Скрипт для определения валидности ИНН

inn_validate.py

# -*- coding: utf-8 -*-


def inn_is_valid(target_inn):
    
    # Проверяет валидность ИНН по контрольному числу
    # Возвращает True в случае валидности и False в обратном случае
    
    length = len(target_inn)
    base = target_inn[:-1]
    
    if length == 10:
        factors_10 = [2, 4, 10, 3, 5, 9, 4, 6, 8, 0]
        sum_products = 0
        for digit in xrange(len(base)):
            sum_products += int(base[digit]) * factors_10[digit]
        result = (sum_products % 11) % 10
        if result > 9:
            key = result % 10
        else:
            key = result
        if key == int(target_inn[-1]):
            return True
        else:
            return False
            
    elif length == 12:
        factors_12_1 = [7, 2, 4, 10, 3, 5, 9, 4, 6, 8, 0]
        factors_12_2 = [3, 7, 2, 4, 10, 3, 5, 9, 4, 6, 8, 0]
        sum_products1 = 0
        for digit in xrange(len(base)):
            sum_products1 += int(base[digit]) * factors_12_1[digit]
        result1 = sum_products1 % 11
        if result1 > 9:
            key_1 = result1 % 10
        else:
            key_1 = result1
        sum_products2 = 0
        for digit in xrange(length):
            sum_products2 += int(target_inn[digit]) * factors_12_2[digit]
        result2 = sum_products2 % 11
        if result2 > 9:
            key_2 = result2 % 10
        else:
            key_2 = result2
        if key_1 == int(target_inn[10]) and key_2 == int(target_inn[11]):
            return True
        else:
            return False

    else:
        return False