CODEWITHSUNDEEP
python
bradb
bradb

Reputation: 139

Power set and Cartesian Product of a set python

I am trying to find the cartesian product of two different sets. I can not find anything on the web about cartesian products of sets it's either of list or dictionaries.

Also power set is very confusing.

Neither one of these are in my book I have been using.

Could one of yall point me to the right direction.

Upvotes: 10

Views: 10927

Answers (1)

Gareth Latty
Gareth Latty

Reputation: 89097

For the Cartesian product, check out itertools.product.

For the powerset, the itertools docs also give us a recipe:

def powerset(iterable):
    "powerset([1,2,3]) --> () (1,) (2,) (3,) (1,2) (1,3) (2,3) (1,2,3)"
    s = list(iterable)
    return chain.from_iterable(combinations(s, r) for r in range(len(s)+1))

For example:

>>> test = {1, 2, 3}
>>> list(powerset(test))
[(), (1,), (2,), (3,), (1, 2), (1, 3), (2, 3), (1, 2, 3)]
>>> list(product(test, test))
[(1, 1), (1, 2), (1, 3), (2, 1), (2, 2), (2, 3), (3, 1), (3, 2), (3, 3)]

Upvotes: 19

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