How to detect Esc Key Press in React and how to handle it

For a reusable React hook solution

import React, { useEffect } from 'react';

const useEscape = (onEscape) => {
    useEffect(() => {
        const handleEsc = (event) => {
            if (event.keyCode === 27) 
                onEscape();
        };
        window.addEventListener('keydown', handleEsc);

        return () => {
            window.removeEventListener('keydown', handleEsc);
        };
    }, []);
}

export default useEscape

Usage:

const [isOpen, setIsOpen] = useState(false);
useEscape(() => setIsOpen(false))

"Input string was not in a correct format."

You might be trying to access a control inside a control, maybe a GridView or DetailsView.

Try using something like this:

empsalary = Convert.ToInt32(((TextBox)DetailsView1.Rows[1].Cells[1].Controls[0]).Text);

How to call a method defined in an AngularJS directive?

You can specify a DOM attribute that can be used to allow the directive to define a function on the parent scope. The parent scope can then call this method like any other. Here's a plunker. And below is the relevant code.

clearfn is an attribute on the directive element into which the parent scope can pass a scope property which the directive can then set to a function that accomplish's the desired behavior.

<!DOCTYPE html>
<html ng-app="myapp">
  <head>
    <script data-require="angular.js@*" data-semver="1.3.0-beta.5" src="https://code.angularjs.org/1.3.0-beta.5/angular.js"></script>
    <link rel="stylesheet" href="style.css" />
    <style>
      my-box{
        display:block;
        border:solid 1px #aaa;
        min-width:50px;
        min-height:50px;
        padding:.5em;
        margin:1em;
        outline:0px;
        box-shadow:inset 0px 0px .4em #aaa;
      }
    </style>
  </head>
  <body ng-controller="mycontroller">
    <h1>Call method on directive</h1>
    <button ng-click="clear()">Clear</button>
    <my-box clearfn="clear" contentEditable=true></my-box>
    <script>
      var app = angular.module('myapp', []);
      app.controller('mycontroller', function($scope){
      });
      app.directive('myBox', function(){
        return {
          restrict: 'E',
          scope: {
            clearFn: '=clearfn'
          },
          template: '',
          link: function(scope, element, attrs){
            element.html('Hello World!');
            scope.clearFn = function(){
              element.html('');
            };
          }
        }
      });
    </script>
  </body>
</html>

How to check if a div is visible state or not?

if element is hide by jquery then use

if($("#elmentid").is(':hidden'))

Difference between $(this) and event.target?

this is a reference for the DOM element for which the event is being handled (the current target). event.target refers to the element which initiated the event. They were the same in this case, and can often be, but they aren't necessarily always so.

You can get a good sense of this by reviewing the jQuery event docs, but in summary:

event.currentTarget

The current DOM element within the event bubbling phase.

event.delegateTarget

The element where the currently-called jQuery event handler was attached.

event.relatedTarget

The other DOM element involved in the event, if any.

event.target

The DOM element that initiated the event.

To get the desired functionality using jQuery, you must wrap it in a jQuery object using either: $(this) or $(evt.target).

The .attr() method only works on a jQuery object, not on a DOM element. $(evt.target).attr('href') or simply evt.target.href will give you what you want.

Programmatically select a row in JTable

It is an old post, but I came across this recently

Selecting a specific interval

As @aleroot already mentioned, by using

table.setRowSelectionInterval(index0, index1);

You can specify an interval, which should be selected.

Adding an interval to the existing selection

You can also keep the current selection, and simply add additional rows by using this here

table.getSelectionModel().addSelectionInterval(index0, index1);

This line of code additionally selects the specified interval. It doesn't matter if that interval already is selected, of parts of it are selected.

Uncaught TypeError: Object #<Object> has no method 'movingBoxes'

I just had this same problem with the jquery Responsive Slides plugin (http://responsive-slides.viljamis.com/).

I fixed it by not using the jQuery short version $(".rslides").responsiveSlides(.. but rather the long version: jQuery(".rslides").responsiveSlides(...

So switching $ to jQuery so as not to cause conflict or using the proper jQuery no conflict mode (http://api.jquery.com/jQuery.noConflict/)

HTTP response header content disposition for attachments

Try the Content-Disposition header

Content-Disposition: attachment; filename=<file name.ext>

A default document is not configured for the requested URL, and directory browsing is not enabled on the server

Following applies to IIS 7

The error is trying to tell you that one of two things is not working properly:

There is no default page (e.g., index.html, default.aspx) for your site. This could mean that the Default Document "feature" is entirely disabled, or just misconfigured.
Directory browsing isn't enabled. That is, if you're not serving a default page for your site, maybe you intend to let users navigate the directory contents of your site via http (like a remote "windows explorer").

See the following link for instructions on how to diagnose and fix the above issues.

http://support.microsoft.com/kb/942062/en-us

If neither of these issues is the problem, another thing to check is to make sure that the application pool configured for your website (under IIS Manager, select your website, and click "Basic Settings" on the far right) is configured with the same .Net framework version (in IIS Manager, under "Application Pools") as the targetFramework configured in your web.config, e.g.:

<configuration>
  <system.web>
    <compilation debug="true" targetFramework="4.0" />
    <httpRuntime targetFramework="4.0" />
  </system.web>

I'm not sure why this would generate such a seemingly unrelated error message, but it did for me.

Class is inaccessible due to its protection level

It may also be the case that the library containing the class in question is not properly signed with a strong name.

How can I set size of a button?

This is how I did it.

            JFrame.setDefaultLookAndFeelDecorated(true);
            JDialog.setDefaultLookAndFeelDecorated(true);
            JFrame frame = new JFrame("SAP Multiple Entries");
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            JPanel panel = new JPanel(new GridLayout(10,10,10,10));
            frame.setLayout(new FlowLayout());
            frame.setSize(512, 512);
            JButton button = new JButton("Select File");
            button.setPreferredSize(new Dimension(256, 256));
            panel.add(button);

            button.addActionListener(new ActionListener() {

                public void actionPerformed(ActionEvent ae) {
                    JFileChooser fileChooser = new JFileChooser();
                    int returnValue = fileChooser.showOpenDialog(null);
                    if (returnValue == JFileChooser.APPROVE_OPTION) {
                        File selectedFile = fileChooser.getSelectedFile();

                        keep = selectedFile.getAbsolutePath();


                       // System.out.println(keep);
                        //out.println(file.flag); 
                       if(file.flag==true) {
                           JOptionPane.showMessageDialog(null, "It is done! \nLocation: " + file.path , "Success Message", JOptionPane.INFORMATION_MESSAGE);
                       }
                       else{
                           JOptionPane.showMessageDialog(null, "failure", "not okay", JOptionPane.INFORMATION_MESSAGE);
                       }
                    }
                }
            });
            frame.add(button);
            frame.pack();
            frame.setVisible(true);

Set focus on TextBox in WPF from view model

An alternative approach based on @Sheridan answer here

 <TextBox Text="{Binding SomeText, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}">
        <TextBox.Style>
            <Style>
                <Style.Triggers>
                    <DataTrigger Binding="{Binding SomeTextIsFocused, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Value="True">
                        <Setter Property="FocusManager.FocusedElement" Value="{Binding RelativeSource={RelativeSource Self}}" />
                    </DataTrigger>
                </Style.Triggers>
            </Style>
        </TextBox.Style>
    </TextBox>

In your view model set up your binding in the usual way and then set the SomeTextIsFocused to true to set the focus on your text box

Winforms TableLayoutPanel adding rows programmatically

Create a table layout panel with two columns in your form and name it tlpFields.

Then, simply add new control to table layout panel (in this case I added 5 labels in column-1 and 5 textboxes in column-2).

tlpFields.RowStyles.Clear();  //first you must clear rowStyles

for (int ii = 0; ii < 5; ii++)
{
    Label l1= new Label();
    TextBox t1 = new TextBox();

    l1.Text = "field : ";

    tlpFields.Controls.Add(l1, 0, ii);  // add label in column0
    tlpFields.Controls.Add(t1, 1, ii);  // add textbox in column1

    tlpFields.RowStyles.Add(new RowStyle(SizeType.Absolute,30)); // 30 is the rows space
}

Finally, run the code.

java.io.IOException: Invalid Keystore format

Maybe maven encoding you KeyStore, you can set filtering=false to fix this problem.

<build>
    ...
    <resources>
        <resource>
            ...
            <!-- set filtering=false to fix -->
            <filtering>false</filtering>
            ...
        </resource>
    </resources>
</build>

Monitoring the Full Disclosure mailinglist

Two generic ways to do the same thing... I'm not aware of any specific open solutions to do this, but it'd be rather trivial to do.

You could write a daily or weekly cron/jenkins job to scrape the previous time period's email from the archive looking for your keyworkds/combinations. Sending a batch digest with what it finds, if anything.

But personally, I'd Setup a specific email account to subscribe to the various security lists you're interested in. Add a simple automated script to parse the new emails for various keywords or combinations of keywords, when it finds a match forward that email on to you/your team. Just be sure to keep the keywords list updated with new products you're using.

You could even do this with a gmail account and custom rules, which is what I currently do, but I have setup an internal inbox in the past with a simple python script to forward emails that were of interest.

Can we use join for two different database tables?

SQL Server allows you to join tables from different databases as long as those databases are on the same server. The join syntax is the same; the only difference is that you must fully specify table names.

Let's suppose you have two databases on the same server - Db1 and Db2. Db1 has a table called Clients with a column ClientId and Db2 has a table called Messages with a column ClientId (let's leave asside why those tables are in different databases).

Now, to perform a join on the above-mentioned tables you will be using this query:

select *
from Db1.dbo.Clients c
join Db2.dbo.Messages m on c.ClientId = m.ClientId

Why can't I initialize non-const static member or static array in class?

It's because there can only be one definition of A::a that all the translation units use.

If you performed static int a = 3; in a class in a header included in all a translation units then you'd get multiple definitions. Therefore, non out-of-line definition of a static is forcibly made a compiler error.

Using static inline or static const remedies this. static inline only concretises the symbol if it is used in the translation unit and ensures the linker only selects and leaves one copy if it's defined in multiple translation units due to it being in a comdat group. const at file scope makes the compiler never emit a symbol because it's always substituted immediately in the code unless extern is used, which is not permitted in a class.

One thing to note is static inline int b; is treated as a definition whereas static const int b or static const A b; are still treated as a declaration and must be defined out-of-line if you don't define it inside the class. Interestingly static constexpr A b; is treated as a definition, whereas static constexpr int b; is an error and must have an initialiser (this is because they now become definitions and like any const/constexpr definition at file scope, they require an initialiser which an int doesn't have but a class type does because it has an implicit = A() when it is a definition -- clang allows this but gcc requires you to explicitly initialise or it is an error. This is not a problem with inline instead). static const A b = A(); is not allowed and must be constexpr or inline in order to permit an initialiser for a static object with class type i.e to make a static member of class type more than a declaration. So yes in certain situations A a; is not the same as explicitly initialising A a = A(); (the former can be a declaration but if only a declaration is allowed for that type then the latter is an error. The latter can only be used on a definition. constexpr makes it a definition). If you use constexpr and specify a default constructor then the constructor will need to be constexpr

#include<iostream>

struct A
{
    int b =2;
    mutable int c = 3; //if this member is included in the class then const A will have a full .data symbol emitted for it on -O0 and so will B because it contains A.
    static const int a = 3;
};

struct B {
    A b;
    static constexpr A c; //needs to be constexpr or inline and doesn't emit a symbol for A a mutable member on any optimisation level
};

const A a;
const B b;

int main()
{
    std::cout << a.b << b.b.b;
    return 0;
}

A static member is an outright file scope declaration extern int A::a; (which can only be made in the class and out of line definitions must refer to a static member in a class and must be definitions and cannot contain extern) whereas a non-static member is part of the complete type definition of a class and have the same rules as file scope declarations without extern. They are implicitly definitions. So int i[]; int i[5]; is a redefinition whereas static int i[]; int A::i[5]; isn't but unlike 2 externs, the compiler will still detect a duplicate member if you do static int i[]; static int i[5]; in the class.

How to use enums as flags in C++?

Currently there is no language support for enum flags, Meta classes might inherently add this feature if it would ever be part of the c++ standard.

My solution would be to create enum-only instantiated template functions adding support for type-safe bitwise operations for enum class using its underlying type:

File: EnumClassBitwise.h

#pragma once
#ifndef _ENUM_CLASS_BITWISE_H_
#define _ENUM_CLASS_BITWISE_H_

#include <type_traits>

//unary ~operator    
template <typename Enum, typename std::enable_if_t<std::is_enum<Enum>::value, int> = 0>
constexpr inline Enum& operator~ (Enum& val)
{
    val = static_cast<Enum>(~static_cast<std::underlying_type_t<Enum>>(val));
    return val;
}

// & operator
template <typename Enum, typename std::enable_if_t<std::is_enum<Enum>::value, int> = 0>
constexpr inline Enum operator& (Enum lhs, Enum rhs)
{
    return static_cast<Enum>(static_cast<std::underlying_type_t<Enum>>(lhs) & static_cast<std::underlying_type_t<Enum>>(rhs));
}

// &= operator
template <typename Enum, typename std::enable_if_t<std::is_enum<Enum>::value, int> = 0>
constexpr inline Enum operator&= (Enum& lhs, Enum rhs)
{
    lhs = static_cast<Enum>(static_cast<std::underlying_type_t<Enum>>(lhs) & static_cast<std::underlying_type_t<Enum>>(rhs));
    return lhs;
}

//| operator

template <typename Enum, typename std::enable_if_t<std::is_enum<Enum>::value, int> = 0>
constexpr inline Enum operator| (Enum lhs, Enum rhs)
{
    return static_cast<Enum>(static_cast<std::underlying_type_t<Enum>>(lhs) | static_cast<std::underlying_type_t<Enum>>(rhs));
}
//|= operator

template <typename Enum, typename std::enable_if_t<std::is_enum<Enum>::value, int> = 0>
constexpr inline Enum& operator|= (Enum& lhs, Enum rhs)
{
    lhs = static_cast<Enum>(static_cast<std::underlying_type_t<Enum>>(lhs) | static_cast<std::underlying_type_t<Enum>>(rhs));
    return lhs;
}

#endif // _ENUM_CLASS_BITWISE_H_

For convenience and for reducing mistakes, you might want to wrap your bit flags operations for enums and for integers as well:

File: BitFlags.h

#pragma once
#ifndef _BIT_FLAGS_H_
#define _BIT_FLAGS_H_

#include "EnumClassBitwise.h"

 template<typename T>
 class BitFlags
 {
 public:

     constexpr inline BitFlags() = default;
     constexpr inline BitFlags(T value) { mValue = value; }
     constexpr inline BitFlags operator| (T rhs) const { return mValue | rhs; }
     constexpr inline BitFlags operator& (T rhs) const { return mValue & rhs; }
     constexpr inline BitFlags operator~ () const { return ~mValue; }
     constexpr inline operator T() const { return mValue; }
     constexpr inline BitFlags& operator|=(T rhs) { mValue |= rhs; return *this; }
     constexpr inline BitFlags& operator&=(T rhs) { mValue &= rhs; return *this; }
     constexpr inline bool test(T rhs) const { return (mValue & rhs) == rhs; }
     constexpr inline void set(T rhs) { mValue |= rhs; }
     constexpr inline void clear(T rhs) { mValue &= ~rhs; }

 private:
     T mValue;
 };
#endif //#define _BIT_FLAGS_H_

Possible usage:

#include <cstdint>
#include <BitFlags.h>
void main()
{
    enum class Options : uint32_t
    { 
          NoOption = 0 << 0
        , Option1  = 1 << 0
        , Option2  = 1 << 1
        , Option3  = 1 << 2
        , Option4  = 1 << 3
    };

    const uint32_t Option1 = 1 << 0;
    const uint32_t Option2 = 1 << 1;
    const uint32_t Option3 = 1 << 2;
    const uint32_t Option4 = 1 << 3;

   //Enum BitFlags
    BitFlags<Options> optionsEnum(Options::NoOption);
    optionsEnum.set(Options::Option1 | Options::Option3);

   //Standard integer BitFlags
    BitFlags<uint32_t> optionsUint32(0);
    optionsUint32.set(Option1 | Option3); 

    return 0;
}

Python multiprocessing PicklingError: Can't pickle <type 'function'>

When this problem comes up with multiprocessing a simple solution is to switch from Pool to ThreadPool. This can be done with no change of code other than the import-

from multiprocessing.pool import ThreadPool as Pool

This works because ThreadPool shares memory with the main thread, rather than creating a new process- this means that pickling is not required.

