大约有 5,685 项符合查询结果（耗时：0.0128秒） [XML]
How to combine two or more querysets in a Django view?
...t_list),
key=lambda instance: instance.date_created)
If you're using Python 2.4 or later, you can use attrgetter instead of a lambda. I remember reading about it being faster, but I didn't see a noticeable speed difference for a million item list.
from operator import attrgetter
result_list =...
Is there an interpreter for C? [closed]
...ng like an interpreter for C. That is, in a Linux terminal I can type in "python" and then code in that interpreter. (I'm not sure interpreter the right word). This is really helpful for testing different things out and I'm curious if something similar exists for C. Though I doubt it. The only ...
Automatically remove Subversion unversioned files
...on to do this:
svn cleanup --remove-unversioned
Before that, I use this python script to do that:
import os
import re
def removeall(path):
if not os.path.isdir(path):
os.remove(path)
return
files=os.listdir(path)
for x in files:
fullpath=os.path.join(path, x)...
Most lightweight way to create a random string and a random hexadecimal number
...
Interesting, I kind of forgot that Python (and the random module) handles bigints natively.
– wump
May 6 '10 at 18:49
3
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Why Collections.sort uses merge sort instead of quicksort?
...was a fine choice, but today but we can
do much better.
Since 2003, Python's list sort has used an algorithm known as timsort
(after Tim Peters, who wrote it). It is a stable, adaptive, iterative
mergesort that requires far fewer than n log(n) comparisons when
running on partially sorte...
How to convert a boolean array to an int array
...d seeing all the different ways to do it. Really opened my mind regarding python.
– Kwolf
Jul 6 '13 at 20:49
...
Bitwise operation and usage
...10 0101
1111 1111 << 4 gives 1111 0000
Note that the left shift in Python is unusual in that it's not using a fixed width where bits are discarded - while many languages use a fixed width based on the data type, Python simply expands the width to cater for extra bits. In order to get the dis...
Keep only date part when using pandas.to_datetime
...osed, it does not really solve the performance problem (it still relies on python datetime objects, and hence any operation on them will be not vectorized - that is, it will be slow).
A better performing alternative is to use df['dates'].dt.floor('d'). Strictly speaking, it does not "keep only date...
Flatten nested dictionaries, compressing keys
...it to test for collections.MutableMapping to make it more generic. But for Python < 2.6, try..except is probably the best option.
– Imran
May 17 '11 at 7:55
...
How do I use itertools.groupby()?
...n't been able to find an understandable explanation of how to actually use Python's itertools.groupby() function. What I'm trying to do is this:
...