note that the hash of an arbitrary object is only derived from its address (closes #21154)
Patch from Armin Rigo.
diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst
index f4e3d63..e076729 100644
--- a/Doc/reference/datamodel.rst
+++ b/Doc/reference/datamodel.rst
@@ -1422,7 +1422,7 @@
User-defined classes have :meth:`__cmp__` and :meth:`__hash__` methods
by default; with them, all objects compare unequal (except with themselves)
- and ``x.__hash__()`` returns ``id(x)``.
+ and ``x.__hash__()`` returns a result derived from ``id(x)``.
Classes which inherit a :meth:`__hash__` method from a parent class but
change the meaning of :meth:`__cmp__` or :meth:`__eq__` such that the hash