List of all possible orders of a set of items in python

Question

I have a set of 6 items, lets call them "1" to "6". What I want to do is create another list with all possible combinations (orders?) of these items. Means in every possible combination, all 6 items have to be included and there cant be duplicates. It may be a combination backwards, since its a different set of numbers.

Heres my idea:

import random

items = [1,2,3,4,5,6]
ListOfCombinations = []
while True:
    random.shuffle(items)
    print(items)
    string = " ".join(str(e) for e in items)
    if string not in ListOfCombinations:
        ListOfCombinations.append(string)

What I tried to do here is create a random order and add it into the second list if its not already inside. But I feel like there has to be a different way of doing and I probably did it wrong to. I'm a noob at python so help would be appreciated!

https://docs.python.org/2/library/itertools.html#itertools.combinations — ewcz, Mar 18 '17 at 19:09
Check here. http://stackoverflow.com/questions/104420/how-to-generate-all-permutations-of-a-list-in-python — Aung, Mar 18 '17 at 19:12

score 17 · Answer 1 · edited Jan 16 '23 at 20:07

17

You are looking for permutations() from the itertools library.

from itertools import permutations

# this will create all permutations of [0,1,2]
list(permutations(range(3)))

# returns:
[(0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), (2, 1, 0)]

edited Jan 16 '23 at 20:07

Nick McCurdy

17,658
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answered Mar 18 '17 at 19:09

James

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python can do that? well okay, thanks for that. How do I enter them into a second list? – diatomym Mar 18 '17 at 19:16
it returns a list on its own. You can just assign it to a new variable or you can extend a list that already exists. – James Mar 18 '17 at 19:36
list(map(list, permutations(your_list))) – Sharan Arumugam Oct 09 '19 at 08:26
1

The second of arg `permutations()` defaults to the length, so just `list(permutations(range(3)))` works – Carl Walsh Feb 08 '22 at 02:50

List of all possible orders of a set of items in python

1 Answers1