Writing all possible combinations of a characters in a string to a file using Python

Question

I have a string s="abcde". I want to generate all possible permutations and write their in txt file. OUT File.txt

a b c d aa ab ac ad ae ba bb bc bd be ca cb cc cd ce da db dc dd de ea eb ec ed ee ... ... eeeda eeedb eeedc eeedd eeede eeeea eeeeb eeeec eeeed eeeee

I used the itertools but it always start with aaaaa.

Answer 1

itertools.permutations takes 2 arguments, the iterable and length of the permutations. If you do not specify the second agrument, it defaults to len(iterable). To get all lengths, you need to print permutations for each length:

import itertools
s = "abcde"
for i in range(len(s)):
    for permutation in (itertools.permutations(s, i+1)):
        print ("".join(permutation))

Source: https://docs.python.org/2/library/itertools.html#itertools.permutations

Answer 2

import itertools

s="abcde"

def upto_n(s,n):

    out = []

    for i in range(1,n+1,1):

        out += list(itertools.combinations(s, i))

    return out

print upto_n(s,2)
print upto_n(s,3)

OutPut

 [('a',), ('b',), ('c',), ('d',), ('e',), ('a', 'b'), ('a', 'c'), ('a', 'd'), ('a', 'e'), ('b', 'c'), ('b', 'd'), ('b', 'e'), ('c', 'd'), ('c', 'e'), ('d', 'e')]

 [('a',), ('b',), ('c',), ('d',), ('e',), ('a', 'b'), ('a', 'c'), ('a', 'd'), ('a', 'e'), ('b', 'c'), ('b', 'd'), ('b', 'e'), ('c', 'd'), ('c', 'e'), ('d', 'e'), ('a', 'b', 'c'), ('a', 'b', 'd'), ('a', 'b', 'e'), ('a', 'c', 'd'), ('a', 'c', 'e'), ('a', 'd', 'e'), ('b', 'c', 'd'), ('b', 'c', 'e'), ('b', 'd', 'e'), ('c', 'd', 'e')]