Credit_Card_Validator.py

#luhn algorithm

class CreditCard:
    def __init__(self,card_no):
        self.card_no = card_no


    @property
    def company(self):
        comp =None
        if str(self.card_no).startswith('4'):
             comp = 'Visa Card'
        elif str(self.card_no).startswith('5'):
            comp = 'Master Card'
        elif str(self.card_no).startswith('37'):
            comp = 'American Express Card'
        elif str(self.card_no).startswith('6'):
            comp = 'Discover Card'
        elif str(self.card_no).startswith('35'):
            comp = 'JCB Card'
        elif str(self.card_no).startswith('50' or '67'or '58'or'63'):
            comp = 'Maestro Card'
        elif str(self.card_no).startswith('7'):
            comp = 'Gasoline Card'

        return 'Company : '+comp



    def first_check(self):
        if 13<=len(self.card_no)<=19:
            message = "First check : Valid in terms of length."

        else:
            message = "First chek : Check Card number once again it must be of 13 or 16 digit long."
        return message




    def validate(self):
        #double every second digit from right to left
        sum_=0
        crd_no = self.card_no[::-1]
        for i in range(len(crd_no)):
            if i%2==1:
                double_it = int(crd_no[i])*2

                if len(str(double_it))==2:
                    sum_ += sum([eval(i) for i in str(double_it)])

                else:
                    sum_+=double_it

            else:
                sum_+=int(crd_no[i])



        if sum_%10==0:
            response = "Valid Card"
        else:
            response = 'Invalid Card'

        return response



    @property
    def checksum(self):
        return '#CHECKSUM# : '+self.card_no[-1]


    @classmethod
    def set_card(cls,card_to_check):
        return cls(card_to_check)



card_number  = input()
card = CreditCard.set_card(card_number)
print(card.company)
print('Card : ',card.card_no)
print(card.first_check())
print(card.checksum)
print(card.validate())



# 79927398713
#4388576018402626
#379354508162306