Answers for "python math permutations"

pyhton permutations

# A Python program to print all permutations using library function 
from itertools import permutations
perm = permutations([1, 2, 3])
for i in list(perm):
    print (i)
# (1, 2, 3)
# (1, 3, 2)
# (2, 1, 3)
# (2, 3, 1)
# (3, 1, 2)
# (3, 2, 1)

permutations python

import itertools
print(list(itertools.permutations([1,2,3])))

python combinations function

def combinations(iterable, r):
    pool = tuple(iterable)
    n = len(pool)
    for indices in permutations(range(n), r):
        if sorted(indices) == list(indices):
            yield tuple(pool[i] for i in indices)

python choose function

>>> from math import comb
>>> comb(20,10)