gh-141510: Update Whats News for frozendict

Doc/whatsnew/3.15.rst

@@ -188,14 +188,30 @@ raise :exc:`SyntaxError`).
 :pep:`814`: Add frozendict built-in type
 ----------------------------------------
 
-A new public immutable type :class:`frozendict` is added to the :mod:`builtins`
-module. It is not a ``dict`` subclass but inherits directly from ``object``.
-
-A ``frozendict`` can be hashed with ``hash(frozendict)`` if all keys and values
-can be hashed.
+A new public immutable type, :class:`frozendict`, is added to the :mod:`builtins` module.
+It does not allow modification after creation. A ``frozendict`` is not a subclass of ``dict``;
+it inherits directly from ``object``. A ``frozendict`` is hashable (i.e., ``hash(frozendict)`` works)
+as long as all of its keys and values are hashable.
+
+>>> a = frozendict(x=1, y=2)
+>>> a
+frozendict({'x': 1, 'y': 2})
+>>> a['z'] = 3
+Traceback (most recent call last):
+  File "<python-input-2>", line 1, in <module>
+    a['z'] = 3
+    ~^^^^^
+TypeError: 'frozendict' object does not support item assignment
+>>> b = frozendict(y=2, x=1)
+>>> hash(a) == hash(b)
+True
+>>> a == b
+True
 
 .. seealso:: :pep:`814` for the full specification and rationale.
 
+(Contributed by Victor Stinner and Donghee Na in :gh:`141510`.)
+
 
 .. _whatsnew315-profiling-package: