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AWS ssh access 'Permission denied (publickey)' issue [closed]
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20 Answers
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Numbering rows within groups in a data frame
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284
Use ave, ddply, dplyr or data.table:
df$num <- ave(df$val, df$cat, FUN = seq_along)
or:
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Check if all elements in a list are identical
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26 Answers
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How to split a string in shell and get the last field
Suppose I have the string 1:2:3:4:5 and I want to get its last field ( 5 in this case). How do I do that using Bash? I tried cut , but I don't know how to specify the last field with -f .
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How do I check if a string is unicode or ascii?
...Unicode characters. There is a bytes type that holds raw bytes.
In Python 2, a string may be of type str or of type unicode. You can tell which using code something like this:
def whatisthis(s):
if isinstance(s, str):
print "ordinary string"
elif isinstance(s, unicode):
pri...
Converting integer to binary in python
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TrebledJ
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answered May 2 '12 at 9:32
eumiroeumiro
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get list of pandas dataframe columns based on data type
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12 Answers
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What is the most efficient way to create a dictionary of two pandas Dataframe columns?
...: pd.Series(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...
How do you downgrade rubygems?
I have rubygems 1.3.1 installed but I want to go back to 1.2.0. What's the command to downgrade rubygems?
6 Answers
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Principal component analysis in Python
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28
You might have a look at MDP.
I have not had the chance to test it myself, but I've bookmar...