CODEWITHSUNDEEP
pythonpermutation
user2586260
user2586260

Reputation: 19

Permutation with redundant overlaps? Python

I used itertools to run a permutation on a list that I have.

mylist = [a, b, c, d, e, f]
mypermutations = itertools.permutations(mylist,2)    
mypermutations_list = list(mypermutations) 
print mypermutations_list

prints:

[(a, b), (a, c), (a, d)...]

However, the permutation list doesn't include (a, a), (b, b), etc. I recognize that's probably because most people don't want such redundant pairings. However, I would like to include such pairings as a control for the program I'm writing.

Is there a way to run a permutation and get these combinations? I have no idea what to use instead of permutations.

Upvotes: 1

Views: 412

Answers (2)

Ashwini Chaudhary
Ashwini Chaudhary

Reputation: 250941

You're looking for itertools.product, it returns the Cartesian product of the iterable:

>>> from itertools import product
>>> list(product('abcdef', repeat=2))
[('a', 'a'), ('a', 'b'), ('a', 'c'), ('a', 'd'), ('a', 'e'), ('a', 'f'), ('b', 'a'), ('b', 'b'), ('b', 'c'), ('b', 'd'), ('b', 'e'), ('b', 'f'), ('c', 'a'), ('c', 'b'), ('c', 'c'), ('c', 'd'), ('c', 'e'), ('c', 'f'), ('d', 'a'), ('d', 'b'), ('d', 'c'), ('d', 'd'), ('d', 'e'), ('d', 'f'), ('e', 'a'), ('e', 'b'), ('e', 'c'), ('e', 'd'), ('e', 'e'), ('e', 'f'), ('f', 'a'), ('f', 'b'), ('f', 'c'), ('f', 'd'), ('f', 'e'), ('f', 'f')]

Upvotes: 1

TerryA
TerryA

Reputation: 59974

You want itertools.product instead:

>>> import itertools
>>> mylist = ['a', 'b', 'c', 'd', 'e', 'f']
>>> list(itertools.product(mylist, repeat=2))
[('a', 'a'), ('a', 'b'), ('a', 'c'), ...]

Upvotes: 2

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