ignoring Null or Zero values

In Case of not considering '0' or 'NULL' in average function. Simply use

AVG(NULLIF(your_column_name,0))

Matplotlib/pyplot: How to enforce axis range?

To answer my own question, the trick is to turn auto scaling off...

p.axis([0.0,600.0, 10000.0,20000.0])
ax = p.gca()
ax.set_autoscale_on(False)

JavaScript Chart Library

Protochart is all you need

How to change the value of attribute in appSettings section with Web.config transformation

Replacing all AppSettings

This is the overkill case where you just want to replace an entire section of the web.config. In this case I will replace all AppSettings in the web.config will new settings in web.release.config. This is my baseline web.config appSettings:

<appSettings>
  <add key="KeyA" value="ValA"/>
  <add key="KeyB" value="ValB"/>
</appSettings>

Now in my web.release.config file, I am going to create a appSettings section except I will include the attribute xdt:Transform=”Replace” since I want to just replace the entire element. I did not have to use xdt:Locator because there is nothing to locate – I just want to wipe the slate clean and replace everything.

<appSettings xdt:Transform="Replace">
  <add key="ProdKeyA" value="ProdValA"/>
  <add key="ProdKeyB" value="ProdValB"/>
  <add key="ProdKeyC" value="ProdValC"/>
</appSettings>

Note that in the web.release.config file my appSettings section has three keys instead of two, and the keys aren’t even the same. Now let’s look at the generated web.config file what happens when we publish:

<appSettings>
   <add key="ProdKeyA" value="ProdValA"/>
   <add key="ProdKeyB" value="ProdValB"/>
   <add key="ProdKeyC" value="ProdValC"/>
 </appSettings>

Just as we expected – the web.config appSettings were completely replaced by the values in web.release config. That was easy!

Select all columns except one in MySQL?

Would a View work better in this case?

CREATE VIEW vwTable
as  
SELECT  
    col1  
    , col2  
    , col3  
    , col..  
    , col53  
FROM table

*.h or *.hpp for your class definitions

Fortunately, it is simple.

You should use the .hpp extension if you're working with C++ and you should use .h for C or mixing C and C++.

Ruby 2.0.0p0 IRB warning: "DL is deprecated, please use Fiddle"

You may want to comment out the DL is deprecated, please use Fiddle warning at

C:\Ruby200\lib\ruby\2.0.0\dl.rb

since it’s annoying and you are not the irb/pry or some other gems code owner

Merge (Concat) Multiple JSONObjects in Java

You can create a new JSONObject like this:

JSONObject merged = new JSONObject();
JSONObject[] objs = new JSONObject[] { Obj1, Obj2 };
for (JSONObject obj : objs) {
    Iterator it = obj.keys();
    while (it.hasNext()) {
        String key = (String)it.next();
        merged.put(key, obj.get(key));
    }
}

With this code, if you have any repeated keys between Obj1 and Obj2 the value in Obj2 will remain. If you want the values in Obj1 to be kept you should invert the order of the array in line 2.

jquery dialog save cancel button styling

I had to use the following construct in jQuery UI 1.8.22:

var buttons = $('.ui-dialog-buttonset').children('button');
buttons.removeClass().addClass('button');

This removes all formatting and applies the replacement styling as needed.
Works in most major browsers.

htaccess <Directory> deny from all

You can use from root directory:

RewriteEngine On
RewriteRule ^(?:system)\b.* /403.html

Or:

RewriteRule ^(?:system)\b.* /403.php # with header('HTTP/1.0 403 Forbidden');

Get Substring between two characters using javascript

If you want to extract all substrings from a string, that occur between two delimiters (different or same), you can use this function. It returns an array with all substrings found:

function get_substrings_between(str, startDelimiter, endDelimiter) 
{
    var contents = [];
    var startDelimiterLength = startDelimiter.length;
    var endDelimiterLength = endDelimiter.length;
    var startFrom = contentStart = contentEnd = 0;
    
    while(false !== (contentStart = strpos(str, startDelimiter, startFrom))) 
    {
        contentStart += startDelimiterLength;
        contentEnd = strpos(str, endDelimiter, contentStart);
        if(false === contentEnd) 
        {
            break;
        }
        contents.push( str.substr(contentStart, contentEnd - contentStart) );
        startFrom = contentEnd + endDelimiterLength;
    }

    return contents;
}

// https://stackoverflow.com/a/3978237/1066234
function strpos(haystack, needle, offset) 
{
    var i = (haystack+'').indexOf(needle, (offset || 0));
    return i === -1 ? false : i;
}

// Example usage
var string = "We want to extract all infos (essential ones) from within the brackets (this should be fun).";
var extracted = get_substrings_between(string, '(', ')');
console.log(extracted); 
// output: (2) ["essential ones", "this should be fun"]

Orginally from PHP by raina77ow, ported to Javascript.

The remote server returned an error: (403) Forbidden

Its a permissions error. Your VS probably runs using an elevated account or different user account than the user using the installed version.

It may be useful to check your IIS permissions and see what accounts have access to the resource you are accessing. Cross reference that with the account you use and the account the installed versions are using.

Equation for testing if a point is inside a circle

This is the same solution as mentioned by Jason Punyon, but it contains a pseudo-code example and some more details. I saw his answer after writing this, but I didn't want to remove mine.

I think the most easily understandable way is to first calculate the distance between the circle's center and the point. I would use this formula:

d = sqrt((circle_x - x)^2 + (circle_y - y)^2)

Then, simply compare the result of that formula, the distance (d), with the radius. If the distance (d) is less than or equal to the radius (r), the point is inside the circle (on the edge of the circle if d and r are equal).

Here is a pseudo-code example which can easily be converted to any programming language:

function is_in_circle(circle_x, circle_y, r, x, y)
{
    d = sqrt((circle_x - x)^2 + (circle_y - y)^2);
    return d <= r;
}

Where circle_x and circle_y is the center coordinates of the circle, r is the radius of the circle, and x and y is the coordinates of the point.

Decreasing for loops in Python impossible?

for n in range(6,0,-1)

This would give you 6,5,4,3,2,1

As for

for n in reversed(range(0,6))

would give you 5,4,3,2,1,0

How to get every first element in 2 dimensional list

use zip

columns = zip(*rows) #transpose rows to columns
print columns[0] #print the first column
#you can also do more with the columns
print columns[1] # or print the second column
columns.append([7,7,7]) #add a new column to the end
backToRows = zip(*columns) # now we are back to rows with a new column
print backToRows

you can also use numpy

a = numpy.array(a)
print a[:,0]

Edit: zip object is not subscriptable. It need to be converted to list to access as list:

column = list(zip(*row))

Installing PIL (Python Imaging Library) in Win7 64 bits, Python 2.6.4

I found a working win7 binary here: Unofficial Windows Binaries for Python Extension Packages It's from Christoph Gohlke at UC Irvine. There are binaries for python 2.5, 2.6, 2.7 , 3.1 and 3.2 for both 32bit and 64 bit windows.

There are a whole lot of other compiled packages here, too.

Be sure to uninstall your old PILfirst. If you used easy_install: easy_install -mnX pil
And then remove the egg in python/Lib/site-packages

Be sure to remove any other failed attempts. I had moved the _image dll into Python*.*/DLLs and I had to remove it.

Reverse HashMap keys and values in Java

To answer your question on how you can do it, you could get the entrySet from your map and then just put into the new map by using getValue as key and getKey as value.

But remember that keys in a Map are unique, which means if you have one value with two different key in your original map, only the second key (in iteration order) will be kep as value in the new map.

Pure JavaScript: a function like jQuery's isNumeric()

function IsNumeric(val) {
    return Number(parseFloat(val)) === val;
}

Is there a version of JavaScript's String.indexOf() that allows for regular expressions?

It does not natively, but you certainly can add this functionality

<script type="text/javascript">

String.prototype.regexIndexOf = function( pattern, startIndex )
{
    startIndex = startIndex || 0;
    var searchResult = this.substr( startIndex ).search( pattern );
    return ( -1 === searchResult ) ? -1 : searchResult + startIndex;
}

String.prototype.regexLastIndexOf = function( pattern, startIndex )
{
    startIndex = startIndex === undefined ? this.length : startIndex;
    var searchResult = this.substr( 0, startIndex ).reverse().regexIndexOf( pattern, 0 );
    return ( -1 === searchResult ) ? -1 : this.length - ++searchResult;
}

String.prototype.reverse = function()
{
    return this.split('').reverse().join('');
}

// Indexes 0123456789
var str = 'caabbccdda';

alert( [
        str.regexIndexOf( /[cd]/, 4 )
    ,   str.regexLastIndexOf( /[cd]/, 4 )
    ,   str.regexIndexOf( /[yz]/, 4 )
    ,   str.regexLastIndexOf( /[yz]/, 4 )
    ,   str.lastIndexOf( 'd', 4 )
    ,   str.regexLastIndexOf( /d/, 4 )
    ,   str.lastIndexOf( 'd' )
    ,   str.regexLastIndexOf( /d/ )
    ]
);

</script>

I didn't fully test these methods, but they seem to work so far.

Want to upgrade project from Angular v5 to Angular v6

simply run the following command:

ng update

note: this will not update globally.

Python name 'os' is not defined

The problem is that you forgot to import os. Add this line of code:

import os

And everything should be fine. Hope this helps!

Error when creating a new text file with python?

If the file does not exists, open(name,'r+') will fail.

You can use open(name, 'w'), which creates the file if the file does not exist, but it will truncate the existing file.

Alternatively, you can use open(name, 'a'); this will create the file if the file does not exist, but will not truncate the existing file.

How can I turn a DataTable to a CSV?

Try to put ; instead of ,

Hope it helps

AngularJS/javascript converting a date String to date object

try this

html

<div ng-controller="MyCtrl">
  Hello, {{newDate | date:'MM/dd/yyyy'}}!
</div>

JS

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

function MyCtrl($scope) {
    var collectionDate = '2002-04-26T09:00:00'; 

    $scope.newDate =new Date(collectionDate);
}

Demo

Disable ONLY_FULL_GROUP_BY

I'm using doctrine and I have added the driverOptions in my doctrine.local.php :

return array(
'doctrine' => array(
    'connection' => array(
        'orm_default' => array(
            'driverClass' => 'Doctrine\DBAL\Driver\PDOMySql\Driver',
            'params' => array(
                'host' => 'localhost',
                'port' => '3306',
                'user' => 'myusr',
                'password' => 'mypwd',
                'dbname' => 'mydb',
                'driverOptions' => array(
                    PDO::MYSQL_ATTR_INIT_COMMAND => "SET sql_mode=(SELECT REPLACE(@@sql_mode,'ONLY_FULL_GROUP_BY',''))"
                ),
            ),
        ),
    ),
));

In phpmyadmin the user needs SUPER activated in the privileges.

JRE installation directory in Windows

where java works for me to list all java exe but java -verbose tells you which rt.jar is used and thus which jre (full path):

[Opened C:\Program Files\Java\jre6\lib\rt.jar]
...

Edit: win7 and java:

java version "1.6.0_20"
Java(TM) SE Runtime Environment (build 1.6.0_20-b02)
Java HotSpot(TM) 64-Bit Server VM (build 16.3-b01, mixed mode)

Can I set state inside a useEffect hook

Effects are always executed after the render phase is completed even if you setState inside the one effect, another effect will read the updated state and take action on it only after the render phase.

