gh-103624: Let pydoc first try to get version from importlib.metadata

Author: dlax

Lib/pydoc.py

@@ -59,6 +59,7 @@ class or function within a module or module in a package.  If the
 import importlib._bootstrap
 import importlib._bootstrap_external
 import importlib.machinery
+import importlib.metadata
 import importlib.util
 import inspect
 import io
@@ -183,6 +184,14 @@ def _getdoc(object):
         return None
     return inspect.cleandoc(doc)
 
+def _getversion(mod, name):
+    try:
+        return importlib.metadata.version(name)
+    except importlib.metadata.PackageNotFoundError:
+        if version := getattr(mod, '__version__', ''):
+            return str(version)
+    return None
+
 def getdoc(object):
     """Get the doc string or comments for an object."""
     result = _getdoc(object) or inspect.getcomments(object)
@@ -766,8 +775,7 @@ def docmodule(self, object, name=None, mod=None, *ignored):
         except TypeError:
             filelink = '(built-in)'
         info = []
-        if hasattr(object, '__version__'):
-            version = str(object.__version__)
+        if version := _getversion(object, name):
             if version[:11] == '$' + 'Revision: ' and version[-1:] == '$':
                 version = version[11:-1].strip()
             info.append('version %s' % self.escape(version))
@@ -1286,8 +1294,7 @@ def docmodule(self, object, name=None, mod=None):
                 contents.append(self.docother(value, key, name, maxlen=70))
             result = result + self.section('DATA', '\n'.join(contents))
 
-        if hasattr(object, '__version__'):
-            version = str(object.__version__)
+        if version := _getversion(object, name):
             if version[:11] == '$' + 'Revision: ' and version[-1:] == '$':
                 version = version[11:-1].strip()
             result = result + self.section('VERSION', version)

Misc/NEWS.d/next/Library/2023-04-19-13-21-40.gh-issue-103624.Z7PBdI.rst

@@ -0,0 +1,2 @@
+Let pydoc first try to get package's version from ``importlib.metadata``,
+then falling back to ``__version__`` attribute.