Validar NIT en Python

nit_is_valid.py

import re

def nit_is_valid(nit):
    if not nit:
        return True

    nit_regex = re.compile(r'^\d+(-?\d|k|K)?$')

    if not nit_regex.match(nit):
        return False

    nit = nit.replace('-', '')
    number = nit[:-1]
    expected_checker = nit[-1].lower()

    total = sum((int(digit) * factor) for factor, digit in enumerate(number[::-1], start=2))
    modulus = (11 - (total % 11)) % 11
    computed_checker = 'k' if modulus == 10 else str(modulus)

    return expected_checker == computed_checker

For readability, you may change total with this version:

    factors = list(range(len(digits) + 1, 1, -1))
    products = [int(digit) * factor for digit, factor in zip(digits, factors)]
    total = sum(products)