Once you’ve migrated code, update your classifiers in the setup.py file to contain Programming Language :: Python :: 3 to indicate your code supports Python 2 and 3.

Here’s one of our favourite guides for reference. Imports Let’s say that you’re using Python 2, and have the following file hierarchy: pkg ├──service.py └──misc.py run.py utils.py ...

Python-Future is a library that supports writing Python 2 and 3 compatible code. This library allows users to utilize a single codebase to support both versions with minimal overhead.