Added | and |= operators to WeakValueDictionary

Updated weakref.py Added tests Updated docs Updated news
python · gvanrossum · Mar 25, 2020 · Mar 18, 2020 · Mar 23, 2020 · Mar 23, 2020
commit bc4e7e7cf5656b7709d60714da1ef6f99ca9b0e5
diff --git a/Doc/library/weakref.rst b/Doc/library/weakref.rst
@@ -201,6 +201,8 @@ than needed.
 same issues as the :meth:`keyrefs` method of :class:`WeakKeyDictionary`
 objects.
 
+   .. versionchanged:: 3.9
+      Added support for ``|`` and ``|=`` operators, specified in :pep:`584`.
 
 .. method:: WeakValueDictionary.valuerefs()
 

diff --git a/Lib/test/test_weakref.py b/Lib/test/test_weakref.py
@@ -1609,6 +1609,21 @@ def test_weak_valued_dict_update(self):
             self.assertEqual(list(d.keys()), [kw])
             self.assertEqual(d[kw], o)
 
+    def test_weak_valued_union_operators(self):
+        class C: pass
+        c1 = C()
+        c2 = C()
+        c3 = C()
+
+        wvd1 = weakref.WeakValueDictionary({'1' : c1, '2': c2})
+        wvd2 = weakref.WeakValueDictionary({'1': c3, '4': c1})
+
+        wvd3 = wvd1 | wvd2
+        self.assertEqual(dict(wvd3), dict(wvd1) | dict(wvd2))
+
+        wvd1 |= wvd2
+        self.assertEqual(wvd1, wvd3)
+
     def test_weak_keyed_dict_update(self):
         self.check_update(weakref.WeakKeyDictionary,
                           {C(): 1, C(): 2, C(): 3})

diff --git a/Lib/weakref.py b/Lib/weakref.py
@@ -310,6 +310,20 @@ def valuerefs(self):
             self._commit_removals()
         return list(self.data.values())
 
+    def __ior__(self, other):
+        self.update(other)
+        return self
+
+    def __or__(self, other):
+        c = self.copy()
+        c.update(other)
+        return c
+
+    def __ror__(self, other):
+        c = other.copy()
+        c.update(self)
+        return c
+
 
 class KeyedRef(ref):
     """Specialized reference that includes a key corresponding to the value.

diff --git a/Misc/NEWS.d/next/Library/2020-03-18-14-51-41.bpo-36144.lQm_RK.rst b/Misc/NEWS.d/next/Library/2020-03-18-14-51-41.bpo-36144.lQm_RK.rst
@@ -0,0 +1 @@
+Added :pep:`584` operators to :class:`weakref.WeakValueDictionary`.
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		Added :pep:`584` operators to :class:`weakref.WeakValueDictionary`.