Your runtime settings looks fine. I suspect the issue might be in your source code because I tried to reproduce it but I was able to deploy without any errors and did not note any errors with python version in stack trace. So, I suggest you follow this Quickstart for deploying a python app in App Engine Flex environment [1]. When you've downloaded the sample code, edit the app.yaml file provided to change the 'python_version' from 3 to 3.5. Then follow the rest of the steps to test the app locally and then deploy it. This will help you identify what steps you might be missing leading to the issue you encountered. Also have a look at this documenation to understand the dependencies for your python apps [2].
I hope you find this helpful. [1] https://cloud.google.com/appengine/docs/flexible/python/quickstart#download_the_hello_world_app [2] https://cloud.google.com/appengine/docs/flexible/python/using-python-libraries -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/google-appengine. To view this discussion on the web visit https://groups.google.com/d/msgid/google-appengine/c82e0307-d711-4121-b5bc-2c6cb791649e%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
