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Calculate difference in keys contained in two Python dictionaries
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234
You can use set operations on the keys:
diff = set(dictb.keys()) - set(dicta.keys())
Here is ...
Can dplyr package be used for conditional mutating?
...f %>%
mutate(g = ifelse(a == 2 | a == 5 | a == 7 | (a == 1 & b == 4), 2,
ifelse(a == 0 | a == 1 | a == 4 | a == 3 | c == 4, 3, NA)))
Added - if_else: Note that in dplyr 0.5 there is an if_else function defined so an alternative would be to replace ifelse with if_else; howev...
How to test valid UUID/GUID?
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439
Currently, UUID's are as specified in RFC4122. An often neglected edge case is the NIL UUID, n...
What is the optimal Jewish toenail cutting algorithm?
...ort ifilter, permutations
validseqs = ifilter(isValid, permutations([1,2,3,4,5]))
for i in validseqs:
print i
(1, 3, 5, 2, 4)
(1, 4, 2, 5, 3)
(2, 4, 1, 3, 5)
(2, 4, 1, 5, 3)
(2, 5, 3, 1, 4)
(3, 1, 4, 2, 5)
(3, 1, 5, 2, 4)
(3, 5, 1, 4, 2)
(3, 5, 2, 4, 1)
(4, 1, 3, 5, 2)
(4, 2, 5, 1, 3)
(4, 2, 5,...
Reduce, fold or scan (Left/Right)?
...e first argument res of our binary operator minus:
val xs = List(1, 2, 3, 4)
def minus(res: Int, x: Int) = {
println(s"op: $res - $x = ${res - x}")
res - x
}
xs.reduceLeft(minus)
// op: 1 - 2 = -1
// op: -1 - 3 = -4 // de-cumulates value -1 in *first* operator arg `res`
// op: -4 - 4 = -8
//...
All combinations of a list of lists
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449
you need itertools.product:
>>> import itertools
>>> a = [[1,2,3],[4,5,6],[...
Print all but the first three columns
...tion that does not add extra leading or trailing whitespace:
awk '{ for(i=4; i<NF; i++) printf "%s",$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...
Base64 length calculation?
After reading the base64 wiki ...
15 Answers
15
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Operation on every pair of element in a list
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4 Answers
4
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