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Swift - Convert to absolute value
...alue.magnitude) // prints: 5
#2. Get absolute value of an Int from abs(_:) method
Swift has a global numeric function called abs(_:) method. abs(_:) has the following declaration:
func abs<T>(_ x: T) -> T where T : Comparable, T : SignedNumeric
Returns the absolute value of the g...
Check if an array contains any element of another array in JavaScript
...nderscorejs.org/ has an intersection method, which can simplify this:
var _ = require('underscore');
var target = [ 'apple', 'orange', 'banana'];
var fruit2 = [ 'apple', 'orange', 'mango'];
var fruit3 = [ 'mango', 'lemon', 'pineapple'];
var fruit4 = [ 'orange', 'lemon', 'grapes'];
console.log(_.i...
Code for Greatest Common Divisor in Python [closed]
...
It doesn't return "the _largest_ number that divides both of them with no remainder" e.g., fractions.gcd(1, -1) is -1 but 1 > -1 i.e., 1 divides both 1 and -1 with no remainder and it is larger than -1, see bugs.python.org/issue22477
...
PostgreSQL error 'Could not connect to server: No such file or directory'
...u are on OS X
Here is the fix:
Stop the database
cd /var
sudo rm -r pgsql_socket
sudo ln -s /tmp pgsql_socket
chown _postgres:_postgres pgsql_socket
Restart PostgreSQL (not your computer)
More information is available at "postgresql 9.0.3. on Lion Dev Preview 1".
...
What is a “callback” in C and how are they implemented?
...y're implemented using function pointers. Here's an example:
void populate_array(int *array, size_t arraySize, int (*getNextValue)(void))
{
for (size_t i=0; i<arraySize; i++)
array[i] = getNextValue();
}
int getNextRandomValue(void)
{
return rand();
}
int main(void)
{
int m...
Why does pylint object to single character variable names?
...riptive and not too short.
You can use this to avoid such short names:
my_list.extend(x_values)
Or tweak PyLint's configuration to tell PyLint what variable name are good.
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Session variables in ASP.NET MVC
...art event
void OnSessionStart(...)
{
HttpContext.Current.Session.Add("__MySessionObject", new MySessionObject());
}
From anywhere in code where the HttpContext.Current property != null you can retrive that object. I do this with an extension method.
public static MySessionObject GetMySession...
How to play audio?
...If you don't want to mess with HTML elements:
var audio = new Audio('audio_file.mp3');
audio.play();
function play() {
var audio = new Audio('https://interactive-examples.mdn.mozilla.net/media/examples/t-rex-roar.mp3');
audio.play();
}
<button onclick="play()">Play Audio</but...
How can I find the current OS in Python? [duplicate]
...t; import platform
>>> platform.platform()
'Linux-3.3.0-8.fc16.x86_64-x86_64-with-fedora-16-Verne'
platform also has some other useful methods:
>>> platform.system()
'Windows'
>>> platform.release()
'XP'
>>> platform.version()
'5.1.2600'
Here's a few differen...
How to print a groupby object
...
Simply do:
grouped_df = df.groupby('A')
for key, item in grouped_df:
print(grouped_df.get_group(key), "\n\n")
This also works,
grouped_df = df.groupby('A')
gb = grouped_df.groups
for key, values in gb.iteritems():
print(df.ix[...