The downside to this method is that python isn't the greatest language with handling threads- it uses something called the Global Interpreter Lock to stay thread safe, which can slow down some use cases here. However, if you're primarily interacting with other systems (running HTTP commands, talking with a database, writing to filesystems) then your code is likely not bound by CPU and won't take much of a hit. In fact I've found when writing HTTP/HTTPS benchmarks that the threaded model used here has less overhead and delays, as the overhead from creating new processes is much higher than the overhead for creating new threads.

So if you're processing a ton of stuff in python userspace this might not be the best method.

Colouring plot by factor in R

There are two ways that I know of to color plot points by factor and then also have a corresponding legend automatically generated. I'll give examples of both:

Using ggplot2 (generally easier)
Using R's built in plotting functionality in combination with the colorRampPallete function (trickier, but many people prefer/need R's built-in plotting facilities)

For both examples, I will use the ggplot2 diamonds dataset. We'll be using the numeric columns diamond$carat and diamond$price, and the factor/categorical column diamond$color. You can load the dataset with the following code if you have ggplot2 installed:

library(ggplot2)
data(diamonds)

Using ggplot2 and qplot

It's a one liner. Key item here is to give qplot the factor you want to color by as the color argument. qplot will make a legend for you by default.

qplot(
  x = carat,
  y = price,
  data = diamonds,
  color = diamonds$color # color by factor color (I know, confusing)
)

Your output should look like this:

Using R's built in plot functionality

Using R's built in plot functionality to get a plot colored by a factor and an associated legend is a 4-step process, and it's a little more technical than using ggplot2.

First, we will make a colorRampPallete function. colorRampPallete() returns a new function that will generate a list of colors. In the snippet below, calling color_pallet_function(5) would return a list of 5 colors on a scale from red to orange to blue:

color_pallete_function <- colorRampPalette(
  colors = c("red", "orange", "blue"),
  space = "Lab" # Option used when colors do not represent a quantitative scale
  )

Second, we need to make a list of colors, with exactly one color per diamond color. This is the mapping we will use both to assign colors to individual plot points, and to create our legend.

num_colors <- nlevels(diamonds$color)
diamond_color_colors <- color_pallet_function(num_colors)

Third, we create our plot. This is done just like any other plot you've likely done, except we refer to the list of colors we made as our col argument. As long as we always use this same list, our mapping between colors and diamond$colors will be consistent across our R script.

plot(
  x = diamonds$carat,
  y = diamonds$price,
  xlab = "Carat",
  ylab = "Price",
  pch = 20, # solid dots increase the readability of this data plot
  col = diamond_color_colors[diamonds$color]
)

Fourth and finally, we add our legend so that someone reading our graph can clearly see the mapping between the plot point colors and the actual diamond colors.

legend(
  x ="topleft",
  legend = paste("Color", levels(diamonds$color)), # for readability of legend
  col = diamond_color_colors,
  pch = 19, # same as pch=20, just smaller
  cex = .7 # scale the legend to look attractively sized
)

Your output should look like this:

Nifty, right?

How can I make the cursor turn to the wait cursor?

Actually,

Cursor.Current = Cursors.WaitCursor;

temporarily sets the Wait cursor, but doesn’t ensure that the Wait cursor shows until the end of your operation. Other programs or controls within your program can easily reset the cursor back to the default arrow as in fact happens when you move mouse while operation is still running.

A much better way to show the Wait cursor is to set the UseWaitCursor property in a form to true:

form.UseWaitCursor = true;

This will display wait cursor for all controls on the form until you set this property to false. If you want wait cursor to be shown on Application level you should use:

Application.UseWaitCursor = true;

Oracle 11g SQL to get unique values in one column of a multi-column query

For efficiency's sake you want to only hit the data once, as Harper does. However you don't want to use rank() because it will give you ties and further you want to group by language rather than order by language. From there you want add an order by clause to distinguish between rows, but you don't want to actually sort the data. To achieve this I would use "order by null" E.g.

count(*) over (group by language order by null)

How to read numbers from file in Python?

Assuming you don't have extraneous whitespace:

with open('file') as f:
    w, h = [int(x) for x in next(f).split()] # read first line
    array = []
    for line in f: # read rest of lines
        array.append([int(x) for x in line.split()])

You could condense the last for loop into a nested list comprehension:

with open('file') as f:
    w, h = [int(x) for x in next(f).split()]
    array = [[int(x) for x in line.split()] for line in f]

How does strcmp() work?

I found this on web.

http://www.opensource.apple.com/source/Libc/Libc-262/ppc/gen/strcmp.c

int strcmp(const char *s1, const char *s2)
{
    for ( ; *s1 == *s2; s1++, s2++)
        if (*s1 == '\0')
            return 0;
    return ((*(unsigned char *)s1 < *(unsigned char *)s2) ? -1 : +1);
}

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

Up above, you mention having compiling your as part of your steps to reproduce, but then below you made an edit saying,

"is there a way to see on which distro a shared library was compiled on?"

Whether or not you compiled this on the same distro, and even a different version of the same distro is an important detail, especially for c++ applications.

Linking to c++ libraries, including libstdc++ can have mixed results, as far as I can tell. Here is a related question about recompiling with different versions of c++.

do we need to recompile libraries with c++11?

Basically, if you compiled against c++ on a different distro (and possibly different gcc version), this may be causing your trouble.

I think you have two options:

Your best bet - recompile your .so if you hadn't compiled it on your current system. If there is a problem with your runtime's system environment, it might even come out in the compile.
Bundle your other compiler's c++ libs along with your application. This may only be viable if it's the same distribution... But it's a useful trick if you rolled your own compiler. You will also have to set and export the LD_LIBRARY_PATH to the path containing your bundled stdc++ libs if you go that route.

How to load images dynamically (or lazily) when users scrolls them into view

Im using jQuery Lazy. It took me about 10 minutes to test out and an hour or two to add to most of the image links on one of my websites (CollegeCarePackages.com). I have NO (none/zero) relationship of any kind to the dev, but it saved me a lot of time and basically helped improve our bounce rate for mobile users and I appreciate it.

Make TextBox uneditable

Using the TextBox.ReadOnly property

TextBox.ReadOnly = true;

For a Non-Grey background you can change the TextBox.BackColor property to SystemColors.Window Color

textBox.BackColor = System.Drawing.SystemColors.Window;

When this property is set to true, the contents of the control cannot be changed by the user at runtime. With this property set to true, you can still set the value of the Text property in code. You can use this feature instead of disabling the control with the Enabled property to allow the contents to be copied and ToolTips to be shown.

Moment.js - two dates difference in number of days

From the moment.js docs: format('E') stands for day of week. thus your diff is being computed on which day of the week, which has to be between 1 and 7.

From the moment.js docs again, here is what they suggest:

var a = moment([2007, 0, 29]);
var b = moment([2007, 0, 28]);
a.diff(b, 'days') // 1

Here is a JSFiddle for your particular case:

_x000D_

$('#test').click(function() {_x000D_
  var startDate = moment("13.04.2016", "DD.MM.YYYY");_x000D_
  var endDate = moment("28.04.2016", "DD.MM.YYYY");_x000D_
_x000D_
  var result = 'Diff: ' + endDate.diff(startDate, 'days');_x000D_
_x000D_
  $('#result').html(result);_x000D_
});

_x000D_

#test {_x000D_
  width: 100px;_x000D_
  height: 100px;_x000D_
  background: #ffb;_x000D_
  padding: 10px;_x000D_
  border: 2px solid #999;_x000D_
}

_x000D_

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.12.0/moment.js"></script>_x000D_
_x000D_
<div id='test'>Click Me!!!</div>_x000D_
<div id='result'></div>

_x000D_

Create a custom event in Java

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

Can I access variables from another file?

As Fermin said, a variable in the global scope should be accessible to all scripts loaded after it is declared. You could also use a property of window or (in the global scope) this to get the same effect.

// first.js
var colorCodes = {

  back  : "#fff",
  front : "#888",
  side  : "#369"

};

... in another file ...

// second.js
alert (colorCodes.back); // alerts `#fff`

... in your html file ...

<script type="text/javascript" src="first.js"></script> 
<script type="text/javascript" src="second.js"></script>

How do I initialize an empty array in C#?

You could inititialize it with a size of 0, but you will have to reinitialize it, when you know what the size is, as you cannot append to the array.

string[] a = new string[0];

how to parse xml to java object?

For performing Unmarshall using JAXB:

1) Convert given XML to XSD(by yourself or by online convertor),

2) Create a JAXB project in eclipse,

3) Create XSD file and paste that converted XSD content in it,

4) Right click on **XSD file--> Generate--> JAXB Classes-->follow the instructions(this will create all nessasary .java files in src, i.e., one package-info, object factory and pojo class),

5) Create another .java file in src to operate unmarshall operation, and run it.

Happy Coding !!

Python requests - print entire http request (raw)?

I use the following function to format requests. It's like @AntonioHerraizS except it will pretty-print JSON objects in the body as well, and it labels all parts of the request.

format_json = functools.partial(json.dumps, indent=2, sort_keys=True)
indent = functools.partial(textwrap.indent, prefix='  ')

def format_prepared_request(req):
    """Pretty-format 'requests.PreparedRequest'

    Example:
        res = requests.post(...)
        print(format_prepared_request(res.request))

        req = requests.Request(...)
        req = req.prepare()
        print(format_prepared_request(res.request))
    """
    headers = '\n'.join(f'{k}: {v}' for k, v in req.headers.items())
    content_type = req.headers.get('Content-Type', '')
    if 'application/json' in content_type:
        try:
            body = format_json(json.loads(req.body))
        except json.JSONDecodeError:
            body = req.body
    else:
        body = req.body
    s = textwrap.dedent("""
    REQUEST
    =======
    endpoint: {method} {url}
    headers:
    {headers}
    body:
    {body}
    =======
    """).strip()
    s = s.format(
        method=req.method,
        url=req.url,
        headers=indent(headers),
        body=indent(body),
    )
    return s

And I have a similar function to format the response:

def format_response(resp):
    """Pretty-format 'requests.Response'"""
    headers = '\n'.join(f'{k}: {v}' for k, v in resp.headers.items())
    content_type = resp.headers.get('Content-Type', '')
    if 'application/json' in content_type:
        try:
            body = format_json(resp.json())
        except json.JSONDecodeError:
            body = resp.text
    else:
        body = resp.text
    s = textwrap.dedent("""
    RESPONSE
    ========
    status_code: {status_code}
    headers:
    {headers}
    body:
    {body}
    ========
    """).strip()

    s = s.format(
        status_code=resp.status_code,
        headers=indent(headers),
        body=indent(body),
    )
    return s

SQL Server - Return value after INSERT

There are many ways to exit after insert

When you insert data into a table, you can use the OUTPUT clause to return a copy of the data that’s been inserted into the table. The OUTPUT clause takes two basic forms: OUTPUT and OUTPUT INTO. Use the OUTPUT form if you want to return the data to the calling application. Use the OUTPUT INTO form if you want to return the data to a table or a table variable.

DECLARE @MyTableVar TABLE (id INT,NAME NVARCHAR(50));

INSERT INTO tableName
(
  NAME,....
)OUTPUT INSERTED.id,INSERTED.Name INTO @MyTableVar
VALUES
(
   'test',...
)

IDENT_CURRENT: It returns the last identity created for a particular table or view in any session.

SELECT IDENT_CURRENT('tableName') AS [IDENT_CURRENT]

SCOPE_IDENTITY: It returns the last identity from a same session and the same scope. A scope is a stored procedure/trigger etc.

SELECT SCOPE_IDENTITY() AS [SCOPE_IDENTITY];

@@IDENTITY: It returns the last identity from the same session.

SELECT @@IDENTITY AS [@@IDENTITY];

How to insert text into the textarea at the current cursor position?

For the sake of proper Javascript

HTMLTextAreaElement.prototype.insertAtCaret = function (text) {
  text = text || '';
  if (document.selection) {
    // IE
    this.focus();
    var sel = document.selection.createRange();
    sel.text = text;
  } else if (this.selectionStart || this.selectionStart === 0) {
    // Others
    var startPos = this.selectionStart;
    var endPos = this.selectionEnd;
    this.value = this.value.substring(0, startPos) +
      text +
      this.value.substring(endPos, this.value.length);
    this.selectionStart = startPos + text.length;
    this.selectionEnd = startPos + text.length;
  } else {
    this.value += text;
  }
};

How to create a sticky left sidebar menu using bootstrap 3?

You can also try to use a Polyfill like Fixed-Sticky. Especially when you are using Bootstrap4 the affix component is no longer included:

Dropped the Affix jQuery plugin. We recommend using a position: sticky polyfill instead.

SQL command to display history of queries

You can see the history from ~/.mysql_history. However the content of the file is encoded by wctomb. To view the content:

shell> cat ~/.mysql_history | python2.7 -c "import sys; print(''.join([l.decode('unicode-escape') for l in sys.stdin]))"

Source:Check MySQL query history from command line

Html.ActionLink as a button or an image, not a link

<button onclick="location.href='@Url.Action("NewCustomer", "Customers")'">Checkout >></button>

How to declare empty list and then add string in scala?

Maybe you can use ListBuffers in scala to create empty list and add strings later because ListBuffers are mutable. Also all the List functions are available for the ListBuffers in scala.

import scala.collection.mutable.ListBuffer 

val dm = ListBuffer[String]()
dm: scala.collection.mutable.ListBuffer[String] = ListBuffer()
dm += "text1"
dm += "text2"
dm = ListBuffer(text1, text2)

if you want you can convert this to a list by using .toList

Passing Variable through JavaScript from one html page to another page

Without reading your code but just your scenario, I would solve by using localStorage. Here's an example, I'll use prompt() for short.

On page1:

window.onload = function() {
   var getInput = prompt("Hey type something here: ");
   localStorage.setItem("storageName",getInput);
}

On page2:

window.onload = alert(localStorage.getItem("storageName"));

You can also use cookies but localStorage allows much more spaces, and they aren't sent back to servers when you request pages.

Best implementation for Key Value Pair Data Structure?

There is a KeyValuePair built-in type. As a matter of fact, this is what the IDictionary is giving you access to when you iterate in it.

Also, this structure is hardly a tree, finding a more representative name might be a good exercise.

How to convert a column number (e.g. 127) into an Excel column (e.g. AA)

Microsoft Excel Miniature, Quick-and-Dirty formula.

Hi,

Here's one way to get the Excel character-column-header from a number....

I created a formula for an Excel cell.

(i.e. I took the approach of not using VBA programming.)

The formula looks at a cell that has a number in it and tells you what the column is -- in letters.

In the attached image:

I put 1,2,3 etc in the top row all the way out to column ABS.
I pasted my formula in the second row all the way out to ABS.
My formula looks at row 1 and converts the number to Excel's column header id.
My formula works for all numbers out to 702 (zz).
I did it in this manner to prove that the formula works so you can look at the output from the formula and look at the column header above and easily visually verify that the formula works. :-)

=CONCATENATE(MID("_abcdefghijklmnopqrstuvwxyz",(IF(MOD(K1,26)>0,INT(K1/26)+1,(INT(K1/26)))),1),MID("abcdefghijklmnopqrstuvwxyz",IF(MOD(K1,26)=0,26,MOD(K1,26)),1))

The underscore was there for debugging purposes - to let you know there was an actual space and that it was working correctly.

With this formula above -- whatever you put in K1 - the formula will tell you what the column header will be.

The formula, in its current form, only goes out to 2 digits (ZZ) but could be modified to add the 3rd letter (ZZZ).

Android: How can I print a variable on eclipse console?