Having said that its probably better to take both actions in the same effect unless there is a possibility that b can change due to reasons other than changing a in which case too you would want to execute the same logic

Is there a bash command which counts files?

You can do this safely (i.e. won't be bugged by files with spaces or \n in their name) with bash:

$ shopt -s nullglob
$ logfiles=(*.log)
$ echo ${#logfiles[@]}

You need to enable nullglob so that you don't get the literal *.log in the $logfiles array if no files match. (See How to "undo" a 'set -x'? for examples of how to safely reset it.)

How to run VBScript from command line without Cscript/Wscript

I am wondering why you cannot put this in a batch file. Example:

cd D:\VBS\
WSCript Converter.vbs

Put the above code in a text file and save the text file with .bat extension. Now you have to simply run this .bat file.

Creating composite primary key in SQL Server

If you use management studio, simply select the wardNo, BHTNo, testID columns and click on the key mark in the toolbar.

enter image description here

Command for this is,

ALTER TABLE dbo.testRequest
ADD CONSTRAINT PK_TestRequest 
PRIMARY KEY (wardNo, BHTNo, TestID)

How to check if a String is numeric in Java

You can use NumberUtils.isCreatable() from Apache Commons Lang.

Since NumberUtils.isNumber will be deprecated in 4.0, so use NumberUtils.isCreatable() instead.

Initialize a Map containing arrays

Per Mozilla's Map documentation, you can initialize as follows:

private _gridOptions:Map<string, Array<string>> = 
    new Map([
        ["1", ["test"]],
        ["2", ["test2"]]
    ]);

Keyboard shortcut to comment lines in Sublime Text 3

On my mac the shortcut is ?cmd + / which makes multi line comment but as single lines:

// if ($username && $password) {
//  echo "You are good to go";
// } else {
//  echo "Fields cannot be blank";
// }

OR

? alt + ?cmd + / and it's result is overall comment, from beggining of the selection to the end.

/*
if ($username && $password) {
    echo "You are good to go";
} else {
    echo "Fields cannot be blank";
}
*/

How do I query for all dates greater than a certain date in SQL Server?

DateTime start1 = DateTime.Parse(txtDate.Text);

SELECT * 
FROM dbo.March2010 A
WHERE A.Date >= start1;

First convert TexBox into the Datetime then....use that variable into the Query

WebDriver - wait for element using Java

Above wait statement is a nice example of Explicit wait.

As Explicit waits are intelligent waits that are confined to a particular web element(as mentioned in above x-path).

By Using explicit waits you are basically telling WebDriver at the max it is to wait for X units(whatever you have given as timeoutInSeconds) of time before it gives up.

Unable to run Java GUI programs with Ubuntu

This command worked for me.

Sudo dnf install java-1.8.0-openjdk (Fedora)

Sudo apt-get install java-1.8.0-openjdk

Should work for Ubuntu.

How to add button in ActionBar(Android)?

An activity populates the ActionBar in its onCreateOptionsMenu() method.

Instead of using setcustomview(), just override onCreateOptionsMenu like this:

@Override    
public boolean onCreateOptionsMenu(Menu menu) {
  MenuInflater inflater = getMenuInflater();
  inflater.inflate(R.menu.mainmenu, menu);
  return true;
}

If an actions in the ActionBar is selected, the onOptionsItemSelected() method is called. It receives the selected action as parameter. Based on this information you code can decide what to do for example:

@Override
public boolean onOptionsItemSelected(MenuItem item) {
  switch (item.getItemId()) {
    case R.id.menuitem1:
      Toast.makeText(this, "Menu Item 1 selected", Toast.LENGTH_SHORT).show();
      break;
    case R.id.menuitem2:
      Toast.makeText(this, "Menu item 2 selected", Toast.LENGTH_SHORT).show();
      break;
  }
  return true;
}

java.math.BigInteger cannot be cast to java.lang.Long

Better option is use SQLQuery#addScalar than casting to Long or BigDecimal.

Here is modified query that returns count column as Long

Query query = session
             .createSQLQuery("SELECT COUNT(*) as count
                             FROM SpyPath 
                             WHERE DATE(time)>=DATE_SUB(CURDATE(),INTERVAL 6 DAY) 
                             GROUP BY DATE(time) 
                             ORDER BY time;")
             .addScalar("count", LongType.INSTANCE);

Then

List<Long> result = query.list(); //No ClassCastException here  

Related link

Add image in title bar

you should be searching about how to add favicon.ico . You can try adding favicon.ico directly in your html pages like this

<link rel="shortcut icon" href="/favicon.png" type="image/png">
<link rel="shortcut icon" type="image/png" href="http://www.example.com/favicon.png" />

Or you can update that in your webserver. It is advised to add in your webserver as you don't need to add this in each of your html pages (assuming no includes).

To add in your apache place the favicon.ico in your root website director and add this in httpd.conf

AddType image/x-icon .ico

Concatenating strings in Razor

String.Format also works in Razor:

String.Format("{0} - {1}", Model.address, Model.city)

format statement in a string resource file

You should add formatted="false" to your string resource


Here is an example

In your strings.xml :

<string name="all" formatted="false">Amount: %.2f%n  for %d days</string>

In your code:

yourTextView.setText(String.format(getString(R.string.all), 3.12, 2));

When using Spring Security, what is the proper way to obtain current username (i.e. SecurityContext) information in a bean?

For the last Spring MVC app I wrote, I didn't inject the SecurityContext holder, but I did have a base controller that I had two utility methods related to this ... isAuthenticated() & getUsername(). Internally they do the static method call you described.

At least then it's only in once place if you need to later refactor.

Counting the number of option tags in a select tag in jQuery

In a multi-select option box, you can use $('#input1 :selected').length; to get the number of selected options. This can be useful to disable buttons if a certain minimum number of options aren't met.

function refreshButtons () {
    if ($('#input :selected').length == 0)
    {
        $('#submit').attr ('disabled', 'disabled');
    }
    else
    {
        $('#submit').removeAttr ('disabled');
    }
}

Functions that return a function

This is super useful in real life.

Working with Express.js

So your regular express route looks like this:

function itWorksHandler( req, res, next ) {
  res.send("It works!");
}

router.get("/check/works", itWorksHandler );

But what if you need to add some wrapper, error handler or smth?

Then you invoke your function off a wrapper.

function loggingWrapper( req, res, next, yourFunction ) {
  try {
    yourFunction( req, res );
  } catch ( err ) {
    console.error( err );
    next( err );
  }
}

router.get("/check/works", function( req, res, next ) {
  loggingWrapper( req, res, next, itWorksHandler );
});

Looks complicated? Well, how about this:

function function loggingWrapper( yourFunction ) => ( req, res, next ) {
  try {
    yourFunction( req, res, next );
  } catch ( err ) {
    console.error( err );
    next( err );
  }
}

router.get("/check/works", loggingWrapper( itWorksHandler ) );

See at the end you're passing a function loggingWrapper having one argument as another function itWorksHandler, and your loggingWrapper returns a new function which takes req, res, next as arguments.

The default XML namespace of the project must be the MSBuild XML namespace

If getting this error trying to build .Net Core 2.0 app on VSTS then ensure your build definition is using the Hosted VS2017 Agent queue.

PHP how to get value from array if key is in a variable

$value = ( array_key_exists($key, $array) && !empty($array[$key]) ) 
         ? $array[$key] 
         : 'non-existant or empty value key';

java collections - keyset() vs entrySet() in map

To make things simple , please note that every time you do itr2.next() the pointer moves to the next element i.e. here if you notice carefully, then the output is perfectly fine according to the logic you have written .
This may help you in understanding better:

1st Iteration of While loop(pointer is before the 1st element):
Key: if ,value: 2 {itr2.next()=if; m.get(itr2.next()=it)=>2}

2nd Iteration of While loop(pointer is before the 3rd element):
Key: is ,value: 2 {itr2.next()=is; m.get(itr2.next()=to)=>2}

3rd Iteration of While loop(pointer is before the 5th element):
Key: be ,value: 1 {itr2.next()="be"; m.get(itr2.next()="up")=>"1"}

4th Iteration of While loop(pointer is before the 7th element):
Key: me ,value: 1 {itr2.next()="me"; m.get(itr2.next()="delegate")=>"1"}

Key: if ,value: 1
Key: it ,value: 2
Key: is ,value: 2
Key: to ,value: 2
Key: be ,value: 1
Key: up ,value: 1
Key: me ,value: 1
Key: delegate ,value: 1

It prints:

Key: if ,value: 2
Key: is ,value: 2
Key: be ,value: 1
Key: me ,value: 1

How to display request headers with command line curl

If you want more alternatives, You can try installing a Modern command line HTTP client like httpie which is available for most of the Operating Systems with package managers like brew, apt-get, pip, yum etc

eg:- For OSX

brew install httpie

Then you can use it on command line with various options

http GET https://www.google.com

enter image description here

How can I parse a time string containing milliseconds in it with python?

I know this is an older question but I'm still using Python 2.4.3 and I needed to find a better way of converting the string of data to a datetime.

The solution if datetime doesn't support %f and without needing a try/except is:

    (dt, mSecs) = row[5].strip().split(".") 
    dt = datetime.datetime(*time.strptime(dt, "%Y-%m-%d %H:%M:%S")[0:6])
    mSeconds = datetime.timedelta(microseconds = int(mSecs))
    fullDateTime = dt + mSeconds 

This works for the input string "2010-10-06 09:42:52.266000"

Android, How to limit width of TextView (and add three dots at the end of text)?

The approach of @AzharShaikh works fine.

android:ellipsize="end"
android:maxLines="1"

But I realize a trouble that TextView will be truncated by word (in default). Show if we have a text like:

test long_line_without_any_space_abcdefgh

the TextView will display:

test...

And I found solution to handle this trouble, replace spaces with the unicode no-break space character, it makes TextView wrap on characters instead of words:

yourString.replace(" ", "\u00A0");

The result:

test long_line_without_any_space_abc...

How to sum up elements of a C++ vector?

Nobody seems to address the case of summing elements of a vector that can have NaN values in it, e.g. numerical_limits<double>::quite_NaN()

I usually loop through the elements and bluntly check.

vector<double> x;

//...

size_t n = x.size();

double sum = 0;

for (size_t i = 0; i < n; i++){

  sum += (x[i] == x[i] ? x[i] : 0);

}

It's not fancy at all, i.e. no iterators or any other tricks but I this is how I do it. Some times if there are other things to do inside the loop and I want the code to be more readable I write

double val = x[i];

sum += (val == val ? val : 0);

//...

inside the loop and re-use val if needed.

What's a redirect URI? how does it apply to iOS app for OAuth2.0?

Take a look at OAuth 2.0 playground.You will get an overview of the protocol.It is basically an environment(like any app) that shows you the steps involved in the protocol.

https://developers.google.com/oauthplayground/

How to get these two divs side-by-side?

