Use importlib.metadata to find and uninstall packages

Author: cottsay

colcon_python_project/metadata.py

@@ -1,13 +1,17 @@
 # Copyright 2022 Open Source Robotics Foundation, Inc.
 # Licensed under the Apache License, Version 2.0
 
-from email.parser import Parser
 from pathlib import Path
 from tempfile import TemporaryDirectory
 
 from colcon_python_project.hook_caller_decorator \
     import get_decorated_hook_caller
 
+try:
+    from importlib.metadata import Distribution
+except ImportError:
+    from importlib_metadata import Distribution
+
 
 async def load_metadata(desc):
     """
@@ -19,10 +23,8 @@ async def load_metadata(desc):
     with TemporaryDirectory() as md_dir:
         md_name = await hook_caller.prepare_metadata_for_build_wheel(
             metadata_directory=md_dir)
-        md_path = Path(md_dir) / md_name / 'METADATA'
-        with open(md_path) as f:
-            metadata = Parser().parse(f)
-    return metadata
+        md_path = Path(md_dir) / md_name
+        return Distribution.at(md_path).metadata
 
 
 async def load_and_cache_metadata(desc):

colcon_python_project/wheel.py

@@ -16,6 +16,11 @@
 from colcon_core.python_install_path import get_python_install_path
 from distlib.scripts import ScriptMaker
 
+try:
+    from importlib.metadata import Distribution
+except ImportError:
+    from importlib_metadata import Distribution
+
 
 def _get_install_path(key, install_base):
     return get_python_install_path(key, {'base': str(install_base)})
@@ -41,6 +46,33 @@ def write_and_record(libdir, path, lines):
         f'{len(raw)}')
 
 
+def remove_distributions(name, install_base):
+    """
+    Remove any installed distributions with the given name.
+
+    :param name: Name of the distribution.
+    :param install_base: Path to the base directory to uninstall from.
+    """
+    for search_path in (
+        _get_install_path('purelib', install_base),
+        _get_install_path('platlib', install_base),
+    ):
+        dirs = set()
+        for dist in Distribution.discover(name=name, path=(search_path,)):
+            for f in dist.files:
+                f_abs = f.locate()
+                if f_abs.is_relative_to(search_path):
+                    f_abs.unlink()
+                    dirs.add(f_abs.parent)
+
+        while dirs:
+            d = dirs.pop()
+            if d == search_path or any(d.iterdir()):
+                continue
+            d.rmdir()
+            dirs.add(d.parent)
+
+
 def install_wheel(wheel_path, install_base, script_dir_override=None):
     """
     Install a wheel file under the given installation base directory.
@@ -61,6 +93,8 @@ def install_wheel(wheel_path, install_base, script_dir_override=None):
     record_file = dist_info_dir + 'RECORD'
     entry_points_file = dist_info_dir + 'entry_points.txt'
 
+    remove_distributions(distribution, install_base)
+
     with ZipFile(
         wheel_path, mode='r', compression=ZIP_DEFLATED, allowZip64=True
     ) as wf:

setup.cfg

@@ -28,6 +28,7 @@ install_requires =
   colcon-core>=0.12.0
   colcon-ros
   distlib
+  importlib_metadata;python_version < "3.8"
   tomli>=1.0.0;python_version < "3.11"
 packages = find:
 zip_safe = true

test/spell_check.words

@@ -65,6 +65,7 @@ toml
 tomli
 tomllib
 traceback
+uninstall
 unittest
 urlsafe
 zipfile