Window->Show View->Other…->Android->LogCat

Convert month name to month number in SQL Server

How about this:

SELECT MONTH('March' + ' 1 2014')

Would return 3.

How to implement a lock in JavaScript

Why don't you disable the button and enable it after you finish the event?

<input type="button" id="xx" onclick="checkEnableSubmit('true');yourFunction();">

<script type="text/javascript">

function checkEnableSubmit(status) {  
  document.getElementById("xx").disabled = status;
}

function yourFunction(){

//add your functionality

checkEnableSubmit('false');
}

</script>

Happy coding !!!

scp or sftp copy multiple files with single command

NOTE: I apologize in advance for answering only a portion of the above question. However, I found these commands to be useful for my current unix needs.

Uploading specific files from a local machine to a remote machine:

~/Desktop/dump_files$ scp file1.txt file2.txt lab1.cpp etc.ext [email protected]:Folder1/DestinationFolderForFiles/

Uploading an entire directory from a local machine to a remote machine:

~$ scp -r Desktop/dump_files [email protected]:Folder1/DestinationFolderForFiles/

Downloading an entire directory from a remote machine to a local machine:

~/Desktop$ scp -r [email protected]:Public/web/ Desktop/

Center a popup window on screen?

Facebook use the following algorithm to position their login popup window:

function PopupCenter(url, title, w, h) {
  var userAgent = navigator.userAgent,
      mobile = function() {
        return /\b(iPhone|iP[ao]d)/.test(userAgent) ||
          /\b(iP[ao]d)/.test(userAgent) ||
          /Android/i.test(userAgent) ||
          /Mobile/i.test(userAgent);
      },
      screenX = typeof window.screenX != 'undefined' ? window.screenX : window.screenLeft,
      screenY = typeof window.screenY != 'undefined' ? window.screenY : window.screenTop,
      outerWidth = typeof window.outerWidth != 'undefined' ? window.outerWidth : document.documentElement.clientWidth,
      outerHeight = typeof window.outerHeight != 'undefined' ? window.outerHeight : document.documentElement.clientHeight - 22,
      targetWidth = mobile() ? null : w,
      targetHeight = mobile() ? null : h,
      V = screenX < 0 ? window.screen.width + screenX : screenX,
      left = parseInt(V + (outerWidth - targetWidth) / 2, 10),
      right = parseInt(screenY + (outerHeight - targetHeight) / 2.5, 10),
      features = [];
  if (targetWidth !== null) {
    features.push('width=' + targetWidth);
  }
  if (targetHeight !== null) {
    features.push('height=' + targetHeight);
  }
  features.push('left=' + left);
  features.push('top=' + right);
  features.push('scrollbars=1');

  var newWindow = window.open(url, title, features.join(','));

  if (window.focus) {
    newWindow.focus();
  }

  return newWindow;
}

Android Respond To URL in Intent

I did it! Using <intent-filter>. Put the following into your manifest file:

<intent-filter>
  <action android:name="android.intent.action.VIEW" />
  <category android:name="android.intent.category.DEFAULT" />
  <category android:name="android.intent.category.BROWSABLE" />
  <data android:host="www.youtube.com" android:scheme="http" />
</intent-filter>

This works perfectly!

How do I make flex box work in safari?

Just try -webkit-flexbox. it's working for safari. webkit-flex safari will not taking.

jQuery - Add active class and remove active from other element on click

$(document).ready(function() {
    $(".tab").click(function () {
        if(!$(this).hasClass('active'))
        {
            $(".tab.active").removeClass("active");
            $(this).addClass("active");        
        }
    });
});

How to format current time using a yyyyMMddHHmmss format?

Time package in Golang has some methods that might be worth looking.

func (Time) Format

func (t Time) Format(layout string) string Format returns a textual representation of the time value formatted according to layout, which defines the format by showing how the reference time,

Mon Jan 2 15:04:05 -0700 MST 2006 would be displayed if it were the value; it serves as an example of the desired output. The same display rules will then be applied to the time value. Predefined layouts ANSIC, UnixDate, RFC3339 and others describe standard and convenient representations of the reference time. For more information about the formats and the definition of the reference time, see the documentation for ANSIC and the other constants defined by this package.

Source (http://golang.org/pkg/time/#Time.Format)

I also found an example of defining the layout (http://golang.org/src/pkg/time/example_test.go)

func ExampleTime_Format() {
        // layout shows by example how the reference time should be represented.
        const layout = "Jan 2, 2006 at 3:04pm (MST)"
        t := time.Date(2009, time.November, 10, 15, 0, 0, 0, time.Local)
        fmt.Println(t.Format(layout))
        fmt.Println(t.UTC().Format(layout))
        // Output:
    // Nov 10, 2009 at 3:00pm (PST)
        // Nov 10, 2009 at 11:00pm (UTC)
    }

Subset of rows containing NA (missing) values in a chosen column of a data frame

NA is a special value in R, do not mix up the NA value with the "NA" string. Depending on the way the data was imported, your "NA" and "NULL" cells may be of various type (the default behavior is to convert "NA" strings to NA values, and let "NULL" strings as is).

If using read.table() or read.csv(), you should consider the "na.strings" argument to do clean data import, and always work with real R NA values.

An example, working in both cases "NULL" and "NA" cells :

DF <- read.csv("file.csv", na.strings=c("NA", "NULL"))
new_DF <- subset(DF, is.na(DF$Var2))

Practical uses for AtomicInteger

There are two main uses of AtomicInteger:

As an atomic counter (incrementAndGet(), etc) that can be used by many threads concurrently

As a primitive that supports compare-and-swap instruction (compareAndSet()) to implement non-blocking algorithms.

Here is an example of non-blocking random number generator from Brian Göetz's Java Concurrency In Practice:

public class AtomicPseudoRandom extends PseudoRandom {
    private AtomicInteger seed;
    AtomicPseudoRandom(int seed) {
        this.seed = new AtomicInteger(seed);
    }

    public int nextInt(int n) {
        while (true) {
            int s = seed.get();
            int nextSeed = calculateNext(s);
            if (seed.compareAndSet(s, nextSeed)) {
                int remainder = s % n;
                return remainder > 0 ? remainder : remainder + n;
            }
        }
    }
    ...
}

As you can see, it basically works almost the same way as incrementAndGet(), but performs arbitrary calculation (calculateNext()) instead of increment (and processes the result before return).

how to count length of the JSON array element

First if the object you're dealing with is a string then you need to parse it then figure out the length of the keys :

obj = JSON.parse(jsonString);
shareInfoLen = Object.keys(obj.shareInfo[0]).length;

How to get values from selected row in DataGrid for Windows Form Application?

Description

Assuming i understand your question.

You can get the selected row using the DataGridView.SelectedRows Collection. If your DataGridView allows only one selected, have a look at my sample.

DataGridView.SelectedRows Gets the collection of rows selected by the user.

Sample

if (dataGridView1.SelectedRows.Count != 0)
{
    DataGridViewRow row = this.dataGridView1.SelectedRows[0];
    row.Cells["ColumnName"].Value
}

More Information

MSDN - DataGridView.SelectedRows Property

HTML input fields does not get focus when clicked

I had the same problem. Tore my hair for hours trying all sorts of solutions. Turned out to be an unclosed a tag.Try validate your HTML code, solution could be an unclosed tag causing issues

Oracle SELECT TOP 10 records

you may use this query for selecting top records in oracle. Rakesh B

select * from User_info where id >= (select max(id)-10 from User_info);

How to split large text file in windows?

Below code split file every 500

@echo off
setlocal ENABLEDELAYEDEXPANSION
REM Edit this value to change the name of the file that needs splitting. Include the extension.
SET BFN=upload.txt
REM Edit this value to change the number of lines per file.
SET LPF=15000
REM Edit this value to change the name of each short file. It will be followed by a number indicating where it is in the list.
SET SFN=SplitFile

REM Do not change beyond this line.

SET SFX=%BFN:~-3%

SET /A LineNum=0
SET /A FileNum=1

For /F "delims==" %%l in (%BFN%) Do (
SET /A LineNum+=1

echo %%l >> %SFN%!FileNum!.%SFX%

if !LineNum! EQU !LPF! (
SET /A LineNum=0
SET /A FileNum+=1
)

)
endlocal
Pause

See below: https://forums.techguy.org/threads/solved-split-a-100000-line-csv-into-5000-line-csv-files-with-dos-batch.1023949/

Detect the Internet connection is offline?

I was looking for a client-side solution to detect if the internet was down or my server was down. The other solutions I found always seemed to be dependent on a 3rd party script file or image, which to me didn't seem like it would stand the test of time. An external hosted script or image could change in the future and cause the detection code to fail.

I've found a way to detect it by looking for an xhrStatus with a 404 code. In addition, I use JSONP to bypass the CORS restriction. A status code other than 404 shows the internet connection isn't working.

$.ajax({
    url:      'https://www.bing.com/aJyfYidjSlA' + new Date().getTime() + '.html',
    dataType: 'jsonp',
    timeout:  5000,

    error: function(xhr) {
        if (xhr.status == 404) {
            //internet connection working
        }
        else {
            //internet is down (xhr.status == 0)
        }
    }
});

Reset CSS display property to default value

According to my understanding to your question, as an example: you had a style at the beginning in style sheet (ex. background-color: red), then using java script you changed it to another style (ex. background-color: green), now you want to reset the style to its original value in style sheet (background-color: red) without mentioning or even knowing its value (ex. element.style.backgroundColor = 'red')...!

If I'm correct, I have a good solution for you which is using another class name for the element:

steps:

set the default styles in style sheet as usual according to your desire.
define a new class name in style sheet and add the new style you want.
when you want to trigger between styles, add the new class name to the element or remove it.

if you want to edit or set a new style, get the element by the new class name and edit the style as desired.

I hope this helps. Regards!

Android Facebook style slide

Recently I have worked on my sliding menu implementation version. It uses popular J.Feinstein Android library SlidingMenu.

Please check the source code at GitHub:

https://github.com/baruckis/Android-SlidingMenuImplementation

Download app directly to the device to try:

https://play.google.com/store/apps/details?id=com.baruckis.SlidingMenuImplementation

Code should be self-explanatory because of comments. I hope it will be helpful! ;)

How to redirect to a 404 in Rails?

these will help you...

Application Controller

class ApplicationController < ActionController::Base
  protect_from_forgery
  unless Rails.application.config.consider_all_requests_local             
    rescue_from ActionController::RoutingError, ActionController::UnknownController, ::AbstractController::ActionNotFound, ActiveRecord::RecordNotFound, with: lambda { |exception| render_error 404, exception }
  end

  private
    def render_error(status, exception)
      Rails.logger.error status.to_s + " " + exception.message.to_s
      Rails.logger.error exception.backtrace.join("\n") 
      respond_to do |format|
        format.html { render template: "errors/error_#{status}",status: status }
        format.all { render nothing: true, status: status }
      end
    end
end

Errors controller

class ErrorsController < ApplicationController
  def error_404
    @not_found_path = params[:not_found]
  end
end

views/errors/error_404.html.haml

.site
  .services-page 
    .error-template
      %h1
        Oops!
      %h2
        404 Not Found
      .error-details
        Sorry, an error has occured, Requested page not found!
        You tried to access '#{@not_found_path}', which is not a valid page.
      .error-actions
        %a.button_simple_orange.btn.btn-primary.btn-lg{href: root_path}
          %span.glyphicon.glyphicon-home
          Take Me Home

How to center a button within a div?

Responsive way to center your button in a div:

<div 
    style="display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 2rem;">
    <button type="button" style="height: 10%; width: 20%;">hello</button>
</div>

How to change the output color of echo in Linux

My favourite answer so far is coloredEcho.

Just to post another option, you can check out this little tool xcol

https://ownyourbits.com/2017/01/23/colorize-your-stdout-with-xcol/

you use it just like grep, and it will colorize its stdin with a different color for each argument, for instance

sudo netstat -putan | xcol httpd sshd dnsmasq pulseaudio conky tor Telegram firefox "[[:digit:]]+\.[[:digit:]]+\.[[:digit:]]+\.[[:digit:]]+" ":[[:digit:]]+" "tcp." "udp." LISTEN ESTABLISHED TIME_WAIT

Note that it accepts any regular expression that sed will accept.

This tool uses the following definitions

#normal=$(tput sgr0)                      # normal text
normal=$'\e[0m'                           # (works better sometimes)
bold=$(tput bold)                         # make colors bold/bright
red="$bold$(tput setaf 1)"                # bright red text
green=$(tput setaf 2)                     # dim green text
fawn=$(tput setaf 3); beige="$fawn"       # dark yellow text
yellow="$bold$fawn"                       # bright yellow text
darkblue=$(tput setaf 4)                  # dim blue text
blue="$bold$darkblue"                     # bright blue text
purple=$(tput setaf 5); magenta="$purple" # magenta text
pink="$bold$purple"                       # bright magenta text
darkcyan=$(tput setaf 6)                  # dim cyan text
cyan="$bold$darkcyan"                     # bright cyan text
gray=$(tput setaf 7)                      # dim white text
darkgray="$bold"$(tput setaf 0)           # bold black = dark gray text
white="$bold$gray"                        # bright white text

I use these variables in my scripts like so

echo "${red}hello ${yellow}this is ${green}coloured${normal}"

Server returned HTTP response code: 401 for URL: https

401 means "Unauthorized", so there must be something with your credentials.

I think that java URL does not support the syntax you are showing. You could use an Authenticator instead.

Authenticator.setDefault(new Authenticator() {

    @Override
    protected PasswordAuthentication getPasswordAuthentication() {          
        return new PasswordAuthentication(login, password.toCharArray());
    }
});

and then simply invoking the regular url, without the credentials.

The other option is to provide the credentials in a Header:

String loginPassword = login+ ":" + password;
String encoded = new sun.misc.BASE64Encoder().encode (loginPassword.getBytes());
URLConnection conn = url.openConnection();
conn.setRequestProperty ("Authorization", "Basic " + encoded);

PS: It is not recommended to use that Base64Encoder but this is only to show a quick solution. If you want to keep that solution, look for a library that does. There are plenty.

Fatal error: Class 'ZipArchive' not found in

PHP 5.2.0 and later

Linux systems

In order to use these functions you must compile PHP with zip support by using the --enable-zip configure option.

Windows

Windows users need to enable php_zip.dll inside of php.ini in order to use these functions.

Delete dynamically-generated table row using jQuery

A simple solution is encapsulate code of button event in a function, and call it when you add TRs too:

 var i = 1;
$("#addbutton").click(function() {
  $("table tr:first").clone().find("input").each(function() {
    $(this).val('').attr({
      'id': function(_, id) {return id + i },
      'name': function(_, name) { return name + i },
      'value': ''               
    });
  }).end().appendTo("table");
  i++;

  applyRemoveEvent();  
});


function applyRemoveEvent(){
    $('button.removebutton').on('click',function() {
        alert("aa");
      $(this).closest( 'tr').remove();
      return false;
    });
};

applyRemoveEvent();

http://jsfiddle.net/Z7fG7/2/

How to remove duplicates from a list?

If the code in your question doesn't work, you probably have not implemented equals(Object) on the Customer class appropriately.

Presumably there is some key (let us call it customerId) that uniquely identifies a customer; e.g.

class Customer {
    private String customerId;
    ...

