A silly numpy-based solution to https://www.codewars.com/kata/56b0f6243196b9d42d000034

sum_factorials.py

def factorial_row(n, length):
    """Create 1d array whose product is the factorial of n, padded to length"""
    return np.pad(np.arange(1, n + 1), (0, length - n), 'constant', constant_values=1)


def sum_factorial(nums):
    """Sum the factorials of the numbers in nums."""
    factorial_matrix = np.vstack([factorial_row(n, max(nums)) for n in nums])
    return factorial_matrix.prod(axis=1).sum()

sum_factorial([2, 3])  # Returns 8 (2! + 3!)