A possible reason a user may believe that autocomplete is not working may be that autocomplete is just taking too long. Circa 2020-11-27 this is particularly true for Pandas when operating with jedi in a Jupiter notebook environment.
The issue can be solved by using the following magic which deactivates jedi
%config Completer.use_jedi = False
For a deeper discussion follow the this thread and the links therein.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…