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Scala how can I count the number of occurrences in a list
...", "banana", "apple", "oranges", "oranges")
s.groupBy(identity).mapValues(_.size)
giving a Map with a count for each item in the original sequence:
Map(banana -> 1, oranges -> 3, apple -> 3)
The question asks how to find the count of a specific item. With this approach, the solution w...
PHP passing $_GET in linux command prompt
...ipt.php -f=world
$opts = getopt('f:');
echo $opts['f']; // prints world
$_GET refers to the HTTP GET method parameters, which are unavailable in command line, since they require a web server to populate.
If you really want to populate $_GET anyway, you can do this:
// bash command:
// export Q...
What does `m_` variable prefix mean?
I often see m_ prefix used for variables ( m_World , m_Sprites ,...) in tutorials, examples and other code mainly related to game development.
...
How can I get all the request headers in Django?
...m HTTP headers.
From the documentation:
With the exception of CONTENT_LENGTH and CONTENT_TYPE, as given above, any HTTP headers in the request are converted to META keys by converting all characters to uppercase, replacing any hyphens with underscores and adding an HTTP_ prefix to the name.
...
C++ Redefinition Header Files (winsock2.h)
...list that <windows.h> is included after <winsock2.h> or define _WINSOCKAPI_ first:
#define _WINSOCKAPI_ // stops windows.h including winsock.h
#include <windows.h>
// ...
#include "MyClass.h" // Which includes <winsock2.h>
See also this.
...
“Uncaught TypeError: Illegal invocation” in Chrome
... for help, clarification, or responding to other answers.Making statements based on opinion; back them up with references or personal experience.To learn more, see our tips on writing great answers.
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Python division
...t:
>>> float(10 - 20) / (100 - 10)
-0.1111111111111111
or from __future__ import division, which the forces / to adopt Python 3.x's behavior that always returns a float.
>>> from __future__ import division
>>> (10 - 20) / (100 - 10)
-0.1111111111111111
...
How do I invert BooleanToVisibilityConverter?
...r<Visibility>
{
public BooleanToVisibilityConverter() :
base(Visibility.Visible, Visibility.Collapsed) {}
}
Finally, this is how you could use BooleanToVisibilityConverter above in XAML and configure it to, for example, use Collapsed for true and Visible for false:
<Applicat...
List of Big-O for PHP functions
...lar case your benchmark is testing is even guaranteed O(1), as it's a zero-based, continuous, numerically-indexed array, which will never have hash collisions. The reason why you're still seeing a dependence on the array size has nothing to do with algorithmic complexity, it is caused by CPU cache e...
How to iterate through two lists in parallel?
... And to zip until both iterators are
exhausted, you would use
itertools.zip_longest.
Python 2
In Python 2, zip
returns a list of tuples. This is fine when foo and bar are not massive. If they are both massive then forming zip(foo,bar) is an unnecessarily massive
temporary variable, and should be r...