I have a problem, with a modal. I have a button on a page, that toggles the modal. When the modal shows up, the page jumps to top.

I have done everything I could to find a solution/etc, but I am really lost.

**EDIT:**

I have also tried with: `$(&#39;#myModal&#39;).modal(&#39;show&#39;);` but it has the exact same effect.

Bootstrap modal: background jumps to top on toggle

It sounds as an easy problem but I do not find any effective solution to change the font (not the font size) in a plot made with matplotlib in python.

I found a couple of tutorials to change the default font of matplotlib by modifying some files in the folders where matplotlib stores its default font - see [this blog post][1] - but I am looking for a less radical solution since I would like to use more than one font in my plot (text, label, axis label, etc).


  [1]: http://blog.olgabotvinnik.com/post/35807476900/how-to-set-helvetica-as-the-default-sans-serif-font-in

How to change fonts in matplotlib (python)?

I saw a loop which I&#39;ve never seen before:

    for (int i = 0; i &lt; (1 &lt;&lt; list.Count); i++)

I can&#39;t understand what `(1 &lt;&lt; list.Count)` means, maybe someone could explain me this?

What do two left angle brackets mean?

I saw a loop which I've never seen before:
<pre><code class="hljs language-css">for (int i = 0; i &#x3C; (1 &#x3C;&#x3C; list.Count); i++)
</code></pre>
I can't understand what <code>(1 &#x3C;&#x3C; list.Count)</code> means, maybe someone could explain me this?

I have a window with the following appearance:

![enter image description here][1]

What I would like, however, is if the `Button` controls (the gray ones with text in the middle) in the `Window`&#39;s main `Grid` had an opacity of 1, totally opaque.  As I inherited this project the opacity was set to 0.75 at the top level, inside the opening `Window` tag.  Now as I understand this will automatically enforce that on all children and that said children cannot override.

How then can I accomplish the transparent background but opaque buttons?  The only way I have found so far (as a relative novice in WPF) is to have two separate Windows, one which is the transparent background, and the other has no background but contains the opaque controls.  This is terribly hacky though and I want to avoid it if I can.

I can supply code if requested, but it is really as simple as a `Window` with windowstyle=none and opacity .75 containing a `Grid`, which contains some very basic `Button` etc controls.

Has anyone built such a `Window` before or otherwise have insight into generating one?  Thanks.


  [1]: http://i.stack.imgur.com/7Jegp.png

WPF Window with transparent background containing opaque controls

I am encrypting the user&#39;s input for generating a string for password. But a line of code gives different results in different versions of the framework. Partial code with value of key pressed by user:

Key pressed: 1. Variable `ascii` is 49. Value of &#39;e&#39; and &#39;n&#39; after some calculation:

    e = 103, 
    n = 143,

    Math.Pow(ascii, e) % n

Result of above code:

- In .NET 3.5 (C#)

        Math.Pow(ascii, e) % n

 gives `9.0`.

- In .NET 4 (C#)

        Math.Pow(ascii, e) % n

 gives `77.0`.

`Math.Pow()` gives the correct (same) result in both versions.

What is the cause, and is there a solution?


The modulo operator (%) gives a different result for different .NET versions in C#

How can I split a C# string based on the first occurrence of the specified character?
Suppose I have a string with value: 
```
101,a,b,c,d
```
I want to split it as 
```
101
``` 

```
a,b,c,d
```
That is by the first occurrence of comma character.

Split string based on the first occurrence of the character

 Please have a look at the following code-

    static void Main(string[] args)
    {
        // Get the task.
        var task = Task.Factory.StartNew&lt;int&gt;(() =&gt; { return div(32, 0); });

        // For error handling.
        task.ContinueWith(t =&gt; { Console.WriteLine(t.Exception.Message); }, 
            TaskContinuationOptions.OnlyOnFaulted);

        // If it succeeded.
        task.ContinueWith(t =&gt; { Console.WriteLine(t.Result); }, 
            TaskContinuationOptions.OnlyOnRanToCompletion);
        Console.ReadKey();
        Console.WriteLine(&quot;Hello&quot;);
    }

    private static int div(int x, int y)
    {
        if (y == 0)
        {
            throw new ArgumentException(&quot;y&quot;);
        }
        return x / y;
    }

