You're technically correct in that GAE standard offers python 3, but it's not the same as their python 2 offering. Python 2 is part of the first generation run

You're technically correct in that GAE standard offers python 3, but it's not the same as their python 2 offering. Python 2 is part of the first generation runtimes, python 3 is part of the second generation runtimes. They are not out of the box compatible, even if your python code works on 2 and 3. The first generation runtime included many APIs that are simply just not available in the second gen (you need to build them yourself). See link for more info. https://cloud.google.com/appengine/docs/standard/runtimes https://cloud.google.com/appengine/docs/standard/runtimes