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What's the 'Ruby way' to iterate over two arrays at once
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Marc-André Lafortune
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answered Aug 26 '10 at 22:31
John La RooyJohn...
How to count the frequency of the elements in an unordered list?
...tertools package if the list is an ordered list.
a = [1,1,1,1,2,2,2,2,3,3,4,5,5]
from itertools import groupby
[len(list(group)) for key, group in groupby(a)]
Output:
[4, 4, 2, 1, 2]
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im...
Regex to match a digit two or four times
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145
There's no specific syntax for that, but there are lots of ways to do it:
(?:\d{4}|\d{2}) &...
Grep regex NOT containing string
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beerbajaybeerbajay
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Apache: “AuthType not set!” 500 Error
...he line that says
Require all granted
it's only needed on Apache >=2.4
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Does the ternary operator exist in R?
...(x)]])
here, you don't need to take care about brackets:
> 1 ? 2*3 : 4
[1] 6
> 0 ? 2*3 : 4
[1] 4
> TRUE ? x*2 : 0
[1] 2
> FALSE ? x*2 : 0
[1] 0
but you need brackets for assignment :(
> y <- 1 ? 2*3 : 4
[1] 6
> y
[1] 1
> y <- (1 ? 2*3 : 4)
> y
[1] 6
Finally, y...
Convert numpy array to tuple
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edited Jul 18 '13 at 22:34
answered Apr 4 '12 at 17:35
Nik...
How to drop columns by name in a data frame
... function. For example :
R> df <- data.frame(x=1:5, y=2:6, z=3:7, u=4:8)
R> df
x y z u
1 1 2 3 4
2 2 3 4 5
3 3 4 5 6
4 4 5 6 7
5 5 6 7 8
Then you can use the which function and the - operator in column indexation :
R> df[ , -which(names(df) %in% c("z","u"))]
x y
1 1 2
2 2 3
3 3 4...
Print all but the first three columns
...tion that does not add extra leading or trailing whitespace:
awk '{ for(i=4; i<NF; i++) printf "%s",$i OFS; if(NF) printf "%s",$NF; printf ORS}'
### Example ###
$ echo '1 2 3 4 5 6 7' |
awk '{for(i=4;i<NF;i++)printf"%s",$i OFS;if(NF)printf"%s",$NF;printf ORS}' |
tr ' ' '-'
4-5-6-7
Sudo...
How do you downgrade rubygems?
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Ryan BiggRyan Bigg
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