#parent_div_1, #parent_div_2, #parent_div_3 {
  width: 100px;
  height: 100px;
  border: 1px solid red;
  margin-right: 10px;
  float: left;
}
.child_div_1 {
  float: left;
  margin-right: 5px;
}

Check working example at http://jsfiddle.net/c6242/1/

In SQL, how can you "group by" in ranges?

This will allow you to not have to specify ranges, and should be SQL server agnostic. Math FTW!

SELECT CONCAT(range,'-',range+9), COUNT(range)
FROM (
  SELECT 
    score - (score % 10) as range
  FROM scores
)

Unexpected token }

You have endless loop in place:

function save() {
    var filename = id('filename').value;
    var name = id('name').value;
    var text = id('text').value;
    save(filename, name, text);
}

No idea what you're trying to accomplish with that endless loop but first of all get rid of it and see if things are working.

Javascript - Get Image height

Just load the image in a hidden <img> tag (style = "display none"), listen to the load event firing with jQuery, create a new Image() with JavaScript, set the source to the invisible image, and get the size like above.

What is the difference between null=True and blank=True in Django?

Here, is the main difference of null=True and blank=True:

The default value of both null and blank is False. Both of these values work at field level i.e., whether we want to keep a field null or blank.

null=True will set the field’s value to NULL i.e., no data. It is basically for the databases column value.

date = models.DateTimeField(null=True)

blank=True determines whether the field will be required in forms. This includes the admin and your own custom forms.

title = models.CharField(blank=True) // title can be kept blank. In the database ("") will be stored. null=True blank=True This means that the field is optional in all circumstances.

epic = models.ForeignKey(null=True, blank=True)
// The exception is CharFields() and TextFields(), which in Django are never saved as NULL. Blank values a

When should I use Memcache instead of Memcached?

This is 2013. Forget about the 2009 comments. Likewise, if you are running serious traffic loads, do not even contemplate how to make-do with a windows based memcache. When dealing with a very large scale (500+ front end web servers) and 20+ back end database servers and replicants (mysql & mssql mix), a farm of memcached servers (12 servers in group) supports multiple high volume OLTP applications answering 25K ~ 40K mc->get calls per-second. These calls are those that do NOT have to reach a database.

IMHO, this use of memcached provided SERIOUS $$$,$$$savings on CAPEX for new DB servers & licences as well as on support contracts for large commercial designs.

Hide div by default and show it on click with bootstrap

I realize this question is a bit dated and since it shows up on Google search for similar issue I thought I will expand a little bit more on top of @CowWarrior's answer. I was looking for somewhat similar solution, and after scouring through countless SO question/answers and Bootstrap documentations the solution was pretty simple. Again, this would be using inbuilt Bootstrap collapse class to show/hide divs and Bootstrap's "Collapse Event".

What I realized is that it is easy to do it using a Bootstrap Accordion, but most of the time even though the functionality required is "somewhat" similar to an Accordion, it's different in a way that one would want to show hide <div> based on, lets say, menu buttons on a navbar. Below is a simple solution to this. The anchor tags (<a>) could be navbar items and based on a collapse event the corresponding div will replace the existing div. It looks slightly sloppy in CodeSnippet, but it is pretty close to achieving the functionality-

All that the JavaScript does is makes all the other <div> hide using

$(".main-container.collapse").not($(this)).collapse('hide');

when the loaded <div> is displayed by checking the Collapse event shown.bs.collapse. Here's the Bootstrap documentation on Collapse Event.

Note: main-container is just a custom class.

Here it goes-

_x000D_
_x000D_
$(".main-container.collapse").on('shown.bs.collapse', function () {    _x000D_
//when a collapsed div is shown hide all other collapsible divs that are visible_x000D_
       $(".main-container.collapse").not($(this)).collapse('hide');_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>_x000D_
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"/>_x000D_
_x000D_
<a href="#Foo" class="btn btn-default" data-toggle="collapse">Toggle Foo</a>_x000D_
<a href="#Bar" class="btn btn-default" data-toggle="collapse">Toggle Bar</a>_x000D_
_x000D_
<div id="Bar" class="main-container collapse in">_x000D_
    This div (#Bar) is shown by default and can toggle_x000D_
</div>_x000D_
<div id="Foo" class="main-container collapse">_x000D_
    This div (#Foo) is hidden by default_x000D_
</div>
_x000D_
_x000D_
_x000D_

How to validate an email address in PHP

This will not only validate your email, but also sanitize it for unexpected characters:

$email  = $_POST['email'];
$emailB = filter_var($email, FILTER_SANITIZE_EMAIL);

if (filter_var($emailB, FILTER_VALIDATE_EMAIL) === false ||
    $emailB != $email
) {
    echo "This email adress isn't valid!";
    exit(0);
}

How to remove all whitespace from a string?

This way you can remove all spaces from all character variables in your data frame. If you would prefer to choose only some of the variables, use mutateor mutate_at.

library(dplyr)
library(stringr)

remove_all_ws<- function(string){
    return(gsub(" ", "", str_squish(string)))
}

df<-df %>%  mutate_if(is.character, remove_all_ws)

Twitter Bootstrap vs jQuery UI?

I have on several projects.

The biggest difference in my opinion

  • jQuery UI is fallback safe, it works correctly and looks good in old browsers, where Bootstrap is based on CSS3 which basically means GREAT in new browsers, not so great in old

  • Update frequency: Bootstrap is getting some great big updates with awesome new features, but sadly they might break previous code, so you can't just install bootstrap and update when there is a new major release, it basically requires a lot of new coding

  • jQuery UI is based on good html structure with transformations from JavaScript, while Bootstrap is based on visually and customizable inline structure. (calling a widget in JQUERY UI, defining it in Bootstrap)

So what to choose?

That always depends on the type of project you are working on. Is cool and fast looking widgets better, or are your users often using old browsers?

I always end up using both, so I can use the best of both worlds.

Here are the links to both frameworks, if you decide to use them.

  1. jQuery UI
  2. Bootstrap

C compiler for Windows?

There is another free C compiler for Windows: Pelles C.

Pelles C is a complete development kit for Windows and Windows Mobile. It contains among other things an optimizing C compiler, a macro assembler, a linker, a resource compiler, a message compiler, a make utility and install builders for both Windows and Windows Mobile. It also contains an integrated development environment (IDE) with project management, debugger, source code editor and resource editors for dialogs, menus, string tables, accelerator tables, bitmaps, icons, cursors, animated cursors, animation videos (AVI's without sound), versions and XP manifests.

URL: http://www.smorgasbordet.com/pellesc/

vba listbox multicolumn add

Simplified example (with counter):

With Me.lstbox
    .ColumnCount = 2
    .ColumnWidths = "60;60"
    .AddItem
    .List(i, 0) = Company_ID
    .List(i, 1) = Company_name 
    i = i + 1

end with

Make sure to start the counter with 0, not 1 to fill up a listbox.

Java - Including variables within strings?

You can always use String.format(....). i.e.,

String string = String.format("A String %s %2d", aStringVar, anIntVar);

I'm not sure if that is attractive enough for you, but it can be quite handy. The syntax is the same as for printf and java.util.Formatter. I've used it much especially if I want to show tabular numeric data.

Apache Spark: map vs mapPartitions?

Map:

Map transformation.

The map works on a single Row at a time.

Map returns after each input Row.

The map doesn’t hold the output result in Memory.

Map no way to figure out then to end the service.

// map example

val dfList = (1 to 100) toList

val df = dfList.toDF()

val dfInt = df.map(x => x.getInt(0)+2)

display(dfInt)

MapPartition:

MapPartition transformation.

MapPartition works on a partition at a time.

MapPartition returns after processing all the rows in the partition.

MapPartition output is retained in memory, as it can return after processing all the rows in a particular partition.

MapPartition service can be shut down before returning.

// MapPartition example

Val dfList = (1 to 100) toList

Val df = dfList.toDF()

Val df1 = df.repartition(4).rdd.mapPartition((int) => Iterator(itr.length))

Df1.collec()

//display(df1.collect())

For more details, please refer to the Spark map vs mapPartitions transformation article.

Hope this is helpful!

Space between border and content? / Border distance from content?

You usually use padding to add distance between a border and a content.However, background are spread on padding.

You can still do it with nested element.

html :

<div id="outter">
    <div id="inner">
        test
    </div>
</div>

outter div :

border-style: ridge;
border-color: #567498;
border-spacing:10px;
min-width: 100px;
min-height: 100px;
float:left;

inner div :

width: 100px;
min-height: 100px;
margin: 10px;
background-image: -webkit-gradient(
    linear,
    left bottom,
    left top,
    color-stop(0, rgb(39,54,73)),
    color-stop(1, rgb(30,42,54))
);
background-image: -moz-linear-gradient(
    center bottom,
    rgb(39,54,73) 0%,
    rgb(30,42,54) 100%
        );}

What is the canonical way to trim a string in Ruby without creating a new string?

If you are using Ruby on Rails there is a squish

> @title = " abc "
 => " abc " 

> @title.squish
 => "abc"
> @title
 => " abc "

> @title.squish!
 => "abc"
> @title
 => "abc" 

If you are using just Ruby you want to use strip

Herein lies the gotcha.. in your case you want to use strip without the bang !

while strip! certainly does return nil if there was no action it still updates the variable so strip! cannot be used inline. If you want to use strip inline you can use the version without the bang !

strip! using multi line approach

> tokens["Title"] = " abc "
 => " abc "
> tokens["Title"].strip!
 => "abc"
> @title = tokens["Title"]
 => "abc"

strip single line approach... YOUR ANSWER

> tokens["Title"] = " abc "
 => " abc "
> @title = tokens["Title"].strip if tokens["Title"].present?
 => "abc"

How to return a resolved promise from an AngularJS Service using $q?

Try this:

myApp.service('userService', [
    '$http', '$q', '$rootScope', '$location', function($http, $q, $rootScope, $location) {
      var deferred= $q.defer();
      this.user = {
        access: false
      };
      try
      {
      this.isAuthenticated = function() {
        this.user = {
          first_name: 'First',
          last_name: 'Last',
          email: '[email protected]',
          access: 'institution'
        };
        deferred.resolve();
      };
    }
    catch
    {
        deferred.reject();
    }

    return deferred.promise;
  ]);

Equivalent of SQL ISNULL in LINQ?

Since aa is the set/object that might be null, can you check aa == null ?

(aa / xx might be interchangeable (a typo in the question); the original question talks about xx but only defines aa)

i.e.

select new {
    AssetID = x.AssetID,
    Status = aa == null ? (bool?)null : aa.Online; // a Nullable<bool>
}

or if you want the default to be false (not null):

select new {
    AssetID = x.AssetID,
    Status = aa == null ? false : aa.Online;
}

Update; in response to the downvote, I've investigated more... the fact is, this is the right approach! Here's an example on Northwind:

        using(var ctx = new DataClasses1DataContext())
        {
            ctx.Log = Console.Out;
            var qry = from boss in ctx.Employees
                      join grunt in ctx.Employees
                          on boss.EmployeeID equals grunt.ReportsTo into tree
                      from tmp in tree.DefaultIfEmpty()
                      select new
                             {
                                 ID = boss.EmployeeID,
                                 Name = tmp == null ? "" : tmp.FirstName
                        };
            foreach(var row in qry)
            {
                Console.WriteLine("{0}: {1}", row.ID, row.Name);
            }
        }

And here's the TSQL - pretty much what we want (it isn't ISNULL, but it is close enough):

SELECT [t0].[EmployeeID] AS [ID],
    (CASE
        WHEN [t2].[test] IS NULL THEN CONVERT(NVarChar(10),@p0)
        ELSE [t2].[FirstName]
     END) AS [Name]
FROM [dbo].[Employees] AS [t0]
LEFT OUTER JOIN (
    SELECT 1 AS [test], [t1].[FirstName], [t1].[ReportsTo]
    FROM [dbo].[Employees] AS [t1]
    ) AS [t2] ON ([t0].[EmployeeID]) = [t2].[ReportsTo]
-- @p0: Input NVarChar (Size = 0; Prec = 0; Scale = 0) []
-- Context: SqlProvider(Sql2008) Model: AttributedMetaModel Build: 3.5.30729.1

QED?

how can I enable PHP Extension intl?

