from itertools import chain, takewhile, dropwhile
from itertools import combinations, permutations

a = [1, 2, 3]
b = 'abc'
print([(x, type(x)) for x in chain(a, b)])
print([u''.join(x) for x in combinations(b, 2)])
print([u''.join(x) for x in permutations(b, 2)])
print(list(takewhile(lambda x: x % 2 == 1, a)))
print(list(dropwhile(lambda x: x in 'aeiou', b)))