itertools

Infinite iterators

• count: count(10)
• cycle: cycle('ABCD')
• repeat: repeat(10, 3)

Iterators terminating on the shortest input sequence

• accumulate: accumulate([1,2,3,4,5])
• chain: chain('ABC', 'DEF')
• chain.from_iterable: chain.from_iterable(['ABC', 'DEF'])
• dropwhile: dropwhile(lambda x: x<5, [1,4,6,4,1])
• filterfalse: filterfalse(lambda x: x%2, range(10))
• islice: islice('ABCDEFG', 2, None)
• starmap: starmap(pow, [(2,5), (3,2), (10,3)])
• takewhile: takewhile(lambda x: x<5, [1,4,6,4,1])
• zip_longest: zip_longest('ABCD', 'xy', fillvalue='-')

Combinatoric iterators

• product
• permutations
• combinations
• combinations_with_replacement