Credit card number redacting script

[ichabod801]

That may work, but it's rather inefficient. I would use redacted_num = 'xxxx xxxx xxxx {}'.format(card_string[-4:]).

If you just change line 3 to return a value, you are not assigning the return value to anything on line 7. Change line 3 to return a value, and change lines 5 to 10 to:

if __name__ == '__main__':
    card_string = str(input("Enter your fake credit card number: "))
    redacted_num = ccredact(card_string)
    print(redacted_num)