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+--- Thread: iterate N elements at a time (/thread-12022.html)
iterate N elements at a time - Skaperen - Aug-06-2018
i have a long iterator. i would like to iterate N elements at a time instead of 1 at a time. this is not an iterator of iterators; it is flat such as an iterator of ints, or an immutable type i am not going to iterate over, here, like a string. in most use cases i will know at the time of coding what N is (very often will be 2 or 3). in other use cases, N will not be known until run time. N will never change over the course of iterating; it will be known when the iterating begins. how can i iterate over an iterator N elements at a time?
RE: iterate N elements at a time - Larz60+ - Aug-06-2018
something like this?:
>>> from itertools import islice >>> loops = iter(range(10)) >>> for i in loops: ... print(i) ... next(islice(loops, n, n), None) ... 0 3 6 9 >>>
RE: iterate N elements at a time - Skaperen - Aug-07-2018
i want to get all N elements (as a list or tuple) each time i iterate N items at a time.
RE: iterate N elements at a time - DeaD_EyE - Aug-07-2018
def chunker(iterable, chunksize):
return zip(*[iter(iterable)] * chunksize)
def chunker_longest(iterable, chunksize):
return itertools.zip_longest(*[iter(iterable)] * chunksize)for chunk in chunker_longest(range(101), 10):
print(chunk)Output:(0, 1, 2, 3, 4, 5, 6, 7, 8, 9)
(10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
(20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
(30, 31, 32, 33, 34, 35, 36, 37, 38, 39)
(40, 41, 42, 43, 44, 45, 46, 47, 48, 49)
(50, 51, 52, 53, 54, 55, 56, 57, 58, 59)
(60, 61, 62, 63, 64, 65, 66, 67, 68, 69)
(70, 71, 72, 73, 74, 75, 76, 77, 78, 79)
(80, 81, 82, 83, 84, 85, 86, 87, 88, 89)
(90, 91, 92, 93, 94, 95, 96, 97, 98, 99)
(100, None, None, None, None, None, None, None, None, None)