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Check if a given key already exists in a dictionary and increment it
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12 Answers
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Fast way of counting non-zero bits in positive integer
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121
For arbitrary-length integers, bin(n).count("1") is the fastest I could find in pure Python.
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Create new tmux session from inside a tmux session
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145
The quickest way (assuming you use ctrl-b as your command prefix) is:
ctrl-b :new
To create...
How can I implode an array while skipping empty array items?
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212
You can use array_filter():
If no callback is supplied, all entries of input equal to FALSE...
CSS Image size, how to fill, not stretch?
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15 Answers
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How to open multiple pull requests on GitHub
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116
Pull requests are based on a branch.
The only way to open up a pull request for multiple commi...
iOS UIImagePickerController result image orientation after upload
I am testing my iPhone application on an iOS 3.1.3 iPhone. I am selecting/capturing an image using a UIImagePickerController :
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How is “int* ptr = int()” value initialization not illegal?
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110
int() is a constant expression with a value of 0, so it's a valid way of producing a null poin...
How to delete an element from an array in C#
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10 Answers
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Pandas count(distinct) equivalent
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Example:
In [2]: table
Out[2]:
CLIENTCODE YEARMONTH
0 1 201301
1 1 201301
2 2 201301
3 1 201302
4 2 201302
5 2 201302
6 3 201302
In [3]: table.groupby('YEARMONTH').CLIENTCODE.nunique()
Out[3...