From c1581a928cc153076593c5c433a8dd36ce10fbfb Mon Sep 17 00:00:00 2001 From: Pankaj Pandey Date: Fri, 26 Aug 2022 10:20:48 -0400 Subject: [PATCH] bpo-33587: inspect.getsource: reorder stat on file in linecache (GH-6805) * inspect.getsource: avoid stat on file in linecache The check for os.path.exists() on source file is postponed in inspect.getsourcefile() until needed avoiding an expensive filesystem stat call and PEP 302 module loader check is moved last for performance since it is an uncommon case. --- Lib/inspect.py | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/Lib/inspect.py b/Lib/inspect.py index cbc0632484b..498ee7ab9ea 100644 --- a/Lib/inspect.py +++ b/Lib/inspect.py @@ -946,6 +946,9 @@ def getsourcefile(object): elif any(filename.endswith(s) for s in importlib.machinery.EXTENSION_SUFFIXES): return None + # return a filename found in the linecache even if it doesn't exist on disk + if filename in linecache.cache: + return filename if os.path.exists(filename): return filename # only return a non-existent filename if the module has a PEP 302 loader @@ -954,9 +957,6 @@ def getsourcefile(object): return filename elif getattr(getattr(module, "__spec__", None), "loader", None) is not None: return filename - # or it is in the linecache - elif filename in linecache.cache: - return filename def getabsfile(object, _filename=None): """Return an absolute path to the source or compiled file for an object.