An appropriate definition of equals(Object) would look like this:

    public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof Customer)) {
            return false;
        }
        Customer other = (Customer) obj;
        return this.customerId.equals(other.customerId);
    }

For completeness, you should also implement hashCode so that two Customer objects that are equal will return the same hash value. A matching hashCode for the above definition of equals would be:

    public int hashCode() {
        return customerId.hashCode();
    }

It is also worth noting that this is not an efficient way to remove duplicates if the list is large. (For a list with N customers, you will need to perform N*(N-1)/2 comparisons in the worst case; i.e. when there are no duplicates.) For a more efficient solution you should use something like a HashSet to do the duplicate checking.

jQuery UI autocomplete with item and id

At last i did it Thanks alot friends, and a special thanks to Mr https://stackoverflow.com/users/87015/salman-a because of his code i was able to solve it properly. finally my code is looking like this as i am using groovy grails i hope this will help somebody there.. Thanks alot

html code looks like this in my gsp page

  <input id="populate-dropdown" name="nameofClient" type="text">
  <input id="wilhaveid" name="idofclient" type="text">

script Function is like this in my gsp page

  <script>
        $( "#populate-dropdown").on('input', function() {
            $.ajax({
                url:'autoCOmp',
                data: {inputField: $("#populate-dropdown").val()},
                success: function(resp){
                    $('#populate-dropdown').autocomplete({
                        source:resp,
                        select: function (event, ui) {
                            $("#populate-dropdown").val(ui.item.label);
                            $("#wilhaveid").val(ui.item.value);
                             return false;
                        }
                    })
                }
            });
        });
    </script>

And my controller code is like this

   def autoCOmp(){
    println(params)
    def c = Client.createCriteria()
    def results = c.list {
        like("nameOfClient", params.inputField+"%")
    }

    def itemList = []
    results.each{
        itemList  << [value:it.id,label:it.nameOfClient]
    }
    println(itemList)
    render itemList as JSON
}

One more thing i have not set id field hidden because at first i was checking that i am getting the exact id , you can keep it hidden just put type=hidden instead of text for second input item in html

Thanks !

Code for best fit straight line of a scatter plot in python

You can use numpy's polyfit. I use the following (you can safely remove the bit about coefficient of determination and error bounds, I just think it looks nice):

#!/usr/bin/python3

import numpy as np
import matplotlib.pyplot as plt
import csv

with open("example.csv", "r") as f:
    data = [row for row in csv.reader(f)]
    xd = [float(row[0]) for row in data]
    yd = [float(row[1]) for row in data]

# sort the data
reorder = sorted(range(len(xd)), key = lambda ii: xd[ii])
xd = [xd[ii] for ii in reorder]
yd = [yd[ii] for ii in reorder]

# make the scatter plot
plt.scatter(xd, yd, s=30, alpha=0.15, marker='o')

# determine best fit line
par = np.polyfit(xd, yd, 1, full=True)

slope=par[0][0]
intercept=par[0][1]
xl = [min(xd), max(xd)]
yl = [slope*xx + intercept  for xx in xl]

# coefficient of determination, plot text
variance = np.var(yd)
residuals = np.var([(slope*xx + intercept - yy)  for xx,yy in zip(xd,yd)])
Rsqr = np.round(1-residuals/variance, decimals=2)
plt.text(.9*max(xd)+.1*min(xd),.9*max(yd)+.1*min(yd),'$R^2 = %0.2f$'% Rsqr, fontsize=30)

plt.xlabel("X Description")
plt.ylabel("Y Description")

# error bounds
yerr = [abs(slope*xx + intercept - yy)  for xx,yy in zip(xd,yd)]
par = np.polyfit(xd, yerr, 2, full=True)

yerrUpper = [(xx*slope+intercept)+(par[0][0]*xx**2 + par[0][1]*xx + par[0][2]) for xx,yy in zip(xd,yd)]
yerrLower = [(xx*slope+intercept)-(par[0][0]*xx**2 + par[0][1]*xx + par[0][2]) for xx,yy in zip(xd,yd)]

plt.plot(xl, yl, '-r')
plt.plot(xd, yerrLower, '--r')
plt.plot(xd, yerrUpper, '--r')
plt.show()

Location of sqlite database on the device

You can find your created database, named <your-database-name>

//data/data/<Your-Application-Package-Name>/databases/<your-database-name>

Pull it out using File explorer and rename it to have .db3 extension to use it in SQLiteExplorer

Use File explorer of DDMS to navigate to emulator directory.

How do I convert strings in a Pandas data frame to a 'date' data type?

Essentially equivalent to @waitingkuo, but I would use to_datetime here (it seems a little cleaner, and offers some additional functionality e.g. dayfirst):

In [11]: df
Out[11]:
   a        time
0  1  2013-01-01
1  2  2013-01-02
2  3  2013-01-03

In [12]: pd.to_datetime(df['time'])
Out[12]:
0   2013-01-01 00:00:00
1   2013-01-02 00:00:00
2   2013-01-03 00:00:00
Name: time, dtype: datetime64[ns]

In [13]: df['time'] = pd.to_datetime(df['time'])

In [14]: df
Out[14]:
   a                time
0  1 2013-01-01 00:00:00
1  2 2013-01-02 00:00:00
2  3 2013-01-03 00:00:00

Handling ValueErrors
If you run into a situation where doing

df['time'] = pd.to_datetime(df['time'])

Throws a

ValueError: Unknown string format

That means you have invalid (non-coercible) values. If you are okay with having them converted to pd.NaT, you can add an errors='coerce' argument to to_datetime:

df['time'] = pd.to_datetime(df['time'], errors='coerce')

jQuery duplicate DIV into another DIV

You'll want to use the clone() method in order to get a deep copy of the element:

$(function(){
  var $button = $('.button').clone();
  $('.package').html($button);
});

Full demo: http://jsfiddle.net/3rXjx/

From the jQuery docs:

The .clone() method performs a deep copy of the set of matched elements, meaning that it copies the matched elements as well as all of their descendant elements and text nodes. When used in conjunction with one of the insertion methods, .clone() is a convenient way to duplicate elements on a page.

How to lay out Views in RelativeLayout programmatically?

call

tv1.setId(1)

after

tv1.setText("A");

How to keep a git branch in sync with master

The accepted answer via git merge will get the job done but leaves a messy commit hisotry, correct way should be 'rebase' via the following steps(assuming you want to keep your feature branch in sycn with develop before you do the final push before PR).

1 git fetch from your feature branch (make sure the feature branch you are working on is update to date)

2 git rebase origin/develop

3 if any conflict shall arise, resolve them one by one

4 use git rebase --continue once all conflicts are dealt with

5 git push --force

create table with sequence.nextval in oracle

In Oracle 12c you can also declare an identity column

CREATE TABLE identity_test_tab (
  id          NUMBER GENERATED BY DEFAULT ON NULL AS IDENTITY,
  description VARCHAR2(30)
);

examples & performance tests here ... where, is shorts, the conclusion is that the direct use of the sequence or the new identity column are much faster than the triggers.

Allow anything through CORS Policy

I've your same requirements on a public API for which I used rails-api.

I've also set header in a before filter. It looks like this:

headers['Access-Control-Allow-Origin'] = '*'
headers['Access-Control-Allow-Methods'] = 'POST, PUT, DELETE, GET, OPTIONS'
headers['Access-Control-Request-Method'] = '*'
headers['Access-Control-Allow-Headers'] = 'Origin, X-Requested-With, Content-Type, Accept, Authorization'

It seems you missed the Access-Control-Request-Method header.

Passing a variable from node.js to html

If using Express it's not necessary to use a View Engine at all, use something like this:

<h1>{{ name }} </h1>

This works if you previously set your application to use HTML instead of any View Engine

Git add all subdirectories

Simple solution:

git rm --cached directory
git add directory

Why is there no ForEach extension method on IEnumerable?

You could write this extension method:

// Possibly call this "Do"
IEnumerable<T> Apply<T> (this IEnumerable<T> source, Action<T> action)
{
    foreach (var e in source)
    {
        action(e);
        yield return e;
    }
}

Pros

Allows chaining:

MySequence
    .Apply(...)
    .Apply(...)
    .Apply(...);

Cons

It won't actually do anything until you do something to force iteration. For that reason, it shouldn't be called .ForEach(). You could write .ToList() at the end, or you could write this extension method, too:

// possibly call this "Realize"
IEnumerable<T> Done<T> (this IEnumerable<T> source)
{
    foreach (var e in source)
    {
        // do nothing
        ;
    }

    return source;
}

This may be too significant a departure from the shipping C# libraries; readers who are not familiar with your extension methods won't know what to make of your code.

How to play a sound using Swift?

This is basic code to find and play an audio file in Swift.

Add your audio file to your Xcode and add the code below.

import AVFoundation

class ViewController: UIViewController {

   var audioPlayer = AVAudioPlayer() // declare globally

   override func viewDidLoad() {
        super.viewDidLoad()

        guard let sound = Bundle.main.path(forResource: "audiofilename", ofType: "mp3") else {
            print("Error getting the mp3 file from the main bundle.")
            return
        }
        do {
            audioPlayer = try AVAudioPlayer(contentsOf: URL(fileURLWithPath: sound))
        } catch {
            print("Audio file error.")
        }
        audioPlayer.play()
    }

    @IBAction func notePressed(_ sender: UIButton) { // Button action
        audioPlayer.stop()
    }
}

Can't bind to 'dataSource' since it isn't a known property of 'table'

The problem is your angular material version, I have the same, and I have resolved this when I have installed the good version of angular material in local.

Hope it solve yours too.

How to read a file into a variable in shell?

You can access 1 line at a time by for loop

#!/bin/bash -eu

#This script prints contents of /etc/passwd line by line

FILENAME='/etc/passwd'
I=0
for LN in $(cat $FILENAME)
do
    echo "Line number $((I++)) -->  $LN"
done

Copy the entire content to File (say line.sh ) ; Execute

chmod +x line.sh
./line.sh

How to convert datetime format to date format in crystal report using C#?

In case the formatting needs to be done on Crystal Report side.

Simple way.

Crystal Report Design Window->Right click on the date field->format Field->Customize the date format per your need.

Works effectively.

Waiting for another flutter command to release the startup lock

On Mac remove hidden file: <FLUTTER_HOME>/bin/cache/.upgrade_lock

div inside table

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
  <head>
    <title>test</title>
  </head>
  <body>
    <table>
      <tr>
        <td>
          <div>content</div>
        </td>
      </tr>
    </table>
  </body>
</html>

This document was successfully checked as XHTML 1.0 Transitional!

How to install "ifconfig" command in my ubuntu docker image?

You could also consider:

RUN apt-get update && apt-get install -y iputils-ping

(as Contango comments: you must first run apt-get update, to avoid error with missing repository).

See "Replacing ifconfig with ip"

it is most often recommended to move forward with the command that has replaced ifconfig. That command is ip, and it does a great job of stepping in for the out-of-date ifconfig.

But as seen in "Getting a Docker container's IP address from the host", using docker inspect can be more useful depending on your use case.

Explicitly assigning values to a 2D Array?

HTML5 required attribute seems not working

As long as have added type="submit" to button you are good.

 <form action="">
    <input type="text" placeholder="name" required>
    <button type="submit">Submit</button>
</form>

Rolling or sliding window iterator?

Trying my part, simple, one liner, pythonic way using islice. But, may not be optimally efficient.

from itertools import islice
array = range(0, 10)
window_size = 4
map(lambda i: list(islice(array, i, i + window_size)), range(0, len(array) - window_size + 1))
# output = [[0, 1, 2, 3], [1, 2, 3, 4], [2, 3, 4, 5], [3, 4, 5, 6], [4, 5, 6, 7], [5, 6, 7, 8], [6, 7, 8, 9]]

Explanation: Create window by using islice of window_size and iterate this operation using map over all array.

T-SQL: Deleting all duplicate rows but keeping one

Example query:

DELETE FROM Table
WHERE ID NOT IN
(
SELECT MIN(ID)
FROM Table
GROUP BY Field1, Field2, Field3, ...
)

Here fields are column on which you want to group the duplicate rows.

How do I get the SharedPreferences from a PreferenceActivity in Android?

Try following source code it worked for me

//Fetching id from shared preferences
    SharedPreferences sharedPreferences;
    sharedPreferences =getSharedPreferences(Constant.SHARED_PREF_NAME, Context.MODE_PRIVATE);
    getUserLogin = sharedPreferences.getString(Constant.ID_SHARED_PREF, "");

How to keep one variable constant with other one changing with row in excel

=(B0+4)/($A$0)

$ means keep same (press a few times F4 after typing A4 to flip through combos quick!)

Difference between angle bracket < > and double quotes " " while including header files in C++?

It's compiler dependent. That said, in general using " prioritizes headers in the current working directory over system headers. <> usually is used for system headers. From to the specification (Section 6.10.2):

A preprocessing directive of the form
  # include <h-char-sequence> new-line
searches a sequence of implementation-defined places for a header identified uniquely by the specified sequence between the < and > delimiters, and causes the replacement of that directive by the entire contents of the header. How the places are specified or the header identified is implementation-defined.

A preprocessing directive of the form
  # include "q-char-sequence" new-line
causes the replacement of that directive by the entire contents of the source file identified by the specified sequence between the " delimiters. The named source file is searched for in an implementation-defined manner. If this search is not supported, or if the search fails, the directive is reprocessed as if it read
  # include <h-char-sequence> new-line
with the identical contained sequence (including > characters, if any) from the original directive.

So on most compilers, using the "" first checks your local directory, and if it doesn't find a match then moves on to check the system paths. Using <> starts the search with system headers.

How to create a numpy array of arbitrary length strings?

You can do so by creating an array of dtype=object. If you try to assign a long string to a normal numpy array, it truncates the string:

>>> a = numpy.array(['apples', 'foobar', 'cowboy'])
>>> a[2] = 'bananas'
>>> a
array(['apples', 'foobar', 'banana'], 
      dtype='|S6')

But when you use dtype=object, you get an array of python object references. So you can have all the behaviors of python strings:

>>> a = numpy.array(['apples', 'foobar', 'cowboy'], dtype=object)
>>> a
array([apples, foobar, cowboy], dtype=object)
>>> a[2] = 'bananas'
>>> a
array([apples, foobar, bananas], dtype=object)

Indeed, because it's an array of objects, you can assign any kind of python object to the array:

>>> a[2] = {1:2, 3:4}
>>> a
array([apples, foobar, {1: 2, 3: 4}], dtype=object)

However, this undoes a lot of the benefits of using numpy, which is so fast because it works on large contiguous blocks of raw memory. Working with python objects adds a lot of overhead. A simple example:

>>> a = numpy.array(['abba' for _ in range(10000)])
>>> b = numpy.array(['abba' for _ in range(10000)], dtype=object)
>>> %timeit a.copy()
100000 loops, best of 3: 2.51 us per loop
>>> %timeit b.copy()
10000 loops, best of 3: 48.4 us per loop

pow (x,y) in Java

^ is the bitwise exclusive OR (XOR) operator in Java (and many other languages). It is not used for exponentiation. For that, you must use Math.pow.

Javascript Uncaught Reference error Function is not defined

If you are using Angular.js then functions imbedded into HTML, such as onclick="function()" or onchange="function()". They will not register. You need to make the change events in the javascript. Such as:

$('#exampleBtn').click(function() {
  function();
});

Nested iframes, AKA Iframe Inception

Hey I got something that seems to be doing what you want a do. It involves some dirty copying but works. You can find the working code here

So here is the main html file :

<!DOCTYPE html>
<html>
<head>
    <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>

    <script type="text/javascript">
        $(document).ready(function(){
            Iframe = $('#frame1');

            Iframe.on('load', function(){
                IframeInner = Iframe.contents().find('iframe');

                IframeInnerClone = IframeInner.clone();

                IframeInnerClone.insertAfter($('#insertIframeAfter')).css({display:'none'});

                IframeInnerClone.on('load', function(){
                    IframeContents = IframeInner.contents();

                    YourNestedEl = IframeContents.find('div');

                    $('<div>Yeepi! I can even insert stuff!</div>').insertAfter(YourNestedEl)
                });
            });
        });
    </script>
</head>
<body>
    <div id="insertIframeAfter">Hello!!!!</div>
    <iframe id="frame1" src="Test_Iframe.html">

    </iframe>
</body>
</html>

As you can see, once the first Iframe is loaded, I get the second one and clone it. I then reinsert it in the dom, so I can get access to the onload event. Once this one is loaded, I retrieve the content from non-cloned one (must have loaded as well, since they use the same src). You can then do wathever you want with the content.

Here is the Test_Iframe.html file :

<!DOCTYPE html>
<html>
<head>
</head>
<body>
    <div>Test_Iframe</div>
    <iframe src="Test_Iframe2.html">
    </iframe>
</body>
</html>

and the Test_Iframe2.html file :

<!DOCTYPE html>
<html>
<head>
</head>
<body>
    <div>I am the second nested iframe</div>
</body>
</html>

What is the simplest SQL Query to find the second largest value?

