Permuting a order of items in a list in python

Question

I have a list of dictionary items

[{'x': 0, 'y': 0}, {'x': 1, 'y': 0}, {'x': 2, 'y': 2}]

I want to have an array of "array of dictionaries" with all the maximum permutation order of the list for example for the above array it would be (3 factorial ways)

[[{'x': 0, 'y': 0}, {'x': 1, 'y': 0}, {'x': 2, 'y': 2}],
[{'x': 0, 'y': 0}, {'x': 2, 'y': 2}, {'x': 1, 'y': 0}],
[{'x': 1, 'y': 0}, {'x': 0, 'y': 0}, {'x': 2, 'y': 2}],
[{'x': 1, 'y': 0}, {'x': 2, 'y': 2}, {'x': 0, 'y': 0}],
[{'x': 2, 'y': 2}, {'x': 1, 'y': 0}, {'x': 0, 'y': 0}],
[{'x': 2, 'y': 2}, {'x': 0, 'y': 0}, {'x': 1, 'y': 0}]]

Possible duplicate of [How to generate all permutations of a list in Python](https://stackoverflow.com/questions/104420/how-to-generate-all-permutations-of-a-list-in-python) — eugenhu, Mar 16 '18 at 07:15

score 0 · Answer 1 · answered Mar 16 '18 at 07:54

itertools can do permutations

#!python2

import itertools

yourlist = [{'x': 0, 'y': 0}, {'x': 1, 'y': 0}, {'x': 2, 'y': 2}]

for seq in itertools.permutations(yourlist):
    print seq

'''
({'y': 0, 'x': 0}, {'y': 0, 'x': 1}, {'y': 2, 'x': 2})
({'y': 0, 'x': 0}, {'y': 2, 'x': 2}, {'y': 0, 'x': 1})
({'y': 0, 'x': 1}, {'y': 0, 'x': 0}, {'y': 2, 'x': 2})
({'y': 0, 'x': 1}, {'y': 2, 'x': 2}, {'y': 0, 'x': 0})
({'y': 2, 'x': 2}, {'y': 0, 'x': 0}, {'y': 0, 'x': 1})
({'y': 2, 'x': 2}, {'y': 0, 'x': 1}, {'y': 0, 'x': 0})
'''

score 0 · Answer 2 · answered Mar 16 '18 at 08:02

Despite the comments, if you are still messed with how to solve your issue, consider the following.

Strategy: Make use of permutations from itertoolswhich returns a list of tuples in this case. Then, iterating through to convert list of tuples to list of lists to match with your required output.

Here is how you could do:

>>> import itertools
>>> lst = [{'x': 0, 'y': 0}, {'x': 1, 'y': 0}, {'x': 2, 'y': 2}]
>>> [list(elem) for elem in list(itertools.permutations(lst))]
[[{'x': 0, 'y': 0}, {'x': 1, 'y': 0}, {'x': 2, 'y': 2}], 
[{'x': 0, 'y': 0}, {'x': 2, 'y': 2}, {'x': 1, 'y': 0}],
[{'x': 1, 'y': 0}, {'x': 0, 'y': 0}, {'x': 2, 'y': 2}], 
[{'x': 1, 'y': 0}, {'x': 2, 'y': 2}, {'x': 0, 'y': 0}], 
[{'x': 2, 'y': 2}, {'x': 0, 'y': 0}, {'x': 1, 'y': 0}], 
[{'x': 2, 'y': 2}, {'x': 1, 'y': 0}, {'x': 0, 'y': 0}]]

Permuting a order of items in a list in python

2 Answers2