Is there any way to check/de-cruft/update Python packages installed using pip?

[Chris Green]

I seem to have quite a lot of old python packages installed over the
years using pip and would like, if I can. to clear some of them out.


Is there any way to tell if a python package was installed by me
directly using pip or was installed from the [x]ubuntu repositories?
'pip list' just tells me every python package that's installed and
this really isn't much help.


Can one uninstall older versions?  For example I seem to have
three versions of Click installed:-

    /usr/local/lib/python2.7/dist-packages/click
    /usr/local/lib/python3.7/dist-packages/click
    /usr/lib/python3/dist-packages/click

Presumably the ones in /usr/local have been pulled in as dependencies
when installing something else using pip, the /usr/lib one has been
installed from the Ubuntu repositories (again as a dependency). How
can I remove the ones in /usr/local?


If one updates a package using pip will it move it as appropriate from
(for example) /usr/local/lib/python3.7 to /usr/local/lib/python3.8?


Can pip (or some other tool) tell me what other python packages depend
on one I'm considering uninstalling?


If there are any tools/utilities one can install to check these things
out I'd love to know about them.

-- 
Chris Green
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