On Wed, 24 Feb 2021 13:47:40 +0100 Stéfane Fermigier <s...@fermigier.com> wrote: > On Wed, Feb 24, 2021 at 12:42 PM Paul Moore > <p.f.moore-re5jqeeqqe8avxtiumw...@public.gmane.org> wrote: > > > On Wed, 24 Feb 2021 at 10:55, Stéfane Fermigier > > <sf-xq1qbjp4wzx54taoqty...@public.gmane.org> wrote: > > > There is probably a clever way to reuse common packages (probably via > > clever symlinking) and reduce the footprint of these installations. > > > > Ultimately the problem is that a general tool can't deal with > > conflicts (except by raising an error). If application A depends on > > lib==1.0 and application B depends on lib==2.0, you simply can't have > > a (consistent) environment that supports both A and B. But that's the > > rare case - 99% of the time, there are no conflicts. One env per app > > is a safe, but heavy handed, approach. Managing environments manually > > isn't exactly *hard*, but it's annoying manual work that pipx does an > > excellent job of automating, so it's a disk space vs admin time > > trade-off. > > > > There are three ways to approach the question: > > 1) Fully isolated envs. The safest option but uses the most space. > > 2) Try to minimise the number of dependencies installed by interpreting the > requirements specification in the looser way possible. This is both > algorithmically hard (see > https://hal.archives-ouvertes.fr/hal-00149566/document for instance, or the > more recent https://hal.archives-ouvertes.fr/hal-03005932/document ) and > risky, as you've noted. > > 3) But the best way IMHO is to compute dependencies for each virtualenv > independently from the others, but still share the packages, using some > indirection mechanisms (hard links, symlinks or some Python-specific > constructs) when the versions match exactly. > > The 3rd solution is probably the best of the 3, but the sharing mechanism > still needs to be specified (and, if needed, implemented) properly.
I wouldn't want to repeat myself too often, but conda and conda-based distributions already have sharing through hardlinks (or, on Windows, whatever is available) baked-in, assuming you install your software from conda packages. That also applies to non-Python packages, and to python itself (which is just a package like any other). Regards Antoine. _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/SIO47UNLRARUCICNOVO75P3BKFE43QK2/ Code of Conduct: http://python.org/psf/codeofconduct/
