From dd3c0fa3fd2795326dae0e0ed63c668f5506cf32 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Thu, 31 Oct 2024 14:05:40 -0500
Subject: [PATCH] gh-126156: Improve performance of creating `Morsel` objects
 (#126157)

Replaces the manually constructed loop with a call to `dict.update`
---
 Lib/http/cookies.py                                          | 5 +++--
 .../Library/2024-10-30-00-12-22.gh-issue-126156.BOSqv0.rst   | 1 +
 2 files changed, 4 insertions(+), 2 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Library/2024-10-30-00-12-22.gh-issue-126156.BOSqv0.rst

diff --git a/Lib/http/cookies.py b/Lib/http/cookies.py
index 6b9ed24ad8e..d7e8d08b2d9 100644
--- a/Lib/http/cookies.py
+++ b/Lib/http/cookies.py
@@ -266,6 +266,8 @@ class Morsel(dict):
         "samesite" : "SameSite",
     }
 
+    _reserved_defaults = dict.fromkeys(_reserved, "")
+
     _flags = {'secure', 'httponly'}
 
     def __init__(self):
@@ -273,8 +275,7 @@ class Morsel(dict):
         self._key = self._value = self._coded_value = None
 
         # Set default attributes
-        for key in self._reserved:
-            dict.__setitem__(self, key, "")
+        dict.update(self, self._reserved_defaults)
 
     @property
     def key(self):
diff --git a/Misc/NEWS.d/next/Library/2024-10-30-00-12-22.gh-issue-126156.BOSqv0.rst b/Misc/NEWS.d/next/Library/2024-10-30-00-12-22.gh-issue-126156.BOSqv0.rst
new file mode 100644
index 00000000000..4fe18275ab9
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2024-10-30-00-12-22.gh-issue-126156.BOSqv0.rst
@@ -0,0 +1 @@
+Improved performances of creating :py:class:`~http.cookies.Morsel` objects by a factor of 3.8x.