Helloworld$ is an invalid credit card number because it has nonnumerical characters.ģ2323 is an invalid credit card number because of its length. > validate_credit_card_number('helloworld$') Return total % 10 = 0 def validate_credit_card_number( credit_card_number: str) -> bool:įunction to validate the given credit card number. # Sum up the remaining digits for i in range( len(cc_number) - 1, - 1, - 2): if digit > 9:Ĭc_number = cc_number + str(digit) + cc_number

Half_len = len(cc_number) - 2 for i in range(half_len, - 1, - 2):ĭigit *= 2 # If doubling of a number results in a two digit number # i.e greater than 9(e.g., 6 × 2 = 12), # then add the digits of the product (e.g., 12: 1 + 2 = 3, 15: 1 + 5 = 6), # to get a single digit number. ''' return credit_card_number.startswith(( '34', '35', '37', '4', '5', '6'))ĭef luhn_validation( credit_card_number: str) -> bool:įunction to luhn algorithm validation for a given credit card number.

> all(validate_initial_digits(cc) is False for cc in invalid.split()) > all(validate_initial_digits(cc) for cc in valid.split())

''' def validate_initial_digits( credit_card_number: str) -> bool:įunction to validate initial digits of a given credit card number. Functions for testing the validity of credit card numbers.

Manual credit card validator