How to bypass or ignore a number?

Question

Hey guys python noobie here. I'm trying to determine which type of credit card a user has and whether it's valid or not. For the following example, Visa cards start with the number 4 and both cards would be valid because they both start with 4. If there are zeros in front, you would skip them. Is there a built in function to bypass a number or do I have to type in every case scenario? Thank you for your time.

Example:

#VISA 0004222222222222 valid
#VISA 4111111111111111 valid

Luhns Algorithm

def calculation( creditNumber ): length = len( creditNumber ) oddSum = 0 evenSum = 0

if ( length == 0 ):
    return 0

else:
    if length % 2 == 0:
        last_number = int( creditNumber[-1])
        evenSum = evenSum + last_number

        return evenSum + calculation( creditNumber[:-1] )

    else:
        last_number = int( creditNumber[-1] )
        last_number = 2 * last_number
        addSum = last_number // 10 + last_number % 10
        oddSum = oddSum + addSum

        return oddSum + calculation( creditNumber[:-1] )

def luhnsCheck():
    creditNumber = input ( "What is your credit card number?" )

    #Check to see which type of credit card the user has

    # American Express starts with 34 or 37 
    if creditNumber[0-15] 


    # Discover starts with 6011

    # MasterCard starts with 51 or 52 or 53 or 54 or 55

    # VISA starts with 4

    creditcard_number = calculation( creditNumber )

    # Valid Card
    if creditcard_number % 10 == 0:
        print( "Valid card" )


    # Invalid Card
    else:
        print( "We do not accept that kind of card" )

luhnsCheck()

You need to 1) Explain more what you mean by 'bypass', and 2) Show us what code you've written thus far. — nbryans, Oct 16 '16 at 01:26
you can use if else to do this. `if str[0:4]=='0000': pass else: do somthing`. if you are facing problem then post your code. — Siva Shanmugam, Oct 16 '16 at 01:30
@SivaShanmugam - `if condition: pass; else: function()` is better expressed as `if not condition: function()`. — TigerhawkT3, Oct 16 '16 at 01:35
example cc validation python code: https://gist.github.com/zahradil/6208954 — Logic1, Oct 16 '16 at 01:35
@nbryans just updated it I'm stuck on where the credit card comments are — bam, Oct 16 '16 at 01:39

score -1 · Answer 1 · answered Oct 16 '16 at 01:32

-1

You could copy then number and put that number in a list. Then if the first number is zero then remove it from the list. Repeat this until there is no zero in front.

answered Oct 16 '16 at 01:32

user7025255

1

That algorithm doesn't make much sense. – TigerhawkT3 Oct 16 '16 at 01:36

How to bypass or ignore a number?

Luhns Algorithm

1 Answers1