大约有 40,000 项符合查询结果（耗时：0.0456秒） [XML]
Create a “with” block on several context managers? [duplicate]
...rite:
with A() as X, B() as Y, C() as Z:
do_something()
This is normally the best method to use, but if you have an unknown-length list of context managers you'll need one of the below methods.
In Python 3.3, you can enter an unknown-length list of context managers by using contextlib.Exit...
$(document).ready equivalent without jQuery
...ent
if ( document.addEventListener ) {
// Use the handy event callback
document.addEventListener( "DOMContentLoaded", function(){
document.removeEventListener( "DOMContentLoaded", arguments.callee, false );
jQuery.ready();
}, false );
// If IE...
Is explicitly closing files important?
In Python, if you either open a file without calling close() , or close the file but not using try - finally or the " with " statement, is this a problem? Or does it suffice as a coding practice to rely on the Python garbage-collection to close all files? For example, if one does this:
...
Sphinx autodoc is not automatic enough
...for modules project.module1 and project.module2 will be generated automatically and placed into _autosummary directory.
PROJECT
=======
.. toctree::
.. autosummary::
:toctree: _autosummary
project.module1
project.module2
By default autosummary will generate only very short summaries fo...
Getting visitors country from their IP
...
why im getting unknow all the time with every ip ? , used same code.
– echo_Me
Feb 18 '14 at 18:12
1
...
Python Unicode Encode Error
...80\x80abcd\xde\xb4'
>>> u.encode('ascii')
Traceback (most recent call last):
File "<stdin>", line 1, in ?
UnicodeEncodeError: 'ascii' codec can't encode character '\ua000' in position 0: ordinal not in range(128)
>>> u.encode('ascii', 'ignore')
'abcd'
>>> u.encode(...
Manually raising (throwing) an exception in Python
...
How do I manually throw/raise an exception in Python?
Use the most specific Exception constructor that semantically fits your issue.
Be specific in your message, e.g.:
raise ValueError('A very specific bad thing happened.')
Don't ...
Is there a way for multiple processes to share a listening socket?
...POSIX type OS), using fork() will cause the forked child to have copies of all the parent's file descriptors. Any that it does not close will continue to be shared, and (for example with a TCP listening socket) can be used to accept() new sockets for clients. This is how many servers, including Apac...
Reverse a string in Python
...
@Tanner [::-1] is fastest because it does not call any external functions, rather it's using slicing, which is highly-optimized in python. ''.join(list(reversed(s))) makes 3 function calls.
– hd1
Apr 27 at 13:51
...
Perl flags -pe, -pi, -p, -w, -d, -i, -t?
...eem to be mostly made up of punctuation :-)
The command line switches are all detailed in perlrun. (available from the command line by calling perldoc perlrun)
Going into the options briefly, one-by-one:
-p: Places a printing loop around your command so that it acts on each
line of standard ...