luke.geelen at gmail.com writes: > when using python script.py 2 \* 2 > i get >> Traceback (most recent call last): > File "math2.py", line 5, in <module> > sign = int(sys.argv[2]) > ValueError: invalid literal for int() with base 10: '*' You've mis-spelt sigh. This is not the code that you posted. You misunderestimate that error message. It tells everything.