Programs & Examples On #Tsvector

MySQL "CREATE TABLE IF NOT EXISTS" -> Error 1050

Well there are lot of answeres already provided and lot are making sense too.

Some mentioned it is just warning and some giving a temp way to disable warnings. All that will work but add risk when number of transactions in your DB is high.

I came across similar situation today and here is the query I came up with...

declare
begin
  execute immediate '
    create table "TBL" ("ID" number not null)';
  exception when others then
    if SQLCODE = -955 then null; else raise; end if;
end;
/

This is simple, if exception come while running query it will be suppressed. and you can use same for SQL or Oracle.

How to debug JavaScript / jQuery event bindings with Firebug or similar tools?

See How to find event listeners on a DOM node.

In a nutshell, assuming at some point an event handler is attached to your element (eg): $('#foo').click(function() { console.log('clicked!') });

You inspect it like so:

  • jQuery 1.3.x

    var clickEvents = $('#foo').data("events").click;
    jQuery.each(clickEvents, function(key, value) {
      console.log(value) // prints "function() { console.log('clicked!') }"
    })
    
  • jQuery 1.4.x

    var clickEvents = $('#foo').data("events").click;
    jQuery.each(clickEvents, function(key, handlerObj) {
      console.log(handlerObj.handler) // prints "function() { console.log('clicked!') }"
    })
    

See jQuery.fn.data (where jQuery stores your handler internally).

  • jQuery 1.8.x

    var clickEvents = $._data($('#foo')[0], "events").click;
    jQuery.each(clickEvents, function(key, handlerObj) {
      console.log(handlerObj.handler) // prints "function() { console.log('clicked!') }"
    })
    

How to select an item in a ListView programmatically?

ListViewItem.IsSelected = true;
ListViewItem.Focus();

Parsing JSON giving "unexpected token o" error

I was seeing this unexpected token o error because my (incomplete) code had run previously (live reload!) and set the particular keyed local storage value to [object Object] instead of {}. It wasn't until I changed keys, that things started working as expected. Alternatively, you can follow these instructions to delete the incorrectly set localStorage value.

No Activity found to handle Intent : android.intent.action.VIEW

try checking with any Url like add

https://www.google.com

in path and start activity if its works than you are adding wrong path

Convert a String In C++ To Upper Case

typedef std::string::value_type char_t;

char_t up_char( char_t ch )
{
    return std::use_facet< std::ctype< char_t > >( std::locale() ).toupper( ch );
}

std::string toupper( const std::string &src )
{
    std::string result;
    std::transform( src.begin(), src.end(), std::back_inserter( result ), up_char );
    return result;
}

const std::string src  = "test test TEST";

std::cout << toupper( src );

What are the differences between Pandas and NumPy+SciPy in Python?

Pandas offer a great way to manipulate tables, as you can make binning easy (binning a dataframe in pandas in Python) and calculate statistics. Other thing that is great in pandas is the Panel class that you can join series of layers with different properties and combine it using groupby function.

how can the textbox width be reduced?

Is not nice to define textbox width without using CSS, be warned ;-)

<input type="text" name="d" value="4" size="4" />

Is there a Subversion command to reset the working copy?

You can recursively revert like this:

svn revert --recursive .

There is no way (without writing a creative script) to remove things that aren't under source control. I think the closest you could do is to iterate over all of the files, use then grep the result of svn list, and if the grep fails, then delete it.

EDIT: The solution for the creative script is here: Automatically remove Subversion unversioned files

So you could create a script that combines a revert with whichever answer in the linked question suits you best.

How to get JSON from URL in JavaScript?

ES8(2017) try

obj = await (await fetch(url)).json();

_x000D_
_x000D_
async function load() {_x000D_
    let url = 'https://my-json-server.typicode.com/typicode/demo/db';_x000D_
    let obj = await (await fetch(url)).json();_x000D_
    console.log(obj);_x000D_
}_x000D_
_x000D_
load();
_x000D_
_x000D_
_x000D_

you can handle errors by try-catch

_x000D_
_x000D_
async function load() {_x000D_
    let url = 'http://query.yahooapis.com/v1/publ...';_x000D_
    let obj = null;_x000D_
    _x000D_
    try {_x000D_
        obj = await (await fetch(url)).json();_x000D_
    } catch(e) {_x000D_
        console.log('error');_x000D_
    }_x000D_
    _x000D_
    console.log(obj);_x000D_
}_x000D_
_x000D_
load();
_x000D_
_x000D_
_x000D_

How do I get the max and min values from a set of numbers entered?

here you need to skip int 0 like following:

val = s.nextInt();
  if ((val < min) && (val!=0)) {
      min = val;
  }

How to install mysql-connector via pip

If loading via pip install mysql-connector and leads an error Unable to find Protobuf include directory then this would be useful pip install mysql-connector==2.1.4

mysql-connector is obsolete, so use pip install mysql-connector-python. Same here

How to add a recyclerView inside another recyclerView

I would like to suggest to use a single RecyclerView and populate your list items dynamically. I've added a github project to describe how this can be done. You might have a look. While the other solutions will work just fine, I would like to suggest, this is a much faster and efficient way of showing multiple lists in a RecyclerView.

The idea is to add logic in your onCreateViewHolder and onBindViewHolder method so that you can inflate proper view for the exact positions in your RecyclerView.

I've added a sample project along with that wiki too. You might clone and check what it does. For convenience, I am posting the adapter that I have used.

public class DynamicListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

    private static final int FOOTER_VIEW = 1;
    private static final int FIRST_LIST_ITEM_VIEW = 2;
    private static final int FIRST_LIST_HEADER_VIEW = 3;
    private static final int SECOND_LIST_ITEM_VIEW = 4;
    private static final int SECOND_LIST_HEADER_VIEW = 5;

    private ArrayList<ListObject> firstList = new ArrayList<ListObject>();
    private ArrayList<ListObject> secondList = new ArrayList<ListObject>();

    public DynamicListAdapter() {
    }

    public void setFirstList(ArrayList<ListObject> firstList) {
        this.firstList = firstList;
    }

    public void setSecondList(ArrayList<ListObject> secondList) {
        this.secondList = secondList;
    }

    public class ViewHolder extends RecyclerView.ViewHolder {
        // List items of first list
        private TextView mTextDescription1;
        private TextView mListItemTitle1;

        // List items of second list
        private TextView mTextDescription2;
        private TextView mListItemTitle2;

        // Element of footer view
        private TextView footerTextView;

        public ViewHolder(final View itemView) {
            super(itemView);

            // Get the view of the elements of first list
            mTextDescription1 = (TextView) itemView.findViewById(R.id.description1);
            mListItemTitle1 = (TextView) itemView.findViewById(R.id.title1);

            // Get the view of the elements of second list
            mTextDescription2 = (TextView) itemView.findViewById(R.id.description2);
            mListItemTitle2 = (TextView) itemView.findViewById(R.id.title2);

            // Get the view of the footer elements
            footerTextView = (TextView) itemView.findViewById(R.id.footer);
        }

        public void bindViewSecondList(int pos) {

            if (firstList == null) pos = pos - 1;
            else {
                if (firstList.size() == 0) pos = pos - 1;
                else pos = pos - firstList.size() - 2;
            }

            final String description = secondList.get(pos).getDescription();
            final String title = secondList.get(pos).getTitle();

            mTextDescription2.setText(description);
            mListItemTitle2.setText(title);
        }

        public void bindViewFirstList(int pos) {

            // Decrease pos by 1 as there is a header view now.
            pos = pos - 1;

            final String description = firstList.get(pos).getDescription();
            final String title = firstList.get(pos).getTitle();

            mTextDescription1.setText(description);
            mListItemTitle1.setText(title);
        }

        public void bindViewFooter(int pos) {
            footerTextView.setText("This is footer");
        }
    }

    public class FooterViewHolder extends ViewHolder {
        public FooterViewHolder(View itemView) {
            super(itemView);
        }
    }

    private class FirstListHeaderViewHolder extends ViewHolder {
        public FirstListHeaderViewHolder(View itemView) {
            super(itemView);
        }
    }

    private class FirstListItemViewHolder extends ViewHolder {
        public FirstListItemViewHolder(View itemView) {
            super(itemView);
        }
    }

    private class SecondListHeaderViewHolder extends ViewHolder {
        public SecondListHeaderViewHolder(View itemView) {
            super(itemView);
        }
    }

    private class SecondListItemViewHolder extends ViewHolder {
        public SecondListItemViewHolder(View itemView) {
            super(itemView);
        }
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        View v;

        if (viewType == FOOTER_VIEW) {
            v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_footer, parent, false);
            FooterViewHolder vh = new FooterViewHolder(v);
            return vh;

        } else if (viewType == FIRST_LIST_ITEM_VIEW) {
            v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_first_list, parent, false);
            FirstListItemViewHolder vh = new FirstListItemViewHolder(v);
            return vh;

        } else if (viewType == FIRST_LIST_HEADER_VIEW) {
            v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_first_list_header, parent, false);
            FirstListHeaderViewHolder vh = new FirstListHeaderViewHolder(v);
            return vh;

        } else if (viewType == SECOND_LIST_HEADER_VIEW) {
            v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_second_list_header, parent, false);
            SecondListHeaderViewHolder vh = new SecondListHeaderViewHolder(v);
            return vh;

        } else {
            // SECOND_LIST_ITEM_VIEW
            v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_second_list, parent, false);
            SecondListItemViewHolder vh = new SecondListItemViewHolder(v);
            return vh;
        }
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {

        try {
            if (holder instanceof SecondListItemViewHolder) {
                SecondListItemViewHolder vh = (SecondListItemViewHolder) holder;
                vh.bindViewSecondList(position);

            } else if (holder instanceof FirstListHeaderViewHolder) {
                FirstListHeaderViewHolder vh = (FirstListHeaderViewHolder) holder;

            } else if (holder instanceof FirstListItemViewHolder) {
                FirstListItemViewHolder vh = (FirstListItemViewHolder) holder;
                vh.bindViewFirstList(position);

            } else if (holder instanceof SecondListHeaderViewHolder) {
                SecondListHeaderViewHolder vh = (SecondListHeaderViewHolder) holder;

            } else if (holder instanceof FooterViewHolder) {
                FooterViewHolder vh = (FooterViewHolder) holder;
                vh.bindViewFooter(position);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Override
    public int getItemCount() {

        int firstListSize = 0;
        int secondListSize = 0;

        if (secondList == null && firstList == null) return 0;

        if (secondList != null)
            secondListSize = secondList.size();
        if (firstList != null)
            firstListSize = firstList.size();

        if (secondListSize > 0 && firstListSize > 0)
            return 1 + firstListSize + 1 + secondListSize + 1;   // first list header, first list size, second list header , second list size, footer
        else if (secondListSize > 0 && firstListSize == 0)
            return 1 + secondListSize + 1;                       // second list header, second list size, footer
        else if (secondListSize == 0 && firstListSize > 0)
            return 1 + firstListSize;                            // first list header , first list size
        else return 0;
    }

    @Override
    public int getItemViewType(int position) {

        int firstListSize = 0;
        int secondListSize = 0;

        if (secondList == null && firstList == null)
            return super.getItemViewType(position);

        if (secondList != null)
            secondListSize = secondList.size();
        if (firstList != null)
            firstListSize = firstList.size();

        if (secondListSize > 0 && firstListSize > 0) {
            if (position == 0) return FIRST_LIST_HEADER_VIEW;
            else if (position == firstListSize + 1)
                return SECOND_LIST_HEADER_VIEW;
            else if (position == secondListSize + 1 + firstListSize + 1)
                return FOOTER_VIEW;
            else if (position > firstListSize + 1)
                return SECOND_LIST_ITEM_VIEW;
            else return FIRST_LIST_ITEM_VIEW;

        } else if (secondListSize > 0 && firstListSize == 0) {
            if (position == 0) return SECOND_LIST_HEADER_VIEW;
            else if (position == secondListSize + 1) return FOOTER_VIEW;
            else return SECOND_LIST_ITEM_VIEW;

        } else if (secondListSize == 0 && firstListSize > 0) {
            if (position == 0) return FIRST_LIST_HEADER_VIEW;
            else return FIRST_LIST_ITEM_VIEW;
        }

        return super.getItemViewType(position);
    }
}

There is another way of keeping your items in a single ArrayList of objects so that you can set an attribute tagging the items to indicate which item is from first list and which one belongs to second list. Then pass that ArrayList into your RecyclerView and then implement the logic inside adapter to populate them dynamically.

Hope that helps.

In SQL Server, what does "SET ANSI_NULLS ON" mean?

It means that no rows will be returned if @region is NULL, when used in your first example, even if there are rows in the table where Region is NULL.

When ANSI_NULLS is on (which you should always set on anyway, since the option to not have it on is going to be removed in the future), any comparison operation where (at least) one of the operands is NULL produces the third logic value - UNKNOWN (as opposed to TRUE and FALSE).

UNKNOWN values propagate through any combining boolean operators if they're not already decided (e.g. AND with a FALSE operand or OR with a TRUE operand) or negations (NOT).

The WHERE clause is used to filter the result set produced by the FROM clause, such that the overall value of the WHERE clause must be TRUE for the row to not be filtered out. So, if an UNKNOWN is produced by any comparison, it will cause the row to be filtered out.


@user1227804's answer includes this quote:

If both sides of the comparison are columns or compound expressions, the setting does not affect the comparison.

from SET ANSI_NULLS*

However, I'm not sure what point it's trying to make, since if two NULL columns are compared (e.g. in a JOIN), the comparison still fails:

create table #T1 (
    ID int not null,
    Val1 varchar(10) null
)
insert into #T1(ID,Val1) select 1,null

create table #T2 (
    ID int not null,
    Val1 varchar(10) null
)
insert into #T2(ID,Val1) select 1,null

select * from #T1 t1 inner join #T2 t2 on t1.ID = t2.ID and t1.Val1 = t2.Val1

The above query returns 0 rows, whereas:

select * from #T1 t1 inner join #T2 t2 on t1.ID = t2.ID and (t1.Val1 = t2.Val1 or t1.Val1 is null and t2.Val1 is null)

Returns one row. So even when both operands are columns, NULL does not equal NULL. And the documentation for = doesn't have anything to say about the operands:

When you compare two NULL expressions, the result depends on the ANSI_NULLS setting:

If ANSI_NULLS is set to ON, the result is NULL1, following the ANSI convention that a NULL (or unknown) value is not equal to another NULL or unknown value.

If ANSI_NULLS is set to OFF, the result of NULL compared to NULL is TRUE.

Comparing NULL to a non-NULL value always results in FALSE2.

However, both 1 and 2 are incorrect - the result of both comparisons is UNKNOWN.


*The cryptic meaning of this text was finally discovered years later. What it actually means is that, for those comparisons, the setting has no effect and it always acts as if the setting were ON. Would have been clearer if it had stated that SET ANSI_NULLS OFF was the setting that had no affect.

enable cors in .htaccess

Should't the .htaccess use add instead of set?

Header add Access-Control-Allow-Origin "*"
Header add Access-Control-Allow-Methods: "GET,POST,OPTIONS,DELETE,PUT"

What does `return` keyword mean inside `forEach` function?

The return exits the current function, but the iterations keeps on, so you get the "next" item that skips the if and alerts the 4...

If you need to stop the looping, you should just use a plain for loop like so:

$('button').click(function () {
   var arr = [1, 2, 3, 4, 5];
   for(var i = 0; i < arr.length; i++) {
     var n = arr[i]; 
     if (n == 3) {
         break;
      }
      alert(n);
   })
})

You can read more about js break & continue here: http://www.w3schools.com/js/js_break.asp

Remove Top Line of Text File with PowerShell

Inspired by AASoft's answer, I went out to improve it a bit more:

  1. Avoid the loop variable $i and the comparison with 0 in every loop
  2. Wrap the execution into a try..finally block to always close the files in use
  3. Make the solution work for an arbitrary number of lines to remove from the beginning of the file
  4. Use a variable $p to reference the current directory

These changes lead to the following code:

$p = (Get-Location).Path

(Measure-Command {
    # Number of lines to skip
    $skip = 1
    $ins = New-Object System.IO.StreamReader ($p + "\test.log")
    $outs = New-Object System.IO.StreamWriter ($p + "\test-1.log")
    try {
        # Skip the first N lines, but allow for fewer than N, as well
        for( $s = 1; $s -le $skip -and !$ins.EndOfStream; $s++ ) {
            $ins.ReadLine()
        }
        while( !$ins.EndOfStream ) {
            $outs.WriteLine( $ins.ReadLine() )
        }
    }
    finally {
        $outs.Close()
        $ins.Close()
    }
}).TotalSeconds

The first change brought the processing time for my 60 MB file down from 5.3s to 4s. The rest of the changes is more cosmetic.

Elevating process privilege programmatically?

You should use Impersonation to elevate the state.

WindowsIdentity identity = new WindowsIdentity(accessToken);
WindowsImpersonationContext context = identity.Impersonate();

Don't forget to undo the impersonated context when you are done.

What is a Python equivalent of PHP's var_dump()?

To display a value nicely, you can use the pprint module. The easiest way to dump all variables with it is to do

from pprint import pprint

pprint(globals())
pprint(locals())

If you are running in CGI, a useful debugging feature is the cgitb module, which displays the value of local variables as part of the traceback.

php exec command (or similar) to not wait for result

"exec nohup setsid your_command"

the nohup allows your_command to continue even though the process that launched may terminate first. If it does, the the SIGNUP signal will be sent to your_command causing it to terminate (unless it catches that signal and ignores it).

XAMPP on Windows - Apache not starting

I encountered the same issue after XAMPP v3.2.1 installation. I do not have Skype as most people would believe, however as a Software Developer I assumed port 80 is already in use by my other apps. So I changed it by simply using the XAMPP Control Panel: enter image description here

Click on the 'Config' button corresponding to the APACHE service and choose the first option 'Apache (httpd.conf)'. In the document that opens (using any text editor - except MS Word!), locate the text:

Listen 12.34.56.78:80

Listen 80

And change this to:

Listen 12.34.56.78:83

Listen 83

This can be any non-used port number. Thanks.

Is there any native DLL export functions viewer?

DLL Export Viewer by NirSoft can be used to display exported functions in a DLL.

This utility displays the list of all exported functions and their virtual memory addresses for the specified DLL files. You can easily copy the memory address of the desired function, paste it into your debugger, and set a breakpoint for this memory address. When this function is called, the debugger will stop in the beginning of this function.

enter image description here

Kafka consumer list

High level consumers are registered into Zookeeper, so you can fetch a list from ZK, similarly to the way kafka-topics.sh fetches the list of topics. I don't think there's a way to collect all consumers; any application sending in a few consume requests is actually a "consumer", and you cannot tell whether they are done already.

On the consumer side, there's a JMX metric exposed to monitor the lag. Also, there is Burrow for lag monitoring.

How to hide a div from code (c#)

one fast and simple way is to make the div as

<div runat="server" id="MyDiv"></div>

and on code behind you set MyDiv.Visible=false

Why doesn't catching Exception catch RuntimeException?

Catching Exception will catch a RuntimeException

How do I reference a local image in React?

import image from './img/one.jpg';

class Icons extends React.Component{
    render(){
      return(
        <img className='profile-image' alt='icon' src={image}/>
    );
    }
}
export default Icons;

What are the rules about using an underscore in a C++ identifier?

The rules to avoid collision of names are both in the C++ standard (see Stroustrup book) and mentioned by C++ gurus (Sutter, etc.).

Personal rule

Because I did not want to deal with cases, and wanted a simple rule, I have designed a personal one that is both simple and correct:

When naming a symbol, you will avoid collision with compiler/OS/standard libraries if you:

  • never start a symbol with an underscore
  • never name a symbol with two consecutive underscores inside.

Of course, putting your code in an unique namespace helps to avoid collision, too (but won't protect against evil macros)

Some examples

(I use macros because they are the more code-polluting of C/C++ symbols, but it could be anything from variable name to class name)

#define _WRONG
#define __WRONG_AGAIN
#define RIGHT_
#define WRONG__WRONG
#define RIGHT_RIGHT
#define RIGHT_x_RIGHT

Extracts from C++0x draft

From the n3242.pdf file (I expect the final standard text to be similar):

17.6.3.3.2 Global names [global.names]

Certain sets of names and function signatures are always reserved to the implementation:

— Each name that contains a double underscore _ _ or begins with an underscore followed by an uppercase letter (2.12) is reserved to the implementation for any use.

— Each name that begins with an underscore is reserved to the implementation for use as a name in the global namespace.

But also:

17.6.3.3.5 User-defined literal suffixes [usrlit.suffix]

Literal suffix identifiers that do not start with an underscore are reserved for future standardization.

This last clause is confusing, unless you consider that a name starting with one underscore and followed by a lowercase letter would be Ok if not defined in the global namespace...

How do I display image in Alert/confirm box in Javascript?

I created a function that might help. All it does is imitate the alert but put an image instead of text.

function alertImage(imgsrc) {
$('.d').css({
    'position': 'absolute',
    'top': '0',
    'left': '50%',
    '-webkit-transform': 'translate(-50%, 0)'
});
$('.d').animate({
    opacity: 0
}, 0)
$('.d').animate({
    opacity: 1,
    top: "10px"
}, 250)
$('.d').append('An embedded page on this page says')
$('.d').append('<br><img src="' + imgsrc + '">')
$('.b').css({
  'position':'absolute',
  '-webkit-transform': 'translate(-100%, -100%)',
  'top':'100%',
  'left':'100%',
  'display':'inline',
  'background-color':'#598cbd',
  'border-radius':'4px',
  'color':'white',
  'border':'none',
  'width':'66',
  'height':'33'
})
}
<script type="text/javascript" src="https://code.jquery.com/jquery-latest.min.js"></script>
<div class="d"><button onclick="$('.d').html('')" class="b">OK</button></div>
.d{
font-size: 17px;
  font-family: sans-serif;
}
.b{
  display: none;
}

Read/Write String from/to a File in Android

public static void writeStringAsFile(final String fileContents, String fileName) {
    Context context = App.instance.getApplicationContext();
    try {
        FileWriter out = new FileWriter(new File(context.getFilesDir(), fileName));
        out.write(fileContents);
        out.close();
    } catch (IOException e) {
        Logger.logError(TAG, e);
    }
}

public static String readFileAsString(String fileName) {
    Context context = App.instance.getApplicationContext();
    StringBuilder stringBuilder = new StringBuilder();
    String line;
    BufferedReader in = null;

    try {
        in = new BufferedReader(new FileReader(new File(context.getFilesDir(), fileName)));
        while ((line = in.readLine()) != null) stringBuilder.append(line);

    } catch (FileNotFoundException e) {
        Logger.logError(TAG, e);
    } catch (IOException e) {
        Logger.logError(TAG, e);
    } 

    return stringBuilder.toString();
}

Can we make unsigned byte in Java

Although it may seem annoying (coming from C) that Java did not include unsigned byte in the language it really is no big deal since a simple "b & 0xFF" operation yields the unsigned value for (signed) byte b in the (rare) situations that it is actually needed. The bits don't actually change -- just the interpretation (which is important only when doing for example some math operations on the values).

JUnit Eclipse Plugin?

Junit is included by default with Eclipse (at least the Java EE version I'm sure). You may just need to add the view to your perspective.

Password must have at least one non-alpha character

Run it through a fairly simple regex: [^a-zA-Z]

And then check it's length separately:

if(string.Length > 7)

How to get a json string from url?

AFAIK JSON.Net does not provide functionality for reading from a URL. So you need to do this in two steps:

using (var webClient = new System.Net.WebClient()) {
    var json = webClient.DownloadString(URL);
    // Now parse with JSON.Net
}

how to set default main class in java?

You can set the Main-Class attribute in the jar file's manifest to point to which file you want to run automatically.

Interview Question: Merge two sorted singly linked lists without creating new nodes

Here is the code on how to merge two sorted linked lists headA and headB:

Node* MergeLists1(Node *headA, Node* headB)
{
    Node *p = headA;
    Node *q = headB;
    Node *result = NULL; 
    Node *pp = NULL;
    Node *qq = NULL;
    Node *head = NULL;
    int value1 = 0;
    int value2 = 0;
    if((headA == NULL) && (headB == NULL))
    {
        return NULL;
    }
    if(headA==NULL)
    {
        return headB;
    }
    else if(headB==NULL)
    {
        return headA;
    }
    else
    {
        while((p != NULL) || (q != NULL))
        {
            if((p != NULL) && (q != NULL))
            {
                int value1 = p->data;
                int value2 = q->data;
                if(value1 <= value2)
                {
                    pp = p->next;
                    p->next = NULL;
                    if(result == NULL)
                    {
                        head = result = p;
                    }
                    else
                    {
                        result->next = p;
                        result = p;
                    }
                    p = pp;
                }
                else
                {
                    qq = q->next;
                    q->next = NULL;
                    if(result == NULL)
                    {
                        head = result = q;
                    }
                    else
                    {
                        result->next = q;
                        result = q;
                    }
                    q = qq;
                }
            }
            else
            {
                if(p != NULL)
                {
                    pp = p->next;
                    p->next = NULL;
                    result->next = p;
                    result = p;
                    p = pp;
                }
                if(q != NULL)
                {
                    qq = q->next;
                    q->next = NULL;
                    result->next = q;
                    result = q;
                    q = qq;
                }
            }
        }
    }
    return head;
}

Skipping Iterations in Python

for i in iterator:
    try:
        # Do something.
        pass
    except:
        # Continue to next iteration.
        continue

MVC 4 Edit modal form using Bootstrap

In $('.editor-container').click(function (){}), shouldn't var url = "/area/controller/MyEditAction"; be var url = "/area/controller/EditPartData";?

How to overwrite styling in Twitter Bootstrap

I know this is an old question but still, I came across a similar problem and i realized that my "not working" css code in my bootstrapOverload.css file was written after the media queries. when I moved it above media queries it started working.

Just in case someone else is facing the same problem

Printing a 2D array in C

...
for(int i=0;i<3;i++){ //Rows
for(int j=0;j<5;j++){ //Cols
 printf("%<...>\t",var);
}
printf("\n");
}
...

considering that <...> would be d,e,f,s,c... etc datatype... X)

Command Prompt Error 'C:\Program' is not recognized as an internal or external command, operable program or batch file

You just need to keep Program Files in double quote & rest of the command don't need any quote.

C:\"Program Files"\IAR Systems\Embedded Workbench 7.0\430\bin\icc430.exe F:\CP00 .....

Check if object value exists within a Javascript array of objects and if not add a new object to array

I think that, this is the shortest way of addressing this problem. Here I have used ES6 arrow function with .filter to check the existence of newly adding username.

var arr = [{
    id: 1,
    username: 'fred'
}, {
    id: 2,
    username: 'bill'
}, {
    id: 3,
    username: 'ted'
}];

function add(name) {
    var id = arr.length + 1;        
            if (arr.filter(item=> item.username == name).length == 0){
            arr.push({ id: id, username: name });
        }
}

add('ted');
console.log(arr);

Link to Fiddle

How to display Woocommerce Category image?

_x000D_
_x000D_
<?php _x000D_
_x000D_
 $terms = get_terms( array(_x000D_
 'taxonomy' => 'product_cat',_x000D_
 'hide_empty' => false,_x000D_
 ) ); // Get Terms_x000D_
_x000D_
foreach ($terms as $key => $value) _x000D_
{_x000D_
 $metaterms = get_term_meta($value->term_id);_x000D_
 $thumbnail_id = get_woocommerce_term_meta($value->term_id, 'thumbnail_id', true );_x000D_
 $image = wp_get_attachment_url( $thumbnail_id );_x000D_
 echo '<img src="'.$image.'" alt="" />';_x000D_
} // Get Images from woocommerce term meta_x000D_
_x000D_
?>
_x000D_
_x000D_
_x000D_

extracting days from a numpy.timedelta64 value

Use dt.days to obtain the days attribute as integers.

For eg:

In [14]: s = pd.Series(pd.timedelta_range(start='1 days', end='12 days', freq='3000T'))

In [15]: s
Out[15]: 
0    1 days 00:00:00
1    3 days 02:00:00
2    5 days 04:00:00
3    7 days 06:00:00
4    9 days 08:00:00
5   11 days 10:00:00
dtype: timedelta64[ns]

In [16]: s.dt.days
Out[16]: 
0     1
1     3
2     5
3     7
4     9
5    11
dtype: int64

More generally - You can use the .components property to access a reduced form of timedelta.

In [17]: s.dt.components
Out[17]: 
   days  hours  minutes  seconds  milliseconds  microseconds  nanoseconds
0     1      0        0        0             0             0            0
1     3      2        0        0             0             0            0
2     5      4        0        0             0             0            0
3     7      6        0        0             0             0            0
4     9      8        0        0             0             0            0
5    11     10        0        0             0             0            0

Now, to get the hours attribute:

In [23]: s.dt.components.hours
Out[23]: 
0     0
1     2
2     4
3     6
4     8
5    10
Name: hours, dtype: int64

Python: Passing variables between functions

return returns a value. It doesn't matter what name you gave to that value. Returning it just "passes it out" so that something else can use it. If you want to use it, you have to grab it from outside:

lst = defineAList()
useTheList(lst)

Returning list from inside defineAList doesn't mean "make it so the whole rest of the program can use that variable". It means "pass this variable out and give the rest of the program one chance to grab it and use it". You need to assign that value to something outside the function in order to make use of it. Also, because of this, there is no need to define your list ahead of time with list = []. Inside defineAList, you create a new list and return it; this list has no relationship to the one you defined with list = [] at the beginning.

Incidentally, I changed your variable name from list to lst. It's not a good idea to use list as a variable name because that is already the name of a built-in Python type. If you make your own variable called list, you won't be able to access the builtin one anymore.

How do I solve the INSTALL_FAILED_DEXOPT error?

One reason is that classes.dex is not found in the root of the .apk-package. Either

  • this file is missing in the apk-package or
  • it is located in a subfolder within the .apk file.

Both situations cause the termination because Android supposedly searches only in the root of the apk file. The confusion is because the build run of the .apk file was without an error message.

Core reasons for that error may be:

  • The dx tool need classes.dex in the current main working folder. But in reality classes.dex is located somewhere other.
  • aapt have a wrong information for the location for classes.dex. For example with aapt.exe add ... bin/classes.dex. Thats would be wrong because classes.dex is in a subfolder /bin of the created .apk file.

Metadata file '.dll' could not be found

I had a class in 4.6.1 refering an interface that was in 4.6.2... upgrading the class to 462 fixed it.

How do I view the SQLite database on an Android device?

There is TKlerx's Android SQLite browser for Eclipse, and it's fully functional alongside Android Studio. I'll recommend it, because it is immensely practical.

To install it on Device Monitor, just place the JAR file in [Path to Android SDK folder]/sdk/tools/lib/monitor-[...]/plugins.

How do I use the built in password reset/change views with my own templates

If you take a look at the sources for django.contrib.auth.views.password_reset you'll see that it uses RequestContext. The upshot is, you can use Context Processors to modify the context which may allow you to inject the information that you need.

The b-list has a good introduction to context processors.

