python- Chapter 4: Programming Project 4

(Business: check ISBN-10) An ISBN-10 (International Standard Book Number) consists of 10 digits: d1d2d3d4d5d6d7d8d9d10. The last digit, d10, is a checksum, which is calculated from the other nine digits using the following formula:

(d1 * 1 + d2 * 2 + d3 * 3 + d4 * 4 + d5 * 5 + d6 * 6 + d7 * 7 + d8 * 8 + d9 * 9) % 11

If the checksum is 10, the last digit is denoted as X according to the ISBN-10 convention. Write a program that prompts the user to enter the first 9 digits and displays the 10-digit ISBN (including leading zeros).

Sample Run 1 Enter the first 9 digits of an ISBN as a string: 3601267 Incorrect input. It must have exact 9 digits

Sample Run 2 Enter the first 9 digits of an ISBN as a string: 013601267 The ISBN-10 number is 0136012671

Sample Run 3 Enter the first 9 digits of an ISBN as a string: 013031997 The ISBN-10 number is 013031997X