大约有 40,000 项符合查询结果（耗时：0.0539秒） [XML]
How do I get a list of column names from a psycopg2 cursor?
... to generate column labels directly from the selected column names, and recall seeing that python's psycopg2 module supports this feature.
...
while (1) vs. while(True) — Why is there a difference (in python 2 bytecode)?
...me byte code for while(True): pass and while(1): pass , but this is actually not the case in python2.7.
3 Answers
...
How can I quickly sum all numbers in a file?
...
For a Perl one-liner, it's basically the same thing as the awk solution in Ayman Hourieh's answer:
% perl -nle '$sum += $_ } END { print $sum'
If you're curious what Perl one-liners do, you can deparse them:
% perl -MO=Deparse -nle '$sum += $_ } END ...
How to retrieve a module's path?
...
import a_module
print(a_module.__file__)
Will actually give you the path to the .pyc file that was loaded, at least on Mac OS X. So I guess you can do:
import os
path = os.path.abspath(a_module.__file__)
You can also try:
path = os.path.dirname(a_module.__file__)
To ge...
Number of elements in a javascript object
...
Although JS implementations might keep track of such a value internally, there's no standard way to get it.
In the past, Mozilla's Javascript variant exposed the non-standard __count__, but it has been removed with version 1.8.5.
For cross-browser scripting you're stuck with explicitly ite...
How to obtain the number of CPUs/cores in Linux from the command line?
... Note that both of these will end up counting twice as many cores as actually exist if you're on a system with hyperthreading (e.g, P4, or Core i7).
– duskwuff -inactive-
Jun 26 '11 at 0:04
...
How to find all the subclasses of a class given its name?
I need a working approach of getting all classes that are inherited from a base class in Python.
10 Answers
...
CSS hack大全 - 创意 - 清泛网 - 专注C/C++及内核技术
...io:0){.bb{background-color:#f1ee18}}{} /* Safari(Chrome) 有效 */
@media all and (min-width: 0px){ .bb{background-color:#f1ee18;/*opera and Safari(Chrome) and firefox*/ background-color:#4cac70\0;}/* 仅 Opera 有效 */ }{}
.bb, x:-moz-any-link, x:default{background-color:#4eff00;/*IE7、Firef...
Execution of Python code with -m option or not
...st python -m foo.bar.baz
foo.bar
__main__
As a result, Python has to actually care about packages when using the -m switch. A normal script can never be a package, so __package__ is set to None.
But run a package or module inside a package with -m and now there is at least the possibility of a pac...
What __init__ and self do on Python?
...to declare it explicitly. When you create an instance of the A class and call its methods, it will be passed automatically, as in ...
a = A() # We do not pass any argument to the __init__ method
a.method_a('Sailor!') # We only pass a single argument
The __init__ method is roughly w...