大约有 44,500 项符合查询结果(耗时:0.0275秒) [XML]

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“ValueError: zero length field name in format” error in Python 3.0,3.1,3.2

... I'm gonna guess that you are running python 2.6 by accident somehow. This feature is only available for at least 3.1 if you are using python 3, or 2.7 if you are using python 2. share ...
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Pandas dataframe get first row of each group

... 248 >>> df.groupby('id').first() value id 1 first 2 first 3 first 4...
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Rotating videos with FFmpeg

... pass: 0 = 90CounterCLockwise and Vertical Flip (default) 1 = 90Clockwise 2 = 90CounterClockwise 3 = 90Clockwise and Vertical Flip Use -vf "transpose=2,transpose=2" for 180 degrees. Make sure you use a recent ffmpeg version from here (a static build will work fine). Note that this will re-encod...
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How can I obtain an 'unbalanced' grid of ggplots?

..., arrangeGrob(p,p,p, heights=c(3/4, 1/4, 1/4), ncol=1), ncol=2) Edit (07/2015): with v>2.0.0 you can use the layout_matrix argument, grid.arrange(p,p,p,p, layout_matrix = cbind(c(1,1,1), c(2,3,4))) shar...
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Set selected option of select box

...code into a $(document).ready: $(function() { $("#gate").val('gateway_2'); }); share | improve this answer | follow | ...
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How do I use spaces in the Command Prompt?

... 267 Single quotation marks won't do in that case. You have to add quotation marks around each path...
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How do you know when to use fold-left and when to use fold-right?

...re, you use a left fold. Example (haskell-style pseudocode) foldl (-) [1, 2, 3] == (1 - 2) - 3 == 1 - 2 - 3 // - is left-associative If your operator is right-associative (right fold), the parentheses would be set like this: A x (B x (C x D)) Example: Cons-Operator foldr (:) [] [1, 2, 3] == 1...
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MongoDB logging all queries

... 268 You can log all queries: $ mongo MongoDB shell version: 2.4.9 connecting to: test > use my...
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What does the “map” method do in Ruby?

... 432 The map method takes an enumerable object and a block, and runs the block for each element, outp...