Question

I’m working with Python 2.7 and PyGTK 2.24. I am working with the following tutorial. Please read it for code context.

http://www.pygtk.org/pygtk2tutorial/sec-PackingDemonstrationProgram.html

The bottom block of code (reprinted below) is throwing the following error when I type it in (verbatum):

if __name__ =="__main__":
    if len(sys.argv) != 2:
       sys.stderr.write("usage: packbox.py num, where num is 1, 2, or 3.\n")
       sys.exit(1)
    PackBox1(string.atoi(sys.argv[1]))
    main()

usage: packbox.py num, where num is 1, 2, or 3.

Traceback (most recent call last): File “C:/GTKTutorial/packbox.py”,
line 161, in
sys.exit(1) SystemExit: 1

Additionally, if I change the code to the following to overcome the first error, I get the next error message:

if __name__ =="__main__":
    if len(sys.argv) != 1:
       sys.stderr.write("usage: packbox.py num, where num is 1, 2, or 3.\n")
       sys.exit(1)
    PackBox1(string.atoi(sys.argv[1]))
    main()

Traceback (most recent call last): File “C:/GTKTutorial/packbox.py”,
line 162, in
PackBox1(string.atoi(sys.argv[1])) IndexError: list index out of
range

What is wrong? How do I fix the code so I can work with the tutorial>

Answer 1

You need to call it from the command line with packbox.py 1, packbox.py 2, or packbox.py 3.

This will result in there being two arguments (the name of the program and the first thing you pass to it), so you won’t trigger the sys.exit(1), and argv[1] will be a valid index access.