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What is the purpose of the single underscore “_” variable in Python?
...cate that part
of a function result is being deliberately ignored (Conceptually, it is being discarded.), as in code like:
label, has_label, _ = text.partition(':').
As part of a function definition (using either def or lambda), where
the signature is fixed (e.g. by a callback or parent class API), ...
Bash continuation lines
... like a single string which crosses lines, while indenting but not getting all those spaces, one approach you can try is to ditch the continuation line and use variables:
$ a="continuation"
$ b="lines"
$ echo $a$b
continuationlines
This will allow you to have cleanly indented code at the expense ...
Get a filtered list of files in a directory
...t a list of files in a directory using Python, but I do not want a list of ALL the files.
14 Answers
...
Timeout a command in bash without unnecessary delay
...y, Bash does not support floating point arithmetic (sleep does),
therefore all delay/time values must be integers.
EOF
}
# Options.
while getopts ":t:i:d:" option; do
case "$option" in
t) timeout=$OPTARG ;;
i) interval=$OPTARG ;;
d) delay=$OPTARG ;;
*) printUsage...
URL rewriting with PHP
...
You can essentially do this 2 ways:
The .htaccess route with mod_rewrite
Add a file called .htaccess in your root folder, and add something like this:
RewriteEngine on
RewriteRule ^/?Some-text-goes-here/([0-9]+)$ /picture.php?id=$1
Thi...
What is the effect of extern “C” in C++?
...very compiler is required to provide "C" linkage
A linkage specification shall occur only in namespace scope
All function types, function names and variable names have a language linkage See Richard's Comment: Only function names and variable names with external linkage have a language linkage
Two ...
Python multiprocessing pool.map for multiple arguments
...rmap method, which accepts a sequence of argument tuples. It then automatically unpacks the arguments from each tuple and passes them to the given function:
import multiprocessing
from itertools import product
def merge_names(a, b):
return '{} & {}'.format(a, b)
if __name__ == '__main__':...
How do I check if a string is a number (float)?
...r.
I'm not sure that anything much could be faster than the above. It calls the function and returns. Try/Catch doesn't introduce much overhead because the most common exception is caught without an extensive search of stack frames.
The issue is that any numeric conversion function has two kin...
PHP function overloading
...um_args() and func_get_arg() to get the arguments passed, and use them normally.
For example:
function myFunc() {
for ($i = 0; $i < func_num_args(); $i++) {
printf("Argument %d: %s\n", $i, func_get_arg($i));
}
}
/*
Argument 0: a
Argument 1: 2
Argument 2: 3.5
*/
myFunc('a', 2, 3...
Threading pool similar to the multiprocessing Pool?
...
I just found out that there actually is a thread-based Pool interface in the multiprocessing module, however it is hidden somewhat and not properly documented.
It can be imported via
from multiprocessing.pool import ThreadPool
It is implemented using a...