cc.py

import random


class CreditCard(object):
    CARD_TYPES = {
        'amex': {
            'prefixes': ['34', '37'],
            'length': [15]
        },
        'diners-carte-blance': {
            'prefixes': [300, 301, 302, 304, 305],
            'length': [14],
        },
        'diners-international': {
            'prefixes': [36],
            'length': [14]
        },
        'diners-uscanada': {
            'prefixes': [54, 55],
            'length': [16]
        },
        'discover': {
            'prefixes': ['6011'] + [str(i) for i in range(622126,622926)] + ['644', '645', '646', '647', '648', '649', '65'],
            'length': [16]
        },
        'jcb': {
            'prefixes': [str(i) for i in range(3528,3590)],
            'length': [16]
        },
        'laser': {
            'prefixes': ['6304', '6706', '6771', '6709'],
            'length': range(16, 20)
        },
        'maestro': {
            'prefixes': ['5018', '5020', '5038', '6304', '6759', '6761', '6762', '6763'],
            'length': range(12, 20)
        },
        'mastercard': {
            'prefixes': ['51', '52', '53', '54', '55'],
            'length': [16]
        },
        'solo': {
            'prefixes': ['6334', '6767'],
            'length': [16, 18, 19]
        },
        'switch': {
            'prefixes': ['4903', '4905', '4911', '4936', '564182', '633110', '6333', '6759'],
            'length': [16, 18, 19]
        },
        'visa': {
            'prefixes': ['4'],
            'length': [16]
        },
        'visa-electron': {
            'prefixes': ['4026', '417500', '4508', '4844', '4913', '4917'],
            'length': [16]
        }
    }

    def __init__(self, type=None):
        type = type.lower()
        if not type in CreditCard.CARD_TYPES.keys():
            type = None
        if not type:
            type = random.choice(CreditCard.CARD_TYPES.keys())
        self.type = type

    def _as_int(self, list):
        return [int(i) for i in list]

    def generate(self):
        # Pick a length & a prefix
        length = random.choice(CreditCard.CARD_TYPES[self.type]['length'])
        result = random.choice(CreditCard.CARD_TYPES[self.type]['prefixes'])
        # Pad the number out to len-1 with random digits
        result += ''.join(str(random.choice(range(10))) for i in range(length-len(result)-1))
        # Generate the check digit, see http://en.wikipedia.org/wiki/Luhn_algorithm for what is going on here
        total = sum(self._as_int(result[-2::-2])) + sum(self._as_int(''.join([str(i*2) for i in self._as_int(result[::-2])])))
        check_digit = ((total / 10 + 1) * 10 - total) % 10
        return '%s%s' % (result, check_digit)