pythonisbncheck-digit

Python Attribute error with ISBN program

I've just fixed my ISBN checkdigit code to be a bit more efficient, but now it's coming back with an attribute error:

AttributeError: 'int' object has no attribute 'append'

Here's the code:

isbn = 0
result = 0
results = 0
print("Please input your ISBN 1 number at a time")
isbn = [int(input("ISBN character {0}: ".format(i))) 
    for i in range(1, 11)]
results.append(isbn[0] * 11)
results.append(isbn[1] * 10)
results.append(isbn[2] * 9)
results.append(isbn[3] * 8)
results.append(isbn[4] * 7)
results.append(isbn[5] * 6)
results.append(isbn[6] * 5)
results.append(isbn[7] * 4)
results.append(isbn[8] * 3)
results.append(isbn[9] * 2)
enter code here
results = sum(results)
result = results % 11
result = 11 - result
result = str(result)

if result == "10":
    result = "X"
print("Your ISBN is '",
      isbn[range(10)],result,"'")
print("The checksum is",result)

Thanks a lot

Solution

  • You have not declared your results to be a list. It should be results = []. It is currently results = 0 which makes it an int and hence the append operation fails with an AttributeError