Learn How to Work with Numbers and Strings by Implementing the Luhn Algorithm - Step 35

Python
1

Tell us what’s happening:

I have changed the value of card_number variable,But It shows that my code is wrong.

Your code so far


# User Editable Region

def verify_card_number(card_number):
    sum_of_odd_digits = 0
    card_number_reversed = card_number[::-1]
    odd_digits = card_number_reversed[::2]

    for digit in odd_digits:
        sum_of_odd_digits += int(digit)

    sum_of_even_digits = 0
    even_digits = card_number_reversed[1::2]
    for digit in even_digits:
        number = int(digit) * 2
        if number >= 10:
            number = (number // 10) + (number % 10)
        sum_of_even_digits += number
    total = sum_of_odd_digits + sum_of_even_digits
    
    return total % 10 == 0

def main():
    card_number = '4111-1111-4555-1141'
    card_translation = str.maketrans({'-': '', ' ': ''})
    translated_card_number = card_number.translate(card_translation)
    verify_card_number(translated_card_number)
    print(card_number)   

main()

# User Editable Region

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36

Challenge Information:

Learn How to Work with Numbers and Strings by Implementing the Luhn Algorithm - Step 35

2

You need to change the card_number variable.

change the card_number back to something valid

    card_number = '4111-1111-4555-1141'
3

Hang on. I don’t think that’s the actual issue. You see it appears that they deleted the “INVALID!” and “VALID!” output from the seeded code.

These four lines are needed to proceed.

    if verify_card_number(translated_card_number):
        print('VALID!')
    else:
        print('INVALID!')

Without them, our challenge has no way of knowing if they actually updated the card_number variable to be something valid.

1 Like
4

remove the print call from the verify_card_number

You removed the print calls from main instead.

Try to reset the step and double check the instructions

5

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