Python Itertools permutations only letters and numbers

Question

I need to get only the permutations that have letters and numbers (The permutation can not be. \"A, B, C, D\" I need it like this: \"A, B, C, 1\")

In short, the perm

Answer 1

You can generate the proper combinations by combining non-empty combinations from the two sequences.

import itertools

def combinations(a, b, n):
    for i in xrange(1, n):
        for ca in itertools.combinations(a, i):
            for cb in itertools.combinations(b, n-i):
                yield ca + cb

for r in combinations(list('abcd'), [1, 2, 3, 4], 4):
    print r

The number of combinations you get is choose(A+B, n) - choose(A, n) - choose(B, n), where A is the number of elements in a, B the number of elements in b, and "choose" is the binomial coefficient.