  1. Go to C:\xampp\php
  2. open the file "php.ini-development" on a text editor.
  3. Then uncomment ;extension=php_intl.dll by removing the semicolon

Is Visual Studio Community a 30 day trial?

Another answer, when you have a machine where you do not have an internet connection and cannot log in, is here - https://dimitri.janczak.net/2019/07/13/trial-period-reset-of-visual-studio-community-edition/.

The files are on github - https://github.com/1Dimitri/VSCELicense/releases/tag/1.0.

From the readme file:

Original Module Usage

  1. Download/clone this repository

  2. Run PowerShell.exe as an Administrator

  3. Import module:

    Import-Module -Name X:\PATH\TO\VSCELicense
    
    

Usage :

Get Visual Studio Community Edition license expiration date
Get-VSCELicenseExpirationDate -Version VS2019
Set license expiration date to current date + 10 days
Set-VSCELicenseExpirationDate -Version VS2019 -AddDays 10

Get the filePath from Filename using Java

I'm not sure I understand you completely, but if you wish to get the absolute file path provided that you know the relative file name, you can always do this:

System.out.println("File path: " + new File("Your file name").getAbsolutePath());

The File class has several more methods you might find useful.

Eclipse - java.lang.ClassNotFoundException

That means your pom.xml has unresolved issues. Open the problems view solve accordingly. Then you will be able to run the test cases successfully without encountering the classnotfoundexception.

How do you build a Singleton in Dart?

I use this simple pattern on dart and previously on Swift. I like that it's terse and only one way of using it.

class Singleton {
  static Singleton shared = Singleton._init();
  Singleton._init() {
    // init work here
  }

  void doSomething() {
  }
}

Singleton.shared.doSomething();

History or log of commands executed in Git

If you use Windows PowerShell, you could type "git" and the press F8. Continue to press F8 to cycle through all your git commands.

Or, if you use cygwin, you could do the same thing with ^R.

pandas dataframe create new columns and fill with calculated values from same df

In [56]: df = pd.DataFrame(np.abs(randn(3, 4)), index=[1,2,3], columns=['A','B','C','D'])

In [57]: df.divide(df.sum(axis=1), axis=0)
Out[57]: 
          A         B         C         D
1  0.319124  0.296653  0.138206  0.246017
2  0.376994  0.326481  0.230464  0.066062
3  0.036134  0.192954  0.430341  0.340571

Angular 2 optional route parameter

{path: 'users', redirectTo: 'users/', pathMatch: 'full'},
{path: 'users/:userId', component: UserComponent}

This way the component isn't re-rendered when the parameter is added.

Usage of \b and \r in C

The interpretation of the backspace and carriage return characters is left to the software you use for display. A terminal emulator, when displaying \b would move the cursor one step back, and when displaying \r to the beginning of the line. If you print these characters somewhere else, like a text file, the software may choose. to do something else.

How do I cast a string to integer and have 0 in case of error in the cast with PostgreSQL?

I found the following code easy and working. Original answer is here https://www.postgresql.org/message-id/[email protected]

prova=> create table test(t text, i integer);
CREATE

prova=> insert into test values('123',123);
INSERT 64579 1

prova=> select cast(i as text),cast(t as int)from test;
text|int4
----+----
123| 123
(1 row)

hope it helps

Changing SVG image color with javascript

Sure, here is an example (standard HTML boilerplate omitted):

_x000D_
_x000D_
<svg id="svg1" xmlns="http://www.w3.org/2000/svg" style="width: 3.5in; height: 1in">_x000D_
  <circle id="circle1" r="30" cx="34" cy="34" _x000D_
            style="fill: red; stroke: blue; stroke-width: 2"/>_x000D_
  </svg>_x000D_
<button onclick="circle1.style.fill='yellow';">Click to change to yellow</button>
_x000D_
_x000D_
_x000D_

How do I export html table data as .csv file?

I've briefly covered a simple way to do this with Google Spreadsheets (importHTML) and in Python (Pandas read_html and to_csv) as well as an example Python script in my SO answer here: https://stackoverflow.com/a/28083469/1588795.

Why does ANT tell me that JAVA_HOME is wrong when it is not?

Actually found this answer on superuser.com, but I had to copy tools.jar from my JDK\lib directory to the JRE\lib directory.

Makes ZERO sense...only thing I can think of is Sun introduced this bug in the latest Java runtime (Java 7 Update 11) or a bug in Ant in how it reads the current JDK location (the JRE is more updated than the JDK obviously which is also stupid of Sun...they should release the JDK each time they update the JRE).

My JAVA_HOME was set correctly. I confirmed by doing "set JAVA_HOME". It pointed to my JDK directory and was spelled correctly. However, Ant was claiming it couldn't find javac, but thought JAVA_HOME was in my JRE directory.

My system worked fine before the latest Sun JRE7 updates (10 and 11). Ant is version 1.8.4

Returning IEnumerable<T> vs. IQueryable<T>

In general you want to preserve the original static type of the query until it matters.

For this reason, you can define your variable as 'var' instead of either IQueryable<> or IEnumerable<> and you will know that you are not changing the type.

If you start out with an IQueryable<>, you typically want to keep it as an IQueryable<> until there is some compelling reason to change it. The reason for this is that you want to give the query processor as much information as possible. For example, if you're only going to use 10 results (you've called Take(10)) then you want SQL Server to know about that so that it can optimize its query plans and send you only the data you'll use.

A compelling reason to change the type from IQueryable<> to IEnumerable<> might be that you are calling some extension function that the implementation of IQueryable<> in your particular object either cannot handle or handles inefficiently. In that case, you might wish to convert the type to IEnumerable<> (by assigning to a variable of type IEnumerable<> or by using the AsEnumerable extension method for example) so that the extension functions you call end up being the ones in the Enumerable class instead of the Queryable class.

C++ Object Instantiation

The only reason I'd worry about is that Dog is now allocated on the stack, rather than the heap. So if Dog is megabytes in size, you may have a problem,

If you do need to go the new/delete route, be wary of exceptions. And because of this you should use auto_ptr or one of the boost smart pointer types to manage the object lifetime.

How to grep and replace

Another option is to use find and then pass it through sed.

find /path/to/files -type f -exec sed -i 's/oldstring/new string/g' {} \;

Is it possible to have different Git configuration for different projects?

You can customize a project's Git config by changing the repository specific configuration file (i.e. /path/to/repo/.git/config). BTW, git config writes to this file by default:

cd /path/to/repo
git config user.name 'John Doe'  # sets user.name locally for the repo

I prefer to create separate profiles for different projects (e.g. in ~/.gitconfig.d/) and then include them in the repository's config file:

cd /path/to/repo
git config include.path '~/.gitconfig.d/myproject.conf'

This works well if you need to use the same set of options in multiple repos that belong to a single project. You can also set up shell aliases or a custom Git command to manipulate the profiles.

How to compare two Carbon Timestamps?

First, Eloquent automatically converts it's timestamps (created_at, updated_at) into carbon objects. You could just use updated_at to get that nice feature, or specify edited_at in your model in the $dates property:

protected $dates = ['edited_at'];

Now back to your actual question. Carbon has a bunch of comparison functions:

  • eq() equals
  • ne() not equals
  • gt() greater than
  • gte() greater than or equals
  • lt() less than
  • lte() less than or equals

Usage:

if($model->edited_at->gt($model->created_at)){
    // edited at is newer than created at
}

How do I view the SQL generated by the Entity Framework?

To have the query always handy, without changing code add this to your DbContext and check it on the output window in visual studio.

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        Database.Log = (query)=> Debug.Write(query);
    }

Similar to @Matt Nibecker answer, but with this you do not have to add it in your current code, every time you need the query.

How to define servlet filter order of execution using annotations in WAR

You can indeed not define the filter execution order using @WebFilter annotation. However, to minimize the web.xml usage, it's sufficient to annotate all filters with just a filterName so that you don't need the <filter> definition, but just a <filter-mapping> definition in the desired order.

For example,

@WebFilter(filterName="filter1")
public class Filter1 implements Filter {}

@WebFilter(filterName="filter2")
public class Filter2 implements Filter {}

with in web.xml just this:

<filter-mapping>
    <filter-name>filter1</filter-name>
    <url-pattern>/url1/*</url-pattern>
</filter-mapping>
<filter-mapping>
    <filter-name>filter2</filter-name>
    <url-pattern>/url2/*</url-pattern>
</filter-mapping>

If you'd like to keep the URL pattern in @WebFilter, then you can just do like so,

@WebFilter(filterName="filter1", urlPatterns="/url1/*")
public class Filter1 implements Filter {}

@WebFilter(filterName="filter2", urlPatterns="/url2/*")
public class Filter2 implements Filter {}

but you should still keep the <url-pattern> in web.xml, because it's required as per XSD, although it can be empty:

<filter-mapping>
    <filter-name>filter1</filter-name>
    <url-pattern />
</filter-mapping>
<filter-mapping>
    <filter-name>filter2</filter-name>
    <url-pattern />
</filter-mapping>

Regardless of the approach, this all will fail in Tomcat until version 7.0.28 because it chokes on presence of <filter-mapping> without <filter>. See also Using Tomcat, @WebFilter doesn't work with <filter-mapping> inside web.xml

npm install -g less does not work: EACCES: permission denied

Mac OS X Answer

You don't have write access to the node_modules directory

npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules

Add your User to the directory with write access

  1. Open folder containing node_modules

    open /usr/local/lib/

  2. Do a cmd+I on the node_modules folder to open the permission dialog
  3. Add your user to have read and write access in the sharing and permissions section enter image description here

How to set value to form control in Reactive Forms in Angular

Setting or Updating of Reactive Forms Form Control values can be done using both patchValue and setValue. However, it might be better to use patchValue in some instances.

patchValue does not require all controls to be specified within the parameters in order to update/set the value of your Form Controls. On the other hand, setValue requires all Form Control values to be filled in, and it will return an error if any of your controls are not specified within the parameter.

In this scenario, we will want to use patchValue, since we are only updating user and questioning:

this.qService.editQue([params["id"]]).subscribe(res => {
  this.question = res;
  this.editqueForm.patchValue({
    user: this.question.user,
    questioning: this.question.questioning
  });
});

EDIT: If you feel like doing some of ES6's Object Destructuring, you may be interested to do this instead

const { user, questioning } = this.question;

this.editqueForm.patchValue({
  user,
  questioning
});

Ta-dah!

