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Can dplyr package be used for conditional mutating?
...), 2L,
ifelse(a %in% c(0,1,3,4) | c==4, 3L, NA_integer_)))
}
BASE_fun <- function(DF) { # R v3.1.0
transform(DF, g = ifelse(a %in% c(2,5,7) | (a==1 & b==4), 2L,
ifelse(a %in% c(0,1,3,4) | c==4, 3L, NA_integer_)))
}
system.time(ans1 <- DT_fun(DT))
# user s...
How to reliably open a file in the same directory as a Python script
... for help, clarification, or responding to other answers.Making statements based on opinion; back them up with references or personal experience.To learn more, see our tips on writing great answers.
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Relational table naming convention [closed]
...who has not read any of the standard materials and has no knowledge of database theory.
Some of the wonderful things about Standards are:
they are all integrated with each other
they work together
they were written by minds greater than ours, so we do not have to
debate them.
The standard ta...
How can I save my secret keys and password securely in my version control system?
...know that it's bad practice to keep secrets (like private keys and database passwords) in a VCS repository.
17 Answers
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What is the best way to implement nested dictionaries?
...oo'])) - min(timeit.repeat(lambda: AutoVivification()))
2.138362169265747
Based on performance, dict.setdefault works the best. I'd highly recommend it for production code, in cases where you care about execution speed.
If you need this for interactive use (in an IPython notebook, perhaps) then per...
I want to get the type of a variable at runtime
... is the same class as b
A ClassTag is limited in that it only covers the base class, but not its type parameters. That is, the ClassTag for List[Int] and List[String] is the same, List. If you need type parameters, then you must use a TypeTag instead. A TypeTag however, cannot be obtained from a v...
How to replace spaces in file names using a bash script
... # do the directories first
find -name "* *" -type f | rename 's/ /_/g'
Based on Jürgen's answer and able to handle multiple layers of files and directories in a single bound using the "Revision 1.5 1998/12/18 16:16:31 rmb1" version of /usr/bin/rename (a Perl script):
find /tmp/ -depth -name ...
sql “LIKE” equivalent in django query
... for help, clarification, or responding to other answers.Making statements based on opinion; back them up with references or personal experience.To learn more, see our tips on writing great answers.
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What is the reason for having '//' in Python? [duplicate]
...0.666666666667
As you see, single / may floor, or it may return a float, based on completely non-local issues, up to and including the value of the -Q flag...;-).
So, if and when you know you want flooring, always use //, which guarantees it. If and when you know you don't want flooring, slap a f...
How do I find all files containing specific text on Linux?
...
Based on my experience, the -i makes it slow down a lot, so don't use it if not necessary. Test it in a certain dir and then generalise. It should be completed within few minutes. I think a regular expression would make it sl...