Itertools

iterator_tools.py

import itertools

# Linking iterators together

# chain: Combines multiple iterators into a single sequential iterator.
# cycle: Repeats an iterator’s items forever.
# tee: Splits a single iterator into multiple parallel iterators.
# zip_longest: A variant of the zip built-in function that works well with iterators of different lengths.

# Filtering items from an iterator

# islice: Slices an iterator by numerical indexes without copying
# takewhile: Returns items from an iterator while a predicate function returns True.
# dropwhile: Returns items from an iterator once the predicate function returns False for the first time.
# filterfalse: Returns all items from an iterator where a predicate function returns False. The opposite of the filter built-in function.

# Combinations of items from iterators

# product: cartesian products of two iterators
# permutations
# combination