大约有 800 项符合查询结果（耗时：0.0176秒） [XML]
Check if something is (not) in a list in Python
... 0.613 ns per loop (mean ± std. dev. of 7 runs, 10000000 loops each)
178 µs ± 5.01 µs per loop (mean ± std. dev. of 7 runs, 10000 loops each)
If you want to do more than just check whether an item is in a list, there are options:
list.index can be used to retrieve the index of an item. If t...
.gitignore is ignored by Git
...red Mar 19 '14 at 23:40
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Python string class like StringBuilder in C#?
...]: %%timeit
...: ''.join(values)
...:
100000 loops, best of 3: 7.37 µs per loop
In [3]: %%timeit
...: result = ''
...: for value in values:
...: result += value
...:
10000 loops, best of 3: 82.8 µs per loop
In [4]: import io
In [5]: %%timeit
...: writer = io.StringIO(...
Replace values in list using Python [duplicate]
....: if not (item % 2):
...: items[index] = None
...:
1.06 µs ± 33.7 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)
In [2]: %%timeit
...: items = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
...: new_items = [x if x % 2 else None for x in items]
...:
891 ns ± 13.6 n...
How to add an extra column to a NumPy array
...b = np.hstack((a, np.zeros((a.shape[0], 1))))
100000 loops, best of 3: 7.5 µs per loop
In [4]: %timeit b = np.zeros((a.shape[0], a.shape[1]+1)); b[:,:-1] = a
100000 loops, best of 3: 2.17 µs per loop
In [5]: %timeit b = np.insert(a, 3, values=0, axis=1)
100000 loops, best of 3: 10.2 µs per loop...
How do I select elements of an array given condition?
...that an intermediate result is being cached.
100000 loops, best of 3: 1.15 µs per loop
>>> %timeit np.logical_and(a < b, b < c)
The slowest run took 32.59 times longer than the fastest. This could mean that an intermediate result is being cached.
1000000 loops, best of 3: 1.17 µs p...
Numpy first occurrence of value greater than existing value
...timeit np.nonzero(aa>N/2)[0][0]
# Output
100000 loops, best of 3: 5.97 µs per loop
10000 loops, best of 3: 46.3 µs per loop
10000 loops, best of 3: 154 µs per loop
10000 loops, best of 3: 154 µs per loop
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Set breakpoint in C or C++ code programmatically for gdb on Linux
... answered Dec 1 '10 at 16:22
Håvard SHåvard S
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Getting error while sending email through Gmail SMTP - “Please log in via your web browser and then
...wered Sep 9 '15 at 0:55
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Extract first item of each sublist
...t numpy-way, transforming the array:
%timeit list(np.array(lst).T[0])
4.9 µs ± 163 ns per loop (mean ± std. dev. of 7 runs, 100000 loops each)
Fully native using list comprehension (as explained by @alecxe):
%timeit [item[0] for item in lst]
379 ns ± 23.1 ns per loop (mean ± std. dev. of 7 ...