As you mentioned duplicate values . In such case you may use DISTINCT and GROUP BY to find out second highest value

Here is a table

salary

GROUP BY

SELECT  amount FROM  salary 
GROUP by amount
ORDER BY  amount DESC 
LIMIT 1 , 1

DISTINCT

SELECT DISTINCT amount
FROM  salary 
ORDER BY  amount DESC 
LIMIT 1 , 1

First portion of LIMIT = starting index

Second portion of LIMIT = how many value

How can I remove all text after a character in bash?

Let's say you have a path with a file in this format:

/dirA/dirB/dirC/filename.file

Now you only want the path which includes four "/". Type

$ echo "/dirA/dirB/dirC/filename.file" | cut -f1-4 -d"/"

and your output will be

/dirA/dirB/dirC

The advantage of using cut is that you can also cut out the uppest directory as well as the file (in this example), so if you type

$ echo "/dirA/dirB/dirC/filename.file" | cut -f1-3 -d"/"

your output would be

/dirA/dirB

Though you can do the same from the other side of the string, it would not make that much sense in this case as typing

$ echo "/dirA/dirB/dirC/filename.file" | cut -f2-4 -d"/"

results in

dirA/dirB/dirC

In some other cases the last case might also be helpful. Mind that there is no "/" at the beginning of the last output.

Using <style> tags in the <body> with other HTML

Yes it can. I checked on Mozilla's page. https://developer.mozilla.org/en-US/docs/Web/HTML/Element/style

VBA for filtering columns

Here's a different approach. The heart of it was created by turning on the Macro Recorder and filtering the columns per your specifications. Then there's a bit of code to copy the results. It will run faster than looping through each row and column:

Sub FilterAndCopy()
Dim LastRow As Long

Sheets("Sheet2").UsedRange.Offset(0).ClearContents
With Worksheets("Sheet1")
    .Range("$A:$E").AutoFilter
    .Range("$A:$E").AutoFilter field:=1, Criteria1:="#N/A"
    .Range("$A:$E").AutoFilter field:=2, Criteria1:="=String1", Operator:=xlOr, Criteria2:="=string2"
    .Range("$A:$E").AutoFilter field:=3, Criteria1:=">0"
    .Range("$A:$E").AutoFilter field:=5, Criteria1:="Number"
    LastRow = .Range("A" & .Rows.Count).End(xlUp).Row
    .Range("A1:A" & LastRow).SpecialCells(xlCellTypeVisible).EntireRow.Copy _
            Destination:=Sheets("Sheet2").Range("A1")
End With
End Sub

As a side note, your code has more loops and counter variables than necessary. You wouldn't need to loop through the columns, just through the rows. You'd then check the various cells of interest in that row, much like you did.

How to show the last queries executed on MySQL?

If mysql binlog is enabled you can check the commands ran by user by executing following command in linux console by browsing to mysql binlog directory

mysqlbinlog binlog.000001 >  /tmp/statements.sql

enabling

[mysqld]
log = /var/log/mysql/mysql.log

or general log will have an effect on performance of mysql

Installed Ruby 1.9.3 with RVM but command line doesn't show ruby -v

You have broken version of RVM. Ubuntu does something to RVM that produces lots of errors, the only safe way of fixing for now is to:

sudo apt-get --purge remove ruby-rvm
sudo rm -rf /usr/share/ruby-rvm /etc/rvmrc /etc/profile.d/rvm.sh

open new terminal and validate environment is clean from old RVM settings (should be no output):

env | grep rvm

if there was output, try to open new terminal, if it does not help then restart your computer.

install RVM:

\curl -L https://get.rvm.io | 
  bash -s stable --ruby --autolibs=enable --auto-dotfiles

If you find you need some hand-holding, take a look at Installing Ruby on Ubuntu 12.04, which gives a bit more explanation.

How to create a circle icon button in Flutter?

RawMaterialButton(
  onPressed: () {},
  constraints: BoxConstraints(),
  elevation: 2.0,
  fillColor: Colors.white,
  child: Icon(
    Icons.pause,
    size: 35.0,
  ),
  padding: EdgeInsets.all(15.0),
  shape: CircleBorder(),
)

note down constraints: BoxConstraints(), it's for not allowing padding in left.

Happy fluttering!!

How to use jQuery in chrome extension?

In my case got a working solution through Cross-document Messaging (XDM) and Executing Chrome extension onclick instead of page load.

manifest.json

{
  "name": "JQuery Light",
  "version": "1",
  "manifest_version": 2,

  "browser_action": {
    "default_icon": "icon.png"
  },

  "content_scripts": [
    {
      "matches": [
        "https://*.google.com/*"
      ],
      "js": [
        "jquery-3.3.1.min.js",
        "myscript.js"
      ]
    }
  ],

  "background": {
    "scripts": [
      "background.js"
    ]
  }

}

background.js

chrome.browserAction.onClicked.addListener(function (tab) {
  chrome.tabs.query({active: true, currentWindow: true}, function (tabs) {
    var activeTab = tabs[0];
    chrome.tabs.sendMessage(activeTab.id, {"message": "clicked_browser_action"});
  });
});

myscript.js

chrome.runtime.onMessage.addListener(
    function (request, sender, sendResponse) {
        if (request.message === "clicked_browser_action") {
        console.log('Hello world!')
        }
    }
);

Catching exceptions from Guzzle

If the Exception is being thrown in that try block then at worst case scenario Exception should be catching anything uncaught.

Consider that the first part of the test is throwing the Exception and wrap that in the try block as well.

What is key=lambda

In Python, lambda is a keyword used to define anonymous functions(functions with no name) and that's why they are known as lambda functions.

Basically it is used for defining anonymous functions that can/can't take argument(s) and returns value of data/expression. Let's see an example.

>>> # Defining a lambda function that takes 2 parameters(as integer) and returns their sum
... 
>>> lambda num1, num2: num1 + num2 
<function <lambda> at 0x1004b5de8>
>>> 
>>> # Let's store the returned value in variable & call it(1st way to call)
... 
>>> addition = lambda num1, num2: num1 + num2
>>> addition(62, 5)
67
>>> addition(1700, 29)
1729
>>> 
>>> # Let's call it in other way(2nd way to call, one line call )
... 
>>> (lambda num1, num2: num1 + num2)(120, 1)
121
>>> (lambda num1, num2: num1 + num2)(-68, 2)
-66
>>> (lambda num1, num2: num1 + num2)(-68, 2**3)
-60
>>>

Now let me give an answer of your 2nd question. The 1st answer is also great. This is my own way to explain with another example.

Suppose we have a list of items(integers and strings with numeric contents) as follows,

nums = ["2", 1, 3, 4, "5", "8", "-1", "-10"]

and I want to sort it using sorted() function, lets see what happens.

>>> nums = ["2", 1, 3, 4, "5", "8", "-1", "-10"]
>>> sorted(nums)
[1, 3, 4, '-1', '-10', '2', '5', '8']
>>>

It didn't give me what I expected as I wanted like below,

['-10', '-1', 1, '2', 3, 4, '5', '8']

It means we need some strategy(so that sorted could treat our string items as an ints) to achieve this. This is why the key keyword argument is used. Please look at the below one.

>>> nums = ["2", 1, 3, 4, "5", "8", "-1", "-10"]
>>> sorted(nums, key=int)
['-10', '-1', 1, '2', 3, 4, '5', '8']
>>>

Lets use lambda function as a value of key

>>> names = ["Rishikesh", "aman", "Ajay", "Hemkesh", "sandeep", "Darshan", "Virendra", "Shwetabh"]
>>> names2 = sorted(names)
>>> names2
['Ajay', 'Darshan', 'Hemkesh', 'Rishikesh', 'Shwetabh', 'Virendra', 'aman', 'sandeep']
>>> # But I don't want this o/p(here our intention is to treat 'a' same as 'A')
...
>>> names3 = sorted(names, key=lambda name:name.lower())
>>> names3
['Ajay', 'aman', 'Darshan', 'Hemkesh', 'Rishikesh', 'sandeep', 'Shwetabh', 'Virendra']
>>>

You can define your own function(callable) and provide it as value of key.

Dear programers, I have written the below code for you, just try to understand it and comment your explanation. I would be glad to see your explanation(it's simple).

>>> def validator(item):
...     try:
...         return int(item)
...     except:
...         return 0
... 
>>> sorted(['gurmit', "0", 5, 2, 1, "front", -2, "great"], key=validator)
[-2, 'gurmit', '0', 'front', 'great', 1, 2, 5]
>>>

I hope it would be useful.

What tools do you use to test your public REST API?

We test our own with our own unit tests and oftentimes a dedicated client app.

Replace tabs with spaces in vim

Once you've got expandtab on as per the other answers, the extremely convenient way to convert existing files according to your new settings is:

:retab

It will work on the current buffer.

How to create a custom exception type in Java?

You have to define your exception elsewhere as a new class

public class YourCustomException extends Exception{

//Required inherited methods here
}

Then you can throw and catch YourCustomException as much as you'd like.

How to auto adjust the <div> height according to content in it?

Just write:

min-height: xxx;
overflow: hidden;

then div will automatically take the height of the content.

How to generate unique ID with node.js

Extending from YaroslavGaponov's answer, the simplest implementation is just using Math.random().

Math.random()

Mathematically, the chances of fractions being the same in a real space [0, 1] is theoretically 0. Probability-wise it is approximately close to 0 for a default length of 16 decimals in node.js. And this implementation should also reduce arithmetic overflows as no operations are performed. Also, it is more memory efficient compared to a string as Decimals occupy less memory than strings.

I call this the "Fractional-Unique-ID".

Wrote code to generate 1,000,000 Math.random() numbers and could not find any duplicates (at least for default decimal points of 16). See code below (please provide feedback if any):

random_numbers = [] 
for (i = 0; i < 1000000; i++) { 
   random_numbers.push(Math.random()); 
   //random_numbers.push(Math.random().toFixed(13)) //depends decimals default 16 
} 

if (i === 1000000) { 
   console.log("Before checking duplicate"); 
   console.log(random_numbers.length); 
   console.log("After checking duplicate"); 
   random_set = new Set(random_numbers); // Set removes duplicates
   console.log([...random_set].length); // length is still the same after removing
}

How to print to console in pytest?

I needed to print important warning about skipped tests exactly when PyTest muted literally everything.

I didn't want to fail a test to send a signal, so I did a hack as follow:

def test_2_YellAboutBrokenAndMutedTests():
    import atexit
    def report():
        print C_patch.tidy_text("""
In silent mode PyTest breaks low level stream structure I work with, so
I cannot test if my functionality work fine. I skipped corresponding tests.
Run `py.test -s` to make sure everything is tested.""")
    if sys.stdout != sys.__stdout__:
        atexit.register(report)

The atexit module allows me to print stuff after PyTest released the output streams. The output looks as follow:

============================= test session starts ==============================
platform linux2 -- Python 2.7.3, pytest-2.9.2, py-1.4.31, pluggy-0.3.1
rootdir: /media/Storage/henaro/smyth/Alchemist2-git/sources/C_patch, inifile: 
collected 15 items 

test_C_patch.py .....ssss....s.

===================== 10 passed, 5 skipped in 0.15 seconds =====================
In silent mode PyTest breaks low level stream structure I work with, so
I cannot test if my functionality work fine. I skipped corresponding tests.
Run `py.test -s` to make sure everything is tested.
~/.../sources/C_patch$

Message is printed even when PyTest is in silent mode, and is not printed if you run stuff with py.test -s, so everything is tested nicely already.

How to select only date from a DATETIME field in MySQL?

Use DATE_FORMAT

select DATE_FORMAT(date,'%d') from tablename =>Date only

example:

select DATE_FORMAT(`date_column`,'%d') from `database_name`.`table_name`;

navbar color in Twitter Bootstrap

Wouldn't occam's razor say to just do this until you need something more complex? It's a bit of a hack, but may suit the needs of someone that wants a quick fix.

.navbar-default .container-fluid{
    background-color:#62ADD7; // Change the color
    margin: -1px -1px 10px -1px; // Get rid of the border
}

Combine two (or more) PDF's

PDFsharp seems to allow merging multiple PDF documents into one.

And the same is also possible with ITextSharp.

How to "grep" for a filename instead of the contents of a file?

No, grep works just fine for this:

 grep -rl "filename" [starting point]

 grep -rL "not in filename"

Pip error: Microsoft Visual C++ 14.0 is required

I got this error when I tried to install pymssql even though Visual C++ 2015 (14.0) is installed in my system.

I resolved this error by downloading the .whl file of pymssql from here.

Once downloaded, it can be installed by the following command :

pip install python_package.whl

Hope this helps

'node' is not recognized as an internal or external command

Everytime I install node.js it needs a reboot and then the path is recognized.

Find MongoDB records where array field is not empty

This also works:

db.getCollection('collectionName').find({'arrayName': {$elemMatch:{}}})

The AWS Access Key Id does not exist in our records

you can configure profiles in the bash_profile file using

<profile_name>
aws_access_key_id = <access_key>
aws_secret_access_key = <acces_key_secret>

if you are using multiple profiles. then use:

aws s3 ls --profile <profile_name>

How do I parse a HTML page with Node.js

Use Cheerio. It isn't as strict as jsdom and is optimized for scraping. As a bonus, uses the jQuery selectors you already know.

? Familiar syntax: Cheerio implements a subset of core jQuery. Cheerio removes all the DOM inconsistencies and browser cruft from the jQuery library, revealing its truly gorgeous API.

? Blazingly fast: Cheerio works with a very simple, consistent DOM model. As a result parsing, manipulating, and rendering are incredibly efficient. Preliminary end-to-end benchmarks suggest that cheerio is about 8x faster than JSDOM.

? Insanely flexible: Cheerio wraps around @FB55's forgiving htmlparser. Cheerio can parse nearly any HTML or XML document.

How to dynamically add a class to manual class names?

Depending on how many dynamic classes you need to add as your project grows it's probably worth checking out the classnames utility by JedWatson on GitHub. It allows you to represent your conditional classes as an object and returns those that evaluate to true.

So as an example from its React documentation:

render () {

var btnClass = classNames({
  'btn': true,
  'btn-pressed': this.state.isPressed,
  'btn-over': !this.state.isPressed && this.state.isHovered
});

return <button className={btnClass}>I'm a button!</button>;

}

Since React triggers a re-render when there is a state change, your dynamic class names are handled naturally and kept up to date with the state of your component.

Where can I download IntelliJ IDEA Color Schemes?

This is just a suggestion, but what I like to do while I'm coding sometimes is to Invert the colors of my Screen. On a Mac it's Ctrl-Cmd-Alt->8 and it inverts the colors.

