itertools.islice
Take part of the items of an iterator, like a slice.
Python 3.13
itertools.islice(iterable, stop)
itertools.islice(iterable, start, stop[, step])Parameters
- iterableIterable
- An iterable.
- startint | Noneoptional
- The position of the first item, 0 by default.
- stopint | None
- The position before which the selection stops; None means to the end.
- stepint | Noneoptional
- The step, 1 by default.
Return value
An iterator over the selected items.
Examples
The first three items
Python 3.13
from itertools import islice
print(list(islice('abcdefg', 3)))['a', 'b', 'c']
A slice with a start and a step
Python 3.13
from itertools import islice
print(list(islice(range(10), 2, 8, 2)))[2, 4, 6]
Details
It works like a slice but for any iterator, including infinite ones and files. Negative values are not supported and raise ValueError. Skipped items of the iterator are consumed and do not come back.