Edit (I seem to have been confused about what the actual question was):

You'll notice that password_reset takes a named parameter called template_name:

def password_reset(request, is_admin_site=False, 
            template_name='registration/password_reset_form.html',
            email_template_name='registration/password_reset_email.html',
            password_reset_form=PasswordResetForm, 
            token_generator=default_token_generator,
            post_reset_redirect=None):

Check password_reset for more information.

... thus, with a urls.py like:

from django.conf.urls.defaults import *
from django.contrib.auth.views import password_reset

urlpatterns = patterns('',
     (r'^/accounts/password/reset/$', password_reset, {'template_name': 'my_templates/password_reset.html'}),
     ...
)

django.contrib.auth.views.password_reset will be called for URLs matching '/accounts/password/reset' with the keyword argument template_name = 'my_templates/password_reset.html'.

Otherwise, you don't need to provide any context as the password_reset view takes care of itself. If you want to see what context you have available, you can trigger a TemplateSyntax error and look through the stack trace find the frame with a local variable named context. If you want to modify the context then what I said above about context processors is probably the way to go.

In summary: what do you need to do to use your own template? Provide a template_name keyword argument to the view when it is called. You can supply keyword arguments to views by including a dictionary as the third member of a URL pattern tuple.

Making Python loggers output all messages to stdout in addition to log file

It's possible using multiple handlers.

import logging
import auxiliary_module

# create logger with 'spam_application'
log = logging.getLogger('spam_application')
log.setLevel(logging.DEBUG)

# create formatter and add it to the handlers
formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')

# create file handler which logs even debug messages
fh = logging.FileHandler('spam.log')
fh.setLevel(logging.DEBUG)
fh.setFormatter(formatter)
log.addHandler(fh)

# create console handler with a higher log level
ch = logging.StreamHandler()
ch.setLevel(logging.ERROR)
ch.setFormatter(formatter)
log.addHandler(ch)

log.info('creating an instance of auxiliary_module.Auxiliary')
a = auxiliary_module.Auxiliary()
log.info('created an instance of auxiliary_module.Auxiliary')

log.info('calling auxiliary_module.Auxiliary.do_something')
a.do_something()
log.info('finished auxiliary_module.Auxiliary.do_something')

log.info('calling auxiliary_module.some_function()')
auxiliary_module.some_function()
log.info('done with auxiliary_module.some_function()')

# remember to close the handlers
for handler in log.handlers:
    handler.close()
    log.removeFilter(handler)

Please see: https://docs.python.org/2/howto/logging-cookbook.html

What is the difference between Session.Abandon() and Session.Clear()

Session.Abandon() 

will destroy/kill the entire session.

Session.Clear()

removes/clears the session data (i.e. the keys and values from the current session) but the session will be alive.

Compare to Session.Abandon() method, Session.Clear() doesn't create the new session, it just make all variables in the session to NULL.

Session ID will remain same in both the cases, as long as the browser is not closed.

Session.RemoveAll()

It removes all keys and values from the session-state collection.

Session.Remove()

It deletes an item from the session-state collection.

Session.RemoveAt()

It deletes an item at a specified index from the session-state collection.

Session.TimeOut()

This property specifies the time-out period assigned to the Session object for the application. (the time will be specified in minutes).

If the user does not refresh or request a page within the time-out period, then the session ends.

Anaconda-Navigator - Ubuntu16.04

Use the following command on your terminal (Ctrl + Alt + T):-

$ conda activate
$ anaconda-navigator

Selected value for JSP drop down using JSTL

If you don't mind using jQuery you can use the code bellow:

    <script>
     $(document).ready(function(){
           $("#department").val("${requestScope.selectedDepartment}").attr('selected', 'selected');
     });
     </script>


    <select id="department" name="department">
      <c:forEach var="item" items="${dept}">
        <option value="${item.key}">${item.value}</option>
      </c:forEach>
    </select>

In the your Servlet add the following:

        request.setAttribute("selectedDepartment", YOUR_SELECTED_DEPARTMENT );

How do I ignore a directory with SVN?

The command to ignore multiple entries is a little tricky and requires backslashes.

svn propset svn:ignore "cache\
tmp\
null\
and_so_on" .

This command will ignore anything named cache, tmp, null, and and_so_on in the current directory.

How to return a PNG image from Jersey REST service method to the browser

I'm not convinced its a good idea to return image data in a REST service. It ties up your application server's memory and IO bandwidth. Much better to delegate that task to a proper web server that is optimized for this kind of transfer. You can accomplish this by sending a redirect to the image resource (as a HTTP 302 response with the URI of the image). This assumes of course that your images are arranged as web content.

Having said that, if you decide you really need to transfer image data from a web service you can do so with the following (pseudo) code:

@Path("/whatever")
@Produces("image/png")
public Response getFullImage(...) {

    BufferedImage image = ...;

    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    ImageIO.write(image, "png", baos);
    byte[] imageData = baos.toByteArray();

    // uncomment line below to send non-streamed
    // return Response.ok(imageData).build();

    // uncomment line below to send streamed
    // return Response.ok(new ByteArrayInputStream(imageData)).build();
}

Add in exception handling, etc etc.

Using wget to recursively fetch a directory with arbitrary files in it

You have to pass the -np/--no-parent option to wget (in addition to -r/--recursive, of course), otherwise it will follow the link in the directory index on my site to the parent directory. So the command would look like this:

wget --recursive --no-parent http://example.com/configs/.vim/

To avoid downloading the auto-generated index.html files, use the -R/--reject option:

wget -r -np -R "index.html*" http://example.com/configs/.vim/

HTTP Error 404.3-Not Found in IIS 7.5

In my case, along with Mekanik's suggestions, I was receiving this error in Windows Server 2012 and I had to tick "HTTP Activation" in "Add Role Services".

In git, what is the difference between merge --squash and rebase?

Merge commits: retains all of the commits in your branch and interleaves them with commits on the base branchenter image description here

Merge Squash: retains the changes but omits the individual commits from history enter image description here

Rebase: This moves the entire feature branch to begin on the tip of the master branch, effectively incorporating all of the new commits in master

enter image description here

More on here

set div height using jquery (stretch div height)

well you can do this:

$(function(){

    var $header = $('#header');
    var $footer = $('#footer');
    var $content = $('#content');
    var $window = $(window).on('resize', function(){
       var height = $(this).height() - $header.height() + $footer.height();
       $content.height(height);
    }).trigger('resize'); //on page load

});

see fiddle here: http://jsfiddle.net/maniator/JVKbR/
demo: http://jsfiddle.net/maniator/JVKbR/show/

XML serialization in Java?

JAXB is part of JDK standard edition version 1.6+. So it is FREE and no extra libraries to download and manage. A simple example can be found here

XStream seems to be dead. Last update was on Dec 6 2008. Simple seems as easy and simpler as JAXB but I could not find any licensing information to evaluate it for enterprise use.

Does Eclipse have line-wrap

In Eclipse v4.7 (Oxygen):

Window menu ? Editor ? Toggle Word Wrap (Shift+Alt+Y)

How to fix Subversion lock error

I get this too. I go to the directory (not in Eclipse) where the files are, go into the .svn dir and delete the file called lock.

Flip back to Eclipse and continue.

There is a similar question here Problems committing file to SVN repository

How to change dataframe column names in pyspark?

this is the approach that I used:

create pyspark session:

import pyspark
from pyspark.sql import SparkSession
spark = SparkSession.builder.appName('changeColNames').getOrCreate()

create dataframe:

df = spark.createDataFrame(data = [('Bob', 5.62,'juice'),  ('Sue',0.85,'milk')], schema = ["Name", "Amount","Item"])

view df with column names:

df.show()
+----+------+-----+
|Name|Amount| Item|
+----+------+-----+
| Bob|  5.62|juice|
| Sue|  0.85| milk|
+----+------+-----+

create a list with new column names:

newcolnames = ['NameNew','AmountNew','ItemNew']

change the column names of the df:

for c,n in zip(df.columns,newcolnames):
    df=df.withColumnRenamed(c,n)

view df with new column names:

df.show()
+-------+---------+-------+
|NameNew|AmountNew|ItemNew|
+-------+---------+-------+
|    Bob|     5.62|  juice|
|    Sue|     0.85|   milk|
+-------+---------+-------+

Calculating a 2D Vector's Cross Product

Implementation 1 returns the magnitude of the vector that would result from a regular 3D cross product of the input vectors, taking their Z values implicitly as 0 (i.e. treating the 2D space as a plane in the 3D space). The 3D cross product will be perpendicular to that plane, and thus have 0 X & Y components (thus the scalar returned is the Z value of the 3D cross product vector).

Note that the magnitude of the vector resulting from 3D cross product is also equal to the area of the parallelogram between the two vectors, which gives Implementation 1 another purpose. In addition, this area is signed and can be used to determine whether rotating from V1 to V2 moves in an counter clockwise or clockwise direction. It should also be noted that implementation 1 is the determinant of the 2x2 matrix built from these two vectors.

Implementation 2 returns a vector perpendicular to the input vector still in the same 2D plane. Not a cross product in the classical sense but consistent in the "give me a perpendicular vector" sense.

Note that 3D euclidean space is closed under the cross product operation--that is, a cross product of two 3D vectors returns another 3D vector. Both of the above 2D implementations are inconsistent with that in one way or another.

Hope this helps...

Get file name from URL

This should about cut it (i'll leave the error handling to you):

int slashIndex = url.lastIndexOf('/');
int dotIndex = url.lastIndexOf('.', slashIndex);
String filenameWithoutExtension;
if (dotIndex == -1) {
  filenameWithoutExtension = url.substring(slashIndex + 1);
} else {
  filenameWithoutExtension = url.substring(slashIndex + 1, dotIndex);
}

How to build & install GLFW 3 and use it in a Linux project

I solved it in this way

A pkg-config file describes all necessary compile-time and link-time flags and dependencies needed to use a library.

pkg-config --static --libs glfw3

shows me that

-L/usr/local/lib -lglfw3 -lrt -lXrandr -lXinerama -lXi -lXcursor -lGL -lm -ldl -lXrender -ldrm -lXdamage -lX11-xcb -lxcb-glx -lxcb-dri2 -lxcb-dri3 -lxcb-present -lxcb-sync -lxshmfence -lXxf86vm -lXfixes -lXext -lX11 -lpthread -lxcb -lXau -lXdmcp  

I don't know if all these libs are actually necessary for compiling but for me it works...

find filenames NOT ending in specific extensions on Unix?

Linux/OS X:

Starting from the current directory, recursively find all files ending in .dll or .exe

find . -type f | grep -P "\.dll$|\.exe$"

Starting from the current directory, recursively find all files that DON'T end in .dll or .exe

find . -type f | grep -vP "\.dll$|\.exe$"

Notes:

(1) The P option in grep indicates that we are using the Perl style to write our regular expressions to be used in conjunction with the grep command. For the purpose of excecuting the grep command in conjunction with regular expressions, I find that the Perl style is the most powerful style around.

(2) The v option in grep instructs the shell to exclude any file that satisfies the regular expression

(3) The $ character at the end of say ".dll$" is a delimiter control character that tells the shell that the filename string ends with ".dll"

Reset auto increment counter in postgres

Here is the command that you are looking for, assuming your sequence for the product table is product_id_seq:

ALTER SEQUENCE product_id_seq RESTART WITH 1453;

Bluetooth pairing without user confirmation

Well, this should really be broken into 2 parts:

  1. Can you pair 2 Bluetooth devices without going through a Bluetooth pairing handshake? No, you can't. That's baked into the protocol so there is no way around this.
  2. Can you perform the handshake without a user interface? Yes, you can: that's just code.

I'm not sure how you do it in Windows land, but in *nix land there are functions buried in the Bluez stack that let you receive notifications about when a new device appears, and send it the pairing code (clearly there have to be these functions: those are what the user interface use). Given sufficient time and experience I'm sure you could figure out how to write your own version of the Bluetooth Settings app that somehow:

  • Detected a new device had arrived
  • Looked at the name/bluetooth mac address and checked some internal database for the pairing code to use.
  • Sent the pairing code and completed the operation

All without having to pop up a user interface.

If you go ahead and write the code I'd LOVE to get my hands on it.

How do I unload (reload) a Python module?

In Python 3.0–3.3 you would use: imp.reload(module)

The BDFL has answered this question.

However, imp was deprecated in 3.4, in favour of importlib (thanks @Stefan!).

I think, therefore, you’d now use importlib.reload(module), although I’m not sure.

MySQL dump by query

If you want to export your last n amount of records into a file, you can run the following:

mysqldump -u user -p -h localhost --where "1=1 ORDER BY id DESC LIMIT 100" database table > export_file.sql

The above will save the last 100 records into export_file.sql, assuming the table you're exporting from has an auto-incremented id column.

You will need to alter the user, localhost, database and table values. You may optionally alter the id column and export file name.

Comparing results with today's date?

For me the query that is working, if I want to compare with DrawDate for example is:

CAST(DrawDate AS DATE) = CAST (GETDATE() as DATE)

This is comparing results with today's date.

or the whole query:

SELECT TOP (1000) *
FROM test
where DrawName != 'NULL' and CAST(DrawDate AS DATE) = CAST (GETDATE() as DATE)
order by id desc

gcc-arm-linux-gnueabi command not found

If you are on a 64bit build of ubuntu or debian (see e.g. 'cat /proc/version') you should simply use the 64bit cross compilers, if you cloned

git clone https://github.com/raspberrypi/tools

then the 64bit tools are in

tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64

use that directory for the gcc-toolchain. A useful tutorial for compiling that I followed is available here Building and compiling Raspberry PI Kernel (use the -x64 path from above as ${CCPREFIX})

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

Your code seems to be fine, make sure that key you specify really exists in the array or such key has a value in your array eg:

$array = array(4 => 'Hello There');
print_r(array_keys($array));
// or better
print_r($array);

Output:

Array
(
    [0] => 4
)

Now:

$key = 4;
$value = $array[$key];
print $value;

Output:

Hello There

Difference between $(window).load() and $(document).ready() functions

  • document.ready is a jQuery event, it runs when the DOM is ready, e.g. all elements are there to be found/used, but not necessarily all content.
  • window.onload fires later (or at the same time in the worst/failing cases) when images and such are loaded, so if you're using image dimensions for example, you often want to use this instead.

Display a message in Visual Studio's output window when not debug mode?

For me this was the fact that debug.writeline shows in the Immediate window, not the Output. My installation of VS2013 by default doesn't even show an option to open the Immediate window, so you have to do the following:

Select Tools -> Customize 
Commands Tab
View | Other Windows menu bar dropdown
Add Command...
The Immediate option is in the Debug section.

Once you have Ok'd that, you can go to View -> Other Windows and select the Immediate Window and hey presto all of the debug output can be seen.

Unfortunately for me it also showed about 50 errors that I wasn't aware of in my project... maybe I'll just turn it off again :-)

TypeError: worker() takes 0 positional arguments but 1 was given

class KeyStatisticCollection(DataDownloadUtilities.DataDownloadCollection):
def GenerateAddressStrings(self):
    pass    
def worker(self):
    pass
def DownloadProc(self):
    pass

How to retry image pull in a kubernetes Pods?

Try with deleting pod it will try to pull image again.

kubectl delete pod <pod_name> -n <namespace_name>

How to list imported modules?

Stealing from @Lila (couldn't make a comment because of no formatting), this shows the module's /path/, as well:

#!/usr/bin/env python
import sys
from modulefinder import ModuleFinder
finder = ModuleFinder()
# Pass the name of the python file of interest
finder.run_script(sys.argv[1])
# This is what's different from @Lila's script
finder.report()

which produces:

Name                      File
----                      ----

...
m token                     /opt/rh/rh-python35/root/usr/lib64/python3.5/token.py
m tokenize                  /opt/rh/rh-python35/root/usr/lib64/python3.5/tokenize.py
m traceback                 /opt/rh/rh-python35/root/usr/lib64/python3.5/traceback.py
...

