Merge pull request #8 from jgosmann/pyversion

Allow activation of venv with version mismatch

.gitignore

@@ -1,6 +1,7 @@
 *.egg-info/
 *.pyc
 .DS_Store
+.vscode
 MANIFEST
 build
 dist

CHANGES.md

@@ -1,37 +1,49 @@
 # Changelog
+
 All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-
 ## [Unreleased]
 
+### Fixed
+
+- Activate virtual environment even if its Python version does not match the
+  Python version used by pylint. Note that Python packages in the virtual
+  environment incombatible with pylint's Python version will not work.
+
 ## [2.1.0] - 2020-03-22
+
 ### Added
+
 - Support for using pylint installed in a virtual environment.
-See `force_venv_activation` parameter on `inithook` method.
+  See `force_venv_activation` parameter on `inithook` method.
 
 ## [2.0.0] - 2019-10-19
+
 ### Added
+
 - Support for Conda and PyPy
 - Documentation improvements
 
 ### Removed
-- Support for Python 2.7.
 
+- Support for Python 2.7.
 
 ## [1.1.0] - 2019-03-26
+
 ### Added
-- Compatibility with Python 3 venv module.
 
+- Compatibility with Python 3 venv module.
 
 ## [1.0.0] - 2015-03-01
+
 ### Added
-- Initial release of inithook for pylint to activate virtual env.
 
+- Initial release of inithook for pylint to activate virtual env.
 
-[Unreleased]: https://github.com/jgosmann/pylint-venv/compare/v2.0.0...HEAD
+[unreleased]: https://github.com/jgosmann/pylint-venv/compare/v2.0.0...HEAD
 [2.1.0]: https://github.com/jgosmann/pylint-venv/compare/v2.0.0...v2.1.0
 [2.0.0]: https://github.com/jgosmann/pylint-venv/compare/v1.1.0...v2.0.0
 [1.1.0]: https://github.com/jgosmann/pylint-venv/compare/v1.0.0...v1.1.0

pylint_venv.py

@@ -38,6 +38,7 @@
 
 import os
 import platform
+import re
 import site
 import sys
 
@@ -46,6 +47,10 @@
 IS_PYPY = platform.python_implementation() == "PyPy"
 
 
+class IncompatibleVenvError(Exception):
+    pass
+
+
 def is_venv():
     """Return *True* if a virtual environment is currently active."""
     is_conda_env = getattr(sys, "base_prefix", sys.prefix) != sys.prefix
@@ -76,8 +81,17 @@ def activate_venv(venv):
     elif IS_WIN:
         site_packages = os.path.join(venv, "Lib", "site-packages")
     else:
-        pyver = f"python{sys.version_info[0]}.{sys.version_info[1]}"
-        site_packages = os.path.join(venv, "lib", pyver, "site-packages")
+        lib_dir = os.path.join(venv, "lib")
+        python_dirs = [d for d in os.listdir(lib_dir) if re.match(r"python\d+.\d+", d)]
+        if len(python_dirs) == 0:
+            raise IncompatibleVenvError(
+                f"The virtual environment {venv!r} is missing a lib/pythonX.Y directory."
+            )
+        if len(python_dirs) > 1:
+            raise IncompatibleVenvError(
+                f"The virtual environment {venv!r} has multiple lib/pythonX.Y directories."
+            )
+        site_packages = os.path.join(lib_dir, python_dirs[0], "site-packages")
 
     prev = set(sys.path)
     site.addsitedir(site_packages)