Alex Kleider wrote:
> On 2017-05-28 13:13, Mats Wichmann wrote:
>
>> FWIW, if checking for multiples, you could also write:
>>
>> if Month in ['January', '1']:
>
> Would
>
>>>> if Month in {'January', '1'}:
>
> be even better? (regarding efficiency perhaps? Trivial point, I know,
> but just wondering.)
Yes, according to timeit there is already a significant difference:
$ python3 -m timeit -s 'month = "September"' 'month == "January" or month ==
"1"'
10000000 loops, best of 3: 0.126 usec per loop
$ python3 -m timeit -s 'month = "September"' 'month in ["January", "1"]'
10000000 loops, best of 3: 0.108 usec per loop
$ python3 -m timeit -s 'month = "September"' 'month in {"January", "1"}'
10000000 loops, best of 3: 0.0684 usec per loop
As the size of the list/set grows you'll see the effects of O(N) versus
O(1):
$ python3 -m timeit -s 'N = 10**6; numbers = list(range(N))' 'N in numbers'
10 loops, best of 3: 32.5 msec per loop
$ python3 -m timeit -s 'N = 10**6; numbers = set(range(N))' 'N in numbers'
10000000 loops, best of 3: 0.0921 usec per loop
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