Managing plug-ins

[DL Neil]

Please recommend a library which will manage plug-ins.


(Regret that searching PyPi or using a web SE results in an overwhelming 
number of 'false positives')

Not wanting to 'reinvent the wheel, have been looking for an 'approved' 
way to manage a set of previously-prepared routines plus user-added 
functionality:
- user selects particular type of analysis (cmdLN)
- take that string and convert to a function/method
- 'plug-in' code could be located within application
- 'plug-in' could be 'included' from user
- interface standardisation/checking not part of question
- Python3

Application is statistical analysis. Users want to control aspects such 
as data selection/inclusion policies, other data 
pre-processing/massaging, distribution curve to be applied, and similar.
NB not looking for stats-code, but to easily manage a range of plug-ins 
from which users may select to suit their particular research objective.
-- 
Regards,
=dn