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Double Iteration in List Comprehension
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answered Apr 20 '16 at 5:34
SkamSkam
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How can I “unuse” a namespace?
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answered Oct 3 '08 at 17:39
Head GeekHead Geek
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How can I check whether an array is null / empty?
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13 Answers
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Elegant ways to support equivalence (“equality”) in Python classes
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342
Consider this simple problem:
class Number:
def __init__(self, number):
self.num...
What is the difference between substr and substring?
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3
@Pawel also when you want it to the end of the string (no second argument)
– André Chalella
Oct 20 '...
How to make the 'cut' command treat same sequental delimiters as one?
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edited Apr 23 '18 at 23:03
Austin Adams
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Is there any pythonic way to combine two dicts (adding values for keys that appear in both)?
...rom collections import Counter
>>> A = Counter({'a':1, 'b':2, 'c':3})
>>> B = Counter({'b':3, 'c':4, 'd':5})
>>> A + B
Counter({'c': 7, 'b': 5, 'd': 5, 'a': 1})
Counters are basically a subclass of dict, so you can still do everything else with them you'd normally do wit...
Ruby: What is the easiest way to remove the first element from an array?
...ther answer.
– Jay
Oct 15 '15 at 21:37
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Most efficient way to prepend a value to an array
...-O but certainly using the unshift method is more concise:
var a = [1, 2, 3, 4];
a.unshift(0);
a; // => [0, 1, 2, 3, 4]
[Edit]
This jsPerf benchmark shows that unshift is decently faster in at least a couple of browsers, regardless of possibly different big-O performance if you are ok with mo...