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

[Mats Wichmann]

On 12/29/20 7:48 AM, Chris Green wrote:
> 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.

There are some tools (on pypi naturally) for fiddling with installed 
packages, but for starters try these two:

python -m pip help list
python -m pip help show

show will list dependencies, among other bits of info.

For older versions, you to use the matching version of Python

python2.7 -m pip show click