Funny error message

[Bob van der Poel]

>     Assuming Python is maintained only at the system-level (cf --user or
> >     venv) then it may be possible that installing some application that
> runs
> >     'on' Python added the local-library (as a "dependency"). Alternately,
> >     many beginners following installation instructions on a
> paint-by-numbers
> >     basis, may type/copy-paste commands without retaining any memory of
> >     same.
> >     [observation, not personal criticism]
> >
> >     Python has been designed to offer flexibility. One of which is the
> >     ability to have multiple, co-resident, versions of Python and/or
> >     libraries. Of course, this also produces exactly the type of 'gotcha'
> >     illustrated (detected, and solved) here.
> >
> >     Someone more familiar with Python-packaging may improve/correct...
> >
> >
> >     On a thematically-related, but OT-note:
> >     I decided to install a 'fresh' version of Fedora 33 on this machine,
> >     rather than performing a version-update. (required one hour from
> >     start-to-finish - try that MS-Win users!) The Python-relevance was to
> >     ensure there was no legacy-Python2 left 'lying-around'. However, the
> >     GIMP (popular graphics package) still uses (and has some sort of
> >     'exemption' to use) Python2. Stymied! Not quite - there's a Flatpak
> >     option - which will enable my Python3-only objective by ring-fencing
> the
> >     GIMP and its dependencies. However... now I have a system package
> >     manager (dnf (~apt)) installing most system-software and 'other
> stuff'
> >     under a different method (I took the same approach with the Chromium
> >     browser) - how long will it be before such 'cleverness' is
> >     forgotten/trips me up?
> >
> >
> > I have installed a few packages using pip. I "try" to do so as root
> > (this is basically a one user machine) ... but I may have installed as
> > user. Still, it should not have brought in a complete py set of
> > libraries. I'm going with the idea that some other package, either via
> > apt or flatpak (which I really don't trust) decided to be nice. But it
> > was a mess to have python distros in /usr/lib, /usr/local/lib and
> > ./local ... I am going to really try in the future to have everything in
> > one spot!
>
> I'm not sure if you mean that you intend moving files from the directory
> where they were loaded to somewhere else - I would hesitate!
>
>
> As before, there is a tradeoff between 'tidiness' and 'flexibility'.
> Perhaps do some reading to ensure a grasp of Python's library/directory
> structures and system/virtual environments, first?
>
> What me? Read? Actually a good suggestion ... I'll make note of the
recommended reading list. Thanks.


> Suggestions:
> sys.path https://docs.python.org/3/using/cmdline.html
> 2.3. Python-related paths and files
> https://docs.python.org/3/using/unix.html#python-related-paths-and-files
> PEP 370 -- Per user site-packages directory
> https://www.python.org/dev/peps/pep-0370/
> and to really dive 'under the covers'
> https://www.python.org/dev/peps/pep-0587/
> - with plenty more, both on-site and externally.
>
> It quickly becomes apparent that there are risks in assuming that what
> 'should be done' for one project/application will 'always' be OK. Sadly,
> such may have an (undesirable) impact on another/others. Thus, the
> virtue of project-dedicated venvs (alternately OpSys-level containers)!
>
>
> > Speaking of "one spot" I also see that some functions do not create the
> > .pyc versions. Running as a user, the compressed version can't be
> > created in /usr/lib/. I assume the installer is supposed to do that, but
> > it does appear that it's not 100%.
>
> There are multiple reasons for this, but the first time that code is
> run, a .pyc will (presumably) be created - and we're back to
> considerations of Python environments, Python cf C, perhaps even
>
>
Oh no! Not these damned dragons again :)

But, seriously. No, I have no idea of moving installed stuff around between
/usr /.local and /usr/local. There lies no dragons but madness :) I meant
that I will pay more attention as to what the installer(s) are doing.

Thanks for the input.


-- 

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Bob van der Poel ** Wynndel, British Columbia, CANADA **
EMAIL: bob at mellowood.ca
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