Issue #29203: functools.lru_cache() now respects PEP 468

2 files changed, 13 insertions, 4 deletions

diff --git a/Lib/functools.py b/Lib/functools.py
index 45e5f87..030c91b 100644
--- a/Lib/functools.py
+++ b/Lib/functools.py
@@ -421,7 +421,7 @@ class _HashedSeq(list):
 def _make_key(args, kwds, typed,
              kwd_mark = (object(),),
              fasttypes = {int, str, frozenset, type(None)},
-             sorted=sorted, tuple=tuple, type=type, len=len):
+             tuple=tuple, type=type, len=len):
     """Make a cache key from optionally typed positional and keyword arguments
 
     The key is constructed in a way that is flat as possible rather than
@@ -434,14 +434,13 @@ def _make_key(args, kwds, typed,
     """
     key = args
     if kwds:
-        sorted_items = sorted(kwds.items())
         key += kwd_mark
-        for item in sorted_items:
+        for item in kwds.items():
             key += item
     if typed:
         key += tuple(type(v) for v in args)
         if kwds:
-            key += tuple(type(v) for k, v in sorted_items)
+            key += tuple(type(v) for v in kwds.values())
     elif len(key) == 1 and type(key[0]) in fasttypes:
         return key[0]
     return _HashedSeq(key)
diff --git a/Lib/test/test_functools.py b/Lib/test/test_functools.py
index 3a40861..27eb576 100644
--- a/Lib/test/test_functools.py
+++ b/Lib/test/test_functools.py
@@ -1306,6 +1306,16 @@ class TestLRU:
         self.assertEqual(fib.cache_info(),
             self.module._CacheInfo(hits=0, misses=0, maxsize=None, currsize=0))
 
+    def test_kwargs_order(self):
+        # PEP 468: Preserving Keyword Argument Order
+        @self.module.lru_cache(maxsize=10)
+        def f(**kwargs):
+            return list(kwargs.items())
+        self.assertEqual(f(a=1, b=2), [('a', 1), ('b', 2)])
+        self.assertEqual(f(b=2, a=1), [('b', 2), ('a', 1)])
+        self.assertEqual(f.cache_info(),
+            self.module._CacheInfo(hits=0, misses=2, maxsize=10, currsize=2))
+
     def test_lru_cache_decoration(self):
         def f(zomg: 'zomg_annotation'):
             """f doc string"""