move extensions to Shell from App

[minrk]

As proposed in #1073, extensions should be a trait of the InteractiveShell object, not the Application. This should be done with a deprecation, as was done with the prompts.

[sloria]

+1. I am trying to use IPython.embed to automatically load extensions, and I'm not sure it's currently possible until this issue is addressed.

[horiacristescu]

I'd like to use autoreload on IPython embed but it doesn't seem to work. Can you provide an example?

[assafmuller]

I would also like to use autoload with an embedded iPython instance.

[csheaff]

Might there be any plans on addressing this? It would be really appreciated and useful - dropping into an Ipython terminal within a function is a really great alternative to Jupyter, and being able to load a startup file or config while doing so would be super convenient.

[Carreau]

Might there be any plans on addressing this?

Not explicit time from the core dev, contribution is welcome.

[dzhang-b]

any plan to address this? If I want to make it work, which files/document should I peek?

[MrMino]

@dzhang-b I think this might be a challenge to a newcomer, but I'd start by looking at the mentioned PR, then try to wrap my head around what happens in IPython.core.shellapp, and how the extensions work.

[dzhang-b]

currently I use the app mode as a work around to load the extension on startup, and for accessing the symbols in interactive shell, I do setattr or delattr on sys.modules['__main__'] to add/remove the symbols in the global namespace.