Haven't personally tried these in Idea10, but it worked on Idea9. http://devnet.jetbrains.net/docs/DOC-1154

@try - catch block in Objective-C

All work perfectly :)

 NSString *test = @"test";
 unichar a;
 int index = 5;
    
 @try {
    a = [test characterAtIndex:index];
 }
 @catch (NSException *exception) {
    NSLog(@"%@", exception.reason);
    NSLog(@"Char at index %d cannot be found", index);
    NSLog(@"Max index is: %lu", [test length] - 1);
 }
 @finally {
    NSLog(@"Finally condition");
 }

Log:

[__NSCFConstantString characterAtIndex:]: Range or index out of bounds

Char at index 5 cannot be found

Max index is: 3

Finally condition

Having a UITextField in a UITableViewCell

Details

Xcode 10.2 (10E125), Swift 5

Full Sample Code

TextFieldInTableViewCell

import UIKit

protocol TextFieldInTableViewCellDelegate: class {
    func textField(editingDidBeginIn cell:TextFieldInTableViewCell)
    func textField(editingChangedInTextField newText: String, in cell: TextFieldInTableViewCell)
}

class TextFieldInTableViewCell: UITableViewCell {

    private(set) weak var textField: UITextField?
    private(set) weak var descriptionLabel: UILabel?

    weak var delegate: TextFieldInTableViewCellDelegate?

    override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
        super.init(style: style, reuseIdentifier: reuseIdentifier)
        setupSubviews()
    }

    private func setupSubviews() {
        let stackView = UIStackView()
        stackView.distribution = .fill
        stackView.alignment = .leading
        stackView.spacing = 8
        contentView.addSubview(stackView)
        stackView.translatesAutoresizingMaskIntoConstraints = false
        stackView.topAnchor.constraint(equalTo: topAnchor, constant: 6).isActive = true
        stackView.bottomAnchor.constraint(equalTo: bottomAnchor, constant: -6).isActive = true
        stackView.leftAnchor.constraint(equalTo: leftAnchor, constant: 16).isActive = true
        stackView.rightAnchor.constraint(equalTo: rightAnchor, constant: -16).isActive = true

        let label = UILabel()
        label.text = "Label"
        stackView.addArrangedSubview(label)
        descriptionLabel = label

        let textField = UITextField()
        textField.textAlignment = .left
        textField.placeholder = "enter text"
        textField.setContentHuggingPriority(.fittingSizeLevel, for: .horizontal)
        stackView.addArrangedSubview(textField)
        textField.addTarget(self, action: #selector(textFieldValueChanged(_:)), for: .editingChanged)
        textField.addTarget(self, action: #selector(editingDidBegin), for: .editingDidBegin)
        self.textField = textField

        stackView.layoutSubviews()
        selectionStyle = .none

        let gesture = UITapGestureRecognizer(target: self, action: #selector(didSelectCell))
        addGestureRecognizer(gesture)
    }

    required init?(coder aDecoder: NSCoder) { super.init(coder: aDecoder) }
}

extension TextFieldInTableViewCell {
    @objc func didSelectCell() { textField?.becomeFirstResponder() }
    @objc func editingDidBegin() { delegate?.textField(editingDidBeginIn: self) }
    @objc func textFieldValueChanged(_ sender: UITextField) {
        if let text = sender.text { delegate?.textField(editingChangedInTextField: text, in: self) }
    }
}

ViewController

import UIKit

class ViewController: UIViewController {

    private weak var tableView: UITableView?
    override func viewDidLoad() {
        super.viewDidLoad()
        setupTableView()
    }
}

extension ViewController {

    func setupTableView() {

        let tableView = UITableView(frame: .zero)
        tableView.register(TextFieldInTableViewCell.self, forCellReuseIdentifier: "TextFieldInTableViewCell")
        view.addSubview(tableView)
        tableView.translatesAutoresizingMaskIntoConstraints = false
        tableView.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
        tableView.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
        tableView.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
        tableView.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
        tableView.rowHeight = UITableView.automaticDimension
        tableView.estimatedRowHeight = UITableView.automaticDimension
        tableView.tableFooterView = UIView()
        self.tableView = tableView
        tableView.dataSource = self

        let gesture = UITapGestureRecognizer(target: tableView, action: #selector(UITextView.endEditing(_:)))
        tableView.addGestureRecognizer(gesture)
    }
}

extension ViewController: UITableViewDataSource {

    func numberOfSections(in tableView: UITableView) -> Int { return 1 }
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int { return 2 }
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "TextFieldInTableViewCell") as! TextFieldInTableViewCell
        cell.delegate = self
        return cell
    }
}

extension ViewController: TextFieldInTableViewCellDelegate {

    func textField(editingDidBeginIn cell: TextFieldInTableViewCell) {
        if let indexPath = tableView?.indexPath(for: cell) {
            print("textfield selected in cell at \(indexPath)")
        }
    }

    func textField(editingChangedInTextField newText: String, in cell: TextFieldInTableViewCell) {
        if let indexPath = tableView?.indexPath(for: cell) {
            print("updated text in textfield in cell as \(indexPath), value = \"\(newText)\"")
        }
    }
}

Result

How to see indexes for a database or table in MySQL?

we can directly see the indexes on to the table if we know the index name with below :

select * from all_indexes where index_name= 'your index'

Using a batch to copy from network drive to C: or D: drive

Most importantly you need to mount the drive

net use z: \\yourserver\sharename

Of course, you need to make sure that the account the batch file runs under has permission to access the share. If you are doing this by using a Scheduled Task, you can choose the account by selecting the task, then:

right click Properties
click on General tab
change account under

"When running the task, use the following user account:" That's on Windows 7, it might be slightly different on different versions of Windows.

Then run your batch script with the following changes

copy "z:\FolderName" "C:\TEST_BACKUP_FOLDER"

Android studio Gradle icon error, Manifest Merger

It seems to be the fault of the mainfest Merger tool for gradle.

http://tools.android.com/tech-docs/new-build-system/user-guide/manifest-merger

Solved it by adding to my manifest tag xmlns:tools="http://schemas.android.com/tools"

Then added tools:replace="android:icon,android:theme" to the application tag

This tells the merger to use my manifest icon and theme and not of other libraries

Hope it helps thanks

How to tell if JRE or JDK is installed

Normally a jdk installation has javac in the environment path variables ... so if you check for javac in the path, that's pretty much a good indicator that you have a jdk installed.

Java: How to set Precision for double value?

You can't set the precision of a double (or Double) to a specified number of decimal digits, because floating-point values don't have decimal digits. They have binary digits.

You will have to convert into a decimal radix, either via BigDecimal or DecimalFormat, depending on what you want to do with the value later.

See also my answer to this question for a refutation of the inevitable *100/100 answers.

Iterating through a JSON object

Adding another solution (Python 3) - Iterating over json files in a directory and on each file iterating over all objects and printing relevant fields.

See comments in the code.

import os,json

data_path = '/path/to/your/json/files'  

# 1. Iterate over directory
directory = os.fsencode(data_path)
for file in os.listdir(directory):
    filename = os.fsdecode(file)
    # 2. Take only json files
    if filename.endswith(".json"):
        file_full_path=data_path+filename
        # 3. Open json file 
        with open(file_full_path, encoding='utf-8', errors='ignore') as json_data:
            data_in_file = json.load(json_data, strict=False)
            # 4. Iterate over objects and print relevant fields
            for json_object in data_in_file:
                print("ttl: %s, desc: %s" % (json_object['title'],json_object['description']) )

Looping through array and removing items, without breaking for loop

The array is being re-indexed when you do a .splice(), which means you'll skip over an index when one is removed, and your cached .length is obsolete.

To fix it, you'd either need to decrement i after a .splice(), or simply iterate in reverse...

var i = Auction.auctions.length
while (i--) {
    ...
    if (...) { 
        Auction.auctions.splice(i, 1);
    } 
}

This way the re-indexing doesn't affect the next item in the iteration, since the indexing affects only the items from the current point to the end of the Array, and the next item in the iteration is lower than the current point.

Error Code: 1406. Data too long for column - MySQL

Try to check the limits of your SQL database. Maybe you'r exceeding the field limit for this row.

HTML: Select multiple as dropdown

    <select name="select_box"  multiple>
        <option>123</option>
        <option>456</option>
        <option>789</option>
     </select>

Warning about SSL connection when connecting to MySQL database

To disable the warning while connecting to a database in Java, use the below concept -

autoReconnect=true&useSSL=false

Just need to change connectionURL like :

String connectionURL = jdbc:mysql://localhost:3306/Peoples?autoReconnect=true&useSSL=false

This will disable SSL and also suppress the SSL errors.

changing textbox border colour using javascript

Add an onchange event to your input element:

<input type="text" id="fName" value="" onchange="fName_Changed(this)" />

Javascript:

function fName_Changed(fName)
{
    fName.style.borderColor = (fName.value != 'correct text') ? "#FF0000"; : fName.style.borderColor="";
}

Twitter Bootstrap date picker

Much confusion stems from the existence of at least three major libraries named bootstrap-datepicker:

A popular fork of eyecon's datepicker by Andrew 'eternicode' Rowls (use this one!):
The original version by Stefan 'eyecon' Petre, still available at http://www.eyecon.ro/bootstrap-datepicker/
A totally unrelated datepicker widget that 'storborg' sought to have merged into bootstrap. It wasn't merged and no proper release version of the widget was ever created.

If you're starting a new project - or heck, even if you're taking over an old project using the eyecon version - I recommend that you use eternicode's version, not eyecon's. The original eyecon version is outright inferior in terms of both functionality and documentation, and this is unlikely to change - it has not been updated since March 2013.

You can see most of the capabilities of the eternicode datepicker on the demo page which lets you play with the datepicker's configuration and observe the results. For more detail, see the succinct but comprehensive documentation, which you can probably consume in its entirety in under an hour.

In case you're impatient, though, here's a very short step-by-step guide to the simplest and most common use case for the datepicker.

Quick start guide

Include the following libraries (minimum versions noted here) on your page:
- jQuery
- Bootstrap - both the JS and CSS
- The latest release version of bootstrap-datepicker - both the JS and CSS
Put an input element on your page somewhere, e.g.
```
<input id="my-date-input">
```
With jQuery, select your input and call the .datepicker() method:
```
jQuery('#my-date-input').datepicker();
```
Load your page and click on or tab into your input element. A datepicker will appear:

Using NULL in C++?

In C++ NULL expands to 0 or 0L. See this quote from Stroustrup's FAQ:

Should I use NULL or 0?

In C++, the definition of NULL is 0, so there is only an aesthetic difference. I prefer to avoid macros, so I use 0. Another problem with NULL is that people sometimes mistakenly believe that it is different from 0 and/or not an integer. In pre-standard code, NULL was/is sometimes defined to something unsuitable and therefore had/has to be avoided. That's less common these days.

If you have to name the null pointer, call it nullptr; that's what it's called in C++11. Then, "nullptr" will be a keyword.

Disable/turn off inherited CSS3 transitions

Based on W3schools default transition value is: all 0s ease 0s, which should be the cross-browser compatible way of disabling the transition.

Here is a link: https://www.w3schools.com/cssref/css3_pr_transition.asp

Calculating how many minutes there are between two times

double minutes = varTime.TotalMinutes;
int minutesRounded = (int)Math.Round(varTime.TotalMinutes);

TimeSpan.TotalMinutes: The total number of minutes represented by this instance.

Make a DIV fill an entire table cell

So, because everyone is posting their solution and none was good for me, here is mine (tested on Chrome & Firefox).

table { height: 1px; } /* Will be ignored, don't worry. */
tr { height: 100%; }
td { height: 100%; }
td > div { height: 100%; }

Fiddle: https://jsfiddle.net/nh6g5fzv/

Edit: one thing you might want to note, if you want to apply a padding to the div in the td, you must add box-sizing: border-box; because of height: 100%.

iPhone Navigation Bar Title text color

It's recommended to set self.title as this is used while pushing child navbars or showing title on tabbars.

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // create and customize title view
        self.title = NSLocalizedString(@"My Custom Title", @"");
        UILabel *titleLabel = [[UILabel alloc] initWithFrame:CGRectZero];
        titleLabel.text = self.title;
        titleLabel.font = [UIFont boldSystemFontOfSize:16];
        titleLabel.backgroundColor = [UIColor clearColor];
        titleLabel.textColor = [UIColor whiteColor];
        [titleLabel sizeToFit];
        self.navigationItem.titleView = titleLabel;
        [titleLabel release];
    }
}

How do I check if a Key is pressed on C++

There is no portable function that allows to check if a key is hit and continue if not. This is always system dependent.

Solution for linux and other posix compliant systems:

Here, for Morgan Mattews's code provide kbhit() functionality in a way compatible with any POSIX compliant system. He uses the trick of desactivating buffering at termios level.

Solution for windows:

For windows, Microsoft offers _kbhit()

FirstOrDefault: Default value other than null

Copied over from comment by @sloth

Instead of YourCollection.FirstOrDefault(), you could use YourCollection.DefaultIfEmpty(YourDefault).First() for example.

Example:

var viewModel = new CustomerDetailsViewModel
    {
            MainResidenceAddressSection = (MainResidenceAddressSection)addresses.DefaultIfEmpty(new MainResidenceAddressSection()).FirstOrDefault( o => o is MainResidenceAddressSection),
            RiskAddressSection = addresses.DefaultIfEmpty(new RiskAddressSection()).FirstOrDefault(o => !(o is MainResidenceAddressSection)),
    };

Failed to load AppCompat ActionBar with unknown error in android studio

I also had this problem and it's solved as change line from res/values/styles.xml

<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">

<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
<style name="AppTheme" parent="Base.Theme.AppCompat.Light.DarkActionBar">

both solutions worked

What is the difference between active and passive FTP?

Active Mode—The client issues a PORT command to the server signaling that it will “actively” provide an IP and port number to open the Data Connection back to the client.

Passive Mode—The client issues a PASV command to indicate that it will wait “passively” for the server to supply an IP and port number, after which the client will create a Data Connection to the server.

There are lots of good answers above, but this blog post includes some helpful graphics and gives a pretty solid explanation: https://titanftp.com/2018/08/23/what-is-the-difference-between-active-and-passive-ftp/

Access nested dictionary items via a list of keys?

Using reduce is clever, but the OP's set method may have issues if the parent keys do not pre-exist in the nested dictionary. Since this is the first SO post I saw for this subject in my google search, I would like to make it slightly better.

The set method in ( Setting a value in a nested python dictionary given a list of indices and value ) seems more robust to missing parental keys. To copy it over:

def nested_set(dic, keys, value):
    for key in keys[:-1]:
        dic = dic.setdefault(key, {})
    dic[keys[-1]] = value

Also, it can be convenient to have a method that traverses the key tree and get all the absolute key paths, for which I have created:

def keysInDict(dataDict, parent=[]):
    if not isinstance(dataDict, dict):
        return [tuple(parent)]
    else:
        return reduce(list.__add__, 
            [keysInDict(v,parent+[k]) for k,v in dataDict.items()], [])

One use of it is to convert the nested tree to a pandas DataFrame, using the following code (assuming that all leafs in the nested dictionary have the same depth).

def dict_to_df(dataDict):
    ret = []
    for k in keysInDict(dataDict):
        v = np.array( getFromDict(dataDict, k), )
        v = pd.DataFrame(v)
        v.columns = pd.MultiIndex.from_product(list(k) + [v.columns])
        ret.append(v)
    return reduce(pd.DataFrame.join, ret)

How to use ng-if to test if a variable is defined

I edited your plunker to include ABOS's solution.

<body ng-controller="MainCtrl">
    <ul ng-repeat='item in items'>
      <li ng-if='item.color'>The color is {{item.color}}</li>
      <li ng-if='item.shipping !== undefined'>The shipping cost is {{item.shipping}}</li>
    </ul>
  </body>

plunkerFork

Pandas DataFrame Groupby two columns and get counts

Followed by @Andy's answer, you can do following to solve your second question:

In [56]: df.groupby(['col5','col2']).size().reset_index().groupby('col2')[[0]].max()
Out[56]: 
      0
col2   
A     3
B     2
C     1
D     3

Watching variables in SSIS during debug

Drag the variable from Variables pane to Watch pane and voila!

Single Result from Database by using mySQLi

Use mysqli_fetch_row(). Try this,

$query = "SELECT ssfullname, ssemail FROM userss WHERE user_id = ".$user_id;
$result = mysqli_query($conn, $query);
$row   = mysqli_fetch_row($result);

$ssfullname = $row['ssfullname'];
$ssemail    = $row['ssemail'];

How to open html file?

You can read HTML page using 'urllib'.

 #python 2.x

  import urllib

  page = urllib.urlopen("your path ").read()
  print page

Could not find default endpoint element

Having tested several options, I finally solved this by using

contract="IMySOAPWebService"

i.e. without the full namespace in the config. For some reason the full name didn't resolve properly

Convert SVG image to PNG with PHP

$command = 'convert -density 300 ';
                        if(Input::Post('height')!='' && Input::Post('width')!=''){
                            $command.='-resize '.Input::Post('width').'x'.Input::Post('height').' ';
                        }
                        $command.=$svg.' '.$source;
                        exec($command);
                        @unlink($svg);

or using : potrace demo :Tool4dev.com

Set ANDROID_HOME environment variable in mac

Here are the steps:

Open Terminal
Type touch .bash_profile and press Enter
Now Type open .bash_profile and again press Enter
A textEdit file will be opened
Now type export ANDROID_HOME="Users/Your_User_Name/Library/Android/sdk"
Then in next line type export PATH="${PATH}:/$ANDROID_HOME/platform-tools:/$ANDROID_HOME/tools:/$ANDROID_HOME/tools/bin"
Now save this .bash_profile file
Close the Terminal

To verify if Path is set successfully open terminal again and type adb if adb version and other details are displayed that means path is set properly.

