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Removing duplicates from a list of lists
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>>> k = [[1, 2], [4], [5, 6, 2], [1, 2], [3], [4]]
>>> import itertools
>>> k.sort()
>>> list(k for k,_ in itertools.groupby(k))
[[1, 2], [3], [4], [5, 6, 2]]
itertools often offers the fastest and most powerf...
Why do enum permissions often have 0, 1, 2, 4 values?
Why are people always using enum values like 0, 1, 2, 4, 8 and not 0, 1, 2, 3, 4 ?
7 Answers
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Does the ternary operator exist in R?
... if-else is equivalent to ?:.
> a <- 1
> x <- if(a==1) 1 else 2
> x
[1] 1
> x <- if(a==2) 1 else 2
> x
[1] 2
The power of R is vectorization. The vectorization of the ternary operator is ifelse:
> a <- c(1, 2, 1)
> x <- ifelse(a==1, 1, 2)
> x
[1] 1 2 1
>...
Limiting floats to two decimal points
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26 Answers
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How do I write stderr to a file while using “tee” with a pipe?
...s substitution and file redirection:
command > >(tee -a stdout.log) 2> >(tee -a stderr.log >&2)
Let's split it up and explain:
> >(..)
>(...) (process substitution) creates a FIFO and lets tee listen on it. Then, it uses > (file redirection) to redirect the STDO...
How to get all possible combinations of a list’s elements?
... list with 15 numbers in, and I need to write some code that produces all 32,768 combinations of those numbers.
27 Answers...
How to drop rows of Pandas DataFrame whose value in a certain column is NaN
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12 Answers
12
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Filter rows which contain a certain string
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263
The answer to the question was already posted by the @latemail in the comments above. You can ...
Numpy - add row to array
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122
What is X? If it is a 2D-array, how can you then compare its row to a number: i < 3?
EDIT a...
Get distance between two points in canvas
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211
You can do it with pythagoras theorem
If you have two points (x1, y1) and (x2, y2)
then you c...