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How to find where gem files are installed
...t about your gem environment:
RubyGems Environment:
- RUBYGEMS VERSION: 2.1.5
- RUBY VERSION: 2.0.0 (2013-06-27 patchlevel 247) [x86_64-darwin12.4.0]
- INSTALLATION DIRECTORY: /Users/ttm/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0
- RUBY EXECUTABLE: /Users/ttm/.rbenv/versions/2.0.0-p247/...
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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Is it possible to use 'else' in a list comprehension? [duplicate]
... c. It can be used in comprehension statements:
>>> [a if a else 2 for a in [0,1,0,3]]
[2, 1, 2, 3]
So for your example,
table = ''.join(chr(index) if index in ords_to_keep else replace_with
for index in xrange(15))
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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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get list of pandas dataframe columns based on data type
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What is the difference between String.slice and String.substring?
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882
slice() works like substring() with a few different behaviors.
Syntax: string.slice(start, stop...
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...
Check if all elements in a list are identical
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Two versions of python on linux. how to make 2.7 the default
...ed by #! /usr/bin/env python. You can usually get away with running Python 2.6 scripts in 2.7, but do you want to risk it?
On top of that, monkeying with /usr/bin can break your package manager's ability to manage packages. And changing the order of directories in your PATH will affect a lot of oth...
C++ preprocessor __VA_ARGS__ number of arguments
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