`scipy.special._basic:perm`

Signature

def perm(N, k, exact = False)

Permutations of N things taken k at a time, i.e., k-permutations of N.

It's also known as "partial permutations".

N : int, ndarray: Number of things.
k : int, ndarray: Number of elements taken.
exact : bool, optional: If True, calculate the answer exactly using long integer arithmetic (N and k must be scalar integers). If False, a floating point approximation is calculated (more rapidly) using poch. Default is False.

import numpy as np
from scipy.special import perm
k = np.array([3, 4])
n = np.array([10, 10])

✓

perm(n, k)

✗

array([ 720., 5040.])

perm(10, 3, exact=True)

✓