I'm not sure what this PR tries to achieve. What's the behavior before and after this change?

The goal of this PR is that when typing out an import for a module (numpy for example)
>>> from numpy import a<tab> should display all submodules and module attributes. Hitting tab might cause numpy to be imported too.

I don't know the status of this PR, it's been on my list to review for a bit; I worked with @etiennerichart on it but haven't been paying attention for a couple months now.

Ah, yes, that's indeed useful.

We just removed 0.20 to fix compatibility with Python 3.9 and now dropped support for Python 2 in master. The latter touched almost the whole code base. Could you please rebase this PR on top of current master? Thanks

I have not been able to test functionality yet since I'm having trouble starting bpython on my PC. I'm getting the following error:
File "c:\users\etien\appdata\local\programs\python\python38-32\lib\site-packages\blessings\__init__.py", line 5, in <module> import curses File "c:\users\etien\appdata\local\programs\python\python38-32\lib\curses\__init__.py", line 13, in <module> from _curses import * ModuleNotFoundError: No module named '_curses'
If someone wants to test it for me, just try:
from <module> import <at least one letter> seeing if there are autocomplete suggestions, then pressing tab to see if you get more suggestions. I usually test on using numpy module but you may have to pip install it.

As far as I can tell, the PR works as expected. I'm just not sure if we need the additional module discovery code.

Okay, I took a look at this PR again. I don't think we should merge it in its current state. from x import y auto completion is already in handled in bpython.importcompletion and bpython.autocomplete. The issue that this PR tries to solve is auto completion when our import completion hasn't processed x. What we could discuss if we can fix the import completion code to process x in bpython.importcompletion.complete if it is not yet known.

But I don't think we should add a curtsies specific workaround that breaks abstraction.