If I execute the code in release mode, The output is &quot;One or more errors occurred&quot; and once I hit the &quot;Enter key, &quot;Hello&quot; is also getting displayed. If I run the code in debug mode, the output is same as release mode. But when debugging in IDE, A IDE exception message (&quot;Unhandled exception in user code&quot; ) appears when the control executes the line 

    throw new ArgumentException(&quot;y&quot;); 

If I continue from there on, the program does not crash and displays the same output as release mode. Is this proper way to handle exception?
            

Proper way of handling exception in task continuewith

I am getting very confused between Namespaces and Assemblies. Are `System.Data` and `System.Web` Namespaces or Assemblies?

I have noticed these are called namespaces and at the same time they are present in `GAC_32` folder. So what exactly are they?

Namespace or Assembly?

I have a piece of my code where I&#39;m supposed to create a switchboard. I want to return a list of all the switches that are on. Here &quot;on&quot; will equal `True` and &quot;off&quot; equal `False`. So now I just want to return a list of all the `True` values and their position. This is all I have but it only return the position of the first occurrence of `True` (this is just a portion of my code):

    self.states = [False, False, False, False, True, True, False, True, False, False, False, False, False, False, False, False]

    def which_switch(self):
	    x = [self.states.index(i) for i in self.states if i == True]


This only returns &quot;4&quot;

Getting indices of True values in a boolean list

I have a list of dictionaries, looking some thing like this:

    list = [{&#39;id&#39;: 123, &#39;data&#39;: &#39;qwerty&#39;, &#39;indices&#39;: [1,10]}, {&#39;id&#39;: 345, &#39;data&#39;: &#39;mnbvc&#39;, &#39;indices&#39;: [2,11]}]

and so on. There may be more documents in the list. I need to convert these to one JSON document, that can be returned via bottle, and I cannot understand how to do this. Please help. I saw similar questions on this website, but I couldn&#39;t understand the solutions there.

Python: converting a list of dictionaries to json

I have a csv file

    col1, col2, col3
    1, 2, 3
    4, 5, 6

I want to create a list of dictionary from this csv.

output as : 

    a= [{&#39;col1&#39;:1, &#39;col2&#39;:2, &#39;col3&#39;:3}, {&#39;col1&#39;:4, &#39;col2&#39;:5, &#39;col3&#39;:6}]

How can I do this?

convert csv file to list of dictionaries

What is the method to convert a Python list of strings to a `pd.Series` object?

(pandas Series objects can be converted to list using `tolist()` method--but how to do the reverse conversion?)

Convert Python list to pandas Series

I need to group a list of objects (`Student`) using an attribute (`Location`) of the particular object. The code is like below:

    public class Grouping {
        public static void main(String[] args) {

            List&lt;Student&gt; studlist = new ArrayList&lt;Student&gt;();
            studlist.add(new Student(&quot;1726&quot;, &quot;John&quot;, &quot;New York&quot;));
            studlist.add(new Student(&quot;4321&quot;, &quot;Max&quot;, &quot;California&quot;));
            studlist.add(new Student(&quot;2234&quot;, &quot;Andrew&quot;, &quot;Los Angeles&quot;));
            studlist.add(new Student(&quot;5223&quot;, &quot;Michael&quot;, &quot;New York&quot;));
            studlist.add(new Student(&quot;7765&quot;, &quot;Sam&quot;, &quot;California&quot;));
            studlist.add(new Student(&quot;3442&quot;, &quot;Mark&quot;, &quot;New York&quot;));

        }
    }
    
    class Student {
        String stud_id;
        String stud_name;
        String stud_location;
    
        Student(String sid, String sname, String slocation) {
            this.stud_id = sid;
            this.stud_name = sname;
            this.stud_location = slocation;
        }
    }

Please suggest me a clean way to do it.

