大约有 2,000 项符合查询结果（耗时：0.0271秒） [XML]
List of zeros in python [duplicate]
...d Feb 10 '13 at 21:21
Seppo ErviäläSeppo Erviälä
5,62044 gold badges3030 silver badges3838 bronze badges
...
How to find whether or not a variable is empty in Bash
...in practice this tests whether $variable is empty or not. As an addition (3½ years after the fact :-) ) I would never use this myself since -z does what I probably want in a clearer way, but I wanted to add this answer since this method is frequently seen "in the wild"; perhaps written this way on ...
Delete rows from a pandas DataFrame based on a conditional expression involving len(string) giving K
...faster than drop:
%%timeit
test = pd.DataFrame({'x': np.random.randn(int(1e6))})
test = test[test.x < 0]
# 54.5 ms ± 2.02 ms per loop (mean ± std. dev. of 7 runs, 10 loops each)
%%timeit
test = pd.DataFrame({'x': np.random.randn(int(1e6))})
test.drop(test[test.x > 0].index, inplace=True)
#...
What does .SD stand for in data.table in R
...ttps://sashat.me/2017/01/11/list-of-20-simple-distinct-colors/
col16 = c('#e6194b', '#3cb44b', '#ffe119', '#0082c8', '#f58231', '#911eb4',
'#46f0f0', '#f032e6', '#d2f53c', '#fabebe', '#008080', '#e6beff',
'#aa6e28', '#fffac8', '#800000', '#aaffc3')
par(oma = c(2, 0, 0, 0))
sappl...
Is there a minlength validation attribute in HTML5?
... Aug 12 '13 at 11:02
Ali ÇarıkçıoğluAli Çarıkçıoğlu
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HTML inside Twitter Bootstrap popover
...wered Nov 2 '12 at 22:27
Mauno VähäMauno Vähä
9,18033 gold badges2525 silver badges5151 bronze badges
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What does the constant 0.0039215689 represent?
... wondering the same thing. But if you use 256, it would scale from 0.0 - 0.996 instead the desired 0.0 - 1.0. (0.996 = 255/256 where 255 is the largest 8-bit integer)
– Mysticial
Mar 25 '14 at 18:53
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Evaluate expression given as a string
... Lumley R-help (February 2005) >
– Martin Mächler
Oct 20 '16 at 20:40
13
@MartinMächl...
How can I clone an SQL Server database on the same server in SQL Server 2008 Express?
I have an MS SQL Server 2008 Express system which contains a database that I would like to 'copy and rename' (for testing purposes) but I am unaware of a simple way to achieve this.
...
Converting DateTime format using razor
...iggs, I feel ya cuz. Glad to share the pain so that we all might gain --6½ years later!
– Jules Bartow
Dec 4 '18 at 8:14
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