You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
24 lines
629 B
24 lines
629 B
from typing import List
|
|
|
|
|
|
def luhn_checksum(number: float) -> int:
|
|
def digits_of(n: float) -> List[int]:
|
|
return [int(d) for d in str(n)]
|
|
|
|
digits = digits_of(number)
|
|
odd_digits = digits[-1::-2]
|
|
even_digits = digits[-2::-2]
|
|
checksum = 0
|
|
checksum += sum(odd_digits)
|
|
for d in even_digits:
|
|
checksum += sum(digits_of(d * 2))
|
|
return checksum % 10
|
|
|
|
|
|
def calculate_luhn(partial_number: float) -> int:
|
|
"""
|
|
Generates the Checksum using Luhn's algorithm
|
|
"""
|
|
check_digit = luhn_checksum(int(partial_number) * 10)
|
|
return check_digit if check_digit == 0 else 10 - check_digit
|