


'''simple docstring'''

def 							__magic_name__(  lowerCamelCase):
						return credit_card_number.startswith(('''34''', '''35''', '''37''', '''4''', '''5''', '''6'''))

def 							__magic_name__(  lowerCamelCase):
						__lowerCAmelCase											= credit_card_number
						__lowerCAmelCase											= 0
						__lowerCAmelCase											= len(a__) - 2
						for i in range(a__, -1, -2):
												#  double the value of every second digit
												__lowerCAmelCase											= int(cc_number[i])
												digit *= 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.
												if digit > 9:
																		digit %= 1_0
																		digit += 1
												__lowerCAmelCase											= cc_number[:i] + str(a__) + cc_number[i + 1 :]
												total += digit

						# Sum up the remaining digits
						for i in range(len(a__) - 1, -1, -2):
												total += int(cc_number[i])

						return total % 1_0 == 0

def 							__magic_name__(  lowerCamelCase):
						__lowerCAmelCase											= F"""{credit_card_number} is an invalid credit card number because"""
						if not credit_card_number.isdigit():
												print(F"""{error_message} it has nonnumerical characters.""")
												return False

						if not 1_3 <= len(a__) <= 1_6:
												print(F"""{error_message} of its length.""")
												return False

						if not validate_initial_digits(a__):
												print(F"""{error_message} of its first two digits.""")
												return False

						if not luhn_validation(a__):
												print(F"""{error_message} it fails the Luhn check.""")
												return False

						print(F"""{credit_card_number} is a valid credit card number.""")
						return True


if __name__ == "__main__":
	import doctest

	doctest.testmod()
	validate_credit_card_number("""4111111111111111""")
	validate_credit_card_number("""32323""")



# flake8: noqa
# Lint as: python3
A     :	Optional[Any]    = [
    'VerificationMode',
    'Version',
    'disable_progress_bar',
    'enable_progress_bar',
    'is_progress_bar_enabled',
    'experimental',
]

from .info_utils import VerificationMode
from .logging import disable_progress_bar, enable_progress_bar, is_progress_bar_enabled
from .version import Version
from .experimental import experimental