Hi all,
I was at SC last week, and many people shared interests in our setup for
python, in particular the fact that we manage to support multiple
versions of Python for the same module. I thought I would share our
solution here.
1) We do not define PYTHONPATH. PYTHONPATH is too intrusive, and it is
not python-version aware. In your PYTHONPATH contains packages for
python 2.7, it won't work with python 3.5 and vice versa.
2) Instead, we define EBPYTHONPREFIXES (our made up environment
variable name), which points to the prefix directory.
3) We have a file called sitecustomize.py (that's standard python)
which contains the following logic (and a bit more that is not relevant
for this crowd since it is related to our nix layer):
if "EBPYTHONPREFIXES" in os.environ:
for prefix in os.environ["EBPYTHONPREFIXES"].split(os.pathsep):
sitedir = os.path.join(prefix, postfix)
if os.path.isdir(sitedir):
site.addsitedir(sitedir)
4) In the modules, we install the python packages for all versions of
python (currently only 2.7 and 3.5, but soon 3.6) under their typical
"lib/pythonX.Y/site-packages" folders.
For examples recipes that use this :
https://github.com/ComputeCanada/easybuild-easyconfigs/blob/computecanada-master/easybuild/easyconfigs/i/igraph/igraph-0.7.1-iomkl-2016.4.11.eb
https://github.com/ComputeCanada/easybuild-easyconfigs/blob/computecanada-master/easybuild/easyconfigs/o/OpenMM/OpenMM-7.1.1-iomkl-2016.4.11.eb
Maxime
