Tips on upgrading to python 3.0? [duplicate]

This question already has an answer here:

So with the final releases of Python 3.0 (and now 3.1), a lot of people are facing the worry of how to upgrade without losing half their codebase due to backwards incompatibility.

What are people’s best tips for avoiding the many pitfalls that will almost-inevitably result from switching to the next-generation of python?

Probably a good place to start is “use 2to3 to convert your python 2.x code to 3.x” :-)

Tips on upgrading to python 3.0? [duplicate]