.. suitable for grepping or what have you. Be warned, it's long!

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

//String to Date Convert

var dateString = "2014-01-12"
var dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd"
let s = dateFormatter.dateFromString(dateString)
println(s)


//CONVERT FROM NSDate to String  

let date = NSDate()
var dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd" 
var dateString = dateFormatter.stringFromDate(date)
println(dateString)  

String or binary data would be truncated. The statement has been terminated

Specify a size for the item and warehouse like in the [dbo].[testing1] FUNCTION

@trackingItems1 TABLE (
item       nvarchar(25)  NULL, -- 25 OR equal size of your item column
warehouse   nvarchar(25) NULL, -- same as above
price int   NULL

) 

Since in MSSQL only saying only nvarchar is equal to nvarchar(1) hence the values of the column from the stock table are truncated

Convert double to Int, rounded down

If the double is a Double with capital D (a boxed primitive value):

Double d = 4.97542;
int i = (int) d.doubleValue();

// or directly:
int i2 = d.intValue();

If the double is already a primitive double, then you simply cast it:

double d = 4.97542;
int i = (int) d;

What bitrate is used for each of the youtube video qualities (360p - 1080p), in regards to flowplayer?

Looking at this official google link: Youtube Live encoder settings, bitrates and resolutions they have this table:

                   240p       360p        480p        720p        1080p
Resolution      426 x 240   640 x 360   854x480     1280x720    1920x1080
Video Bitrates                   
Maximum         700 Kbps    1000 Kbps   2000 Kbps   4000 Kbps   6000 Kbps
Recommended     400 Kbps    750 Kbps    1000 Kbps   2500 Kbps   4500 Kbps
Minimum         300 Kbps    400 Kbps    500 Kbps    1500 Kbps   3000 Kbps

It would appear as though this is the case, although the numbers dont sync up to the google table above:

// the bitrates, video width and file names for this clip
      bitrates: [
        { url: "bbb-800.mp4", width: 480, bitrate: 800 }, //360p video
        { url: "bbb-1200.mp4", width: 720, bitrate: 1200 }, //480p video
        { url: "bbb-1600.mp4", width: 1080, bitrate: 1600 } //720p video
      ],

How can I add or update a query string parameter?

I realize this question is old and has been answered to death, but here's my stab at it. I'm trying to reinvent the wheel here because I was using the currently accepted answer and the mishandling of URL fragments recently bit me in a project.

The function is below. It's quite long, but it was made to be as resilient as possible. I would love suggestions for shortening/improving it. I put together a small jsFiddle test suite for it (or other similar functions). If a function can pass every one of the tests there, I say it's probably good to go.

Update: I came across a cool function for using the DOM to parse URLs, so I incorporated that technique here. It makes the function shorter and more reliable. Props to the author of that function.

/**
 * Add or update a query string parameter. If no URI is given, we use the current
 * window.location.href value for the URI.
 * 
 * Based on the DOM URL parser described here:
 * http://james.padolsey.com/javascript/parsing-urls-with-the-dom/
 *
 * @param   (string)    uri     Optional: The URI to add or update a parameter in
 * @param   (string)    key     The key to add or update
 * @param   (string)    value   The new value to set for key
 *
 * Tested on Chrome 34, Firefox 29, IE 7 and 11
 */
function update_query_string( uri, key, value ) {

    // Use window URL if no query string is provided
    if ( ! uri ) { uri = window.location.href; }

    // Create a dummy element to parse the URI with
    var a = document.createElement( 'a' ), 

        // match the key, optional square brackets, an equals sign or end of string, the optional value
        reg_ex = new RegExp( key + '((?:\\[[^\\]]*\\])?)(=|$)(.*)' ),

        // Setup some additional variables
        qs,
        qs_len,
        key_found = false;

    // Use the JS API to parse the URI 
    a.href = uri;

    // If the URI doesn't have a query string, add it and return
    if ( ! a.search ) {

        a.search = '?' + key + '=' + value;

        return a.href;
    }

    // Split the query string by ampersands
    qs = a.search.replace( /^\?/, '' ).split( /&(?:amp;)?/ );
    qs_len = qs.length; 

    // Loop through each query string part
    while ( qs_len > 0 ) {

        qs_len--;

        // Remove empty elements to prevent double ampersands
        if ( ! qs[qs_len] ) { qs.splice(qs_len, 1); continue; }

        // Check if the current part matches our key
        if ( reg_ex.test( qs[qs_len] ) ) {

            // Replace the current value
            qs[qs_len] = qs[qs_len].replace( reg_ex, key + '$1' ) + '=' + value;

            key_found = true;
        }
    }   

    // If we haven't replaced any occurrences above, add the new parameter and value
    if ( ! key_found ) { qs.push( key + '=' + value ); }

    // Set the new query string
    a.search = '?' + qs.join( '&' );

    return a.href;
}

PHP simple foreach loop with HTML

This will work although when embedding PHP in HTML it is better practice to use the following form:

<table>
    <?php foreach($array as $key=>$value): ?>
    <tr>
        <td><?= $key; ?></td>
    </tr>
    <?php endforeach; ?>
</table>

You can find the doc for the alternative syntax on PHP.net

How do I prevent a form from being resized by the user?

If you want to prevent resize by dragging sizegrips and by the maximize button and by maximize by doubleclick on the header text, than insert the following code in the load event of the form:

    Me.FormBorderStyle = Windows.Forms.FormBorderStyle.FixedSingle ' Prevent size grips
    Me.MaximumSize = Me.Size ' Prevent maximize (also by doubleclick of header text)

Of course all choices of a formborderstyle beginning with Fixed will do.

Sleep/Wait command in Batch

timeout 5

to delay

timeout 5 >nul

to delay without asking you to press any key to cancel

How to write a UTF-8 file with Java?

Try this

Writer out = new BufferedWriter(new OutputStreamWriter(
    new FileOutputStream("outfilename"), "UTF-8"));
try {
    out.write(aString);
} finally {
    out.close();
}

What characters are valid for JavaScript variable names?

Wrote a glitch workspace that iterates over all the codepoints and emit the character if eval('var ' + String.fromCodePoint(#) + ' = 1') works.

It just keeps going, and going, and going....

Powershell get ipv4 address into a variable

To grab the device's IPv4 addresses, and filter to only grab ones that match your scheme (i.e. Ignore and APIPA addresses or the LocalHost address). You could say to grab the address matching 192.168.200.* for example.

$IPv4Addr = Get-NetIPAddress -AddressFamily ipV4 | where {$_.IPAddress -like X.X.X.X} | Select IPAddress

Drop rows with all zeros in pandas data frame

Replace the zeros with nan and then drop the rows with all entries as nan. After that replace nan with zeros.

import numpy as np
df = df.replace(0, np.nan)
df = df.dropna(how='all', axis=0)
df = df.replace(np.nan, 0)

Reading local text file into a JavaScript array

Using Node.js

sync mode:

var fs = require("fs");
var text = fs.readFileSync("./mytext.txt");
var textByLine = text.split("\n")

async mode:

var fs = require("fs");
fs.readFile("./mytext.txt", function(text){
    var textByLine = text.split("\n")
});

UPDATE

As of at least Node 6, readFileSync returns a Buffer, so it must first be converted to a string in order for split to work:

var text = fs.readFileSync("./mytext.txt").toString('utf-8');

Or

var text = fs.readFileSync("./mytext.txt", "utf-8");

How do I create executable Java program?

Java Web Start is a good technology for installing Java rich clients off the internet direct to the end user's desktop (whether the OS is Windows, Mac or *nix). It comes complete with desktop integration and automatic updates, among many other goodies.

For more information on JWS, see the JWS info page.

What are good message queue options for nodejs?

I used KUE with socketIO like you described. I stored the socketID with the job and could then retreive it in the Job Complete.. KUE is based on redis and has good examples on github

something like this....

jobs.process('YourQueuedJob',10, function(job, done){
    doTheJob(job, done);
});


function doTheJob(job, done){
    var socket = io.sockets.sockets[job.data.socketId];
    try {
        socket.emit('news', { status : 'completed' , task : job.data.task });
    } catch(err){
        io.sockets.emit('news', { status : 'fail' , task : job.data.task , socketId: job.data.socketId});
    }
    job.complete();
}

use "netsh wlan set hostednetwork ..." to create a wifi hotspot and the authentication can't work correctly

I am using Windows 10 Home edition.

I tried various combination,

netsh wlan show drivers
netsh wlan show hostednetwork
netsh wlan set hostednetwork mode=allow ssid=happy key=12345678
netsh wlan start hostednetwork

and also,

Control Panel\Network and Internet\Network Connections\Ethernet Properties\Sharing\Internet Connection Sharing\Allow other network users to connect through this computer Internet connection...

But still cannot activate WiFi hotspot.

While I have given up, somehow I click on Network icon on the taskbar, suddenly I see the buttons:

[ Wi-Fi ] [ Airplane Mode ] [ Mobile hotspot ]

Just like how our mobile phone can enable Mobile hotspot, Windows 10 has Mobile hotspot build-in. Just click on [ Mobile hotspot ] button and it works.

How can I save multiple documents concurrently in Mongoose/Node.js?

Bulk inserts in Mongoose can be done with .insert() unless you need to access middleware.

Model.collection.insert(docs, options, callback)

https://github.com/christkv/node-mongodb-native/blob/master/lib/mongodb/collection.js#L71-91

how to update spyder on anaconda

You can easily install update version if you use Anaconda by closing Spyder and then running the following command in a system terminal (Anaconda Prompt on Windows, xterm on Linux or Terminal.app on macOS):

conda install spyder= Your desire version

(For example, Version is 3.1)

conda install spyder=3.1

Or you can use pip with this command in a system terminal (cmd.exe on Windows, xterm on Linux or Terminal.app on macOS):

pip install --pre -U spyder

Note: Do not use this command if you are using Anaconda because it could break your installation.

Fastest way to check a string contain another substring in JavaScript?

For finding a simple string, using the indexOf() method and using regex is pretty much the same: http://jsperf.com/substring - so choose which ever one that seems easier to write.

How to call function that takes an argument in a Django template?

What you could do is, create the "function" as another template file and then include that file passing the parameters to it.

Inside index.html

<h3> Latest Songs </h3>
{% include "song_player_list.html" with songs=latest_songs %}

Inside song_player_list.html

<ul>
{%  for song in songs %}
<li>
<div id='songtile'>
<a href='/songs/download/{{song.id}}/'><i class='fa fa-cloud-download'></i>&nbsp;Download</a>

</div>
</li>
{% endfor %}
</ul>

Can't open file 'svn/repo/db/txn-current-lock': Permission denied

Try to disable SELinux by this command /usr/sbin/setenforce 0. In my case it solved the problem.

How to use setprecision in C++

Replace These Headers

#include <iomanip.h>
#include <iomanip>

With These.

#include <iostream>
#include <iomanip>
using namespace std;

Thats it...!!!

Is there a replacement for unistd.h for Windows (Visual C)?

No, IIRC there is no getopt() on Windows.

Boost, however, has the program_options library... which works okay. It will seem like overkill at first, but it isn't terrible, especially considering it can handle setting program options in configuration files and environment variables in addition to command line options.

rsync copy over only certain types of files using include option

The answer by @chepner will copy all the sub-directories irrespective of the fact if it contains the file or not. If you need to exclude the sub-directories that dont contain the file and still retain the directory structure, use

rsync -zarv  --prune-empty-dirs --include "*/"  --include="*.sh" --exclude="*" "$from" "$to"

Google Play error "Error while retrieving information from server [DF-DFERH-01]"

suggestions of solving this problem is, If you already had installed app in your phone before downloading from google play.(obviously run from your code ) then first uninstal it. and then download and install app from google play . it worked for me .Thanks and regards.

Call parent method from child class c#

To access properties and methods of a parent class use the base keyword. So in your child class LoadData() method you would do this:

public class Child : Parent 
{
    public void LoadData() 
    {
        base.MyMethod(); // call method of parent class
        base.CurrentRow = 1; // set property of parent class
        // other stuff...
    }
}

Note that you would also have to change the access modifier of your parent MyMethod() to at least protected for the child class to access it.

Play an audio file using jQuery when a button is clicked

What about:

_x000D_
_x000D_
$('#play').click(function() {_x000D_
  const audio = new Audio("https://freesound.org/data/previews/501/501690_1661766-lq.mp3");_x000D_
  audio.play();_x000D_
});
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
_x000D_
_x000D_
_x000D_

ActiveXObject in Firefox or Chrome (not IE!)

ActiveX is only supported by IE - the other browsers use a plugin architecture called NPAPI. However, there's a cross-browser plugin framework called Firebreath that you might find useful.

Copy folder recursively in Node.js

I wrote this function for both copying (copyFileSync) or moving (renameSync) files recursively between directories:

// Copy files
copyDirectoryRecursiveSync(sourceDir, targetDir);
// Move files
copyDirectoryRecursiveSync(sourceDir, targetDir, true);


function copyDirectoryRecursiveSync(source, target, move) {
    if (!fs.lstatSync(source).isDirectory())
        return;

    var operation = move ? fs.renameSync : fs.copyFileSync;
    fs.readdirSync(source).forEach(function (itemName) {
        var sourcePath = path.join(source, itemName);
        var targetPath = path.join(target, itemName);

        if (fs.lstatSync(sourcePath).isDirectory()) {
            fs.mkdirSync(targetPath);
            copyDirectoryRecursiveSync(sourcePath, targetDir);
        }
        else {
            operation(sourcePath, targetPath);
        }
    });
}

How to set column widths to a jQuery datatable?

Configuration Options:

$(document).ready(function () {

  $("#companiesTable").dataTable({
    "sPaginationType": "full_numbers",
    "bJQueryUI": true,
    "bAutoWidth": false, // Disable the auto width calculation 
    "aoColumns": [
      { "sWidth": "30%" }, // 1st column width 
      { "sWidth": "30%" }, // 2nd column width 
      { "sWidth": "40%" } // 3rd column width and so on 
    ]
  });
});

Specify the css for the table:

table.display {
  margin: 0 auto;
  width: 100%;
  clear: both;
  border-collapse: collapse;
  table-layout: fixed;         // add this 
  word-wrap:break-word;        // add this 
}

HTML:

<table id="companiesTable" class="display"> 
  <thead>
    <tr>
      <th>Company name</th>
      <th>Address</th>
      <th>Town</th>
    </tr>
  </thead>
  <tbody>

    <% for(Company c: DataRepository.GetCompanies()){ %>
      <tr>  
        <td><%=c.getName()%></td>
        <td><%=c.getAddress()%></td>
        <td><%=c.getTown()%></td>
      </tr>
    <% } %>

  </tbody>
</table>

It works for me!

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

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

What is the best way to manage a user's session in React?

This not the best way to manage session in react you can use web tokens to encrypt your data that you want save,you can use various number of services available a popular one is JSON web tokens(JWT) with web-tokens you can logout after some time if there no action from the client And after creating the token you can store it in your local storage for ease of access.

jwt.sign({user}, 'secretkey', { expiresIn: '30s' }, (err, token) => {
    res.json({
      token
  });

user object in here is the user data which you want to keep in the session

localStorage.setItem('session',JSON.stringify(token));

Is there a way to pass jvm args via command line to maven?

I think MAVEN_OPTS would be most appropriate for you. See here: http://maven.apache.org/configure.html

In Unix:

Add the MAVEN_OPTS environment variable to specify JVM properties, e.g. export MAVEN_OPTS="-Xms256m -Xmx512m". This environment variable can be used to supply extra options to Maven.

