Generating all combinations of a list in python

Question

Here\'s the question:

Given a list of items in Python, how would I go by to get all the possible combinations of the items?

There are several similar questio

Answer 1

I assume you want all possible combinations as 'sets' of values. Here is a piece of code that I wrote that might help give you an idea:

def getAllCombinations(object_list):
    uniq_objs = set(object_list)
    combinations = []
    for obj in uniq_objs:
        for i in range(0,len(combinations)):
            combinations.append(combinations[i].union([obj]))
        combinations.append(set([obj]))
return combinations

Here is a sample:

combinations = getAllCombinations([20,10,30])
combinations.sort(key = lambda s: len(s))
print combinations
... [set([10]), set([20]), set([30]), set([10, 20]), set([10, 30]), set([20, 30]), set([10, 20, 30])]

I think this has n! time complexity, so be careful. This works but may not be most efficient