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Is there an equivalent for the Zip function in Clojure Core or Contrib?
...
(map vector '(1 2 3) '(4 5 6))
does what you want:
=> ([1 4] [2 5] [3 6])
Haskell needs a collection of zipWith (zipWith3, zipWith4, ...) functions, because they all need to be of a specific type; in particular, the number of input lists th...
How to reorder data.table columns (without copying)
... a b c
# [1,] 1 3 0.2880365
# [2,] 2 2 0.7785115
# [3,] 3 1 0.3297416
setcolorder(x, c("c", "b", "a"))
x
# c b a
# [1,] 0.2880365 3 1
# [2,] 0.7785115 2 2
# [3,] 0.3297416 1 3
From ?setcolorder:
In data.table parlance, all set* functions change their input by reference. T...
Replacing NAs with latest non-NA value
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164
You probably want to use the na.locf() function from the zoo package to carry the last observati...
How to get a specific output iterating a hash in Ruby?
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answered Aug 4 '09 at 13:38
community wiki
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jQuery map vs. each
...u can potentially waste a lot of memory.
For example:
var items = [1,2,3,4];
$.each(items, function() {
alert('this is ' + this);
});
var newItems = $.map(items, function(i) {
return i + 1;
});
// newItems is [2,3,4,5]
You can also use the map function to remove an item from an array. For...
Backporting Python 3 open(encoding=“utf-8”) to Python 2
...tions.html#open.
– pmdarrow
Oct 9 '14 at 18:34
7
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Apache Spark: map vs mapPartitions?
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Alberto Bonsanto
14.1k88 gold badges5151 silver badges8383 bronze badges
answered Jan 17 '14 at 19:46
Alexey RomanovAle...
How does zip(*[iter(s)]*n) work in Python?
... zip(), and it pulls an item from the iterator each time.
x = iter([1,2,3,4,5,6,7,8,9])
print zip(x, x, x)
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Pandas dataframe get first row of each group
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248
>>> df.groupby('id').first()
value
id
1 first
2 first
3 first
4 ...