Python判断给定的字符串是否是有效的银行卡号

def is_valid_bank_card(card_number):
    """检查是否是有效的银行卡卡号，编写：pidancode.com"""

    def digits_of(n):
        return [int(d) for d in str(n)]

    result = False
    digits = digits_of(card_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))
    t = checksum % 10
    if t == 0:
        result = True
    return result