In Win, you need to set environment variable via the dialogue box

Add ... environment variable by opening up the system properties (WinKey + Pause),... In the same dialog, add the MAVEN_OPTS environment variable in the user variables to specify JVM properties, e.g. the value -Xms256m -Xmx512m. This environment variable can be used to supply extra options to Maven.

Angularjs $http post file and form data

here is my solution:

_x000D_
_x000D_
// Controller_x000D_
$scope.uploadImg = function( files ) {_x000D_
  $scope.data.avatar = files[0];_x000D_
}_x000D_
_x000D_
$scope.update = function() {_x000D_
  var formData = new FormData();_x000D_
  formData.append('desc', data.desc);_x000D_
  formData.append('avatar', data.avatar);_x000D_
  SomeService.upload( formData );_x000D_
}_x000D_
_x000D_
_x000D_
// Service_x000D_
upload: function( formData ) {_x000D_
  var deferred = $q.defer();_x000D_
  var url = "/upload" ;_x000D_
  _x000D_
  var request = {_x000D_
    "url": url,_x000D_
    "method": "POST",_x000D_
    "data": formData,_x000D_
    "headers": {_x000D_
      'Content-Type' : undefined // important_x000D_
    }_x000D_
  };_x000D_
_x000D_
  console.log(request);_x000D_
_x000D_
  $http(request).success(function(data){_x000D_
    deferred.resolve(data);_x000D_
  }).error(function(error){_x000D_
    deferred.reject(error);_x000D_
  });_x000D_
  return deferred.promise;_x000D_
}_x000D_
_x000D_
_x000D_
// backend use express and multer_x000D_
// a part of the code_x000D_
var multer = require('multer');_x000D_
var storage = multer.diskStorage({_x000D_
  destination: function (req, file, cb) {_x000D_
    cb(null, '../public/img')_x000D_
  },_x000D_
  filename: function (req, file, cb) {_x000D_
    cb(null, file.fieldname + '-' + Date.now() + '.jpg');_x000D_
  }_x000D_
})_x000D_
_x000D_
var upload = multer({ storage: storage })_x000D_
app.post('/upload', upload.single('avatar'), function(req, res, next) {_x000D_
  // do something_x000D_
  console.log(req.body);_x000D_
  res.send(req.body);_x000D_
});
_x000D_
<div>_x000D_
  <input type="file" accept="image/*" onchange="angular.element( this ).scope().uploadImg( this.files )">_x000D_
  <textarea ng-model="data.desc" />_x000D_
  <button type="button" ng-click="update()">Update</button>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Show hide fragment in android

This worked for me

FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
        if(tag.equalsIgnoreCase("dashboard")){

            DashboardFragment dashboardFragment = (DashboardFragment)
                    fragmentManager.findFragmentByTag("dashboard");
            if(dashboardFragment!=null) ft.show(dashboardFragment);

            ShowcaseFragment showcaseFragment = (ShowcaseFragment)
                    fragmentManager.findFragmentByTag("showcase");
            if(showcaseFragment!=null) ft.hide(showcaseFragment);

        } else if(tag.equalsIgnoreCase("showcase")){
            DashboardFragment dashboardFragment = (DashboardFragment)
                    fragmentManager.findFragmentByTag("dashboard");
            if(dashboardFragment!=null) ft.hide(dashboardFragment);

            ShowcaseFragment showcaseFragment = (ShowcaseFragment)
                    fragmentManager.findFragmentByTag("showcase");
            if(showcaseFragment!=null) ft.show(showcaseFragment);
        }

        ft.commit();

Read/write to file using jQuery

Yes it is possible.

The technique is described below

http://jquery.tiddlywiki.org/twFile.html

what does mysql_real_escape_string() really do?

Best explained here.

http://www.w3schools.com/php/func_mysql_real_escape_string.asp

http://www.tizag.com/mysqlTutorial/mysql-php-sql-injection.php

It generally it helps to avoid SQL injection, for example consider the following code:

<?php
// Query database to check if there are any matching users
$query = "SELECT * FROM users WHERE user='{$_POST['username']}' AND password='{$_POST['password']}'";
mysql_query($query);

// We didn't check $_POST['password'], it could be anything the user wanted! For example:
$_POST['username'] = 'aidan';
$_POST['password'] = "' OR ''='";

// This means the query sent to MySQL would be:
echo $query;
?>

and a hacker can send a query like:

SELECT * FROM users WHERE user='aidan' AND password='' OR ''=''

This would allow anyone to log in without a valid password.

How do I create test and train samples from one dataframe with pandas?

You can use ~ (tilde operator) to exclude the rows sampled using df.sample(), letting pandas alone handle sampling and filtering of indexes, to obtain two sets.

train_df = df.sample(frac=0.8, random_state=100)
test_df = df[~df.index.isin(train_df.index)]

git pull while not in a git directory

As some of my servers are on an old Ubuntu LTS versions, I can't easily upgrade git to the latest version (which supports the -C option as described in some answers).

This trick works well for me, especially because it does not have the side effect of some other answers that leave you in a different directory from where you started.

pushd /X/Y
git pull
popd

Or, doing it as a one-liner:

pushd /X/Y; git pull; popd

Both Linux and Windows have pushd and popd commands.

How to hide command output in Bash

>/dev/null 2>&1 will mute both stdout and stderr

yum install nano >/dev/null 2>&1

Which regular expression operator means 'Don't' match this character?

You can use negated character classes to exclude certain characters: for example [^abcde] will match anything but a,b,c,d,e characters.

Instead of specifying all the characters literally, you can use shorthands inside character classes: [\w] (lowercase) will match any "word character" (letter, numbers and underscore), [\W] (uppercase) will match anything but word characters; similarly, [\d] will match the 0-9 digits while [\D] matches anything but the 0-9 digits, and so on.

If you use PHP you can take a look at the regex character classes documentation.

UTF-8 all the way through

Data Storage:

  • Specify the utf8mb4 character set on all tables and text columns in your database. This makes MySQL physically store and retrieve values encoded natively in UTF-8. Note that MySQL will implicitly use utf8mb4 encoding if a utf8mb4_* collation is specified (without any explicit character set).

  • In older versions of MySQL (< 5.5.3), you'll unfortunately be forced to use simply utf8, which only supports a subset of Unicode characters. I wish I were kidding.

Data Access:

  • In your application code (e.g. PHP), in whatever DB access method you use, you'll need to set the connection charset to utf8mb4. This way, MySQL does no conversion from its native UTF-8 when it hands data off to your application and vice versa.

  • Some drivers provide their own mechanism for configuring the connection character set, which both updates its own internal state and informs MySQL of the encoding to be used on the connection—this is usually the preferred approach. In PHP:

    • If you're using the PDO abstraction layer with PHP = 5.3.6, you can specify charset in the DSN:

       $dbh = new PDO('mysql:charset=utf8mb4');
      
    • If you're using mysqli, you can call set_charset():

        $mysqli->set_charset('utf8mb4');       // object oriented style
        mysqli_set_charset($link, 'utf8mb4');  // procedural style
      
    • If you're stuck with plain mysql but happen to be running PHP = 5.2.3, you can call mysql_set_charset.

  • If the driver does not provide its own mechanism for setting the connection character set, you may have to issue a query to tell MySQL how your application expects data on the connection to be encoded: SET NAMES 'utf8mb4'.

  • The same consideration regarding utf8mb4/utf8 applies as above.

Output:

  • If your application transmits text to other systems, they will also need to be informed of the character encoding. With web applications, the browser must be informed of the encoding in which data is sent (through HTTP response headers or HTML metadata).

  • In PHP, you can use the default_charset php.ini option, or manually issue the Content-Type MIME header yourself, which is just more work but has the same effect.

  • When encoding the output using json_encode(), add JSON_UNESCAPED_UNICODE as a second parameter.

Input:

  • Unfortunately, you should verify every received string as being valid UTF-8 before you try to store it or use it anywhere. PHP's mb_check_encoding() does the trick, but you have to use it religiously. There's really no way around this, as malicious clients can submit data in whatever encoding they want, and I haven't found a trick to get PHP to do this for you reliably.

  • From my reading of the current HTML spec, the following sub-bullets are not necessary or even valid anymore for modern HTML. My understanding is that browsers will work with and submit data in the character set specified for the document. However, if you're targeting older versions of HTML (XHTML, HTML4, etc.), these points may still be useful:

    • For HTML before HTML5 only: you want all data sent to you by browsers to be in UTF-8. Unfortunately, if you go by the only way to reliably do this is add the accept-charset attribute to all your <form> tags: <form ... accept-charset="UTF-8">.
    • For HTML before HTML5 only: note that the W3C HTML spec says that clients "should" default to sending forms back to the server in whatever charset the server served, but this is apparently only a recommendation, hence the need for being explicit on every single <form> tag.

Other Code Considerations:

  • Obviously enough, all files you'll be serving (PHP, HTML, JavaScript, etc.) should be encoded in valid UTF-8.

  • You need to make sure that every time you process a UTF-8 string, you do so safely. This is, unfortunately, the hard part. You'll probably want to make extensive use of PHP's mbstring extension.

  • PHP's built-in string operations are not by default UTF-8 safe. There are some things you can safely do with normal PHP string operations (like concatenation), but for most things you should use the equivalent mbstring function.

  • To know what you're doing (read: not mess it up), you really need to know UTF-8 and how it works on the lowest possible level. Check out any of the links from utf8.com for some good resources to learn everything you need to know.

Load a WPF BitmapImage from a System.Drawing.Bitmap

It took me some time to get the conversion working both ways, so here are the two extension methods I came up with:

using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Windows.Media.Imaging;

public static class BitmapConversion {

    public static Bitmap ToWinFormsBitmap(this BitmapSource bitmapsource) {
        using (MemoryStream stream = new MemoryStream()) {
            BitmapEncoder enc = new BmpBitmapEncoder();
            enc.Frames.Add(BitmapFrame.Create(bitmapsource));
            enc.Save(stream);

            using (var tempBitmap = new Bitmap(stream)) {
                // According to MSDN, one "must keep the stream open for the lifetime of the Bitmap."
                // So we return a copy of the new bitmap, allowing us to dispose both the bitmap and the stream.
                return new Bitmap(tempBitmap);
            }
        }
    }

    public static BitmapSource ToWpfBitmap(this Bitmap bitmap) {
        using (MemoryStream stream = new MemoryStream()) {
            bitmap.Save(stream, ImageFormat.Bmp);

            stream.Position = 0;
            BitmapImage result = new BitmapImage();
            result.BeginInit();
            // According to MSDN, "The default OnDemand cache option retains access to the stream until the image is needed."
            // Force the bitmap to load right now so we can dispose the stream.
            result.CacheOption = BitmapCacheOption.OnLoad;
            result.StreamSource = stream;
            result.EndInit();
            result.Freeze();
            return result;
        }
    }
}

When do I need to do "git pull", before or after "git add, git commit"?

You want your change to sit on top of the current state of the remote branch. So probably you want to pull right before you commit yourself. After that, push your changes again.

"Dirty" local files are not an issue as long as there aren't any conflicts with the remote branch. If there are conflicts though, the merge will fail, so there is no risk or danger in pulling before committing local changes.

Does a `+` in a URL scheme/host/path represent a space?

Space characters may only be encoded as "+" in one context: application/x-www-form-urlencoded key-value pairs.

The RFC-1866 (HTML 2.0 specification), paragraph 8.2.1. subparagraph 1. says: "The form field names and values are escaped: space characters are replaced by `+', and then reserved characters are escaped").

Here is an example of such a string in URL where RFC-1866 allows encoding spaces as pluses: "http://example.com/over/there?name=foo+bar". So, only after "?", spaces can be replaced by pluses (in other cases, spaces should be encoded to %20). This way of encoding form data is also given in later HTML specifications, for example, look for relevant paragraphs about application/x-www-form-urlencoded in HTML 4.01 Specification, and so on.

But, because it's hard to always correctly determine the context, it's the best practice to never encode spaces as "+". It's better to percent-encode all character except "unreserved" defined in RFC-3986, p.2.3. Here is a code example that illustrates what should be encoded. It is given in Delphi (pascal) programming language, but it is very easy to understand how it works for any programmer regardless of the language possessed:

(* percent-encode all unreserved characters as defined in RFC-3986, p.2.3 *)
function UrlEncodeRfcA(const S: AnsiString): AnsiString;
const    
  HexCharArrA: array [0..15] of AnsiChar = '0123456789ABCDEF';
var
  I: Integer;
  c: AnsiChar;
begin
 // percent-encoding, see RFC-3986, p. 2.1
  Result := S;
  for I := Length(S) downto 1 do
  begin
    c := S[I];
    case c of
      'A' .. 'Z', 'a' .. 'z', // alpha
      '0' .. '9',             // digit
      '-', '.', '_', '~':;    // rest of unreserved characters as defined in the RFC-3986, p.2.3
      else
        begin
          Result[I] := '%';
          Insert('00', Result, I + 1);
          Result[I + 1] := HexCharArrA[(Byte(C) shr 4) and $F)];
          Result[I + 2] := HexCharArrA[Byte(C) and $F];
        end;
    end;
  end;
end;

function UrlEncodeRfcW(const S: UnicodeString): AnsiString;
begin
  Result := UrlEncodeRfcA(Utf8Encode(S));
end;

Correct way to set Bearer token with CURL

<?php
$curl = curl_init();

curl_setopt_array($curl, array(
CURLOPT_URL => "your api goes here",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 0,
CURLOPT_FOLLOWLOCATION => true,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "GET",
CURLOPT_HTTPHEADER => array(
"Authorization: Bearer eyJ0eciOiJSUzI1NiJ9.eyJMiIsInNjb3BlcyI6W119.K3lW1STQhMdxfAxn00E4WWFA3uN3iIA"
  ),
 ));

$response = curl_exec($curl);
$data = json_decode($response, true);

echo $data;

?>

ImportError: No module named matplotlib.pyplot

So I used python3 -m pip install matplotlib' thenimport matplotlib.pyplot as plt` and it worked.

How do I create the small icon next to the website tab for my site?

This is for the icon in the browser (most of the sites omit the type):

<link rel="icon" type="image/vnd.microsoft.icon"
     href="http://example.com/favicon.ico" />

or

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

or

<link rel="apple-touch-icon"
     href="http://example.com//apple-touch-icon.png">

for the shortcut icon:

<link rel="shortcut icon"
     href="http://example.com/favicon.ico" />

Place them in the <head></head> section.

Edit may 2019 some additional examples from MDN

How to add a primary key to a MySQL table?

