NEEDS TO BE IN PYTHON:ISBN-13 is a new standard for indentifying books. It uses 13 digits d1d2d3d4d5d6d7d8d910d11d12d13 . The last digit d13 is a checksum, which is calculated from the other digits using the following formula:10 - (d1 + 3*d2 + d3 + 3*d4 + d5 + 3*d6 + d7 + 3*d8 + d9 + 3*d10 + d11 + 3*d12) % 10If the checksum is 10, replace it with 0. Your program should read the input as a string. Display "incorrect input" if the input is incorrect. Sample Run 1Enter the first 12 digits of an ISBN-13 as a string: 978013213080The ISBN-13 number is 9780132130806Sample Run 2Enter the first 12 digits of an ISBN-13 as a string: 978013213079The ISBN-13 number is 9780132130790

Follows are the code to this question:

n=input("Enter the first 12 digits of an ISBN-13 as a string:")#defining a varaible isbn for input value

if len(n)!=12: #use if block to check input value is equal to 12 digits

   print("incorrect input") #print error message

elif n.isdigit()==False: #use else if that check input is equal to digit

   print("incorrect input") #print error message

else:# defining else block

   s=0 #defining integer vaiable s to 0

   for i in range(12):#defining for loop to calculate sum of digit

       if i%2==0: #defining if block to check even value

           s=s+int(n[i])#add even numbers in s vaiable  

       else: #use else block for odd numbers

           s=s+int(n[i])*3 #multiply the digit with 3 and add into s vaiable

   s=s%10#calculate the remainder value  

   s=10-s#subtract the remainder value with 10 and hold its value

   if s==10: #use if to check s variable value equal to 10  

       s=0#use s variable to assign the value 0

   n=n+s.__str__() #u

Output:

please find attached file.

Explanation:In the above Python code, the "n" variable is used for input the number into the string format uses multiple conditional statements for a check input value, which can be defined as follows:

answer:

rawr

explanation: