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multiprocessing.Pool: When to use apply, apply_async or map?
I have not seen clear examples with use-cases for Pool.apply , Pool.apply_async and Pool.map . I am mainly using Pool.map ; what are the advantages of others?
...
__proto__ VS. prototype in JavaScript
What are the differences between __proto__ and prototype ?
30 Answers
30
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How to create a video from images with FFmpeg?
...utput framerate
ffmpeg -r 1/5 -i img%03d.png -c:v libx264 -vf fps=25 -pix_fmt yuv420p out.mp4
Alternatively the format video filter can be added to the filter chain to replace -pix_fmt yuv420p like "fps=25,format=yuv420p". The advantage of this method is that you can control which filter goes...
Behaviour of increment and decrement operators in Python
...so far as they don't explain what happens.
To be exact, +x evaluates to x.__pos__() and ++x to x.__pos__().__pos__().
I could imagine a VERY weird class structure (Children, don't do this at home!) like this:
class ValueKeeper(object):
def __init__(self, value): self.value = value
def __s...
“Too many values to unpack” Exception
...ame.models.modelname" or "projectname.appname.models.modelname" in the AUTH_PROFILE_MODULE setting will cause Django to blow up with the dreaded "too many values to unpack" error, so make sure you've put "appname.modelname", and nothing else, in the value of AUTH_PROFILE_MODULE.
If the OP had copie...
Scala: What is a TypeTag and how do I use it?
...ss Foo
class Bar extends Foo
def meth[A](xs: List[A]) = xs match {
case _: List[String] => "list of strings"
case _: List[Foo] => "list of foos"
}
we will get warnings:
<console>:23: warning: non-variable type argument String in type pattern List[String]↩
is unchecked since it ...
How do you get a query string on Flask?
... as with a dict and .get, you'd just get None.
– JPEG_
Oct 23 '16 at 8:46
5
@LyndsySimon: Well sp...
Submitting a multidimensional array via POST with php
...
On submitting, you would get an array as if created like this:
$_POST['topdiameter'] = array( 'first value', 'second value' );
$_POST['bottomdiameter'] = array( 'first value', 'second value' );
However, I would suggest changing your form names to this format instead:
name="diameters[0]...
PDO Prepared Inserts multiple rows in single query
...
$pdo->beginTransaction(); // also helps speed up your inserts.
$insert_values = array();
foreach($data as $d){
$question_marks[] = '(' . placeholders('?', sizeof($d)) . ')';
$insert_values = array_merge($insert_values, array_values($d));
}
$sql = "INSERT INTO table (" . implode(",", $...
Fixed size queue which automatically dequeues old values upon new enques
...T> : IReadOnlyCollection<T>
{
private readonly Queue<T> _queue = new Queue<T>();
private readonly object _lock = new object();
public int Count { get { lock (_lock) { return _queue.Count; } } }
public int Limit { get; }
public FixedSizedQueue(int limit)
...