Can I use Python 2/appcfg and Python 3/gcloud for two separate projects at the same time?

[Mark Summerfield]

I have an app engine domain, say foo.appspot.com that uses Python 2 with the appcfg tool.

I want to create a new domain, say foo2.appspot.com that uses Python 3 with the glcoud tool.

Can I do this without any conflict (assuming each is kept in its own directory and each project has its own name)?

My plan is to get the new domain working, and then when it is okay, to migrate my traffic to it.

Also, is it possible to copy or move data (e.g., a GQL database) from one project to another?

[Blaine Garrett]

This should be possible, yes. It seems like you are making these two separate projects, thus you would just route subdomains for both via the appengine domain settings for both projects.

An alternate approach you could take is to use dispatching to route traffic to foo2 to a new "service" (formerly modules) within the same project. This approach would address not having to migrate data over to a new project id. 
Once you are ready to switch traffic, you can just update the 'catch all' rule in the dispatch.yaml 

You can run different services in different languages under the same project. Prior to node GA support on AppEngine, I even had a flex env service (node) and a standard env service (py2.7) running side by side. 

See: https://cloud.google.com/appengine/docs/flexible/python/reference/dispatch-yaml


Cheers,
~Blaine