From 8e66fbc444727f75a54c055bfcc5504c49f6418c Mon Sep 17 00:00:00 2001
From: Daniel Hollas <daniel.hollas@bristol.ac.uk>
Date: Mon, 5 Aug 2024 19:40:35 +0100
Subject: [PATCH 1/4] Defer import inspect

---
 importlib_metadata/__init__.py | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/importlib_metadata/__init__.py b/importlib_metadata/__init__.py
index 2eefb1d6..a8dead9b 100644
--- a/importlib_metadata/__init__.py
+++ b/importlib_metadata/__init__.py
@@ -8,7 +8,6 @@
 import zipp
 import email
 import types
-import inspect
 import pathlib
 import operator
 import textwrap
@@ -1071,6 +1070,9 @@ def _topmost(name: PackagePath) -> Optional[str]:
     return top if rest else None
 
 
+inspect = None
+
+
 def _get_toplevel_name(name: PackagePath) -> str:
     """
     Infer a possibly importable module name from a name presumed on
@@ -1089,11 +1091,14 @@ def _get_toplevel_name(name: PackagePath) -> str:
     >>> _get_toplevel_name(PackagePath('foo.dist-info'))
     'foo.dist-info'
     """
-    return _topmost(name) or (
-        # python/typeshed#10328
-        inspect.getmodulename(name)  # type: ignore
-        or str(name)
-    )
+    n = _topmost(name)
+    if n:
+        return n
+
+    global inspect
+    if inspect is None:
+        import inspect
+    return inspect.getmodulename(name) or str(name)
 
 
 def _top_level_inferred(dist):

From debb5165a88b1a4433150b265e155c21b497d154 Mon Sep 17 00:00:00 2001
From: Daniel Hollas <daniel.hollas@bristol.ac.uk>
Date: Tue, 20 Aug 2024 12:23:17 +0100
Subject: [PATCH 2/4] Don't use global var

- wallrusify
- add a note about deffered import
---
 importlib_metadata/__init__.py | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/importlib_metadata/__init__.py b/importlib_metadata/__init__.py
index a8dead9b..f76ef2cc 100644
--- a/importlib_metadata/__init__.py
+++ b/importlib_metadata/__init__.py
@@ -1070,9 +1070,6 @@ def _topmost(name: PackagePath) -> Optional[str]:
     return top if rest else None
 
 
-inspect = None
-
-
 def _get_toplevel_name(name: PackagePath) -> str:
     """
     Infer a possibly importable module name from a name presumed on
@@ -1091,13 +1088,12 @@ def _get_toplevel_name(name: PackagePath) -> str:
     >>> _get_toplevel_name(PackagePath('foo.dist-info'))
     'foo.dist-info'
     """
-    n = _topmost(name)
-    if n:
+    if n := _topmost(name):
         return n
 
-    global inspect
-    if inspect is None:
-        import inspect
+    # We're deffering import of inspect to speed up overall import time
+    import inspect
+
     return inspect.getmodulename(name) or str(name)
 
 

From e99c10510d48e840b0550bd05d1167633dcfaea7 Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Tue, 20 Aug 2024 13:00:48 -0400
Subject: [PATCH 3/4] Restore single-expression logic.

---
 importlib_metadata/__init__.py | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/importlib_metadata/__init__.py b/importlib_metadata/__init__.py
index f76ef2cc..b1a15350 100644
--- a/importlib_metadata/__init__.py
+++ b/importlib_metadata/__init__.py
@@ -1088,13 +1088,14 @@ def _get_toplevel_name(name: PackagePath) -> str:
     >>> _get_toplevel_name(PackagePath('foo.dist-info'))
     'foo.dist-info'
     """
-    if n := _topmost(name):
-        return n
-
     # We're deffering import of inspect to speed up overall import time
     import inspect
 
-    return inspect.getmodulename(name) or str(name)
+    return _topmost(name) or (
+        # python/typeshed#10328
+        inspect.getmodulename(name)  # type: ignore
+        or str(name)
+    )
 
 
 def _top_level_inferred(dist):

From a7aaf72702b3a49ea3e33c9cf7f223839067c883 Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Tue, 20 Aug 2024 13:01:47 -0400
Subject: [PATCH 4/4] Use third-person imperative voice and link to issue in
 comment.

---
 importlib_metadata/__init__.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/importlib_metadata/__init__.py b/importlib_metadata/__init__.py
index b1a15350..c2b76dd2 100644
--- a/importlib_metadata/__init__.py
+++ b/importlib_metadata/__init__.py
@@ -1088,7 +1088,7 @@ def _get_toplevel_name(name: PackagePath) -> str:
     >>> _get_toplevel_name(PackagePath('foo.dist-info'))
     'foo.dist-info'
     """
-    # We're deffering import of inspect to speed up overall import time
+    # Defer import of inspect for performance (python/cpython#118761)
     import inspect
 
     return _topmost(name) or (