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Most lightweight way to create a random string and a random hexadecimal number
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Interesting, I kind of forgot that Python (and the random module) handles bigints natively.
– wump
May 6 '10 at 18:49
3
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Why Collections.sort uses merge sort instead of quicksort?
...was a fine choice, but today but we can
do much better.
Since 2003, Python's list sort has used an algorithm known as timsort
(after Tim Peters, who wrote it). It is a stable, adaptive, iterative
mergesort that requires far fewer than n log(n) comparisons when
running on partially sorte...
How to convert a boolean array to an int array
...d seeing all the different ways to do it. Really opened my mind regarding python.
– Kwolf
Jul 6 '13 at 20:49
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Keep only date part when using pandas.to_datetime
...osed, it does not really solve the performance problem (it still relies on python datetime objects, and hence any operation on them will be not vectorized - that is, it will be slow).
A better performing alternative is to use df['dates'].dt.floor('d'). Strictly speaking, it does not "keep only date...
Bitwise operation and usage
...10 0101
1111 1111 << 4 gives 1111 0000
Note that the left shift in Python is unusual in that it's not using a fixed width where bits are discarded - while many languages use a fixed width based on the data type, Python simply expands the width to cater for extra bits. In order to get the dis...
Get array of object's keys
...oerce the following onto one line by the one-liner request, don't know how Pythonic it is though ;)
var keys = (function(o){var ks=[]; for(var k in o) ks.push(k); return ks})(foo);
share
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improve...
pytest: assert almost equal
...thing that works not only with floats but for example Decimals you can use python's math.isclose:
# - rel_tol=0.01` is 1% difference tolerance.
assert math.isclose(actual_value, expected_value, rel_tol=0.01)
Docs - https://docs.python.org/3/library/math.html#math.isclose
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Flatten nested dictionaries, compressing keys
...it to test for collections.MutableMapping to make it more generic. But for Python < 2.6, try..except is probably the best option.
– Imran
May 17 '11 at 7:55
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How do I use itertools.groupby()?
...n't been able to find an understandable explanation of how to actually use Python's itertools.groupby() function. What I'm trying to do is this:
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Common elements comparison between 2 lists
...ed by S.Mark and SilentGhost generally tell you how it should be done in a Pythonic way, but I thought you might also benefit from knowing why your solution doesn't work. The problem is that as soon as you find the first common element in the two lists, you return that single element only. Your solu...