Debug an ISBN Validator - Debug an ISBN Validator

Python
1

Tell us what’s happening:

im stuck on step 9, been here for hours please mind to help me

Your code so far

def validate_isbn(isbn, length):
    if len(isbn) != length:
        print(f'ISBN-{length} code should be {length} digits long.')
        return
    main_digits = isbn[0:length]
    given_check_digit = isbn[length]
    main_digits_list = [int(digit) for digit in main_digits]
    # Calculate the check digit from other digits
    if length == 10:
        expected_check_digit = calculate_check_digit_10(main_digits_list)
    else:
        expected_check_digit = calculate_check_digit_13(main_digits_list)
    # Check if the given check digit matches with the calculated check digit
    if given_check_digit == expected_check_digit:
        print('Valid ISBN Code.')
    else:
        print('Invalid ISBN Code.')
def calculate_check_digit_10(main_digits_list):
    # Note: You don't have to fully understand the logic in this function.
    digits_sum = 0
    # Multiply each of the first 9 digits by its corresponding weight (10 to 2) and sum up the results
    for index, digit in enumerate(main_digits_list):
        digits_sum += digit * (10 - index)
    # Find the remainder of dividing the sum by 11, then subtract it from 11
    result = 11 - digits_sum % 11
    # The calculation result can range from 1 to 11.
    # If the result is 11, use 0.
    # If the result is 10, use upper case X.
    # Use the value as it is for other numbers.
    if result == 11:
        expected_check_digit = '0'
    elif result == 10:
        expected_check_digit = 'X'
    else:
        expected_check_digit = str(result)
    return expected_check_digit
def calculate_check_digit_13(main_digits_list):
    # Note: You don't have to fully understand the logic in this function.
    digits_sum = 0
    # Multiply each of the first 12 digits by 1 and 3 alternately (starting with 1), and sum up the results
    for index, digit in enumerate(main_digits_list):
        if index % 2 == 0:
            digits_sum += digit * 1
        else:
            digits_sum += digit * 3
    # Find the remainder of dividing the sum by 10, then subtract it from 10
    result = 10 - digits_sum % 10
    # The calculation result can range from 1 to 10.
    # If the result is 10, use 0.
    # Use the value as it is for other numbers.
    if result == 10:
        expected_check_digit = '0'
    else:
        expected_check_digit = str(result)
    return expected_check_digit
def main():
    user_input = input('Enter ISBN and length: ')
    if "," not in user_input:
        print("Enter comma-separated values.")
    if user_input!=int:
        print("Length must be a number.")
        print("Invalid character was found.")



    values = user_input.split(',')
    isbn = values[0]
    length = int(values[1])
    if length == 10 or length == 13:
     validate_isbn(isbn, length)
    else:
     print('Length should be 10 or 13.')
     

# main()

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Challenge Information:

Debug an ISBN Validator - Debug an ISBN Validator

2

Here are some troubleshooting steps you can follow. Focus on one test at a time:

  1. Are there any errors or messages in the console?
  2. What is the requirement of the first failing test?
  3. Check the related User Story and ensure it’s followed precisely.
  4. What line of code implements this?
  5. What is the result of the code and does it match the requirement? (Write the value of a variable to the console at that point in the code if needed.)

If this does not help you solve the problem, please reply with answers to these questions.

  1. When the user enters 1530051126,10, you should see the message Valid ISBN Code. in the console.

Did you test this?

When I test I get this output

Enter ISBN and length: 
1530051126,10
Length must be a number.
Invalid character was found.
Traceback (most recent call last):
  File "main.py", line 76, in <module>
  File "main.py", line 70, in main
  File "main.py", line 6, in validate_isbn
IndexError: string index out of range

Does this help?

3

where do I insert that?

4

Uncomment main() and type it into the prompt.

5

Enter ISBN and length:
1530051126,10
Length must be a number.
Invalid character was found.
Traceback (most recent call last):
File “main.py”, line 75, in
File “main.py”, line 70, in main
File “main.py”, line 6, in validate_isbn
IndexError: string index out of range

6

Yes this is the same error that I got.

Does that help to find the problem? Check those lines of code.

8

It is great that you solved the challenge, but instead of posting your full working solution, it is best to stay focused on answering the original poster’s question(s) and help guide them with hints and suggestions to solve their own issues with the challenge. How to Help Someone with Their Code Using the Socratic Method

We are trying to cut back on the number of spoiler solutions found on the forum and instead focus on helping other campers with their questions and definitely not posting full working solutions.