scripts/pythondistdeps: Fix for Python 3.10

self.name in PathDistribution is a property in Python 3.10+ and thus we
can't redefine it as an instance variable. Instead we explicitly define
it as a property, which works on all supported Python versions.

python-rpm-generators.spec

@@ -1,7 +1,7 @@
 Name:           python-rpm-generators
 Summary:        Dependency generators for Python RPMs
 Version:        12
-Release:        2%{?dist}
+Release:        3%{?dist}
 
 # Originally all those files were part of RPM, so license is kept here
 License:        GPLv2+
@@ -47,6 +47,9 @@ install -Dpm0755 -t %{buildroot}%{_rpmconfigdir} *.py
 %{_rpmconfigdir}/pythonbundles.py
 
 %changelog
+* Mon Feb 22 2021 Tomas Orsava <torsava@redhat.com> - 12-3
+- scripts/pythondistdeps: Fix for Python 3.10
+
 * Wed Feb 17 2021 Tomas Orsava <torsava@redhat.com> - 12-2
 - scripts/pythondistdeps: Switch from using pkg_resources to importlib.metadata
   for reading the egg/dist-info metadata

pythondistdeps.py

@@ -53,7 +53,6 @@ class Requirement(Requirement_):
 class Distribution(PathDistribution):
     def __init__(self, path):
         super(Distribution, self).__init__(Path(path))
-        self.name = self.metadata['Name']
         self.normalized_name = normalize_name(self.name)
         self.legacy_normalized_name = legacy_normalize_name(self.name)
         self.requirements = [Requirement(r) for r in self.requires or []]
@@ -61,6 +60,15 @@ class Distribution(PathDistribution):
             v for k, v in self.metadata.items() if k == 'Provides-Extra']
         self.py_version = self._parse_py_version(path)
 
+    # `name` is defined as a property exactly like this in Python 3.10 in the
+    # PathDistribution class. Due to that we can't redefine `name` as a normal
+    # attribute. So we copied the Python 3.10 definition here into the code so
+    # that it works also on previous Python/importlib_metadata versions.
+    @property
+    def name(self):
+        """Return the 'Name' metadata for the distribution package."""
+        return self.metadata['Name']
+
     def _parse_py_version(self, path):
         # Try to parse the Python version from the path the metadata
         # resides at (e.g. /usr/lib/pythonX.Y/site-packages/...)