CODEWITHSUNDEEP
pythonloops
neurothew
neurothew

Reputation: 185

Failure of a simple nested loop

I am implementing a nested for loop which the inner for loop is about looping through combinations. However, I dont understand why this do not work...

import numpy as np
from itertools import combinations
comb = combinations(range(0, 3), 2)
for i in range(0, 2):
    for j in comb:
        print(i, j)

The output is:

0 (0, 1)
0 (0, 2)
0 (1, 2)

It did not loop the outer loop...however if it is not combination, it works as expected

for i in range(0, 2):
    for j in range(0, 2):
        print(i, j)

the results are:

0 0
0 1
1 0
1 1

Am i missing some important properties of combinations? I could not figure out why this do not work...sorry if it is a stupid question, any help will be greatly appreciated, thank you.

Upvotes: 1

Views: 91

Answers (2)

Praveenkumar
Praveenkumar

Reputation: 2182

I think what you are looking for is not combination, but product. The below code should work.

from itertools import product
prod = product(range(0, 2), repeat = 2)
for i, j in prod:
    print(i, j)

Output:

0 0
0 1
1 0
1 1

Upvotes: 0

Andrew Allen
Andrew Allen

Reputation: 8002

You can convert to a list first

from itertools import combinations
comb = list(combinations(range(0, 3), 2))
for i in range(0, 2):
    for j in comb:
        print(i, j)

Result

0 (0, 1)
0 (0, 2)
0 (1, 2)
1 (0, 1)
1 (0, 2)
1 (1, 2)

Upvotes: 1

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