Not sure if this matters to anyone else, but I prefer the id for the table to be the first column in the database. The syntax for that is:

ALTER TABLE your_db.your_table ADD COLUMN `id` int(10) UNSIGNED PRIMARY KEY AUTO_INCREMENT FIRST;

Which is just a slight improvement over the first answer. If you wanted it to be in a different position, then

ALTER TABLE unique_address ADD COLUMN `id` int(10) UNSIGNED PRIMARY KEY AUTO_INCREMENT AFTER some_other_column;

HTH, -ft

How to read .pem file to get private and public key

Java libs makes it almost a one liner to read the public cert, as generated by openssl:

val certificate: X509Certificate = ByteArrayInputStream(
        publicKeyCert.toByteArray(Charsets.US_ASCII))
        .use {
            CertificateFactory.getInstance("X.509")
                    .generateCertificate(it) as X509Certificate
        }

But, o hell, reading the private key was problematic:

  1. First had to remove the begin and end tags, which is not nessarry when reading the public key.
  2. Then I had to remove all the new lines, otherwise it croaks!
  3. Then I had to decode back to bytes using byte 64
  4. Then I was able to produce an RSAPrivateKey.

see this: Final solution in kotlin

Full-screen responsive background image

http://css-tricks.com/perfect-full-page-background-image/

//HTML
<img src="images/bg.jpg" id="bg" alt="">

//CSS
#bg {
  position: fixed; 
  top: 0; 
  left: 0; 

  /* Preserve aspet ratio */
  min-width: 100%;
  min-height: 100%;
}

OR

img.bg {
  /* Set rules to fill background */
  min-height: 100%;
  min-width: 1024px;

  /* Set up proportionate scaling */
  width: 100%;
  height: auto;

  /* Set up positioning */
  position: fixed;
  top: 0;
  left: 0;
}

@media screen and (max-width: 1024px) { /* Specific to this particular image */
  img.bg {
    left: 50%;
    margin-left: -512px;   /* 50% */
  }
}

OR

//HTML
<img src="images/bg.jpg" id="bg" alt="">

//CSS
#bg { position: fixed; top: 0; left: 0; }
.bgwidth { width: 100%; }
.bgheight { height: 100%; }

//jQuery
$(window).load(function() {    

        var theWindow        = $(window),
            $bg              = $("#bg"),
            aspectRatio      = $bg.width() / $bg.height();

        function resizeBg() {

                if ( (theWindow.width() / theWindow.height()) < aspectRatio ) {
                    $bg
                        .removeClass()
                        .addClass('bgheight');
                } else {
                    $bg
                        .removeClass()
                        .addClass('bgwidth');
                }

        }

        theWindow.resize(resizeBg).trigger("resize");

});

Concatenating bits in VHDL

The concatenation operator '&' is allowed on the right side of the signal assignment operator '<=', only

Excel formula to get week number in month (having Monday)

Jonathan from the ExcelCentral forums suggests:

=WEEKNUM(A1,2)-WEEKNUM(DATE(YEAR(A1),MONTH(A1),1),2)+1 

This formula extracts the week of the year [...] and then subtracts it from the week of the first day in the month to get the week of the month. You can change the day that weeks begin by changing the second argument of both WEEKNUM functions (set to 2 [for Monday] in the above example). For weeks beginning on Sunday, use:

=WEEKNUM(A1,1)-WEEKNUM(DATE(YEAR(A1),MONTH(A1),1),1)+1

For weeks beginning on Tuesday, use:

=WEEKNUM(A1,12)-WEEKNUM(DATE(YEAR(A1),MONTH(A1),1),12)+1

etc.

I like it better because it's using the built in week calculation functionality of Excel (WEEKNUM).

Age from birthdate in python

Slightly modified Danny's solution for easier reading and understanding

    from datetime import date

    def calculate_age(birth_date):
        today = date.today()
        age = today.year - birth_date.year
        full_year_passed = (today.month, today.day) < (birth_date.month, birth_date.day)
        if not full_year_passed:
            age -= 1
        return age

How to define custom configuration variables in rails

In Rails 3.0.5, the following approach worked for me:

In config/environments/development.rb, write

config.custom_config_key = :config_value

The value custom_config_key can then be referenced from other files using

Rails.application.config.custom_config_key

IN vs ANY operator in PostgreSQL

(Neither IN nor ANY is an "operator". A "construct" or "syntax element".)

Logically, quoting the manual:

IN is equivalent to = ANY.

But there are two syntax variants of IN and two variants of ANY. Details:

IN taking a set is equivalent to = ANY taking a set, as demonstrated here:

But the second variant of each is not equivalent to the other. The second variant of the ANY construct takes an array (must be an actual array type), while the second variant of IN takes a comma-separated list of values. This leads to different restrictions in passing values and can also lead to different query plans in special cases:

ANY is more versatile

The ANY construct is far more versatile, as it can be combined with various operators, not just =. Example:

SELECT 'foo' LIKE ANY('{FOO,bar,%oo%}');

For a big number of values, providing a set scales better for each:

Related:

Inversion / opposite / exclusion

"Find rows where id is in the given array":

SELECT * FROM tbl WHERE id = ANY (ARRAY[1, 2]);

Inversion: "Find rows where id is not in the array":

SELECT * FROM tbl WHERE id <> ALL (ARRAY[1, 2]);
SELECT * FROM tbl WHERE id <> ALL ('{1, 2}');  -- equivalent array literal
SELECT * FROM tbl WHERE NOT (id = ANY ('{1, 2}'));

All three equivalent. The first with array constructor, the other two with array literal. The data type can be derived from context unambiguously. Else, an explicit cast may be required, like '{1,2}'::int[].

Rows with id IS NULL do not pass either of these expressions. To include NULL values additionally:

SELECT * FROM tbl WHERE (id = ANY ('{1, 2}')) IS NOT TRUE;

Format telephone and credit card numbers in AngularJS

Simple filter something like this (use numeric class on input end filter charchter in []):

<script type="text/javascript">
// Only allow number input
$('.numeric').keyup(function () {
    this.value = this.value.replace(/[^0-9+-\.\,\;\:\s()]/g, ''); // this is filter for telefon number !!!
});

Turning off eslint rule for a specific line

To disable a single rule for the rest of the file below:

/* eslint no-undef: "off"*/
const uploadData = new FormData();

What causes the error "_pickle.UnpicklingError: invalid load key, ' '."?

I had a similar error but with different context when I uploaded a *.p file to Google Drive. I tried to use it later in a Google Colab session, and got this error:

    1 with open("/tmp/train.p", mode='rb') as training_data:
----> 2     train = pickle.load(training_data)
UnpicklingError: invalid load key, '<'.

I solved it by compressing the file, upload it and then unzip on the session. It looks like the pickle file is not saved correctly when you upload/download it so it gets corrupted.

How do I change UIView Size?

I know that there is already a solution to this question, but I found an alternative to this issue and maybe it could help someone.

I was having trouble with setting the frame of my sub view because certain values were referring to its position within the main view. So if you don't want to update your frame by changing the whole frame via CGRect, you can simply change a value of the frame and then update it.

// keep reference to you frames
var questionView = questionFrame.frame
var answerView = answerFrame.frame

// update the values of the copy        
questionView.size.height = CGFloat(screenSize.height * 0.70)
answerView.size.height = CGFloat(screenSize.height * 0.30)

// set the frames to the new frames
questionFrame.frame = questionView
answerFrame.frame = answerView

"Debug only" code that should run only when "turned on"

I think it may be worth mentioning that [ConditionalAttribute] is in the System.Diagnostics; namespace. I stumbled a bit when I got:

Error 2 The type or namespace name 'ConditionalAttribute' could not be found (are you missing a using directive or an assembly reference?)

after using it for the first time (I thought it would have been in System).

OnClick in Excel VBA

In order to trap repeated clicks on the same cell, you need to move the focus to a different cell, so that each time you click, you are in fact moving the selection.

The code below will select the top left cell visible on the screen, when you click on any cell. Obviously, it has the flaw that it won't trap a click on the top left cell, but that can be managed (eg by selecting the top right cell if the activecell is the top left).

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
  'put your code here to process the selection, then..
  ActiveWindow.VisibleRange.Cells(1, 1).Select
End Sub

How to create a self-signed certificate for a domain name for development?

I had to puzzle my way through self-signed certificates on Windows by combining bits and pieces from the given answers and further resources. Here is my own (and hopefully complete) walk-through. Hope it will spare you some of my own painful learning curve. It also contains infos on related topics that will pop up sooner or later when you create your own certs.

Create a self-signed certificate on Windows 10 and below

Don't use makecert.exe. It has been deprecated by Microsoft.
The modern way uses a Powershell command.

Windows 10:

Open Powershell with Administrator privileges:

New-SelfSignedCertificate  -DnsName "*.dev.local", "dev.local", "localhost"  -CertStoreLocation cert:\LocalMachine\My  -FriendlyName "Dev Cert *.dev.local, dev.local, localhost"  -NotAfter (Get-Date).AddYears(15)

Windows 8, Windows Server 2012 R2:

In Powershell on these systems the parameters -FriendlyName and -NotAfter do not exist. Simply remove them from the above command line.
Open Powershell with Administrator privileges:

New-SelfSignedCertificate  -DnsName "*.dev.local", "dev.local", "localhost"  -CertStoreLocation cert:\LocalMachine\My

An alternative is to use the method for older Windows version below, which allows you to use all the features of Win 10 for cert creation...

Older Windows versions:

My recommendation for older Windows versions is to create the cert on a Win 10 machine, export it to a .PFX file using an mmc instance (see "Trust the certificate" below) and import it into the cert store on the target machine with the old Windows OS. To import the cert do NOT right-click it. Although there is an "Import certificate" item in the context menu, it failed all my trials to use it on Win Server 2008. Instead open another mmc instance on the target machine, navigate to "Certificates (Local Computer) / Personal / Certificates", right click into the middle pane and select All tasks ? Import.

The resulting certificate

Both of the above commands create a certificate for the domains localhost and *.dev.local.
The Win10 version additionally has a live time of 15 years and a readable display name of "Dev Cert *.dev.local, dev.local, localhost".

Update: If you provide multiple hostname entries in parameter -DnsName (as shown above) the first of these entries will become the domain's Subject (AKA Common Name). The complete list of all hostname entries will be stored in the field Subject Alternative Name (SAN) of the certificate. (Thanks to @BenSewards for pointing that out.)

After creation the cert will be immediately available in any HTTPS bindings of IIS (instructions below).

Trust the certificate

The new cert is not part of any chain of trust and is thus not considered trustworthy by any browsers. To change that, we will copy the cert to the certificate store for Trusted Root CAs on your machine:

Open mmc.exe, File ? Add/Remove Snap-In ? choose "Certificates" in left column ? Add ? choose "Computer Account" ? Next ? "Local Computer..." ? Finish ? OK

In the left column choose "Certificates (Local Computer) / Personal / Certificates".
Find the newly created cert (in Win 10 the column "Friendly name" may help).
Select this cert and hit Ctrl-C to copy it to clipboard.

In the left column choose "Certificates (Local Computer) / Trusted Root CAs / Certificates".
Hit Ctrl-V to paste your certificate to this store.
The certificate should appear in the list of Trusted Root Authorities and is now considered trustworthy.

Use in IIS

Now you may go to IIS Manager, select the bindings of a local website ? Add ? https ? enter a host name of the form myname.dev.local (your cert is only valid for *.dev.local) and select the new certificate ? OK.

Add to hosts

Also add your host name to C:\Windows\System32\drivers\etc\hosts:

127.0.0.1  myname.dev.local

Happy

Now Chrome and IE should treat the certificate as trustworthy and load your website when you open up https://myname.dev.local.

Firefox maintains its own certificate store. To add your cert here, you must open your website in FF and add it to the exceptions when FF warns you about the certificate.

For Edge browser there may be more action needed (see further down).

Test the certificate

To test your certs, Firefox is your best choice. (Believe me, I'm a Chrome fan-boy myself, but FF is better in this case.)

Here are the reasons:

  • Firefox uses its own SSL cache, which is purged on shift-reload. So any changes to the certs of your local websites will reflect immediately in the warnings of FF, while other browsers may need a restart or a manual purging of the windows SSL cache.
  • Also FF gives you some valuable hints to check the validity of your certificate: Click on Advanced when FF shows its certificate warning. FF will show you a short text block with one or more possible warnings in the central lines of the text block:

The certificate is not trusted because it is self-signed.

This warning is correct! As noted above, Firefox does not use the Windows certificate store and will only trust this certificate, if you add an exception for it. The button to do this is right below the warnings.

The certificate is not valid for the name ...

This warning shows, that you did something wrong. The (wildcard) domain of your certificate does not match the domain of your website. The problem must be solved by either changing your website's (sub-)domain or by issuing a new certificate that matches. In fact you could add an exception in FF even if the cert does not match, but you would never get a green padlock symbol in Chrome with such a combination.

Firefox can display many other nice and understandable cert warnings at this place, like expired certs, certs with outdated signing algorithms, etc. I found no other browser that gave me that level of feedback to nail down any problems.

Which (sub-)domain pattern should I choose to develop?

In the above New-SelfSignedCertificate command we used the wildcard domain *.dev.local.

You may think: Why not use *.local?

Simple reason: It is illegal as a wildcard domain.
Wildcard certificates must contain at least a second level domain name.

So, domains of the form *.local are nice to develop HTTP websites. But not so much for HTTPS, because you would be forced to issue a new matching certificate for each new project that you start.

Important side notes:

  • Valid host domains may ONLY contain letters a trough z, digits, hyphens and dots. No underscores allowed! Some browsers are really picky about this detail and can give you a hard time when they stubbornly refuse to match your domain motör_head.dev.local to your wildcard pattern *.dev.local. They will comply when you switch to motoer-head.dev.local.
  • A wildcard in a certificate will only match ONE label (= section between two dots) in a domain, never more. *.dev.local matches myname.dev.local but NOT other.myname.dev.local!
  • Multi level wildcards (*.*.dev.local) are NOT possible in certificates. So other.myname.dev.local can only be covered by a wildcard of the form *.myname.dev.local. As a result, it is best not to use a forth level domain part. Put all your variations into the third level part. This way you will get along with a single certificate for all your dev sites.

The problem with Edge

This is not really about self-signed certificates, but still related to the whole process:
After following the above steps, Edge may not show any content when you open up myname.dev.local.
The reason is a characteristic feature of the network management of Windows 10 for Modern Apps, called "Network Isolation".

To solve that problem, open a command prompt with Administrator privileges and enter the following command once:

CheckNetIsolation LoopbackExempt -a -n=Microsoft.MicrosoftEdge_8wekyb3d8bbwe

More infos about Edge and Network Isolation can be found here: https://blogs.msdn.microsoft.com/msgulfcommunity/2015/07/01/how-to-debug-localhost-on-microsoft-edge/

Tomcat manager/html is not available?

You have to check if you have the folder with name manager inside the folder webapps in your tomcat.

Rubens-MacBook-Pro:tomcat rfanjul$ ls -la webapps/
total 16
drwxr-xr-x   8 rfanjul  staff   272 21 May 12:20 .
drwxr-xr-x  14 rfanjul  staff   476 21 May 12:22 ..
-rw-r--r--@  1 rfanjul  staff  6148 21 May 12:20 .DS_Store
drwxr-xr-x  19 rfanjul  staff   646 17 Feb 15:13 ROOT
drwxr-xr-x  51 rfanjul  staff  1734 17 Feb 15:13 docs
drwxr-xr-x   6 rfanjul  staff   204 17 Feb 15:13 examples
drwxr-xr-x   7 rfanjul  staff   238 17 Feb 15:13 host-manager
drwxr-xr-x   8 rfanjul  staff   272 17 Feb 15:13 manager

After that you will be sure that you have this permmint for you user in the file conf/tomcat-users.xml:

<role rolename="admin-gui"/>
<role rolename="manager-gui"/>
<user username="test" password="test" roles="admin-gui,manager-gui"/>

restart tomcat and stat tomcat again.

sh bin/shutdown.sh 
sh bin/startup.sh

I hope that will works fine for you.

What is the best way to iterate over multiple lists at once?

You can use zip:

>>> a = [1, 2, 3]
>>> b = ['a', 'b', 'c']
>>> for x, y in zip(a, b):
...   print x, y
... 
1 a
2 b
3 c

history.replaceState() example?

I really wanted to respond to @Sev's answer.

Sev is right, there is a bug inside the window.history.replaceState

To fix this simply rewrite the constructor to set the title manually.

var replaceState_tmp = window.history.replaceState.constructor;
window.history.replaceState.constructor = function(obj, title, url){
    var title_ = document.getElementsByTagName('title')[0];
    if(title_ != undefined){
        title_.innerHTML = title;
    }else{
        var title__ = document.createElement('title');
        title__.innerHTML = title;
        var head_ = document.getElementsByTagName('head')[0];
        if(head_ != undefined){
            head_.appendChild(title__);
        }else{
            var head__ = document.createElement('head');
            document.documentElement.appendChild(head__);
            head__.appendChild(title__);
        }
    }
    replaceState_tmp(obj,title, url);
}

How to get css background color on <tr> tag to span entire row

Have you tried setting the spacing to zero?

