I am looking for an algorithm that would find all possible combinations of list elements without using itertools. eg. : for [1,2,3,4,5] it prints [[1],[2],[3],[4],[5],[1,2],[1,3],[1,4],[1,5],[2,1].......]
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Why the restriction against itertools? itertools is a negligible dependency and will probably be faster than any pure-Python solution – Edward Minnix Jul 03 '19 at 12:19
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Possible duplicate of [How to get all possible combinations of a list’s elements?](https://stackoverflow.com/questions/464864/how-to-get-all-possible-combinations-of-a-list-s-elements) – mbrg Jul 13 '19 at 06:54
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A solution is presented here using recursion.
>>> import copy
>>> def combinations(target,data):
... for i in range(len(data)):
... new_target = copy.copy(target)
... new_data = copy.copy(data)
... new_target.append(data[i])
... new_data = data[i+1:]
... print new_target
... combinations(new_target,
... new_data)
...
...
>>> target = []
>>> data = ['a','b','c','d']
>>>
>>> combinations(target,data)
['a']
['a', 'b']
['a', 'b', 'c']
['a', 'b', 'c', 'd']
['a', 'b', 'd']
['a', 'c']
['a', 'c', 'd']
['a', 'd']
['b']
['b', 'c']
['b', 'c', 'd']
['b', 'd']
['c']
['c', 'd']
['d']
blackbrandt
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