Generate all string combinations from given character list in python

Question

I would like to generate all possible combinations of a given character list with a given length and exclude a few combinations. For example, if I have this list: chars = ['a', 'b', 'c', '1', '2'] Now I want to exclude character formations of more than 2characters in a row so that combinations like aaaaa or 111111 aren't possible. And I also want the output to be a given length, for example, 5 characters. Is this possible? I thought of itertools Thanks for any help in advance.

Answer 1

import itertools

chars = ['a', 'b', 'c', '1', '2']

for combination in itertools.product(chars, repeat = 5):
    if all(combination.count(x) < 3 for x in combination):
        print (combination)

Output:

('c', '1', '1', '2', 'c')
('c', '1', '1', '2', '2')
('c', '1', '2', 'a', 'a')
('c', '1', '2', 'a', 'b')
('c', '1', '2', 'a', 'c')
('c', '1', '2', 'a', '1')
('c', '1', '2', 'a', '2')
('c', '1', '2', 'b', 'a')
('c', '1', '2', 'b', 'b')
('c', '1', '2', 'b', 'c')
('c', '1', '2', 'b', '1')
('c', '1', '2', 'b', '2')
('c', '1', '2', 'c', 'a')
('c', '1', '2', 'c', 'b')
('c', '1', '2', 'c', '1')
('c', '1', '2', 'c', '2')
('c', '1', '2', '1', 'a')
('c', '1', '2', '1', 'b')
('c', '1', '2', '1', 'c')
('c', '1', '2', '1', '2')
('c', '1', '2', '2', 'a')
('c', '1', '2', '2', 'b')
('c', '1', '2', '2', 'c')
('c', '1', '2', '2', '1')
('c', '2', 'a', 'a', 'b')
('c', '2', 'a', 'a', 'c')
('c', '2', 'a', 'a', '1')
('c', '2', 'a', 'a', '2')
('c', '2', 'a', 'b', 'a')
('c', '2', 'a', 'b', 'b')
('c', '2', 'a', 'b', 'c')
('c', '2', 'a', 'b', '1')
('c', '2', 'a', 'b', '2')
('c', '2', 'a', 'c', 'a')
('c', '2', 'a', 'c', 'b')
('c', '2', 'a', 'c', '1')
('c', '2', 'a', 'c', '2')
('c', '2', 'a', '1', 'a')
('c', '2', 'a', '1', 'b')
('c', '2', 'a', '1', 'c')
('c', '2', 'a', '1', '1')
('c', '2', 'a', '1', '2')
('c', '2', 'a', '2', 'a')
('c', '2', 'a', '2', 'b')
('c', '2', 'a', '2', 'c')
('c', '2', 'a', '2', '1')
('c', '2', 'b', 'a', 'a')
('c', '2', 'b', 'a', 'b')
('c', '2', 'b', 'a', 'c')
('c', '2', 'b', 'a', '1')
('c', '2', 'b', 'a', '2')
('c', '2', 'b', 'b', 'a')
('c', '2', 'b', 'b', 'c')
('c', '2', 'b', 'b', '1')
('c', '2', 'b', 'b', '2')
('c', '2', 'b', 'c', 'a')
('c', '2', 'b', 'c', 'b')
('c', '2', 'b', 'c', '1')
('c', '2', 'b', 'c', '2')
('c', '2', 'b', '1', 'a')
('c', '2', 'b', '1', 'b')
('c', '2', 'b', '1', 'c')
('c', '2', 'b', '1', '1')
('c', '2', 'b', '1', '2')
('c', '2', 'b', '2', 'a')
('c', '2', 'b', '2', 'b')
('c', '2', 'b', '2', 'c')
('c', '2', 'b', '2', '1')
('c', '2', 'c', 'a', 'a')
('c', '2', 'c', 'a', 'b')
('c', '2', 'c', 'a', '1')
('c', '2', 'c', 'a', '2')
('c', '2', 'c', 'b', 'a')
('c', '2', 'c', 'b', 'b')
('c', '2', 'c', 'b', '1')
('c', '2', 'c', 'b', '2')
etc...