/*alternating row*/
table, tr, td, th {margin:0;border:0;padding:0;spacing:0;}
tr.rowhighlight {background-color:#f0f8ff;margin:0;border:0;padding:0;spacing:0;}

Foreach in a Foreach in MVC View

You have:

foreach (var category in Model.Categories)

and then

@foreach (var product in Model)

Based on that view and model it seems that Model is of type Product if yes then the second foreach is not valid. Actually the first one could be the one that is invalid if you return a collection of Product.

UPDATE:

You are right, I am returning the model of type Product. Also, I do understand what is wrong now that you've pointed it out. How am I supposed to do what I'm trying to do then if I can't do it this way?

I'm surprised your code compiles when you said you are returning a model of Product type. Here's how you can do it:

@foreach (var category in Model)
{
    <h3><u>@category.Name</u></h3>

    <div>
        <ul>    
            @foreach (var product in category.Products)
            {
                <li>
                    put the rest of your code
                </li>
            }
        </ul>
    </div>
}

That suggest that instead of returning a Product, you return a collection of Category with Products. Something like this in EF:

// I am typing it here directly 
// so I'm not sure if this is the correct syntax.
// I assume you know how to do this,
// anyway this should give you an idea.
context.Categories.Include(o=>o.Product)

Finding local maxima/minima with Numpy in a 1D numpy array

Another approach (more words, less code) that may help:

The locations of local maxima and minima are also the locations of the zero crossings of the first derivative. It is generally much easier to find zero crossings than it is to directly find local maxima and minima.

Unfortunately, the first derivative tends to "amplify" noise, so when significant noise is present in the original data, the first derivative is best used only after the original data has had some degree of smoothing applied.

Since smoothing is, in the simplest sense, a low pass filter, the smoothing is often best (well, most easily) done by using a convolution kernel, and "shaping" that kernel can provide a surprising amount of feature-preserving/enhancing capability. The process of finding an optimal kernel can be automated using a variety of means, but the best may be simple brute force (plenty fast for finding small kernels). A good kernel will (as intended) massively distort the original data, but it will NOT affect the location of the peaks/valleys of interest.

Fortunately, quite often a suitable kernel can be created via a simple SWAG ("educated guess"). The width of the smoothing kernel should be a little wider than the widest expected "interesting" peak in the original data, and its shape will resemble that peak (a single-scaled wavelet). For mean-preserving kernels (what any good smoothing filter should be) the sum of the kernel elements should be precisely equal to 1.00, and the kernel should be symmetric about its center (meaning it will have an odd number of elements.

Given an optimal smoothing kernel (or a small number of kernels optimized for different data content), the degree of smoothing becomes a scaling factor for (the "gain" of) the convolution kernel.

Determining the "correct" (optimal) degree of smoothing (convolution kernel gain) can even be automated: Compare the standard deviation of the first derivative data with the standard deviation of the smoothed data. How the ratio of the two standard deviations changes with changes in the degree of smoothing cam be used to predict effective smoothing values. A few manual data runs (that are truly representative) should be all that's needed.

All the prior solutions posted above compute the first derivative, but they don't treat it as a statistical measure, nor do the above solutions attempt to performing feature preserving/enhancing smoothing (to help subtle peaks "leap above" the noise).

Finally, the bad news: Finding "real" peaks becomes a royal pain when the noise also has features that look like real peaks (overlapping bandwidth). The next more-complex solution is generally to use a longer convolution kernel (a "wider kernel aperture") that takes into account the relationship between adjacent "real" peaks (such as minimum or maximum rates for peak occurrence), or to use multiple convolution passes using kernels having different widths (but only if it is faster: it is a fundamental mathematical truth that linear convolutions performed in sequence can always be convolved together into a single convolution). But it is often far easier to first find a sequence of useful kernels (of varying widths) and convolve them together than it is to directly find the final kernel in a single step.

Hopefully this provides enough info to let Google (and perhaps a good stats text) fill in the gaps. I really wish I had the time to provide a worked example, or a link to one. If anyone comes across one online, please post it here!

How do I clear the dropdownlist values on button click event using jQuery?

If you want to reset the selected options

$('select option:selected').removeAttr('selected');

If you actually want to remove the options (although I don't think you mean this).

$('select').empty();

Substitute select for the most appropriate selector in your case (this may be by id or by CSS class). Using as is will reset all <select> elements on the page

How to show particular image as thumbnail while implementing share on Facebook?

Facebook uses og:tags and the Open Graph Protocol to decipher what information to display when previewing your URL in a share dialog or in a news feed on facebook.

The og:tags contain information such as :

  • The title of the page
  • The type of page
  • The URL
  • The websites name
  • A description of the page
  • Facebook user_id's of administrators of the page ( on facebook )

Here is an example ( taken from the facebook documentation ) of some og:tags

<meta property="og:title" content="The Rock"/>
<meta property="og:type" content="movie"/>
<meta property="og:url" content="http://www.imdb.com/title/tt0117500/"/>
<meta property="og:image" content="http://ia.media-imdb.com/rock.jpg"/>

Once you have implemented the correct markup of the og:tags and set their values, you can test how facebook will view your URL by using the Facebook Debugger. The debugger tool will also highlight any problems it finds with the og:tags on the page or lack there-of.

One thing to keep in mind is that facebook does do some caching with regard to this information, so in order for changes to take effect your page will have t be scraped as stated in the documentation :

Editing Meta Tags

You can update the attributes of your page by updating your page's tags. Note that og:title and og:type are only editable initially - after your page receives 50 likes the title becomes fixed, and after your page receives 10,000 likes the type becomes fixed. These properties are fixed to avoid surprising users who have liked the page already. Changing the title or type tags after these limits are reached does nothing, your page retains the original title and type.

For the changes to be reflected on Facebook, you must force your page to be scraped. The page is scraped when an admin for the page clicks the Like button or when the URL is entered into the Facebook URL Linter Facebook Debugger...

jQuery selector regular expressions

These can be helpful.

If you're finding by Contains then it'll be like this

    $("input[id*='DiscountType']").each(function (i, el) {
         //It'll be an array of elements
     });

If you're finding by Starts With then it'll be like this

    $("input[id^='DiscountType']").each(function (i, el) {
         //It'll be an array of elements
     });

If you're finding by Ends With then it'll be like this

     $("input[id$='DiscountType']").each(function (i, el) {
         //It'll be an array of elements
     });

If you want to select elements which id is not a given string

    $("input[id!='DiscountType']").each(function (i, el) {
         //It'll be an array of elements
     });

If you want to select elements which name contains a given word, delimited by spaces

     $("input[name~='DiscountType']").each(function (i, el) {
         //It'll be an array of elements
     });

If you want to select elements which id is equal to a given string or starting with that string followed by a hyphen

     $("input[id|='DiscountType']").each(function (i, el) {
         //It'll be an array of elements
     });

Unable to import a module that is definitely installed

I had this problem with 2.7 and 3.5 installed on my system trying to test a telegram bot with Python-Telegram-Bot.

I couldn't get it to work after installing with pip and pip3, with sudo or without. I always got:

Traceback (most recent call last):
  File "telegram.py", line 2, in <module>
    from telegram.ext import Updater
  File "$USER/telegram.py", line 2, in <module>
    from telegram.ext import Updater
ImportError: No module named 'telegram.ext'; 'telegram' is not a package

Reading the error message correctly tells me that python is looking in the current directory for a telegram.py. And right, I had a script lying there called telegram.py and this was loaded by python when I called import.

Conclusion, make sure you don't have any package.py in your current working dir when trying to import. (And read error message thoroughly).

android pinch zoom

I have an open source library that does this very well. It's a four gesture library that comes with an out-of-the-box pan zoom setting. You can find it here: https://bitbucket.org/warwick/hacergestov3 Or you can download the demo app here: https://play.google.com/store/apps/details?id=com.WarwickWestonWright.HacerGestoV3Demo This is a pure canvas library so it can be used in pretty any scenario. Hope this helps.

Hibernate: hbm2ddl.auto=update in production?

Applications' schema may evolve in time; if you have several installations, which may be at different versions, you should have some way to ensure that your application, some kind of tool or script is capable of migrating schema and data from one version stepwise to any following one.

Having all your persistence in Hibernate mappings (or annotations) is a very good way for keeping schema evolution under control.

You should consider that schema evolution has several aspects to be considered:

  1. evolution of the database schema in adding more columns and tables

  2. dropping of old columns, tables and relations

  3. filling new columns with defaults

Hibernate tools are important in particular in case (like in my experience) you have different versions of the same application on many different kinds of databases.

Point 3 is very sensitive in case you are using Hibernate, as in case you introduce a new boolean valued property or numeric one, if Hibernate will find any null value in such columns, if will raise an exception.

So what I would do is: do indeed use the Hibernate tools capacity of schema update, but you must add alongside of it some data and schema maintenance callback, like for filling defaults, dropping no longer used columns, and similar. In this way you get the advantages (database independent schema update scripts and avoiding duplicated coding of the updates, in peristence and in scripts) but you also cover all the aspects of the operation.

So for example if a version update consists simply in adding a varchar valued property (hence column), which may default to null, with auto update you'll be done. Where more complexity is necessary, more work will be necessary.

This is assuming that the application when updated is capable of updating its schema (it can be done), which also means that it must have the user rights to do so on the schema. If the policy of the customer prevents this (likely Lizard Brain case), you will have to provide the database - specific scripts.

Why do I get an UnsupportedOperationException when trying to remove an element from a List?

I think that replacing:

List<String> list = Arrays.asList(split);

with

List<String> list = new ArrayList<String>(Arrays.asList(split));

resolves the problem.

angularjs ng-style: background-image isn't working

Correct syntax for background-image is:

background-image: url("path_to_image");

Correct syntax for ng-style is:

ng-style="{'background-image':'url(https://www.google.com/images/srpr/logo4w.png)'}">

Laravel Fluent Query Builder Join with subquery

I can't comment because my reputation is not high enough. @Franklin Rivero if you are using Laravel 5.2 you can set the bindings on the main query instead of the join using the setBindings method.

So the main query in @ph4r05's answer would look something like this:

$q = DnsResult::query()
    ->from($dnsTable . ' AS s')
    ->join(
        DB::raw('(' . $qqSql. ') AS ss'),
        function(JoinClause $join) {
            $join->on('s.watch_id', '=', 'ss.watch_id')
                 ->on('s.last_scan_at', '=', 'ss.last_scan');
        })
    ->setBindings($subq->getBindings());

nodejs send html file to client

After years, I want to add another approach by using a view engine in Express.js

var fs = require('fs');

app.get('/test', function(req, res, next) {
    var html = fs.readFileSync('./html/test.html', 'utf8')
    res.render('test', { html: html })
    // or res.send(html)
})

Then, do that in your views/test if you choose res.render method at the above code (I'm writing in EJS format):

<%- locals.html %>

That's all.

In this way, you don't need to break your View Engine arrangements.

Multiple left-hand assignment with JavaScript

Actually,

var var1 = 1, var2 = 1, var3 = 1;

is not equivalent to:

var var1 = var2 = var3 = 1;

The difference is in scoping:

_x000D_
_x000D_
function good() {_x000D_
  var var1 = 1, var2 = 1, var3 = 1;_x000D_
}_x000D_
_x000D_
function bad() {_x000D_
  var var1 = var2 = var3 = 1;_x000D_
}_x000D_
_x000D_
good();_x000D_
console.log(window.var2); // undefined_x000D_
_x000D_
bad();_x000D_
console.log(window.var2); // 1. Aggh!
_x000D_
_x000D_
_x000D_

Actually this shows that assignment are right associative. The bad example is equivalent to:

var var1 = (window.var2 = (window.var3 = 1));

Property 'value' does not exist on type EventTarget in TypeScript

You should use event.target.value prop with onChange handler if not you could see :

index.js:1437 Warning: Failed prop type: You provided a `value` prop to a form field without an `onChange` handler. This will render a read-only field. If the field should be mutable use `defaultValue`. Otherwise, set either `onChange` or `readOnly`.

Or If you want to use other handler than onChange, use event.currentTarget.value

Django - Static file not found

TEMPLATE_DIR=os.path.join(BASE_DIR,'templates')
STATIC_DIR=os.path.join(BASE_DIR,'static')

STATICFILES_DIRS=[STATIC_DIR]

Convert Dictionary to JSON in Swift

private func convertDictToJson(dict : NSDictionary) -> NSDictionary?
{
    var jsonDict : NSDictionary!

    do {
        let jsonData = try JSONSerialization.data(withJSONObject:dict, options:[])
        let jsonDataString = String(data: jsonData, encoding: String.Encoding.utf8)!
        print("Post Request Params : \(jsonDataString)")
        jsonDict = [ParameterKey : jsonDataString]
        return jsonDict
    } catch {
        print("JSON serialization failed:  \(error)")
        jsonDict = nil
    }
    return jsonDict
}

How to select all instances of selected region in Sublime Text

On Mac:

?+CTRL+g

However, you can reset any key any way you'd like using "Customize your Sublime Text 2 configuration for awesome coding." for Mac.


On Windows/Linux:

Alt+F3

If anyone has how-tos or articles on this, I'd be more than happy to update.

How can I concatenate strings in VBA?

The main (very interesting) difference for me is that:
"string" & Null -> "string"
while
"string" + Null -> Null

But that's probably more useful in database apps like Access.

'Connect-MsolService' is not recognized as the name of a cmdlet

I had to do this in that order:

Install-Module MSOnline
Install-Module AzureAD
Import-Module AzureAD

How to check if a character in a string is a digit or letter

import java.util.*;

public class String_char 
{

    public static void main(String arg[]){   

        Scanner in = new Scanner(System.in);
        System.out.println("Enter the value");
        String data;
        data = in.next();

        int len = data.length();
        for (int i = 0 ; i < len ; i++){
            char ch = data.charAt(i);

            if ((ch >= '0' && ch <= '9')){
                System.out.println("Number ");
            }
            else if((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z')){
            System.out.println("Character");
            }
            else{
                System.out.println("Symbol");
             }
        }
    } 
}

Custom exception type

From WebReference:

throw { 
  name:        "System Error", 
  level:       "Show Stopper", 
  message:     "Error detected. Please contact the system administrator.", 
  htmlMessage: "Error detected. Please contact the <a href=\"mailto:[email protected]\">system administrator</a>.",
  toString:    function(){return this.name + ": " + this.message;} 
}; 

Setting PHP tmp dir - PHP upload not working

create php-file with:

<?php
    print shell_exec( 'whoami' );
?>

or

<?php echo exec('whoami'); ?>

try the output in your web-browser. if the output is not your user example: www-data then proceed to next step

open as root:

/etc/apache2/envvars

look for these lines:

export APACHE_RUN_USER=user-name

export APACHE_RUN_GROUP=group-name

example:

export APACHE_RUN_USER=www-data

export APACHE_RUN_GROUP=www-data

where:

username = your username that has access to the folder you are using group = group you've given read+write+execute access

change it to:

export APACHE_RUN_USER="username"

export APACHE_RUN_GROUP="group"

if your user have no access yet:

sudo chmod 775 -R "directory of folder you want to give r/w/x access"

How to use jquery $.post() method to submit form values

You have to select and send the form data as well:

$("#post-btn").click(function(){        
    $.post("process.php", $("#reg-form").serialize(), function(data) {
        alert(data);
    });
});

Take a look at the documentation for the jQuery serialize method, which encodes the data from the form fields into a data-string to be sent to the server.

How is CountDownLatch used in Java Multithreading?