Regular expression that matches valid IPv6 addresses

In Java, you can use the library class sun.net.util.IPAddressUtil:

IPAddressUtil.isIPv6LiteralAddress(iPaddress);

Node.js request CERT_HAS_EXPIRED

Add this at the top of your file:

process.env.NODE_TLS_REJECT_UNAUTHORIZED = '0';

DANGEROUS This disables HTTPS / SSL / TLS checking across your entire node.js environment. Please see the solution using an https agent below.

How can I use tabs for indentation in IntelliJ IDEA?

I have started using IntelliJ IDEA Community Edition version 12.1.3 and I found the setting in the following place: -

File > Other Settings > Default Settings > {choose from Code Style dropdown}

Bulk package updates using Conda

You want conda update --all.

conda search --outdated will show outdated packages, and conda update --all will update them (note that the latter will not update you from Python 2 to Python 3, but the former will show Python as being outdated if you do use Python 2).

Icons missing in jQuery UI

They arent missing, the path is wrong. Its looking in non-existent dir 'img' for a file that is in dir 'images'.

To fix either edit the file that declares the wrong path or as I did just make a softlink like

ln -s images img

Using multiple parameters in URL in express

app.get('/fruit/:fruitName/:fruitColor', function(req, res) {
    var data = {
        "fruit": {
            "apple": req.params.fruitName,
            "color": req.params.fruitColor
        }
    }; 

    send.json(data);
});

If that doesn't work, try using console.log(req.params) to see what it is giving you.

How to place and center text in an SVG rectangle

Full Detail Blog :http://blog.techhysahil.com/svg/how-to-center-text-in-svg-shapes/

_x000D_
_x000D_
<svg width="600" height="600">_x000D_
  <!--   Circle -->_x000D_
  <g transform="translate(50,40)">_x000D_
    <circle cx="0" cy="0" r="35" stroke="#aaa" stroke-width="2" fill="#fff"></circle>_x000D_
    <text x="0" y="0" alignment-baseline="middle" font-size="12" stroke-width="0" stroke="#000" text-anchor="middle">HueLink</text>_x000D_
  </g>_x000D_
  _x000D_
  <!--   In Rectangle text position needs to be given half of width and height of rectangle respectively -->_x000D_
  <!--   Rectangle -->_x000D_
  <g transform="translate(150,20)">_x000D_
    <rect width="150" height="40" stroke="#aaa" stroke-width="2" fill="#fff"></rect>_x000D_
    <text x="75" y="20" alignment-baseline="middle" font-size="12" stroke-width="0" stroke="#000" text-anchor="middle">HueLink</text>_x000D_
  </g>_x000D_
  _x000D_
  <!--   Rectangle -->_x000D_
  <g transform="translate(120,140)">_x000D_
    <ellipse cx="0" cy="0" rx="100" ry="50" stroke="#aaa" stroke-width="2" fill="#fff"></ellipse>_x000D_
    <text x="0" y="0" alignment-baseline="middle" font-size="12" stroke-width="0" stroke="#000" text-anchor="middle">HueLink</text>_x000D_
  </g>_x000D_
  _x000D_
  _x000D_
</svg>
_x000D_
_x000D_
_x000D_

How to subtract date/time in JavaScript?

You can use getTime() method to convert the Date to the number of milliseconds since January 1, 1970. Then you can easy do any arithmetic operations with the dates. Of course you can convert the number back to the Date with setTime(). See here an example.

Generate a random date between two other dates

Here's a solution modified from emyller's approach which returns an array of random dates at any resolution

import numpy as np

def random_dates(start, end, size=1, resolution='s'):
    """
    Returns an array of random dates in the interval [start, end]. Valid 
    resolution arguments are numpy date/time units, as documented at: 
        https://docs.scipy.org/doc/numpy-dev/reference/arrays.datetime.html
    """
    start, end = np.datetime64(start), np.datetime64(end)
    delta = (end-start).astype('timedelta64[{}]'.format(resolution))
    delta_mat = np.random.randint(0, delta.astype('int'), size)
    return start + delta_mat.astype('timedelta64[{}]'.format(resolution))

Part of what's nice about this approach is that np.datetime64 is really good at coercing things to dates, so you can specify your start/end dates as strings, datetimes, pandas timestamps... pretty much anything will work.

How to approach a "Got minus one from a read call" error when connecting to an Amazon RDS Oracle instance

We faced the same issue and fixed it. Below is the reason and solution.

Problem

When the connection pool mechanism is used, the application server (in our case, it is JBOSS) creates connections according to the min-connection parameter. If you have 10 applications running, and each has a min-connection of 10, then a total of 100 sessions will be created in the database. Also, in every database, there is a max-session parameter, if your total number of connections crosses that border, then you will get Got minus one from a read call.

FYI: Use the query below to see your total number of sessions:

SELECT username, count(username) FROM v$session 
WHERE username IS NOT NULL group by username

Solution: With the help of our DBA, we increased that max-session parameter, so that all our application min-connection can accommodate.

dynamic_cast and static_cast in C++

A dynamic_cast performs a type checking using RTTI. If it fails it'll throw you an exception (if you gave it a reference) or NULL if you gave it a pointer.

How to get rid of the "No bootable medium found!" error in Virtual Box?

FIX 1:

Step1: Go to settings > then select the following configuration(Disable Floppy)

Config

Alternatively, you can press F12 while booting the Guest OS and select CD from there, this is a one time setting, good enough for the installation.

Step 2: Place your Existing Guest OS bootable CD in the Disk Drive and start the Guest OS.

FIX 2:

Go to Settings > And Perform the following:

Config1

FIX 3:

Try Fix 1 & 2 together..

Android MediaPlayer Stop and Play

You should use only one mediaplayer object

    public class PlayaudioActivity extends Activity {

        private MediaPlayer mp;

        /** Called when the activity is first created. */
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.main);
            Button b = (Button) findViewById(R.id.button1);
            Button b2 = (Button) findViewById(R.id.button2);
            final TextView t = (TextView) findViewById(R.id.textView1);

            b.setOnClickListener(new View.OnClickListener() {

                @Override
                public void onClick(View v) {
                    stopPlaying();
                    mp = MediaPlayer.create(PlayaudioActivity.this, R.raw.far);
                    mp.start();
                }

            });

            b2.setOnClickListener(new View.OnClickListener() {

                @Override
                public void onClick(View v) {
                    stopPlaying();
                    mp = MediaPlayer.create(PlayaudioActivity.this, R.raw.beet);
                    mp.start();
                }
            });
        }

        private void stopPlaying() {
            if (mp != null) {
                mp.stop();
                mp.release();
                mp = null;
           }
        }
    }

Pandas: Appending a row to a dataframe and specify its index label

There is another solution. The next code is bad (although I think pandas needs this feature):

import pandas as pd

# empty dataframe
a = pd.DataFrame()
a.loc[0] = {'first': 111, 'second': 222}

But the next code runs fine:

import pandas as pd

# empty dataframe
a = pd.DataFrame()
a = a.append(pd.Series({'first': 111, 'second': 222}, name=0))

How to write multiple line string using Bash with variables?

The syntax (<<<) and the command used (echo) is wrong.

Correct would be:

#!/bin/bash

kernel="2.6.39"
distro="xyz"
cat >/etc/myconfig.conf <<EOL
line 1, ${kernel}
line 2, 
line 3, ${distro}
line 4 line
... 
EOL

cat /etc/myconfig.conf

This construction is referred to as a Here Document and can be found in the Bash man pages under man --pager='less -p "\s*Here Documents"' bash.

How to initialize a vector in C++

You can also do like this:

template <typename T>
class make_vector {
public:
  typedef make_vector<T> my_type;
  my_type& operator<< (const T& val) {
    data_.push_back(val);
    return *this;
  }
  operator std::vector<T>() const {
    return data_;
  }
private:
  std::vector<T> data_;
};

And use it like this:

std::vector<int> v = make_vector<int>() << 1 << 2 << 3;

How to get the mysql table columns data type?

The query below returns a list of information about each field, including the MySQL field type. Here is an example:

SHOW FIELDS FROM tablename
/* returns "Field", "Type", "Null", "Key", "Default", "Extras" */

See this manual page.

Find the number of columns in a table

SELECT COUNT(*)
  FROM INFORMATION_SCHEMA.COLUMNS
 WHERE table_catalog = 'database_name' -- the database
   AND table_name = 'table_name'

Oracle date to string conversion

The data in COL1 is in dd-mon-yy

No it's not. A DATE column does not have any format. It is only converted (implicitely) to that representation by your SQL client when you display it.

If COL1 is really a DATE column using to_date() on it is useless because to_date() converts a string to a DATE.

You only need to_char(), nothing else:

SELECT TO_CHAR(col1, 'mm/dd/yyyy') 
FROM TABLE1

What happens in your case is that calling to_date() converts the DATE into a character value (applying the default NLS format) and then converting that back to a DATE. Due to this double implicit conversion some information is lost on the way.


Edit

So you did make that big mistake to store a DATE in a character column. And that's why you get the problems now.

The best (and to be honest: only sensible) solution is to convert that column to a DATE. Then you can convert the values to any rerpresentation that you want without worrying about implicit data type conversion.

But most probably the answer is "I inherited this model, I have to cope with it" (it always is, apparently no one ever is responsible for choosing the wrong datatype), then you need to use RR instead of YY:

SELECT TO_CHAR(TO_DATE(COL1,'dd-mm-rr'), 'mm/dd/yyyy')
FROM TABLE1

should do the trick. Note that I also changed mon to mm as your example is 27-11-89 which has a number for the month, not an "word" (like NOV)

For more details see the manual: http://docs.oracle.com/cd/B28359_01/server.111/b28286/sql_elements004.htm#SQLRF00215

Optional Parameters in Go?

Go language does not support method overloading, but you can use variadic args just like optional parameters, also you can use interface{} as parameter but it is not a good choice.

How do I make a batch file terminate upon encountering an error?

One minor update, you should change the checks for "if errorlevel 1" to the following...

IF %ERRORLEVEL% NEQ 0 

This is because on XP you can get negative numbers as errors. 0 = no problems, anything else is a problem.

And keep in mind the way that DOS handles the "IF ERRORLEVEL" tests. It will return true if the number you are checking for is that number or higher so if you are looking for specific error numbers you need to start with 255 and work down.

Chart.js - Formatting Y axis

Chart.js 2.X.X

I know this post is old. But if anyone is looking for more flexible solution, here it is

var options = {
        scales: {
            yAxes: [{
                ticks: {
                    beginAtZero: true,
                    callback: function(label, index, labels) {
                        return Intl.NumberFormat().format(label);
                        // 1,350

                        return Intl.NumberFormat('hi', { 
                            style: 'currency', currency: 'INR', minimumFractionDigits: 0, 
                        }).format(label).replace(/^(\D+)/, '$1 ');
                        // ? 1,350

                        // return Intl.NumberFormat('hi', {
                            style: 'currency', currency: 'INR', currencyDisplay: 'symbol', minimumFractionDigits: 2 
                        }).format(label).replace(/^(\D+)/, '$1 ');
                        // ? 1,350.00
                    }
                }
            }]
        }
    }

'hi' is Hindi. Check here for other locales argument
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl#Locale_identification_and_negotiation#locales_argument

for more currency symbol
https://www.currency-iso.org/en/home/tables/table-a1.html

Eclipse: Syntax Error, parameterized types are only if source level is 1.5

THIS CAN BE A QUICK FIX FOR ECLIPSE

When I was trying to create array list it gave error that array list cannot be resolved to type and something about "parametrised type are only in level 1.5"

Only I did was I tried to import java.util.ArrayList;

And that error went away.

