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Diffstat (limited to 'gnu/packages/aux-files/python/sitecustomize.py')
| -rw-r--r-- | gnu/packages/aux-files/python/sitecustomize.py | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/gnu/packages/aux-files/python/sitecustomize.py b/gnu/packages/aux-files/python/sitecustomize.py new file mode 100644 index 0000000000..71e328b9ac --- /dev/null +++ b/gnu/packages/aux-files/python/sitecustomize.py @@ -0,0 +1,55 @@ +# -*- coding: utf-8 -*- +# GNU Guix --- Functional package management for GNU +# Copyright © 2021 Maxim Cournoyer <maxim.cournoyer@gmail.com> +# +# This file is part of GNU Guix. +# +# GNU Guix is free software; you can redistribute it and/or modify it +# under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3 of the License, or (at +# your option) any later version. +# +# GNU Guix is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with GNU Guix. If not, see <http://www.gnu.org/licenses/>. + +import os +import sys + +# Commentary: +# +# Site-specific customization for Guix. +# +# The program below honors the GUIX_PYTHONPATH environment variable to +# discover Python packages. File names appearing in this variable that match +# a predefined versioned installation prefix are added to the sys.path. To be +# considered, a Python package must be installed under the +# 'lib/pythonX.Y/site-packages' directory, where X and Y are the major and +# minor version numbers of the Python interpreter. +# +# Code: + +major_minor = '{}.{}'.format(*sys.version_info) +site_packages_prefix = os.path.join( + 'lib', 'python' + major_minor, 'site-packages') +python_site = os.path.join(sys.prefix, site_packages_prefix) + +try: + all_sites_raw = os.environ['GUIX_PYTHONPATH'].split(os.path.pathsep) +except KeyError: + all_sites_raw = [] +# Normalize paths, otherwise a trailing slash would cause it to not match. +all_sites_norm = [os.path.normpath(p) for p in all_sites_raw] +matching_sites = [p for p in all_sites_norm + if p.endswith(site_packages_prefix)] + +# Insert sites matching the current version into sys.path, right before +# Python's own site. This way, the user can override the libraries provided +# by Python itself. +sys_path_absolute = [os.path.realpath(p) for p in sys.path] +index = sys_path_absolute.index(python_site) +sys.path[index:index] = matching_sites |