NikolaB explained it very well, However example would be helpful to understand, So here is one simple example...

 import java.util.concurrent.*;


  public class CountDownLatchExample {

  public static class ProcessThread implements Runnable {

    CountDownLatch latch;
    long workDuration;
    String name;

    public ProcessThread(String name, CountDownLatch latch, long duration){
        this.name= name;
        this.latch = latch;
        this.workDuration = duration;
    }


    public void run() {
        try {
            System.out.println(name +" Processing Something for "+ workDuration/1000 + " Seconds");
            Thread.sleep(workDuration);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println(name+ "completed its works");
        //when task finished.. count down the latch count...

        // basically this is same as calling lock object notify(), and object here is latch
        latch.countDown();
    }
}


public static void main(String[] args) {
    // Parent thread creating a latch object
    CountDownLatch latch = new CountDownLatch(3);

    new Thread(new ProcessThread("Worker1",latch, 2000)).start(); // time in millis.. 2 secs
    new Thread(new ProcessThread("Worker2",latch, 6000)).start();//6 secs
    new Thread(new ProcessThread("Worker3",latch, 4000)).start();//4 secs


    System.out.println("waiting for Children processes to complete....");
    try {
        //current thread will get notified if all chidren's are done 
        // and thread will resume from wait() mode.
        latch.await();
    } catch (InterruptedException e) {
        e.printStackTrace();
    }

    System.out.println("All Process Completed....");

    System.out.println("Parent Thread Resuming work....");



     }
  }

How to represent the double quotes character (") in regex?

Firstly, double quote character is nothing special in regex - it's just another character, so it doesn't need escaping from the perspective of regex.

However, because java uses double quotes to delimit String constants, if you want to create a string in java with a double quote in it, you must escape them.

This code will test if your String matches:

if (str.matches("\".*\"")) {
    // this string starts and end with a double quote
}

Note that you don't need to add start and end of input markers (^ and $) in the regex, because matches() requires that the whole input be matched to return true - ^ and $ are implied.

C char array initialization

  1. These are equivalent

    char buf[10] = "";
    char buf[10] = {0};
    char buf[10] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
    
  2. These are equivalent

    char buf[10] = " ";
    char buf[10] = {' '};
    char buf[10] = {' ', 0, 0, 0, 0, 0, 0, 0, 0, 0};
    
  3. These are equivalent

    char buf[10] = "a";
    char buf[10] = {'a'};
    char buf[10] = {'a', 0, 0, 0, 0, 0, 0, 0, 0, 0};
    

How can I see the request headers made by curl when sending a request to the server?

I think curl --verbose/-v is the easiest. It will spit out the request headers (lines prefixed with '>') without having to write to a file:

$ curl -v -I -H "Testing: Test header so you see this works" http://stackoverflow.com/
* About to connect() to stackoverflow.com port 80 (#0)
*   Trying 69.59.196.211... connected
* Connected to stackoverflow.com (69.59.196.211) port 80 (#0)
> HEAD / HTTP/1.1
> User-Agent: curl/7.16.3 (i686-pc-cygwin) libcurl/7.16.3 OpenSSL/0.9.8h zlib/1.2.3 libssh2/0.15-CVS
> Host: stackoverflow.com
> Accept: */*
> Testing: Test header so you see this works
>
< HTTP/1.0 200 OK
...

How to submit a form using PhantomJS

Sending raw POST requests can be sometimes more convenient. Below you can see post.js original example from PhantomJS

// Example using HTTP POST operation

var page = require('webpage').create(),
    server = 'http://posttestserver.com/post.php?dump',
    data = 'universe=expanding&answer=42';

page.open(server, 'post', data, function (status) {
    if (status !== 'success') {
        console.log('Unable to post!');
    } else {
        console.log(page.content);
    }
    phantom.exit();
});

Android studio logcat nothing to show

Logcat has a little icon to the right of logcat. You can use the icon to turn logcat on and off. I can usually make logcat active by clicking the icon (maybe several times).

The relationship could not be changed because one or more of the foreign-key properties is non-nullable

If you are using AutoMapper with Entity Framework on the same class, you might hit this problem. For instance if your class is

class A
{
    public ClassB ClassB { get; set; }
    public int ClassBId { get; set; }
}

AutoMapper.Map<A, A>(input, destination);

This will try to copy both properties. In this case, ClassBId is non Nullable. Since AutoMapper will copy destination.ClassB = input.ClassB; this will cause a problem.

Set your AutoMapper to Ignore ClassB property.

 cfg.CreateMap<A, A>()
     .ForMember(m => m.ClassB, opt => opt.Ignore()); // We use the ClassBId

What is a void pointer in C++?

A void* does not mean anything. It is a pointer, but the type that it points to is not known.

It's not that it can return "anything". A function that returns a void* generally is doing one of the following:

  • It is dealing in unformatted memory. This is what operator new and malloc return: a pointer to a block of memory of a certain size. Since the memory does not have a type (because it does not have a properly constructed object in it yet), it is typeless. IE: void.
  • It is an opaque handle; it references a created object without naming a specific type. Code that does this is generally poorly formed, since this is better done by forward declaring a struct/class and simply not providing a public definition for it. Because then, at least it has a real type.
  • It returns a pointer to storage that contains an object of a known type. However, that API is used to deal with objects of a wide variety of types, so the exact type that a particular call returns cannot be known at compile time. Therefore, there will be some documentation explaining when it stores which kinds of objects, and therefore which type you can safely cast it to.

This construct is nothing like dynamic or object in C#. Those tools actually know what the original type is; void* does not. This makes it far more dangerous than any of those, because it is very easy to get it wrong, and there's no way to ask if a particular usage is the right one.

And on a personal note, if you see code that uses void*'s "often", you should rethink what code you're looking at. void* usage, especially in C++, should be rare, used primary for dealing in raw memory.

Linux: copy and create destination dir if it does not exist

mkdir -p "$d" && cp file "$d"

(there's no such option for cp).

Multiple IF statements between number ranges

standalone one cell solution based on VLOOKUP

US syntax:

=IFERROR(ARRAYFORMULA(IF(LEN(A2:A),
        IF(A2:A>2000, "More than 2000",VLOOKUP(A2:A,
 {{(TRANSPOSE({{{0;   "Less than 500"},
               {500;  "Between 500 and 1000"}},
              {{1000; "Between 1000 and 1500"},
               {1500; "Between 1500 and 2000"}}}))}}, 2)),)), )

EU syntax:

=IFERROR(ARRAYFORMULA(IF(LEN(A2:A);
        IF(A2:A>2000; "More than 2000";VLOOKUP(A2:A;
 {{(TRANSPOSE({{{0;   "Less than 500"}\
               {500;  "Between 500 and 1000"}}\
              {{1000; "Between 1000 and 1500"}\
               {1500; "Between 1500 and 2000"}}}))}}; 2));)); )

alternatives: https://webapps.stackexchange.com/questions/123729/

ImportError: cannot import name

This can also happen if you've been working on your scripts and functions and have been moving them around (i.e. changed the location of the definition) which could have accidentally created a looping reference.

You may find that the situation is solved if you just reset the iPython kernal to clear any old assignments:

%reset

or menu->restart terminal

How to see PL/SQL Stored Function body in Oracle

If is a package then you can get the source for that with:

    select text from all_source where name = 'PADCAMPAIGN' 
    and type = 'PACKAGE BODY'
    order by line;

Oracle doesn't store the source for a sub-program separately, so you need to look through the package source for it.

Note: I've assumed you didn't use double-quotes when creating that package, but if you did , then use

    select text from all_source where name = 'pAdCampaign' 
    and type = 'PACKAGE BODY'
    order by line;

How to execute a bash command stored as a string with quotes and asterisk

Have you tried:

eval $cmd

For the follow-on question of how to escape * since it has special meaning when it's naked or in double quoted strings: use single quotes.

MYSQL='mysql AMORE -u username -ppassword -h localhost -e'
QUERY="SELECT "'*'" FROM amoreconfig" ;# <-- "double"'single'"double"
eval $MYSQL "'$QUERY'"

Bonus: It also reads nice: eval mysql query ;-)

Configuring user and password with Git Bash

add remote as:

git remote add https://username:[email protected]/repodir/myrepo.git

CSS Margin: 0 is not setting to 0

You need to set the actual page to margin:0 and padding: 0 to the actual html, not just the body.

use this in your css stylesheet.

*, html {
    margin:0;
    padding:0;  
}

that will set the whole page to 0, for a fresh clean start with no margin or paddings.

Why would Oracle.ManagedDataAccess not work when Oracle.DataAccess does?

A "little" late to the party but the real answer to this - if you use Oracle.ManagedDataAccess ODP.NET provider, you should forget about things like network\admin, Oracle client, Oracle_Home, etc.

Here is what you need

  1. Download and install Oracle Developer Tools for VS or ODAC. Note - Dev tools will install ODAC for you. This will create relatively small installation under C:\Program Files (x86). With full dev tools, under 60Mb
  2. In your project you will install Nuget package with corresponding version of ODP.net (Oracle.ManagedDataAccess.dll) which you will reference
  3. At this point you have 2 options to connect.

    • a) In the connection string set datasource in the following format

      DataSource=ServerName:Port/SID . . . or DataSource=IP:Port/SID . . .

    • b) Create tnsnames.ora file (only it is going to be different from previous experiences). Have entry in it:

      AAA = (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = ServerNameOrIP)(PORT = 1521))
      (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = SIDNAME)))

      And place this file into your bin folder, where your application is running from. Now you can connect using your connection name - DataSource=AAA . . . So, even though you have tnsnames.ora, with ODP.net managed it works a bit different - you create local TNS file. And now, it is easy to manage it.

To summarize - with managed, no need for heavy Oracle Client, Oracle_home or knowing depths of oracle installation folders. Everything can be done within your .net application structures.

Docker - Ubuntu - bash: ping: command not found

I have used the statement below on debian 10

apt-get install iputils-ping

SELECT list is not in GROUP BY clause and contains nonaggregated column .... incompatible with sql_mode=only_full_group_by

In Ubuntu

Step 1:

sudo vi /etc/mysql/mysql.conf.d/mysqld.cnf

Step 2: Go to last line and add the following

sql_mode = ""

Step 3: Save

Step 4: Restart mysql server.

OS X Terminal shortcut: Jump to beginning/end of line

I use a handy app called Karabiner to do this, and many other things. It's free and open source.

It's a keyboard remapper, with a lot of handy presets for many common remaps that people may want to do.

As you can see from the screenshot, this remap is included as a preset in Karabiner.

Screenshot of Karabiner preferences showing the preset to map cmd+left/right to ctrl+a/e

Hope this helps. Happy remapping!

Determining image file size + dimensions via Javascript?

Service workers have access to header informations, including the Content-Length header.

Service workers are a bit complicated to understand, so I've built a small library called sw-get-headers.

Than you need to:

  1. subscribe to the library's response event
  2. identify the image's url among all the network requests
  3. here you go, you can read the Content-Length header!

Note that your website needs to be on HTTPS to use Service Workers, the browser needs to be compatible with Service Workers and the images must be on the same origin as your page.

Safest way to get last record ID from a table

One more way -

select * from <table> where  id=(select max(id) from <table>)

Also you can check on this link -

http://msdn.microsoft.com/en-us/library/ms175098.aspx

Select multiple records based on list of Id's with linq

Solution with .Where and .Contains has complexity of O(N square). Simple .Join should have a lot better performance (close to O(N) due to hashing). So the correct code is:

_dataContext.UserProfile.Join(idList, up => up.ID, id => id, (up, id) => up);

And now result of my measurement. I generated 100 000 UserProfiles and 100 000 ids. Join took 32ms and .Where with .Contains took 2 minutes and 19 seconds! I used pure IEnumerable for this testing to prove my statement. If you use List instead of IEnumerable, .Where and .Contains will be faster. Anyway the difference is significant. The fastest .Where .Contains is with Set<>. All it depends on complexity of underlying coletions for .Contains. Look at this post to learn about linq complexity.Look at my test sample below:

    private static void Main(string[] args)
    {
        var userProfiles = GenerateUserProfiles();
        var idList = GenerateIds();
        var stopWatch = new Stopwatch();
        stopWatch.Start();
        userProfiles.Join(idList, up => up.ID, id => id, (up, id) => up).ToArray();
        Console.WriteLine("Elapsed .Join time: {0}", stopWatch.Elapsed);
        stopWatch.Restart();
        userProfiles.Where(up => idList.Contains(up.ID)).ToArray();
        Console.WriteLine("Elapsed .Where .Contains time: {0}", stopWatch.Elapsed);
        Console.ReadLine();
    }

    private static IEnumerable<int> GenerateIds()
    {
       // var result = new List<int>();
        for (int i = 100000; i > 0; i--)
        {
            yield return i;
        }
    }

    private static IEnumerable<UserProfile> GenerateUserProfiles()
    {
        for (int i = 0; i < 100000; i++)
        {
            yield return new UserProfile {ID = i};
        }
    }

Console output:

Elapsed .Join time: 00:00:00.0322546

Elapsed .Where .Contains time: 00:02:19.4072107

Left Join without duplicate rows from left table

Using the DISTINCT flag will remove duplicate rows.

SELECT DISTINCT
C.Content_ID,
C.Content_Title,
M.Media_Id

FROM tbl_Contents C
LEFT JOIN tbl_Media M ON M.Content_Id = C.Content_Id 
ORDER BY C.Content_DatePublished ASC

HTTP Error 403.14 - Forbidden The Web server is configured to not list the contents

In my case index.aspx file was not created by default and after adding another web form i did not set the form as start page ...After setting the page as start page my issue get resolved . So right click a web form and set the form as start page :)

Shortcut key for commenting out lines of Python code in Spyder

on Windows F9 to run single line

Select the lines which you want to run on console and press F9 button for multi line

Take a screenshot via a Python script on Linux

It's an old question. I would like to answer it using new tools.

Works with python 3 (should work with python 2, but I haven't test it) and PyQt5.

Minimal working example. Copy it to the python shell and get the result.

from PyQt5.QtWidgets import QApplication
app = QApplication([])
screen = app.primaryScreen()
screenshot = screen.grabWindow(QApplication.desktop().winId())
screenshot.save('/tmp/screenshot.png')

How to prune local tracking branches that do not exist on remote anymore

The Powershell Version of git branch --merged master | grep -v '^[ *]*master$' | xargs git branch -d

git branch --merged master | %{ if($_ -notmatch '\*.*master'){ git branch -d "$($_.Trim())" }}

This will remove any local branches that have been merged into master, while you are on the master branch.

git checkout master to switch.

Is there an easy way to strike through text in an app widget?

I've done this on a regular (local) TextView, and it should work on the remote variety since the docs list the method as equivalent between the two:

remote_text_view.setText(Html.fromHtml("This is <del>crossed off</del>."));

input() error - NameError: name '...' is not defined

Here is an input function which is compatible with both Python 2.7 and Python 3+: (Slightly modified answer by @Hardian) to avoid UnboundLocalError: local variable 'input' referenced before assignment error

def input_compatible(prompt=None):
    try:
        input_func = raw_input
    except NameError:
        input_func = input
    return input_func(prompt)

Are PostgreSQL column names case-sensitive?

Identifiers (including column names) that are not double-quoted are folded to lower case in PostgreSQL. Column names that were created with double-quotes and thereby retained upper-case letters (and/or other syntax violations) have to be double-quoted for the rest of their life:

"first_Name"

Values (string literals / constants) are enclosed in single quotes:

'xyz'

So, yes, PostgreSQL column names are case-sensitive (when double-quoted):

SELECT * FROM persons WHERE "first_Name" = 'xyz';

Read the manual on identifiers here.

My standing advice is to use legal, lower-case names exclusively so double-quoting is not needed.