Is this for AppEngine standard or for Cloud Functions? I don't see any mention of python 3 on the appengine page: https://cloud.google.com/appengine/docs/standard/

Oh, I think you're right.

> Today we are announcing support for new second-generation App Engine standard runtimes such as Python 3.7

I'm still a bit confused what AppEngine 2nd gen is.

2nd gen is the new standard runtimes using gVisor. I had read comments by googlers here before that the first gen standard runtimes required a lot of custom work on their end to run on the Google infrastructure which was why they were a bit slow supporting new versions of php, java etc, while the new gvisor based runtimes should be easier to roll out updates.

The link you provided is for Google Cloud Functions, not AppEngine Standard, though TFA does mention Python 3.7 for both. Looks like AppEngine doesn't have docs up for the new, second generation, standard runtimes (which, aside from the new language versions, sound fundamentally more capable.)

Python 3.7 on the App Engine standard environment was announced today but not yet released to the public. We'll have more to share soon.