Why does Python compile libraries that are used in a script, but not the script being called itself?
For instance,
If there is main.py and module.py, and Python is run by doing python main.py, there will be a compiled file module.pyc but not one for main.  Why?
Edit
Adding bounty. I don't think this has been properly answered.

If the response is potential disk permissions for the directory of main.py, why does Python compile modules? They are just as likely (if not more likely) to appear in a location where the user does not have write access. Python could compile main if it is writable, or alternatively in another directory.
If the reason is that benefits will be minimal, consider the situation when the script will be used a large number of times (such as in a CGI application).
Because the script being run may be somewhere where it is inappropriate to generate .pyc files, such as /usr/bin.
Why does Python compile modules but not the script being run?