"Don't install on the system Python"

[Chris Angelico]

On Mon, Dec 2, 2019 at 6:56 PM <niktnobodynikt at gmail.com> wrote:
>
> W dniu niedziela, 1 grudnia 2019 05:42:35 UTC+1 użytkownik John Ladasky napisał:
>
> > For years, I've read warnings about not installing one's personal stack of Python modules on top of the system Python.  It is possible to corrupt the OS, or so I've gathered.
> >
> > Well, I've never heeded this advice, and so far nothing bad has happened to me.  I don't like Anaconda, or virtual environments in general.  I don't like heavyweight IDE's.  I like to be able to type "python3" at the command prompt and be sure what I'll be getting.  I have multiple user accounts on a system that I manage, and I want every user account to have access to the same modules.
> >
> > Maybe the modules that I require are safe to install on the system Python, I'm not sure.  My must-haves are mostly scientific computing and data management modules: Numpy, Scipy, Scikit-learn, Matplotlib, Pandas, Biopython, and Tensorflow.  I also use PyQt5 from time to time.
> >
> > Can anyone provide concrete examples of problems arising from installing modules on top of the system Python?  Am I courting disaster?
>
>
> I did not heard of such problems. But I have another warning. Ubuntu 18.4 uses Python 3.6. Do not try to install 3.7 or 3.8 as systemwide python3 version. It breaks some programs including standard terminal.
>

And that's where the distinction between "system Python" and "default
Python" comes in. You are absolutely right that you shouldn't replace
the *system* Python. However, changing what the command "python3" runs
is safe.

ChrisA