How can you search Google Programmatically Java API

As an alternative to BalusC answer as it has been deprecated and you have to use proxies, you can use this package. Code sample:

Map<String, String> parameter = new HashMap<>();
parameter.put("q", "Coffee");
parameter.put("location", "Portland");
GoogleSearchResults serp = new GoogleSearchResults(parameter);

JsonObject data = serp.getJson();
JsonArray results = (JsonArray) data.get("organic_results");
JsonObject first_result = results.get(0).getAsJsonObject();
System.out.println("first coffee: " + first_result.get("title").getAsString());

Library on GitHub

How can I get a side-by-side diff when I do "git diff"?

ydiff

Formerly called cdiff, this tool can display side by side, incremental, and colorful diff.

Instead of doing git diff, do:

ydiff -s -w0

This will launch ydiff in side-by-side display mode for each of the files with differences.

Install with:

python3 -m pip install --user ydiff

-or-

brew install ydiff

For git log, you can use:

ydiff -ls -w0

-w0 auto-detects your terminal width. See the ydiff GitHub repository page for detail and demo.

Tested in Git 2.18.0, ydiff 1.1.

Laravel 5.4 Specific Table Migration

You can only rollback:

php artisan migrate:rollback

https://laravel.com/docs/5.4/migrations#rolling-back-migrations

You can specify how many migrations to roll back to using the 'step' option:

php artisan migrate:rollback --step=1

Some tricks are available here:

Rollback one specific migration in Laravel

Android Button setOnClickListener Design

Android lambada solution

public void registerButtons(){
    register(R.id.buttonName1, ()-> {/*Your code goes here*/});
    register(R.id.buttonName2, ()-> {/*Your code goes here*/});
    register(R.id.buttonName3, ()-> {/*Your code goes here*/});
}

private void register(int buttonResourceId, Runnable r){
    findViewById(buttonResourceId).setOnClickListener(v -> r.run());
}

Switch case solution solution

public void registerButtons(){
    register(R.id.buttonName1);
    register(R.id.buttonName2);
    register(R.id.buttonName3);
}

private void register(int buttonResourceId){
    findViewById(buttonResourceId).setOnClickListener(buttonClickListener);
}

private OnClickListener buttonClickListener = new OnClickListener() {

    @Override
    public void onClick(View v){
        switch (v.getId()) {
            case R.id.buttonName1:
                // TODO Auto-generated method stub
                break;
            case R.id.buttonName2:
                // TODO Auto-generated method stub
                break;
            case View.NO_ID:
            default:
                // TODO Auto-generated method stub
                break;
        }
    }
};

Regular expression to allow spaces between words

Had a good look at many of these supposed answers...

...and bupkis after scouring Stack Overflow as well as other sites for a regex that matches any string with no starting or trailing white-space and only a single space between strictly alpha character words.

^[a-zA-Z]+[(?<=\d\s]([a-zA-Z]+\s)*[a-zA-Z]+$

Thus easily modified to alphanumeric:

^[a-zA-Z0-9]+[(?<=\d\s]([a-zA-Z0-9]+\s)*[a-zA-Z0-9]+$

(This does not match single words but just use a switch/if-else with a simple ^[a-zA-Z0-9]+$ if you need to catch single words in addition.)

enjoy :D

python tuple to dict

If there are multiple values for the same key, the following code will append those values to a list corresponding to their key,

d = dict()
for x,y in t:
    if(d.has_key(y)):
        d[y].append(x)
    else:
        d[y] = [x]

Prolog "or" operator, query

Just another viewpoint. Performing an "or" in Prolog can also be done with the "disjunct" operator or semi-colon:

registered(X, Y) :-
    X = ct101; X = ct102; X = ct103.

For a fuller explanation:

Predicate control in Prolog

How to import an Oracle database from dmp file and log file?

If you are using impdp command example from @sathyajith-bhat response:

impdp <username>/<password> directory=<directoryname> dumpfile=<filename>.dmp logfile=<filename>.log full=y;

you will need to use mandatory parameter directory and create and grant it as:

CREATE OR REPLACE DIRECTORY DMP_DIR AS 'c:\Users\USER\Downloads';
GRANT READ, WRITE ON DIRECTORY DMP_DIR TO {USER};

or use one of defined:

select * from DBA_DIRECTORIES;

My ORACLE Express 11g R2 has default named DATA_PUMP_DIR (located at {inst_dir}\app\oracle/admin/xe/dpdump/) you sill need to grant it for your user.

Division of integers in Java

Converting the output is too late; the calculation has already taken place in integer arithmetic. You need to convert the inputs to double:

System.out.println((double)completed/(double)total);

Note that you don't actually need to convert both of the inputs. So long as one of them is double, the other will be implicitly converted. But I prefer to do both, for symmetry.

Promise.all().then() resolve?

Today NodeJS supports new async/await syntax. This is an easy syntax and makes the life much easier

async function process(promises) { // must be an async function
    let x = await Promise.all(promises);  // now x will be an array
    x = x.map( tmp => tmp * 10);              // proccessing the data.
}

const promises = [
   new Promise(resolve => setTimeout(resolve, 0, 1)),
   new Promise(resolve => setTimeout(resolve, 0, 2))
];

process(promises)

Learn more:

How to set text color to a text view programmatically

Great answers. Adding one that loads the color from an Android resources xml but still sets it programmatically:

textView.setTextColor(getResources().getColor(R.color.some_color));

Please note that from API 23, getResources().getColor() is deprecated. Use instead:

textView.setTextColor(ContextCompat.getColor(context, R.color.some_color));

where the required color is defined in an xml as:

<resources>
  <color name="some_color">#bdbdbd</color>
</resources>

Update:

This method was deprecated in API level 23. Use getColor(int, Theme) instead.

Check this.

How to present a simple alert message in java?

Call "setWarningMsg()" Method and pass the text that you want to show.

exm:- setWarningMsg("thank you for using java");


public static void setWarningMsg(String text){
    Toolkit.getDefaultToolkit().beep();
    JOptionPane optionPane = new JOptionPane(text,JOptionPane.WARNING_MESSAGE);
    JDialog dialog = optionPane.createDialog("Warning!");
    dialog.setAlwaysOnTop(true);
    dialog.setVisible(true);
}

Or Just use

JOptionPane optionPane = new JOptionPane("thank you for using java",JOptionPane.WARNING_MESSAGE);
JDialog dialog = optionPane.createDialog("Warning!");
dialog.setAlwaysOnTop(true); // to show top of all other application
dialog.setVisible(true); // to visible the dialog

You can use JOptionPane. (WARNING_MESSAGE or INFORMATION_MESSAGE or ERROR_MESSAGE)

Is there a command to restart computer into safe mode?

My first answer!

This will set the safemode switch:

bcdedit /set {current} safeboot minimal 

with networking:

bcdedit /set {current} safeboot network

then reboot the machine with

shutdown /r

to put back in normal mode via dos:

bcdedit /deletevalue {current} safeboot

How do I create a round cornered UILabel on the iPhone?

If you want rounded corner of UI objects like (UILabel, UIView, UIButton, UIImageView) by storyboard then set clip to bounds true and set User Defined Runtime Attributes Key path as layer.cornerRadius, type = Number and value = 9 (as your requirement)

Set clip to bounds as Set User Defined Runtime Attributes as

error while loading shared libraries: libncurses.so.5:

In Fedora 28 use:

sudo dnf install ncurses-compat-libs

Can you disable tabs in Bootstrap?

You could remove the data-toggle="tab" attribute from the tab as it's hooked up using live/delegate events

Get encoding of a file in Windows

Some C code here for reliable ascii, bom's, and utf8 detection: https://unicodebook.readthedocs.io/guess_encoding.html

Only ASCII, UTF-8 and encodings using a BOM (UTF-7 with BOM, UTF-8 with BOM, UTF-16, and UTF-32) have reliable algorithms to get the encoding of a document. For all other encodings, you have to trust heuristics based on statistics.

EDIT:

A powershell version of a C# answer from: Effective way to find any file's Encoding. Only works with signatures (boms).

# get-encoding.ps1
param([Parameter(ValueFromPipeline=$True)] $filename)    
begin {
  # set .net current directoy                                                                                                   
  [Environment]::CurrentDirectory = (pwd).path
}
process {
  $reader = [System.IO.StreamReader]::new($filename, 
    [System.Text.Encoding]::default,$true)
  $peek = $reader.Peek()
  $encoding = $reader.currentencoding
  $reader.close()
  [pscustomobject]@{Name=split-path $filename -leaf
                BodyName=$encoding.BodyName
                EncodingName=$encoding.EncodingName}
}


.\get-encoding chinese8.txt

Name         BodyName EncodingName
----         -------- ------------
chinese8.txt utf-8    Unicode (UTF-8)


get-childitem -file | .\get-encoding

How to get a variable value if variable name is stored as string?

For my fellow zsh users, the way to accomplish the same thing as the accepted answer is to use:

${(P)a}

It is appropriately called Parameter name replacement

This forces the value of the parameter name to be interpreted as a further parameter name, whose value will be used where appropriate. Note that flags set with one of the typeset family of commands (in particular case transformations) are not applied to the value of name used in this fashion.

If used with a nested parameter or command substitution, the result of that will be taken as a parameter name in the same way. For example, if you have ‘foo=bar’ and ‘bar=baz’, the strings ${(P)foo}, ${(P)${foo}}, and ${(P)$(echo bar)} will be expanded to ‘baz’.

Likewise, if the reference is itself nested, the expression with the flag is treated as if it were directly replaced by the parameter name. It is an error if this nested substitution produces an array with more than one word. For example, if ‘name=assoc’ where the parameter assoc is an associative array, then ‘${${(P)name}[elt]}’ refers to the element of the associative subscripted ‘elt’.

Generating CSV file for Excel, how to have a newline inside a value

I found this and it has worked for me

$delimiter = ',';
$enc1 = '"';
$enc2 = '""';

Then where you need to have stuff enclosed

$myfile = ('/path/to/myfile.csv');
//erase any previous contents
$fp = fopen($myfile, 'w+');
fwrite($fp, $enc1 .  'Column Heading 1' . $enc1 . $delimiter );
//append to new file
$fp2 = fopen($myfile, 'a');
fwrite($fp2, $enc1 .  'Column Heading 2' . $enc1 . $delimiter );

.....

fwrite($fp2, $enc1 .  'Last Column Heading' . $enc1 . $delimiter. PHP_EOL );

Then when you need to write something out - like HTML that includes the " you can do this

fwrite($fp2, $enc2 .  $myhtmlstring . $enc2 . $delimiter);

New lines end with . PHP_EOL

The end of the script prints out a link so that the user can download the file.

echo 'Click <a href="myfile.csv">here</a> to download file';

What is PHPSESSID?

