The wrong python interpreter is called

Question

I updated my python interpreter, but I think the old one is still called. When I check for the version I get:

$ python -V
Python 3.0.1

But

Answer 1

Firstly, the recommended shebang line is:

#!/usr/bin/env python

This will make sure the python interpreter that is invoked when you ./foo.py is the same interpreter that is invoked when you invoke python from the command line.

From your description, I suspect that if you did:

which python

It would not give you /usr/bin/python. It would give you something else, which is where the python 3 interpreter lives. You can either modify your shebang line to the above, or replace the path to the python interpreter with the path returned by which.