Group a list of objects by an attribute

I try to use a simple loop, in my real code this loop is more complex, and I need to `break` this iteration like:

    {% for post in posts %}
        {% if post.id == 10 %}
            {# break #}
        {% endif %}
        &lt;h2&gt;{{ post.heading }}&lt;/h2&gt;
    {% endfor %}

How can I use behavior of `break` or `continue` of PHP control structures in Twig?

How can I use break or continue within for loop in Twig template?

I generated two matrices of `1000` x `1000`:

First Matrix: `O` and `#`.  
Second Matrix: `O` and `B`.

Using the following code, the first matrix took 8.52 seconds to complete:

    Random r = new Random();
    for (int i = 0; i &lt; 1000; i++) {
        for (int j = 0; j &lt; 1000; j++) {
            if(r.nextInt(4) == 0) {
                System.out.print(&quot;O&quot;);
            } else {
                System.out.print(&quot;#&quot;);
            }
        }
                
       System.out.println(&quot;&quot;);
     }


With this code, the second matrix took 259.152 seconds to complete:

    Random r = new Random();
    for (int i = 0; i &lt; 1000; i++) {
        for (int j = 0; j &lt; 1000; j++) {
            if(r.nextInt(4) == 0) {
                System.out.print(&quot;O&quot;);
            } else {
                System.out.print(&quot;B&quot;); //only line changed
            }
        }
                    
        System.out.println(&quot;&quot;);
    }

What is the reason behind the dramatically different run times?

---

As suggested in the comments, printing only `System.out.print(&quot;#&quot;);` takes `7.8871` seconds, whereas `System.out.print(&quot;B&quot;);` gives `still printing...`.

As others who pointed out that it works for them normally, I tried [Ideone.com](http://ideone.com) for instance, and both pieces of code execute at the same speed.

Test Conditions:

 - I ran this test from _Netbeans 7.2_, with the output into its console
 - I used `System.nanoTime()` for measurements

Why is printing &quot;B&quot; dramatically slower than printing &quot;#&quot;?

In terms of performance in Python, is a list-comprehension, or functions like `map()`, `filter()` and `reduce()` faster than a for loop? Why, technically, they **run in a C speed**, while **the for loop runs in the python virtual machine speed**?.

Suppose that in a game that I&#39;m developing I need to draw complex and huge maps using for loops. This question would be definitely relevant, for if a list-comprehension, for example, is indeed faster, it would be a much better option in order to avoid lags (Despite the visual complexity of the code).

Are list-comprehensions and functional functions faster than &quot;for loops&quot;?

I was asked in an interview what is the advantage of using iterator over `for` loop or what is the advantage of using `for` loop over iterator?

Can any body please answer this?

Iterator vs for

I&#39;m very new to C++ and struggling to figure out how I should iterate through a list of objects and access their members.

I&#39;ve been trying this where `data` is a `std::list` and `Student` a class.

    std::list&lt;Student&gt;::iterator&lt;Student&gt; it;
	for (it = data.begin(); it != data.end(); ++it) {
	    std::cout&lt;&lt;(*it)-&gt;name;
	}

and getting the following error:
    
    error: base operand of ‘-&gt;’ has non-pointer type ‘Student’

How to iterate through a list of objects in C++?

I&#39;ve come across a (seemingly) very strange case.

Take the number 2 (`0b10`) and bitmask it with 1 (`0b01`)

This should produce `0b00` which is equivalent to 0.

However, here&#39;s where Mr Schr&#246;dinger comes in:

    var_dump(0b10 &amp; 0b01); // int(0)
    var_dump(0b10 &amp; 0b01 == 0); // int(0)
    var_dump(0b10 &amp; 0b01 != 0); // int(0)

Whiskey. Tango. Foxtrot.

I am, admittedly, not the sharpest when it comes to bitwise operators - so maybe I&#39;ve got horribly, horribly wrong somewhere?

However, in Python:

`0b10 &amp; 0b01 == 0` = `True`

`0b10 &amp; 0b01 != 0` = `False`

...so?

Precedence and bitmask operations

In Apple&#39;s documentation about interacting with C APIs, they describe the way `NS_ENUM`-marked C-style enumerations are imported as Swift enumerations. This makes sense, and since enumerations in Swift are readily provided as the `enum` value type it&#39;s easy to see how to create our own.