PHPSESSID is an auto generated session cookie by the server which contains a random long number which is given out by the server itself

How to convert minutes to hours/minutes and add various time values together using jQuery?

This code can be used with timezone

javascript:

_x000D_
_x000D_
let minToHm = (m) => {_x000D_
  let h = Math.floor(m / 60);_x000D_
  h += (h < 0) ? 1 : 0;_x000D_
  let m2 = Math.abs(m % 60);_x000D_
  m2 = (m2 < 10) ? '0' + m2 : m2;_x000D_
  return (h < 0 ? '' : '+') + h + ':' + m2;_x000D_
}_x000D_
_x000D_
console.log(minToHm(210)) // "+3:30"_x000D_
console.log(minToHm(-210)) // "-3:30"_x000D_
console.log(minToHm(0)) // "+0:00"
_x000D_
_x000D_
_x000D_

minToHm(210)
"+3:30"

minToHm(-210)
"-3:30"

minToHm(0)
"+0:00"

Pandas: Return Hour from Datetime Column Directly

Here is a simple solution:

import pandas as pd
# convert the timestamp column to datetime
df['timestamp'] = pd.to_datetime(df['timestamp'])

# extract hour from the timestamp column to create an time_hour column
df['time_hour'] = df['timestamp'].dt.hour

Indent starting from the second line of a paragraph with CSS

Is it literally just the second line you want to indent, or is it from the second line (ie. a hanging indent)?

If it is the latter, something along the lines of this JSFiddle would be appropriate.

_x000D_
_x000D_
    div {_x000D_
        padding-left: 1.5em;_x000D_
        text-indent:-1.5em;_x000D_
    }_x000D_
    _x000D_
    span {_x000D_
        padding-left: 1.5em;_x000D_
        text-indent:-1.5em;_x000D_
    }
_x000D_
<div>Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut laoreet dolore magna aliquam erat volutpat. Ut wisi enim ad minim veniam, quis nostrud exerci tation ullamcorper suscipit lobortis nisl ut aliquip ex ea commodo consequat.</div>_x000D_
_x000D_
<span>Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut laoreet dolore magna aliquam erat volutpat. Ut wisi enim ad minim veniam, quis nostrud exerci tation ullamcorper suscipit lobortis nisl ut aliquip ex ea commodo consequat.</span>
_x000D_
_x000D_
_x000D_

This example shows how using the same CSS syntax in a DIV or SPAN produce different effects.

SQL JOIN - WHERE clause vs. ON clause

For an inner join, WHERE and ON can be used interchangeably. In fact, it's possible to use ON in a correlated subquery. For example:

update mytable
set myscore=100
where exists (
select 1 from table1
inner join table2
on (table2.key = mytable.key)
inner join table3
on (table3.key = table2.key and table3.key = table1.key)
...
)

This is (IMHO) utterly confusing to a human, and it's very easy to forget to link table1 to anything (because the "driver" table doesn't have an "on" clause), but it's legal.

How do I apply CSS3 transition to all properties except background-position?

Try:

-webkit-transition: all .2s linear, background-position 0;

This worked for me on something similar..

Ternary operation in CoffeeScript

a = if true then 5 else 10
a = if false then 5 else 10 

See documentation.

Angular CLI - Please add a @NgModule annotation when using latest

In my case, I created a new ChildComponent in Parentcomponent whereas both in the same module but Parent is registered in a shared module so I created ChildComponent using CLI which registered Child in the current module but my parent was registered in the shared module.

So register the ChildComponent in Shared Module manually.

Rails filtering array of objects by attribute value

have you tried eager loading?

@attachments = Job.includes(:attachments).find(1).attachments

Powershell Log Off Remote Session

Below script will work well for both active and disconnected sessions as long as user has access to run logoff command remotely. All you have to do is change the servername from "YourServerName" on 4th line.

param (
    $queryResults = $null,
    [string]$UserName = $env:USERNAME,
    [string]$ServerName = "YourServerName"
)


if (Test-Connection $ServerName -Count 1 -Quiet) {  
    Write-Host "`n`n`n$ServerName is online!" -BackgroundColor Green -ForegroundColor Black


    Write-Host ("`nQuerying Server: `"$ServerName`" for disconnected sessions under UserName: `"" + $UserName.ToUpper() + "`"...") -BackgroundColor Gray -ForegroundColor Black

        query user $UserName /server:$ServerName 2>&1 | foreach {  

            if ($_ -match "Active") {
                Write-Host "Active Sessions"
                $queryResults = ("`n$ServerName," + (($_.trim() -replace ' {2,}', ','))) | ConvertFrom-Csv -Delimiter "," -Header "ServerName","UserName","SessionName","SessionID","CurrentState","IdealTime","LogonTime"


                $queryResults | ft
                Write-Host "Starting logoff procedure..." -BackgroundColor Gray -ForegroundColor Black

                $queryResults | foreach {
                    $Sessionl = $_.SessionID
                    $Serverl = $_.ServerName
                    Write-Host "Logging off"$_.username"from $serverl..." -ForegroundColor black -BackgroundColor Gray
                    sleep 2
                    logoff $Sessionl /server:$Serverl /v

                }


            }                
            elseif ($_ -match "Disc") {
                Write-Host "Disconnected Sessions"
                $queryResults = ("`n$ServerName," + (($_.trim() -replace ' {2,}', ','))) |  ConvertFrom-Csv -Delimiter "," -Header "ServerName","UserName","SessionID","CurrentState","IdealTime","LogonTime"

                $queryResults | ft
                Write-Host "Starting logoff procedure..." -BackgroundColor Gray -ForegroundColor Black

                $queryResults | foreach {
                    $Sessionl = $_.SessionID
                    $Serverl = $_.ServerName
                    Write-Host "Logging off"$_.username"from $serverl..."
                    sleep 2
                    logoff $Sessionl /server:$Serverl /v

                }
            }
            elseif ($_ -match "The RPC server is unavailable") {

                Write-Host "Unable to query the $ServerName, check for firewall settings on $ServerName!" -ForegroundColor White -BackgroundColor Red
            }
            elseif ($_ -match "No User exists for") {Write-Host "No user session exists"}

    }
}
else {

    Write-Host "`n`n`n$ServerName is Offline!" -BackgroundColor red -ForegroundColor white
    Write-Host "Error: Unable to connect to $ServerName!" -BackgroundColor red -ForegroundColor white
    Write-Host "Either the $ServerName is down or check for firewall settings on server $ServerName!" -BackgroundColor Yellow -ForegroundColor black
}





Read-Host "`n`nScript execution finished, press enter to exit!"

Some sample outputs. For active session: enter image description here

For disconnected sessions: enter image description here

if no sessions found: enter image description here Check out this solution as well to query all AD servers for your username and logoff only disconnected sessions. The script will also tell you if there were error connecting or querying the server.

Powershell to find out disconnected RDP session and log off at the same time

Tooltips for cells in HTML table (no Javascript)

You can use css and the :hover pseudo-property. Here is a simple demo. It uses the following css:

a span.tooltip {display:none;}
a:hover span.tooltip {position:absolute;top:30px;left:20px;display:inline;border:2px solid green;}

Note that older browsers have limited support for :hover.

How to start Activity in adapter?

For newer versions of sdk you have to set flag activity task.

public void onClick(View v)
 {
     Intent myactivity = new Intent(context.getApplicationContext(), OtherActivity.class);
     myactivity.addFlags(FLAG_ACTIVITY_NEW_TASK);
     context.getApplicationContext().startActivity(myactivity);
 }

Check if a value is in an array or not with Excel VBA

You can brute force it like this:

Public Function IsInArray(stringToBeFound As String, arr As Variant) As Boolean
    Dim i
    For i = LBound(arr) To UBound(arr)
        If arr(i) = stringToBeFound Then
            IsInArray = True
            Exit Function
        End If
    Next i
    IsInArray = False

End Function

Use like

IsInArray("example", Array("example", "someother text", "more things", "and another"))

How to create a delay in Swift?

To create a simple time delay, you can import Darwin and then use sleep(seconds) to do the delay. That only takes whole seconds, though, so for more precise measurements you can import Darwin and use usleep(millionths of a second) for very precise measurement. To test this, I wrote:

import Darwin
print("This is one.")
sleep(1)
print("This is two.")
usleep(400000)
print("This is three.")

Which prints, then waits for 1 sec and prints, then waits for 0.4 sec then prints. All worked as expected.

Gson library in Android Studio

Read Google-gson

Gson is a Java library that can be used to convert Java Objects into their JSON representation. It can also be used to convert a JSON string to an equivalent Java object.

Add the following line to your MODULE LEVEL build.gradle configuration:

dependencies {
     implementation 'com.google.code.gson:gson:2.8.5' // Old 2.8.2
}

What is process.env.PORT in Node.js?

In some scenarios, port can only be designated by the environment and is saved in a user environment variable. Below is how node.js apps work with it.

The process object is a global that provides information about, and control over, the current Node.js process. As a global, it is always available to Node.js applications without using require().

The process.env property returns an object containing the user environment.

An example of this object looks like:

{
  TERM: 'xterm-256color',
  SHELL: '/usr/local/bin/bash',
  USER: 'maciej',
  PATH: '~/.bin/:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin',
  PWD: '/Users/maciej',
  EDITOR: 'vim',
  SHLVL: '1',
  HOME: '/Users/maciej',
  LOGNAME: 'maciej',
  _: '/usr/local/bin/node'
}

For example,

terminal: set a new user environment variable, not permanently

export MY_TEST_PORT=9999

app.js: read the new environment variable from node app

console.log(process.env.MY_TEST_PORT)

terminal: run the node app and get the value

$ node app.js
9999

Save file to specific folder with curl command

curl doesn't have an option to that (without also specifying the filename), but wget does. The directory can be relative or absolute. Also, the directory will automatically be created if it doesn't exist.

wget -P relative/dir "$url"

wget -P /absolute/dir "$url"

How to pass a PHP variable using the URL

You're passing link=$a and link=$b in the hrefs for A and B, respectively. They are treated as strings, not variables. The following should fix that for you:

echo '<a href="pass.php?link=' . $a . '">Link 1</a>';

// and

echo '<a href="pass.php?link=' . $b . '">Link 2</a>';

The value of $a also isn't included on pass.php. I would suggest making a common variable file and include it on all necessary pages.

Easy way to write contents of a Java InputStream to an OutputStream

PipedInputStream and PipedOutputStream should only be used when you have multiple threads, as noted by the Javadoc.

Also, note that input streams and output streams do not wrap any thread interruptions with IOExceptions... So, you should consider incorporating an interruption policy to your code:

byte[] buffer = new byte[1024];
int len = in.read(buffer);
while (len != -1) {
    out.write(buffer, 0, len);
    len = in.read(buffer);
    if (Thread.interrupted()) {
        throw new InterruptedException();
    }
}

This would be an useful addition if you expect to use this API for copying large volumes of data, or data from streams that get stuck for an intolerably long time.

C# JSON Serialization of Dictionary into {key:value, ...} instead of {key:key, value:value, ...}

use property UseSimpleDictionaryFormat on DataContractJsonSerializer and set it to true.

