replace long with int

Doc/library/weakref.rst

@@ -72,9 +72,9 @@ support weak references but can add support through subclassing::
 
    obj = Dict(red=1, green=2, blue=3)   # this object is weak referenceable
 
-Other built-in types such as :class:`tuple` and :class:`long` do not support
-weak references even when subclassed (This is an implementation detail and may
-be different across various Python implementations.).
+Other built-in types such as :class:`tuple` and :class:`int` do not support weak
+references even when subclassed (This is an implementation detail and may be
+different across various Python implementations.).
 
 Extension types can easily be made to support weak references; see
 :ref:`weakref-support`.