Hi, everyone, I'm an Developer Programs Engineer for App Engine.
There are still many Python 2.7 applications on App Engine, even though the Python Software Foundation sunset it over a year ago. For many people that's not due to the language differences in Python 3, but rather to changes in the App Engine runtime for the different language versions. I'm one of the people trying to help developers make that move.
We provide migration resources such as sample apps and documentation on our website, but those of you who have already made the move, or are working on doing so now, likely have some great material that others could use. We'd like to make it easy for you to share that with the App Engine community.
There is a new GitHub repository at https://github.com/GoogleCloudPlatform/appengine-python2-3-migration
. We've seeded it with a couple of examples of migrated apps, but we need your feedback and contributions. If this subject is relevant to you, please take a look and submit issues and pull requests to make the repository better. I look forward to hearing from you.