itertools.combinations

itertools.combinations(itr, r)

  • The combinations function is used to:

    • Cycle through each element of an iterable
    • Return r length subsequences of elements
  • This iterable is based on the itr parameter
  • The length of subsequences is based on the r parameter
  • combinations returns an iterator of r length subsequences of elements from the iterable itr

Illustrating the combinations Function

>>> from itertools import combinations

>>> itr = combinations('ABC', 2)
>>> for i in itr: print(i)
('A', 'B')
('A', 'C')
('B', 'C')

>>> itr = combinations(range(4))
>>> for i in itr: print(i)
(0, 1, 2)
(0, 1, 3)
(0, 2, 3)
(1, 2, 3)

>>> from itertools import combinations_with_replacement
>>> itr = combinations_with_replacement('ABC', 2)
>>> for i in itr: print(i)
('A', 'A')
('A', 'B')
('A', 'C')
('B', 'B')
('B', 'C')
('C', 'C')

References

Previous

itertools.permutations

BlogAbout MeProjectsNotes