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cartesian product in pandas
...rom pandas import DataFrame, merge
df1 = DataFrame({'key':[1,1], 'col1':[1,2],'col2':[3,4]})
df2 = DataFrame({'key':[1,1], 'col3':[5,6]})
merge(df1, df2,on='key')[['col1', 'col2', 'col3']]
Output:
col1 col2 col3
0 1 3 5
1 1 3 6
2 2 4 5
3 2 4 6...
What is the use of the ArraySegment class?
...l array, get the first item, and so on:
var array = new byte[] { 5, 8, 9, 20, 70, 44, 2, 4 };
array.Dump();
var segment = new ArraySegment<byte>(array, 2, 3);
segment.Dump(); // output: 9, 20, 70
segment.Reverse().Dump(); // output 70, 20, 9
segment.Any(s => s == 99).Dump(); // output fals...
Is there a reason that we cannot iterate on “reverse Range” in ruby?
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What exactly do “u” and “r” string flags do, and what are raw string literals?
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702
There's not really any "raw string"; there are raw string literals, which are exactly the string...
Round to 5 (or other number) in Python
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312
I don't know of a standard function in Python, but this works for me:
Python 2
def myround(x, ...
CALayer with transparent hole in it
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219
I was able to solve this with Jon Steinmetz suggestion. If any one cares, here's the final sol...
Is there a way to make mv create the directory to be moved to if it doesn't exist?
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edited Feb 25 '17 at 20:31
Elijah Lynn
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surface plots in matplotlib
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122
For surfaces it's a bit different than a list of 3-tuples, you should pass in a grid for the do...
Programmer Puzzle: Encoding a chess board state throughout a game
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