Sending credentials with cross-domain posts?

In jQuery 3 and perhaps earlier versions, the following simpler config also works for individual requests:

$.ajax(
        'https://foo.bar.com,
        {
            dataType: 'json',
            xhrFields: {
                withCredentials: true
            },
            success: successFunc
        }
    );

The full error I was getting in Firefox Dev Tools -> Network tab (in the Security tab for an individual request) was:

An error occurred during a connection to foo.bar.com.SSL peer was unable to negotiate an acceptable set of security parameters.Error code: SSL_ERROR_HANDSHAKE_FAILURE_ALERT

Working with SQL views in Entity Framework Core

Here is a new way to work with SQL views in EF Core: Query Types.

Create an ArrayList of unique values

HashSet hs = new HashSet();
                hs.addAll(arrayList);
                arrayList.clear();
                arrayList.addAll(hs);

problem with php mail 'From' header

The web host is not really playing foul. It's not strictly according to the rules - but compared with some some of the amazing inventions intended to prevent spam, its not a particularly bad one.

If you really do want to send mail from '@gmail.com' why not just use the gmail SMTP service? If you can't reconfigure the server where PHP is running, then there are lots of email wrapper tools out there which allow you to specify a custom SMTP relay phpmailer springs to mind.

Rails find_or_create_by more than one attribute?

For anyone else who stumbles across this thread but needs to find or create an object with attributes that might change depending on the circumstances, add the following method to your model:

# Return the first object which matches the attributes hash
# - or -
# Create new object with the given attributes
#
def self.find_or_create(attributes)
  Model.where(attributes).first || Model.create(attributes)
end

Optimization tip: regardless of which solution you choose, consider adding indexes for the attributes you are querying most frequently.

java.io.IOException: Invalid Keystore format

(Re)installing the latest JDK (e.g. Oracle's) fixed it for me.

Prior to installing the latest JDK, when I executed the following command in Terminal.app:

keytool -list -keystore $(/usr/libexec/java_home)/jre/lib/security/cacerts -v

It resulted in:

keytool error: java.io.IOException: Invalid keystore format
java.io.IOException: Invalid keystore format
    at sun.security.provider.JavaKeyStore.engineLoad(JavaKeyStore.java:650)
    at sun.security.provider.JavaKeyStore$JKS.engineLoad(JavaKeyStore.java:55)
    at java.security.KeyStore.load(KeyStore.java:1445)
    at sun.security.tools.keytool.Main.doCommands(Main.java:792)
    at sun.security.tools.keytool.Main.run(Main.java:340)
    at sun.security.tools.keytool.Main.main(Main.java:333)

But, after installing the latest Oracle JDK and restarting Terminal, executing the following command:

keytool -list -keystore $(/usr/libexec/java_home)/jre/lib/security/cacerts -v

Results in:

Enter keystore password:

Which indicates that the keytool on path can access the keystore.

Dealing with multiple Python versions and PIP?

You can go to for example C:\Python2.7\Scripts and then run cmd from that path. After that you can run pip2.7 install yourpackage...

That will install package for that version of Python.

tkinter: Open a new window with a button prompt

Here's the nearly shortest possible solution to your question. The solution works in python 3.x. For python 2.x change the import to Tkinter rather than tkinter (the difference being the capitalization):

import tkinter as tk
#import Tkinter as tk  # for python 2
    
def create_window():
    window = tk.Toplevel(root)

root = tk.Tk()
b = tk.Button(root, text="Create new window", command=create_window)
b.pack()

root.mainloop()

This is definitely not what I recommend as an example of good coding style, but it illustrates the basic concepts: a button with a command, and a function that creates a window.

How to check if that data already exist in the database during update (Mongoose And Express)

There is a more simpler way using the mongoose exists function

router.post("/groups/members", async (ctx) => {
    const group_name = ctx.request.body.group_membership.group_name;
    const member_name = ctx.request.body.group_membership.group_members;
    const GroupMembership = GroupModels.GroupsMembers;
    console.log("group_name : ", group_name, "member : ", member_name);
    try {
        if (
            (await GroupMembership.exists({
                "group_membership.group_name": group_name,
            })) === false
        ) {
            console.log("new function");
            const newGroupMembership = await GroupMembership.insertMany({
                group_membership: [
                    { group_name: group_name, group_members: [member_name] },
                ],
            });
            await newGroupMembership.save();
        } else {
            const UpdateGroupMembership = await GroupMembership.updateOne(
                { "group_membership.group_name": group_name },
                { $push: { "group_membership.$.group_members": member_name } },
            );
            console.log("update function");
            await UpdateGroupMembership.save();
        }
        ctx.response.status = 201;
        ctx.response.message = "A member added to group successfully";
    } catch (error) {
        ctx.body = {
            message: "Some validations failed for Group Member Creation",
            error: error.message,
        };
        console.log(error);
        ctx.throw(400, error);
    }
});

How do I use a regular expression to match any string, but at least 3 characters?

If you want to match starting from the beginning of the word, use:

\b\w{3,}

\b: word boundary

\w: word character

{3,}: three or more times for the word character

Onclick function based on element id

you can try these:

document.getElementById("RootNode").onclick = function(){/*do something*/};

$('#RootNode').click(function(){/*do something*/});

$(document).on("click", "#RootNode", function(){/*do something*/});

There is a point for the first two method which is, it matters where in your page DOM, you should put them, the whole DOM should be loaded, to be able to find the, which is usually it gets solved if you wrap them in a window.onload or DOMReady event, like:

//in Vanilla JavaScript
window.addEventListener("load", function(){
     document.getElementById("RootNode").onclick = function(){/*do something*/};
});
//for jQuery
$(document).ready(function(){
    $('#RootNode').click(function(){/*do something*/});
});

collapse cell in jupyter notebook

The hide_code extension allows you to hide individual cells, and/or the prompts next to them. Install as

pip3 install hide_code

Visit https://github.com/kirbs-/hide_code/ for more info about this extension.

Subset dataframe by multiple logical conditions of rows to remove

And also

library(dplyr)
data %>% filter(!v1 %in% c("b", "d", "e"))

data %>% filter(v1 != "b" & v1 != "d" & v1 != "e")

data %>% filter(v1 != "b", v1 != "d", v1 != "e")

Since the & operator is implied by the comma.

How to start rails server?

You have to cd to your master directory and then rails s command will work without problems.

But do not forget bundle-install command when you didn't do it before.

The HTTP request is unauthorized with client authentication scheme 'Negotiate'. The authentication header received from the server was 'NTLM'

THE ANSWER: The problem was all of the posts for such an issue were related to older kerberos and IIS issues where proxy credentials or AllowNTLM properties were helping. My case was different. What I have discovered after hours of picking worms from the ground was that somewhat IIS installation did not include Negotiate provider under IIS Windows authentication providers list. So I had to add it and move up. My WCF service started to authenticate as expected. Here is the screenshot how it should look if you are using Windows authentication with Anonymous auth OFF.

You need to right click on Windows authentication and choose providers menu item.

enter image description here

Hope this helps to save some time.

What's the fastest way in Python to calculate cosine similarity given sparse matrix data?

I have tried some methods above. However, the experiment by @zbinsd has its limitation. The sparsity of matrix used in the experiment is extremely low while the real sparsity is usually over 90%. In my condition, the sparse is with the shape of (7000, 25000) and the sparsity of 97%. The method 4 is extremely slow and I can't tolerant getting the results. I use the method 6 which is finished in 10 s. Amazingly, I try the method below and it's finished in only 0.247 s.

import sklearn.preprocessing as pp

def cosine_similarities(mat):
    col_normed_mat = pp.normalize(mat.tocsc(), axis=0)
    return col_normed_mat.T * col_normed_mat

This efficient method is linked by enter link description here

How to generate a Makefile with source in sub-directories using just one makefile

This will do it without painful manipulation or multiple command sequences:

build/%.o: src/%.cpp
src/%.o: src/%.cpp
%.o:
    $(CC) -c $< -o $@

build/test.exe: build/widgets/apple.o build/widgets/knob.o build/tests/blend.o src/ui/flash.o
    $(LD) $^ -o $@

JasperE has explained why "%.o: %.cpp" won't work; this version has one pattern rule (%.o:) with commands and no prereqs, and two pattern rules (build/%.o: and src/%.o:) with prereqs and no commands. (Note that I put in the src/%.o rule to deal with src/ui/flash.o, assuming that wasn't a typo for build/ui/flash.o, so if you don't need it you can leave it out.)

build/test.exe needs build/widgets/apple.o,
build/widgets/apple.o looks like build/%.o, so it needs src/%.cpp (in this case src/widgets/apple.cpp),
build/widgets/apple.o also looks like %.o, so it executes the CC command and uses the prereqs it just found (namely src/widgets/apple.cpp) to build the target (build/widgets/apple.o)

Class file has wrong version 52.0, should be 50.0

i faced the same problem "Class file has wrong version 52.0, should be 50.0" when running java through ant... all i did was add fork="true" wherever i used the javac task and it worked...

NPM Install Error:Unexpected end of JSON input while parsing near '...nt-webpack-plugin":"0'

These commands worked for me

sudo npm cache clean --force

sudo npm cache verify

sudo npm i npm@latest -g

How to get the last character of a string in a shell?

For anyone interested in a pure POSIX method:

https://github.com/spiralofhope/shell-random/blob/master/live/sh/scripts/string-fetch-last-character.sh

#!/usr/bin/env  sh

string_fetch_last_character() {
  length_of_string=${#string}
  last_character="$string"
  i=1
  until [ $i -eq "$length_of_string" ]; do
    last_character="${last_character#?}"
    i=$(( i + 1 ))
  done

  printf  '%s'  "$last_character"
}


string_fetch_last_character  "$string"

Setting up JUnit with IntelliJ IDEA

Create and setup a "tests" folder
- In the Project sidebar on the left, right-click your project and do New > Directory. Name it "test" or whatever you like.
- Right-click the folder and choose "Mark Directory As > Test Source Root".
Adding JUnit library
- Right-click your project and choose "Open Module Settings" or hit F4. (Alternatively, File > Project Structure, Ctrl-Alt-Shift-S is probably the "right" way to do this)
- Go to the "Libraries" group, click the little green plus (look up), and choose "From Maven...".
- Search for "junit" -- you're looking for something like "junit:junit:4.11".
- Check whichever boxes you want (Sources, JavaDocs) then hit OK.
- Keep hitting OK until you're back to the code.

Write your first unit test

Right-click on your test folder, "New > Java Class", call it whatever, e.g. MyFirstTest.

Write a JUnit test -- here's mine:

import org.junit.Assert;
import org.junit.Test;

public class MyFirstTest {
    @Test
    public void firstTest() {
        Assert.assertTrue(true);
    }
}

Run your tests
- Right-click on your test folder and choose "Run 'All Tests'". Presto, testo.
- To run again, you can either hit the green "Play"-style button that appeared in the new section that popped on the bottom of your window, or you can hit the green "Play"-style button in the top bar.

Android studio, gradle and NDK

configure project in android studio from eclipse: you have to import eclipse ndk project to android studio without exporting to gradle and it works , also you need to add path of ndk in local.properties ,if shows error then add

sourceSets.main {
        jniLibs.srcDir 'src/main/libs' 
        jni.srcDirs = [] //disable automatic ndk-build callenter code here
    }

in build.gradle file then create jni folder and file using terminal and run it will work

:not(:empty) CSS selector is not working?

Another pure CSS solution

_x000D_

.form{_x000D_
  position:relative;_x000D_
  display:inline-block;_x000D_
}_x000D_
.form input{_x000D_
  margin-top:10px;_x000D_
}_x000D_
.form label{_x000D_
    position:absolute;_x000D_
    left:0;_x000D_
    top:0;_x000D_
    opacity:0;_x000D_
    transition:all 1s ease;_x000D_
}_x000D_
input:not(:placeholder-shown) + label{_x000D_
    top:-10px;_x000D_
    opacity:1;_x000D_
}

_x000D_

<div class="form">_x000D_
    <input type="text" id="inputFName" placeholder="Firstname">_x000D_
    <label class="label" for="inputFName">Firstname</label>_x000D_
</div>_x000D_
<div class="form">_x000D_
    <input type="text" id="inputLName" placeholder="Lastname">_x000D_
    <label class="label" for="inputLName">Lastname</label>_x000D_
</div>

_x000D_

mysql: get record count between two date-time

for speed you can do this

WHERE date(created_at) ='2019-10-21'

What is a "callback" in C and how are they implemented?

A simple call back program. Hope it answers your question.

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include "../../common_typedef.h"

typedef void (*call_back) (S32, S32);

void test_call_back(S32 a, S32 b)
{
    printf("In call back function, a:%d \t b:%d \n", a, b);
}

void call_callback_func(call_back back)
{
    S32 a = 5;
    S32 b = 7;

    back(a, b);
}

S32 main(S32 argc, S8 *argv[])
{
    S32 ret = SUCCESS;

    call_back back;

    back = test_call_back;

    call_callback_func(back);

    return ret;
}

How do I get the height of a div's full content with jQuery?

If you can possibly help it, DO NOT USE .scrollHeight.

.scrollHeight does not yield the same kind of results in different browsers in certain circumstances (most prominently while scrolling).

For example:

<div id='outer' style='width:100px; height:350px; overflow-y:hidden;'>
<div style='width:100px; height:150px;'></div>
<div style='width:100px; height:150px;'></div>
<div style='width:100px; height:150px;'></div>
<div style='width:100px; height:150px;'></div>
<div style='width:100px; height:150px;'></div>
<div style='width:100px; height:150px;'></div>
</div>

If you do

console.log($('#outer').scrollHeight);

you'll get 900px in Chrome, FireFox and Opera. That's great.

But, if you attach a wheelevent / wheel event to #outer, when you scroll it, Chrome will give you a constant value of 900px (correct) but FireFox and Opera will change their values as you scroll down (incorrect).

A very simple way to do this is like so (a bit of a cheat, really). (This example works while dynamically adding content to #outer as well):

$('#outer').css("height", "auto");
var outerContentsHeight = $('#outer').height();
$('#outer').css("height", "350px");

console.log(outerContentsHeight); //Should get 900px in these 3 browsers

The reason I pick these three browsers is because all three can disagree on the value of .scrollHeight in certain circumstances. I ran into this issue making my own scrollpanes. Hope this helps someone.

How to find the minimum value of a column in R?

If you need minimal value for particular column

min(data[,2])

Note: R considers NA both the minimum and maximum value so if you have NA's in your column, they return: NA. To remedy, use:

min(data[,2], na.rm=T)

C++ Object Instantiation

On the contrary, you should always prefer stack allocations, to the extent that as a rule of thumb, you should never have new/delete in your user code.

As you say, when the variable is declared on the stack, its destructor is automatically called when it goes out of scope, which is your main tool for tracking resource lifetime and avoiding leaks.

So in general, every time you need to allocate a resource, whether it's memory (by calling new), file handles, sockets or anything else, wrap it in a class where the constructor acquires the resource, and the destructor releases it. Then you can create an object of that type on the stack, and you're guaranteed that your resource gets freed when it goes out of scope. That way you don't have to track your new/delete pairs everywhere to ensure you avoid memory leaks.

The most common name for this idiom is RAII

Also look into smart pointer classes which are used to wrap the resulting pointers on the rare cases when you do have to allocate something with new outside a dedicated RAII object. You instead pass the pointer to a smart pointer, which then tracks its lifetime, for example by reference counting, and calls the destructor when the last reference goes out of scope. The standard library has std::unique_ptr for simple scope-based management, and std::shared_ptr which does reference counting to implement shared ownership.

Many tutorials demonstrate object instantiation using a snippet such as ...

So what you've discovered is that most tutorials suck. ;) Most tutorials teach you lousy C++ practices, including calling new/delete to create variables when it's not necessary, and giving you a hard time tracking lifetime of your allocations.

How to submit a form on enter when the textarea has focus?

