PYTHON

- Using functions

-can't use map, panda, sys or any other type of import other than math

Every book is identified by a 10-character International Standard Book Number (ISBN), which is

usually printed on the back cover of the book. The first nine characters are digits and the last

character is either a digit or the letter X (which stands for ten). Three examples of ISBNs are 0-13-

030657-6, 0-32-108599-X, and 0-471-58719-2. The hyphens separate the characters into four

blocks.

The first block usually consists of a single digit and identifies the language (0 for English, 2 for

French, 3 for German, etc.). The second block identifies the publisher. The third block is the

number the publisher has chosen for the book. The fourth block, which always consists of a

single character called the check digit, is used to test for errors.

Lets refer to the 10 characters of the ISBN as d1,d2,d3,d4,d5,d6,d7,d8,d9,d1, d2, d3, d4, d5, d6, d7, d8, d9, and d10. The check digit is chosen so that the sum 10*d1 + 9* d2 + 8*d3 + 7*d4 + 6*d5 + 5*d6 + 4*d7 + 3*d8 + 2*d9 + 1*d10(*)

is a multiple of 11. If the last character of the ISBN is an X, then in the sum (*) is replaced with 10.

For example, with the ISBN 0-32-108599-X, the sum would be

10*0 + 9*3 + 8*2 + 7*1 + 6*0 + 5*8 + 4 *5 + 3*9 + 2*9 +10*1 = 165

Since 10*0 + 9*3 + 8*2 + 7*1 + 6*0 + 5*8 + 4 *5 + 3*9 + 2*9 +10*1 = 165

is 165, the sum is a multiple of 11

This checking scheme will detect every single digit and transposition-of-adjacent-digits error.

That is, if while copying an ISBN number you miscopy a single character or transpose two

adjacent characters, then the sum will no longer be a multiple of 11.

Input

You will be given a list with isbns: one per each line. You will need to ask the user running your

program for the specific filenames, but what we do know is that each file will be saved as a txt

file, with one isbn per file line.

.

This is the sample run of the beginning of the program (yellow highlighting indicate possible user

input):

Enter the name of the file with isbns: isbns.txt

Requirements

Your ISBN is invalid If the count of the number of characters is not equal to 13

If any of the characters are not digits other than the last character which can be an X and a hyphen

If there arent enough digits

If the country code is not between 0 and 9

If the sum isnt a multiple of 11

Output

Your program has to generate a report as a csv file, called

isbnresults.csv

. The report has to

contain all isbns that appear on the list, sum, and their validity. Examine and follow the format of

the provided sample output file.

You must test for other cases as this file doesnt contain every

possible case.

Your program

must also

output the following (same as the csv file) on the interactive output

when it is run. Dont include asterisks in your output.

**************************************************

Sum is 110

The ISBN: 0-13-030657-6 is valid

Sum is 165

The ISBN: 0-32-108599-X is valid

Sum is 219

The ISBN: 0-471-58719-1 is invalid

**************************************************