Upgrade to Python 3

[gerardsimons]

Seeing that Python 2 will sunset January 1st 2020 I think it should be upgraded to Python 3. I am looking into it but unfortunately webapp2 support for Python 3 seems very spotty (GoogleCloudPlatform/webapp2#137).

Should we move to a different platform or can we fix webapp2 for Python 3?

[javdrher]

Back when we created the package, there was no Python 3 on App Engine so yes, thanks for bringing this up. We should definately migrate to Python 3.

Regarding webapp2, ML2Grow never uses this framework, it was chosen for this package in order to be more in line with the software available on app engine. Looking at the issue you are referring to, the biggest issue seems to be that no support exists for integrations with other App Engine services (Memcache, firestore etc). We currently use none of these: do we encounter any issues with webapp2 on Python 3? If so, my suggestion is to switch to tornado, this can be accomplished fairly easily.

[gerardsimons]

Cool. I'll try that!