大约有 3,516 项符合查询结果（耗时：0.0184秒） [XML]
Checking the equality of two slices
...
}
if len(a) != len(b) {
return false
}
for i := range a {
if a[i] != b[i] {
return false
}
}
return true
}
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Counting the number of True Booleans in a Python List
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In [1]: import random
In [2]: x = [random.choice([True, False]) for i in range(100)]
In [3]: %timeit x.count(True)
970 ns ± 41.1 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)
In [4]: %timeit sum(x)
1.72 µs ± 161 ns per loop (mean ± std. dev. of 7 runs, 100000 loops each)
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plot with custom text for x axis points
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rotation is also sometimes useful: plt.xticks(range(5), ["some", "words", "as", "x", "ticks"], rotation=45)
– Adobe
Jan 23 '13 at 18:10
4
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javascript: recursive anonymous function?
...ctions. Below we'll see two more functions defined using the Y combinator (range and reduce) and a derivative of reduce, map.
const U = f => f (f)
const Y = U (h => f => f (x => U (h) (f) (x)))
const range = Y (f => acc => min => max =>
min > max ? acc : f ([...
How can I measure the similarity between two images? [closed]
...use a combining scaling algorithm instead of nearest pixel
scale the color ranges so that the darkest is black and lightest is white
rotate and flip the image so that the lighest color is top left, and then top-right is next darker, bottom-left is next darker (as far as possible of course)
Edit A ...
How to calculate the time interval between two time strings
... # +day
assert end > start
return end - start
for time_range in ['10:33:26-11:15:49', '23:55:00-00:25:00']:
s, e = [datetime.strptime(t, '%H:%M:%S') for t in time_range.split('-')]
print(time_diff(s, e))
assert time_diff(s, e) == time_diff(s.time(), e.time())
Output...
In practice, what are the main uses for the new “yield from” syntax in Python 3.3?
..."""A generator that fakes a read from a file, socket, etc."""
for i in range(4):
yield '<< %s' % i
def reader_wrapper(g):
# Manually iterate over data produced by reader
for v in g:
yield v
wrap = reader_wrapper(reader())
for i in wrap:
print(i)
# Result
<...
numpy: most efficient frequency counts for unique values in an array
...els=[bincount, unique, itemfreq, unique_count, pandas_value_counts],
n_range=[2 ** k for k in range(26)],
logx=True,
logy=True,
xlabel="len(a)",
)
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How to calculate the number of days between two dates? [duplicate]
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Warning: not all days are 24 hours long. If your date range spans a daylight saving change, you'll lose or gain an hour (typically). Use Math.round() on the result (avoid floor or ceil).
– Mark
Sep 20 '11 at 2:33
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What's the purpose of SQL keyword “AS”?
...the SQL Standard, is inappropriate. The underlying concept is that of a ‘range variable’.
UPDATE 3: I just re-read what Celko wrote and he is wrong: the table is not being renamed! I now think:
A correlation name is more often called an alias, but I will be formal. In Standard SQL they ca...