While working through this exercise I ran into a problem.
from sys import argv
from os.path import exists
script, from_file, to_file = argv
print \"Copying from
You should think of this as an exercise to understand that input
is just a name for what open
returns rather than as advice that you ought to do it the shorter way.
As other answers mention, in this particular case the problem you've correctly identified isn't that much of an issue - your script closes fairly quickly, so any files you open will get closed fairly quickly. But that isn't always the case, and the usual way of guaranteeing that a file will close once you're done with it is to use a with
statement - which you will find out about as you continue with Python.