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Return two and more values from a method
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def sumdiff(x, y)
return x+y, x-y
end
#=> nil
sumdiff(3, 4)
#=> [7, -1]
a = sumdiff(3,4)
#=> [7, -1]
a
#=> [7, -1]
a,b=sumdiff(3,4)
#=> [7, -1]
a
#=> 7
b
#=> -1
a,b,c=sumdiff(3,4)
#=> [7, -1]
a
#=> 7
b
#=> -1
c
#=> nil
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What is the most efficient way to create a dictionary of two pandas Dataframe columns?
...ies(df.Letter.values,index=df.Position).to_dict()
Out[9]: {1: 'a', 2: 'b', 3: 'c', 4: 'd', 5: 'e'}
Speed comparion (using Wouter's method)
In [6]: df = pd.DataFrame(randint(0,10,10000).reshape(5000,2),columns=list('AB'))
In [7]: %timeit dict(zip(df.A,df.B))
1000 loops, best of 3: 1.27 ms per loo...
Backporting Python 3 open(encoding=“utf-8”) to Python 2
I have a Python codebase, built for Python 3, which uses Python 3 style open() with encoding parameter:
6 Answers
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If vs. Switch Speed
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answered Jan 14 '09 at 23:16
Konrad RudolphKonrad Rudolph
461k118118 gold badges863863 silver badges11101110 bronze badges
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Operation on every pair of element in a list
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233
Check out product() in the itertools module. It does exactly what you describe.
import iterto...
Plot a legend outside of the plotting area in base graphics?
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113
Maybe what you need is par(xpd=TRUE) to enable things to be drawn outside the plot region. So if...
No secret option provided to Rack::Session::Cookie warning?
I am running Rails 3.2.3, Ruby 1.9 under Fedora 17. I get this warning, when I run rails s , and how do I fix?
7 Answers
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How to drop columns by name in a data frame
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389
You should use either indexing or the subset function. For example :
R> df <- data.fram...