Patch #403985: Add support for weak-keyed dictionaries
diff --git a/Lib/weakref.py b/Lib/weakref.py
index f1222fa..9d5eac0 100644
--- a/Lib/weakref.py
+++ b/Lib/weakref.py
@@ -20,11 +20,14 @@
ProxyTypes = (ProxyType, CallableProxyType)
-def mapping(dict=None):
- return WeakDictionary(dict)
+def mapping(dict=None,weakkeys=0):
+ if weakkeys:
+ return WeakKeyDictionary(dict)
+ else:
+ return WeakValueDictionary(dict)
-class WeakDictionary(UserDict.UserDict):
+class WeakValueDictionary(UserDict.UserDict):
# We inherit the constructor without worrying about the input
# dictionary; since it uses our .update() method, we get the right
@@ -112,5 +115,59 @@
return L
+class WeakKeyDictionary(UserDict.UserDict):
+
+ def __init__(self, dict=None):
+ self.data = {}
+ if dict is not None: self.update(dict)
+ def remove(k, data=self.data):
+ del data[k]
+ self._remove = remove
+
+ def __getitem__(self, key):
+ return self.data[ref(key)]
+
+ def __repr__(self):
+ return "<WeakKeyDictionary at %s>" % id(self)
+
+ def __setitem__(self, key, value):
+ self.data[ref(key, self._remove)] = value
+
+ def copy(self):
+ new = WeakKeyDictionary()
+ for key, value in self.data.items():
+ o = key()
+ if o is not None:
+ new[o] = value
+
+ def get(self, key, default):
+ return self.data.get(ref(key),default)
+
+ def items(self):
+ L = []
+ for key, value in self.data.items():
+ o = key()
+ if o is not None:
+ L.append((o, value))
+ return L
+
+ def popitem(self):
+ while 1:
+ key, value = self.data.popitem()
+ o = key()
+ if o is not None:
+ return o, value
+
+ def setdefault(self, key, default):
+ return self.data.setdefault(ref(key, self._remove),default)
+
+ def update(self, dict):
+ d = self.data
+ L = []
+ for key, value in dict.items():
+ L.append(ref(key, self._remove), value)
+ for key, r in L:
+ d[key] = r
+
# no longer needed
del UserDict