<form id="myform">
    <input type="textbox" id="field"/>
    <input type="button" value="submit">
</form>

<script>
    $(function () {
        $("#field").keyup(function (event) {
            if (event.which === 13) {
                document.myform.submit();
            }
        }
    });
</script>

How do you add input from user into list in Python

shopList = [] 
maxLengthList = 6
while len(shopList) < maxLengthList:
    item = input("Enter your Item to the List: ")
    shopList.append(item)
    print shopList
print "That's your Shopping List"
print shopList

Stateless vs Stateful

A stateful app is one that stores information about what has happened or changed since it started running. Any public info about what "mode" it is in, or how many records is has processed, or whatever, makes it stateful.

Stateless apps don't expose any of that information. They give the same response to the same request, function or method call, every time. HTTP is stateless in its raw form - if you do a GET to a particular URL, you get (theoretically) the same response every time. The exception of course is when we start adding statefulness on top, e.g. with ASP.NET web apps :) But if you think of a static website with only HTML files and images, you'll know what I mean.

Selenium: Can I set any of the attribute value of a WebElement in Selenium?

Another to answer this question available here answered by @nilesh https://stackoverflow.com/a/19934852/2079692

public void setAttributeValue(WebElement elem, String value){
    JavascriptExecutor js = (JavascriptExecutor) driver;
    js.executeScript("arguments[0].setAttribute(arguments[1],arguments[2])",
        elem, "value", value
    );
}

this takes advantage of selenium findElementBy function where xpath can be used also.

Oracle - Insert New Row with Auto Incremental ID

ELXAN@DB1> create table cedvel(id integer,ad varchar2(15));

Table created.

ELXAN@DB1> alter table cedvel add constraint pk_ad primary key(id);

Table altered.

ELXAN@DB1> create sequence test_seq start with 1 increment by 1;

Sequence created.

ELXAN@DB1> create or replace trigger ad_insert
before insert on cedvel
REFERENCING NEW AS NEW OLD AS OLD
for each row
begin
    select test_seq.nextval into :new.id from dual;
end;
/  2    3    4    5    6    7    8 

Trigger created.

ELXAN@DB1> insert into cedvel (ad) values ('nese');

1 row created.

ASP.NET Core return JSON with status code

Awesome answers I found here and I also tried this return statement see StatusCode(whatever code you wish) and it worked!!!

return Ok(new {
                    Token = new JwtSecurityTokenHandler().WriteToken(token),
                    Expiration = token.ValidTo,
                    username = user.FullName,
                    StatusCode = StatusCode(200)
                });

Difference between two DateTimes C#?

You can do the following:

TimeSpan duration = b - a;

There's plenty of built in methods in the timespan class to do what you need, i.e.

duration.TotalSeconds
duration.TotalMinutes

More info can be found here.

Android Service needs to run always (Never pause or stop)

Add this in manifest.

      <service
        android:name=".YourServiceName"
        android:enabled="true"
        android:exported="false" />

Add a service class.

public class YourServiceName extends Service {


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

      // Timer task makes your service will repeat after every 20 Sec.
       TimerTask doAsynchronousTask = new TimerTask() {
            @Override
            public void run() {
                handler.post(new Runnable() {
                    public void run() {
                       // Add your code here.

                     }

               });
            }
        };
  //Starts after 20 sec and will repeat on every 20 sec of time interval.
        timer.schedule(doAsynchronousTask, 20000,20000);  // 20 sec timer 
                              (enter your own time)
    }
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        // TODO do something useful

      return START_STICKY;
    }

}

Git Remote: Error: fatal: protocol error: bad line length character: Unab

After loading the SSH private key in Git Extensions, this issue gets resolved.

Adding 1 hour to time variable

You can do like this

    echo date('Y-m-d H:i:s', strtotime('4 minute'));
    echo date('Y-m-d H:i:s', strtotime('6 hour'));
    echo date('Y-m-d H:i:s', strtotime('2 day'));

sql query with multiple where statements

This..

(
        (meta_key = 'lat' AND meta_value >= '60.23457047672217')
    OR
        (meta_key = 'lat' AND meta_value <= '60.23457047672217')
)

is the same as

(
        (meta_key = 'lat')
)

Adding it all together (the same applies to the long filter) you have this impossible WHERE clause which will give no rows because meta_key cannot be 2 values in one row

WHERE
    (meta_key = 'lat' AND meta_key = 'long' )

You need to review your operators to make sure you get the correct logic

How do I use an image as a submit button?

Just remove the border and add a background image in css

Example:

_x000D_

$("#form").on('submit', function() {_x000D_
   alert($("#submit-icon").val());_x000D_
});

_x000D_

#submit-icon {_x000D_
  background-image: url("https://pixabay.com/static/uploads/photo/2016/10/18/21/22/california-1751455__340.jpg"); /* Change url to wanted image */_x000D_
  background-size: cover;_x000D_
  border: none;_x000D_
  width: 32px;_x000D_
  height: 32px;_x000D_
  cursor: pointer;_x000D_
  color: transparent;_x000D_
}

_x000D_

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<form id="form">_x000D_
  <input type="submit" id="submit-icon" value="test">_x000D_
</form>

_x000D_

Inserting the iframe into react component

You can use property dangerouslySetInnerHTML, like this

_x000D_

const Component = React.createClass({_x000D_
  iframe: function () {_x000D_
    return {_x000D_
      __html: this.props.iframe_x000D_
    }_x000D_
  },_x000D_
_x000D_
  render: function() {_x000D_
    return (_x000D_
      <div>_x000D_
        <div dangerouslySetInnerHTML={ this.iframe() } />_x000D_
      </div>_x000D_
    );_x000D_
  }_x000D_
});_x000D_
_x000D_
const iframe = '<iframe src="https://www.example.com/show?data..." width="540" height="450"></iframe>'; _x000D_
_x000D_
ReactDOM.render(_x000D_
  <Component iframe={iframe} />,_x000D_
  document.getElementById('container')_x000D_
);

_x000D_

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>_x000D_
<div id="container"></div>

_x000D_

also, you can copy all attributes from the string(based on the question, you get iframe as a string from a server) which contains <iframe> tag and pass it to new <iframe> tag, like that

_x000D_

/**_x000D_
 * getAttrs_x000D_
 * returns all attributes from TAG string_x000D_
 * @return Object_x000D_
 */_x000D_
const getAttrs = (iframeTag) => {_x000D_
  var doc = document.createElement('div');_x000D_
  doc.innerHTML = iframeTag;_x000D_
_x000D_
  const iframe = doc.getElementsByTagName('iframe')[0];_x000D_
  return [].slice_x000D_
    .call(iframe.attributes)_x000D_
    .reduce((attrs, element) => {_x000D_
      attrs[element.name] = element.value;_x000D_
      return attrs;_x000D_
    }, {});_x000D_
}_x000D_
_x000D_
const Component = React.createClass({_x000D_
  render: function() {_x000D_
    return (_x000D_
      <div>_x000D_
        <iframe {...getAttrs(this.props.iframe) } />_x000D_
      </div>_x000D_
    );_x000D_
  }_x000D_
});_x000D_
_x000D_
const iframe = '<iframe src="https://www.example.com/show?data..." width="540" height="450"></iframe>'; _x000D_
_x000D_
ReactDOM.render(_x000D_
  <Component iframe={iframe} />,_x000D_
  document.getElementById('container')_x000D_
);

_x000D_

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>_x000D_
<div id="container"><div>

_x000D_

How to properly and completely close/reset a TcpClient connection?

The correct way to close the socket so you can re-open is:

tcpClient.Client.Disconnect(true);

The Boolean parameter indicates if you want to reuse the socket:

Could not get constructor for org.hibernate.persister.entity.SingleTableEntityPersister

I resolved this issue by excluding byte-buddy dependency from springfox

<dependency>
  <groupId>io.springfox</groupId>
  <artifactId>springfox-swagger2</artifactId>
  <version>2.7.0</version>
  <exclusions>
  <exclusion>
    <groupId>net.bytebuddy</groupId>
    <artifactId>byte-buddy</artifactId>
  </exclusion>
  </exclusions>
</dependency>

<dependency>
  <groupId>io.springfox</groupId>
  <artifactId>springfox-swagger-ui</artifactId>
  <version>2.7.0</version>
  <exclusions>
  <exclusion>
    <groupId>net.bytebuddy</groupId>
    <artifactId>byte-buddy</artifactId>
  </exclusion>
</exclusions>
</dependency>

How can I search (case-insensitive) in a column using LIKE wildcard?

I've always solved this using lower:

SELECT * FROM trees WHERE LOWER( trees.title ) LIKE  '%elm%'

Enable & Disable a Div and its elements in Javascript

The following selects all descendant elements and disables them:

$("#dcacl").find("*").prop("disabled", true);

But it only really makes sense to disable certain element types: inputs, buttons, etc., so you want a more specific selector:

$("#dcac1").find(":input").prop("disabled",true);
// noting that ":input" gives you the equivalent of
$("#dcac1").find("input,select,textarea,button").prop("disabled",true);

To re-enable you just set "disabled" to false.

I want to Disable them at loading the page and then by a click i can enable them

OK, so put the above code in a document ready handler, and setup an appropriate click handler:

$(document).ready(function() {
    var $dcac1kids = $("#dcac1").find(":input");
    $dcac1kids.prop("disabled",true);

    // not sure what you want to click on to re-enable
    $("selector for whatever you want to click").one("click",function() {
       $dcac1kids.prop("disabled",false);
    }
}

I've cached the results of the selector on the assumption that you're not adding more elements to the div between the page load and the click. And I've attached the click handler with .one() since you haven't specified a requirement to re-disable the elements so presumably the event only needs to be handled once. Of course you can change the .one() to .click() if appropriate.

Installing Numpy on 64bit Windows 7 with Python 2.7.3

Download numpy-1.9.2+mkl-cp27-none-win32.whl from http://www.lfd.uci.edu/~gohlke/pythonlibs/#numpy .

Copy the file to C:\Python27\Scripts

Run cmd from the above location and type

pip install numpy-1.9.2+mkl-cp27-none-win32.whl

You will hopefully get the below output:

Processing c:\python27\scripts\numpy-1.9.2+mkl-cp27-none-win32.whl
Installing collected packages: numpy
Successfully installed numpy-1.9.2

Hope that works for you.

EDIT 1
Adding @oneleggedmule 's suggestion:

You can also run the following command in the cmd:

pip2.7 install numpy-1.9.2+mkl-cp27-none-win_amd64.whl

Basically, writing pip alone also works perfectly (as in the original answer). Writing the version 2.7 can also be done for the sake of clarity or specification.

How to convert string to date to string in Swift iOS?

See answer from Gary Makin. And you need change the format or data. Because the data that you have do not fit under the chosen format. For example this code works correct:

let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "MM-dd-yyyy"
let dateObj = dateFormatter.dateFromString("10 10 2001")
print("Dateobj: \(dateObj)")

In Java, how to find if first character in a string is upper case without regex

Make sure you first check for null and empty and ten converts existing string to upper. Use S.O.P if want to see outputs otherwise boolean like Rabiz did.

 public static void main(String[] args)
 {
     System.out.println("Enter name");
     Scanner kb = new Scanner (System.in);
     String text =  kb.next();

     if ( null == text || text.isEmpty())
     {
         System.out.println("Text empty");
     }
     else if (text.charAt(0) == (text.toUpperCase().charAt(0)))
     {
         System.out.println("First letter in word "+ text + " is upper case");
     }
  }

SQL Server : export query as a .txt file

You can use windows Powershell to execute a query and output it to a text file

Invoke-Sqlcmd -Query "Select * from database" -ServerInstance "Servername\SQL2008" -Database "DbName" > c:\Users\outputFileName.txt

How to check if a variable is equal to one string or another string?

This does not do what you expect:

if var is 'stringone' or 'stringtwo':
    dosomething()

It is the same as:

if (var is 'stringone') or 'stringtwo':
    dosomething()

Which is always true, since 'stringtwo' is considered a "true" value.

There are two alternatives:

if var in ('stringone', 'stringtwo'):
    dosomething()

Or you can write separate equality tests,

if var == 'stringone' or var == 'stringtwo':
    dosomething()

Don't use is, because is compares object identity. You might get away with it sometimes because Python interns a lot of strings, just like you might get away with it in Java because Java interns a lot of strings. But don't use is unless you really want object identity.

>>> 'a' + 'b' == 'ab'
True
>>> 'a' + 'b' is 'abc'[:2]
False # but could be True
>>> 'a' + 'b' is 'ab'
True  # but could be False

Jquery function return value

I'm not entirely sure of the general purpose of the function, but you could always do this:

function getMachine(color, qty) {
    var retval;
    $("#getMachine li").each(function() {
        var thisArray = $(this).text().split("~");
        if(thisArray[0] == color&& qty>= parseInt(thisArray[1]) && qty<= parseInt(thisArray[2])) {
            retval = thisArray[3];
            return false;
        }
    });
    return retval;
}

var retval = getMachine(color, qty);

How to write LDAP query to test if user is member of a group?

You must set your query base to the DN of the user in question, then set your filter to the DN of the group you're wondering if they're a member of. To see if jdoe is a member of the office group then your query will look something like this:

ldapsearch -x -D "ldap_user" -w "user_passwd" -b "cn=jdoe,dc=example,dc=local" -h ldap_host '(memberof=cn=officegroup,dc=example,dc=local)'

If you want to see ALL the groups he's a member of, just request only the 'memberof' attribute in your search, like this:

ldapsearch -x -D "ldap_user" -w "user_passwd" -b "cn=jdoe,dc=example,dc=local" -h ldap_host **memberof**

Limit characters displayed in span

Here's an example of using text-overflow:

_x000D_

.text {_x000D_
  display: block;_x000D_
  width: 100px;_x000D_
  overflow: hidden;_x000D_
  white-space: nowrap;_x000D_
  text-overflow: ellipsis;_x000D_
}

_x000D_

<span class="text">Hello world this is a long sentence</span>

_x000D_

How to scp in Python?

Try the Python scp module for Paramiko. It's very easy to use. See the following example:

import paramiko
from scp import SCPClient

def createSSHClient(server, port, user, password):
    client = paramiko.SSHClient()
    client.load_system_host_keys()
    client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
    client.connect(server, port, user, password)
    return client

ssh = createSSHClient(server, port, user, password)
scp = SCPClient(ssh.get_transport())

Then call scp.get() or scp.put() to do SCP operations.

(SCPClient code)

COALESCE Function in TSQL

I'm not sure why you think the documentation is vague.

It simply goes through all the parameters one by one, and returns the first that is NOT NULL.

COALESCE(NULL, NULL, NULL, 1, 2, 3)
=> 1


COALESCE(1, 2, 3, 4, 5, NULL)
=> 1


COALESCE(NULL, NULL, NULL, 3, 2, NULL)
=> 3


COALESCE(6, 5, 4, 3, 2, NULL)
=> 6


COALESCE(NULL, NULL, NULL, NULL, NULL, NULL)
=> NULL

It accepts pretty much any number of parameters, but they should be the same data-type. (If they're not the same data-type, they get implicitly cast to an appropriate data-type using data-type order of precedence.)

It's like ISNULL() but for multiple parameters, rather than just two.

It's also ANSI-SQL, where-as ISNULL() isn't.

How can you speed up Eclipse?

While not directly related to Eclipse:

If you're running Windows 7 (and presumably Windows Vista), be sure to disable the file indexing of your workspace folder if your stuff is is in the default place - your home folder. Windows by default indexes everything in you home folder, and it's normally just a waste for your workspace. (Right click the workspace folder in explorer , Properties -> Advanced.)

How to do Base64 encoding in node.js?

The accepted answer previously contained new Buffer(), which is considered a security issue in node versions greater than 6 (although it seems likely for this usecase that the input can always be coerced to a string).

The Buffer constructor is deprecated according to the documentation.

Here is an example of a vulnerability that can result from using it in the ws library.

The code snippets should read:

console.log(Buffer.from("Hello World").toString('base64'));
console.log(Buffer.from("SGVsbG8gV29ybGQ=", 'base64').toString('ascii'));

After this answer was written, it has been updated and now matches this.

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