Further down, it says this about `NS_OPTIONS`-marked C-style options:

&gt; Swift also imports options marked with the `NS_OPTIONS` macro. Whereas
&gt; options behave similarly to imported enumerations, options can also
&gt; support some bitwise operations, such as `&amp;`, `|`, and `~`. In Objective-C,
&gt; you represent an empty option set with the constant zero (`0`). In
&gt; Swift, use `nil` to represent the absence of any options.

Given that there isn&#39;t an `options` value type in Swift, how can we create a C-Style options variable to work with?

How to create NS_OPTIONS-style bitmask enumerations in Swift?

I was reading a chapter on bitwise operators, I came across 1&#39;s complement operator program and decided to run it on Visual C++.

    int main ()
    {
       unsigned char c = 4, d;
       d = ~c;
       printf(&quot;%d\n&quot;, d);
    }

It gives the valid output: `251`

Then instead of using `d` as a variable to hold the value of `~c`, I decided to directly print the value of `~c`.

    int main ()
    {
       unsigned char c=4;
       printf(&quot;%d\n&quot;, ~c);
    }

It gives the output `-5`.

Why didn&#39;t it work?

Why does the complement behave differently through printf?

When browsing the source code of Guava, I came across the following piece of code (part of the implementation of `hashCode` for the inner class `CartesianSet`):

    int adjust = size() - 1;
    for (int i = 0; i &lt; axes.size(); i++) {
        adjust *= 31;
        adjust = ~~adjust;
        // in GWT, we have to deal with integer overflow carefully
    }
    int hash = 1;
    for (Set&lt;E&gt; axis : axes) {
        hash = 31 * hash + (size() / axis.size() * axis.hashCode());

        hash = ~~hash;
    }
    hash += adjust;
    return ~~hash;

Both of `adjust` and `hash` are `int`s. From what I know about Java, `~` means bitwise negation, so `adjust = ~~adjust` and `hash = ~~hash` should leave the variables unchanged. Running the small test (with assertions enabled, of course),

    for (int i = Integer.MIN_VALUE; i &lt; Integer.MAX_VALUE; i++) {
        assert i == ~~i;
    }

confirms this. Assuming that the Guava guys know what they are doing, there must be a reason for them to do this. The question is what?

**EDIT** As pointed out in the comments, the test above doesn&#39;t include the case where `i` equals `Integer.MAX_VALUE`. Since `i &lt;= Integer.MAX_VALUE` is always true, we will need to check that case outside the loop to prevent it from looping forever. However, the line

    assert Integer.MAX_VALUE == ~~Integer.MAX_VALUE;

yields the compiler warning &quot;Comparing identical expressions&quot;, which pretty much nails it.

What is the meaning of double tilde (~~) in Java?

What does &#39;x &lt;&lt; ~y&#39; represent in JavaScript?

I understand that the bitwise `SHIFT` operation does this:

&lt;pre&gt;x &amp;lt;&amp;lt; y AS x * 2&lt;sup&gt;y&lt;/sup&gt;&lt;/pre&gt;

And a tilde `~` operator does:

    ~x AS -(x+1)

So, I assume the following:

&lt;pre&gt;5 &amp;lt;&amp;lt; ~3 AS 5 * 2&lt;sup&gt;-4&lt;/sup&gt; or 5 * Math.pow(2, -4)&lt;/pre&gt;

It should result in `0.3125`.

But, when I run `5 &lt;&lt; ~3` it results in `1342177280`.

What is a step-by-step explanation? How and why does this combination of operations result in `1342177280` instead of `0.3125`?

&lt;sub&gt;(This question is similar to Stack&amp;nbsp;Overflow question *[What are bitwise operators?][1]* about the bitwise `SHIFT` operator.)&lt;/sub&gt;

  [1]: https://stackoverflow.com/questions/276706/what-are-bitwise-operators


What do two left angle brackets mean?

C# Problem Overview

C# Solutions

How to change fonts in matplotlib (python)?

Bootstrap modal: background jumps to top on toggle

Attributions