Does the job :)

How do you get the string length in a batch file?

If you are on Windows Vista +, then try this Powershell method:

For /F %%L in ('Powershell $Env:MY_STRING.Length') do (
    Set MY_STRING_LEN=%%L
)

or alternatively:

Powershell $Env:MY_STRING.Length > %Temp%\TmpFile.txt
Set /p MY_STRING_LEN = < %Temp%\TmpFile.txt
Del %Temp%\TmpFile.txt

I'm on Windows 7 x64 and this is working for me.

Spring JUnit: How to Mock autowired component in autowired component

I created blog post on the topic. It contains also link to Github repository with working example.

The trick is using test configuration, where you override original spring bean with fake one. You can use @Primary and @Profile annotations for this trick.

How to define two angular apps / modules in one page?

I made a POC for an Angular application using multiple modules and router-outlets to nest sub apps in a single page app. You can get the source code at: https://github.com/AhmedBahet/ng-sub-apps

Hope this will help

Different between parseInt() and valueOf() in java?

From this forum:

parseInt() returns primitive integer type (int), whereby valueOf returns java.lang.Integer, which is the object representative of the integer. There are circumstances where you might want an Integer object, instead of primitive type.

Of course, another obvious difference is that intValue is an instance method whereby parseInt is a static method.

PHP using Gettext inside <<<EOF string

As far as I can see in the manual, it is not possible to call functions inside HEREDOC strings. A cumbersome way would be to prepare the words beforehand:

<?php

    $world = _("World");

    $str = <<<EOF
    <p>Hello</p>
    <p>$world</p>
EOF;
    echo $str;
?>

a workaround idea that comes to mind is building a class with a magic getter method.

You would declare a class like this:

class Translator
{
 public function __get($name) {
  return _($name); // Does the gettext lookup
  }
 }

Initialize an object of the class at some point:

  $translate = new Translator();

You can then use the following syntax to do a gettext lookup inside a HEREDOC block:

    $str = <<<EOF
    <p>Hello</p>
    <p>{$translate->World}</p>
EOF;
    echo $str;
?>

$translate->World will automatically be translated to the gettext lookup thanks to the magic getter method.

To use this method for words with spaces or special characters (e.g. a gettext entry named Hello World!!!!!!, you will have to use the following notation:

 $translate->{"Hello World!!!!!!"}

This is all untested but should work.

Update: As @mario found out, it is possible to call functions from HEREDOC strings after all. I think using getters like this is a sleek solution, but using a direct function call may be easier. See the comments on how to do this.

Bootstrap 4 navbar color

I got it. This is very simple. Using the class bg you can achieve this easily.

Let me show you:

<nav class="navbar navbar-expand-lg navbar-dark navbar-full bg-primary"></nav>

This gives you the default blue navbar

If you want to change your favorite color, then simply use the style tag within the nav:

<nav class="navbar navbar-expand-lg navbar-dark navbar-full" style="background-color: #FF0000">

FFmpeg on Android

To make my FFMPEG application I used this project (https://github.com/hiteshsondhi88/ffmpeg-android-java) so, I don't have to compile anything. I think it's the easy way to use FFMPEG in our Android applications.

More info on http://hiteshsondhi88.github.io/ffmpeg-android-java/

MVC Form not able to post List of objects

Please read this: http://haacked.com/archive/2008/10/23/model-binding-to-a-list.aspx
You should set indicies for your html elements "name" attributes like planCompareViewModel[0].PlanId, planCompareViewModel[1].PlanId to make binder able to parse them into IEnumerable.
Instead of @foreach (var planVM in Model) use for loop and render names with indexes.

Regex doesn't work in String.matches()

You can make your pattern case insensitive by doing:

Pattern p = Pattern.compile("[a-z]+", Pattern.CASE_INSENSITIVE);

How to upgrade R in ubuntu?

Since R is already installed, you should be able to upgrade it with this method. First of all, you may want to have the packages you installed in the previous version in the new one,so it is convenient to check this post. Then, follow the instructions from here

  1. Open the sources.list file:

     sudo nano /etc/apt/sources.list    
    
  2. Add a line with the source from where the packages will be retrieved. For example:

     deb https://cloud.r-project.org/bin/linux/ubuntu/ version/
    

    Replace https://cloud.r-project.org with whatever mirror you would like to use, and replace version/ with whatever version of Ubuntu you are using (eg, trusty/, xenial/, and so on). If you're getting a "Malformed line error", check to see if you have a space between /ubuntu/ and version/.

  3. Fetch the secure APT key:

     gpg --keyserver keyserver.ubuntu.com --recv-key E298A3A825C0D65DFD57CBB651716619E084DAB9
    

or

    gpg --hkp://keyserver keyserver.ubuntu.com:80 --recv-key E298A3A825C0D65DFD57CBB651716619E084DAB9
  1. Add it to keyring:

     gpg -a --export E084DAB9 | sudo apt-key add -
    
  2. Update your sources and upgrade your installation:

     sudo apt-get update && sudo apt-get upgrade
    
  3. Install the new version

     sudo apt-get install r-base-dev
    
  4. Recover your old packages following the solution that best suits to you (see this). For instance, to recover all the packages (not only those from CRAN) the idea is:

-- copy the packages from R-oldversion/library to R-newversion/library, (do not overwrite a package if it already exists in the new version!).

-- Run the R command update.packages(checkBuilt=TRUE, ask=FALSE).

Eclipse internal error while initializing Java tooling

Delete your existing workspace and then recreate the workspace and add your projects.

Remove padding from columns in Bootstrap 3

Sometimes you might lose the padding that you want for the columns. They end up sticking to each other. To prevent that, you could update the class as follows:

<div class="col-md-3 NoPaddingForChildren">
        <div class="col-md-6">
                    <label>Id</label>
                    <input ng-model="ID" class="form-control">
        </div>
        <div class="col-md-6">
                    <label>Value</label>
                    <input ng-model="Val" class="form-control">
        </div>
</div>

and corresponding class:

.NoPaddingForChildren > div:not(:first-child):not(:last-child) {
    padding-left: 0;
    padding-right: 0;
}

.NoPaddingForChildren > div:first-child {
    padding-left: 0;
}

.NoPaddingForChildren > div:last-child {    
    padding-right: 0;
}

How to read a specific line using the specific line number from a file in Java?

In Java 8,

For small files:

String line = Files.readAllLines(Paths.get("file.txt")).get(n);

For large files:

String line;
try (Stream<String> lines = Files.lines(Paths.get("file.txt"))) {
    line = lines.skip(n).findFirst().get();
}

In Java 7

String line;
try (BufferedReader br = new BufferedReader(new FileReader("file.txt"))) {
    for (int i = 0; i < n; i++)
        br.readLine();
    line = br.readLine();
}

Source: Reading nth line from file

How to get a file directory path from file path?

Here is a script I used for recursive trimming. Replace $1 with the directory you want, of course.

BASEDIR="$1"
IFS=$'\n'
cd $BASEDIR
 for f in $(find . -type f -name ' *')
 do 
    DIR=$(dirname "$f")
    DIR=${DIR:1}
    cd $BASEDIR$DIR
    rename 's/^ *//' *
 done

Create SQLite Database and table

The next link will bring you to a great tutorial, that helped me a lot!

How to SQLITE in C#

I nearly used everything in that article to create the SQLite database for my own C# Application.

Don't forget to download the SQLite.dll, and add it as a reference to your project. This can be done using NuGet and by adding the dll manually.

After you added the reference, refer to the dll from your code using the following line on top of your class:

using System.Data.SQLite;

You can find the dll's here:

SQLite DLL's

You can find the NuGet way here:

NuGet

Up next is the create script. Creating a database file:

SQLiteConnection.CreateFile("MyDatabase.sqlite");

SQLiteConnection m_dbConnection = new SQLiteConnection("Data Source=MyDatabase.sqlite;Version=3;");
m_dbConnection.Open();

string sql = "create table highscores (name varchar(20), score int)";

SQLiteCommand command = new SQLiteCommand(sql, m_dbConnection);
command.ExecuteNonQuery();

sql = "insert into highscores (name, score) values ('Me', 9001)";

command = new SQLiteCommand(sql, m_dbConnection);
command.ExecuteNonQuery();

m_dbConnection.Close();

After you created a create script in C#, I think you might want to add rollback transactions, it is safer and it will keep your database from failing, because the data will be committed at the end in one big piece as an atomic operation to the database and not in little pieces, where it could fail at 5th of 10 queries for example.

Example on how to use transactions:

 using (TransactionScope tran = new TransactionScope())
 {
     //Insert create script here.

     //Indicates that creating the SQLiteDatabase went succesfully, so the database can be committed.
     tran.Complete();
 }

How to check the maximum number of allowed connections to an Oracle database?

The sessions parameter is derived from the processes parameter and changes accordingly when you change the number of max processes. See the Oracle docs for further info.

To get only the info about the sessions:

    select current_utilization, limit_value 
    from v$resource_limit 
    where resource_name='sessions';
CURRENT_UTILIZATION LIMIT_VALUE
------------------- -----------
                110         792

Try this to show info about both:

    select resource_name, current_utilization, max_utilization, limit_value 
    from v$resource_limit 
    where resource_name in ('sessions', 'processes');
RESOURCE_NAME CURRENT_UTILIZATION MAX_UTILIZATION LIMIT_VALUE
------------- ------------------- --------------- -----------
processes                      96             309         500
sessions                      104             323         792

Failed linking file resources

Look at the error you are getting:

C:\Projects\TimeTable\app\src\main\res\layout-land\activity_main.xml Error:error: resource android:attr/colorSwitchThumbNormal is private.

It means that in your activity_main.xml you are referencing the color "android:colorSwitchThumbNormal", but inside the 'android' namespace that resource is private. What you probably meant to do is try to reference that color from the support version of this attribute, so without the "android:" prefix.

<item name="android:colorSwitchThumbNormal">@color/myColor</item>

Replace with:

<item name="colorSwitchThumbNormal">@color/second</item>

HTML&CSS + Twitter Bootstrap: full page layout or height 100% - Npx

I've found a post here on Stackoverflow and implemented your design:

http://jsfiddle.net/bKsad/25/

Here's the original post: https://stackoverflow.com/a/5768262/1368423

Is that what you're looking for?

HTML:

<div class="container-fluid wrapper">

  <div class="row-fluid columns content"> 

    <div class="span2 article-tree">
      navigation column
    </div>

    <div class="span10 content-area">
      content column 
    </div>
  </div>

  <div class="footer">
     footer content
  </div>
</div>

CSS:

html, body {
    height: 100%;
}
.container-fluid {
    margin: 0 auto;
    height: 100%;
    padding: 20px 0;

    -moz-box-sizing: border-box;
    -webkit-box-sizing: border-box;
    box-sizing: border-box;
}

.columns {
    background-color: #C9E6FF;
    height: 100%;   
}

.content-area, .article-tree{
    background: #bada55;
    overflow:auto;
    height: 100%;
}

.footer {
    background: red;
    height: 20px;
}

variable or field declared void

It for example happens in this case here:

void initializeJSP(unknownType Experiment);

Try using std::string instead of just string (and include the <string> header). C++ Standard library classes are within the namespace std::.