add support for SAGE_PYTHONPATH

[was]

>
> > On Aug 6, 9:33 am, Rupert <rupert.n...@gmail.com> wrote:
> >> Hello there,
>
> > Hi Rupert,
>
> >> I installed sage this morning and am doing some testing. I noticed
> >> that sage was ignoring some python modules that live in a directory on
> >> my PYTHONPATH environment variable.
>
> >> Looking in $SAGE_ROOT/local/bin/sage-env, I see that it completely
> >> overrides my $PYTHONPATH, rather than prepending its own directories.
>
> > Yes, we do that on purpose.

Hi,

> I propose offering a workaround, e.g.,
>         SAGE_PYTHONPATH
> which *does* get appended to PYTHONPATH
> on startup.

That sounds reasonable to me.

> Note that this is for picking up *user* code, so
> it makes a huge amount of sense to support this.
> It's not an issue of system-wide python being
> different than Sage's at all.

Well, people will use it to have Sage pick up the extensions of the
system Python, but then I get to tell you "I told you so" :)

Add something to sage-env that does what is described above. Also add something to the README.txt that documents this behavior.

[ddrake]

This would be very nice for SageTeX, so that the user could put sagetex.py somewhere and use $SAGE_PYTHONPATH to help Sage automatically find the module.

[ddrake]

patch for $SAGE_ROOT/local/bin/sage-env

[ddrake]

patch for README.txt in $SAGE_ROOT

[mabshoff]

I would highly recommend to append PYTHONPATH instead of prepending it. That way if someone has a duplicate python package installed somewhere else, i.e. the system, the Sage packages get preferred treatment. Other people might disagree, so in that case we should take it to sage-devel. So "needs work" for now.

Cheers,

Michael

[mhansen]

This is already the SAGE_PATH variable that is supposed to be for this purpose.

[burcin]

Does the SAGE_PATH variable provide all the functionality requested here? (IMHO, it does.)

In that case, I suggest we close this ticket. There is already a ticket to document the environment variables used by Sage, #8263. I added a comment mentioning SAGE_PATH there.

[jhpalmieri]

Should this be closed? As Burcin says, SAGE_PATH solves the problem.

[chapoton]

I think this can be closed.