大约有 6,000 项符合查询结果（耗时：0.0332秒） [XML]
Check if element exists in jQuery [duplicate]
...swered Feb 13 '14 at 4:38
Gaurav123Gaurav123
4,18566 gold badges4040 silver badges7070 bronze badges
...
How do I install pip on macOS or OS X?
I spent most of the day yesterday searching for a clear answer for installing pip (package manager for Python). I can't find a good solution.
...
How accurate is python's time.sleep()?
...
The accuracy of the time.sleep function depends on your underlying OS's sleep accuracy. For non-realtime OS's like a stock Windows the smallest interval you can sleep for is about 10-13ms. I have seen accurate sleeps within several milliseconds of that time when above the minimum 10-13ms.
...
Can you do a partial checkout with Subversion?
...directories under trunk/ with lots of files in each and only needed 3 of those directories, would it be possible to do a Subversion checkout with only those 3 directories under trunk?
...
Is there a standard way to list names of Python modules in a package?
...
Maybe this will do what you're looking for?
import imp
import os
MODULE_EXTENSIONS = ('.py', '.pyc', '.pyo')
def package_contents(package_name):
file, pathname, description = imp.find_module(package_name)
if file:
raise ImportError('Not a package: %r', package_name)
...
Find duplicate lines in a file and count how many time each line was duplicated?
...iq -c | grep -v '^ *1 '
For the given example, the result would be:
3 123
2 234
If you want to print counts for all lines including those that appear only once:
sort FILE | uniq -c
or, with GNU long options (on Linux):
sort FILE | uniq --count
For the given input, the output is:
...
How do you remove all the options of a select box and then add one option and select it with jQuery?
.../attr/text like: .append($("<option></option>").attr("value", '123').text('ABC!')
– Brock Hensley
Jun 27 '13 at 21:58
...
Can I change the height of an image in CSS :before/:after pseudo-elements?
...nswered Jan 23 '12 at 21:39
user123444555621user123444555621
123k2323 gold badges101101 silver badges120120 bronze badges
...
Python exit commands - why so many and when should each be used?
...xecution. The choices I've found are: quit() , exit() , sys.exit() , os._exit()
4 Answers
...
Redirecting stdout to “nothing” in python
...
Cross-platform:
import os
import sys
f = open(os.devnull, 'w')
sys.stdout = f
On Windows:
f = open('nul', 'w')
sys.stdout = f
On Linux:
f = open('/dev/null', 'w')
sys.stdout = f
...