PEP 352 implementation. Creates a new base class, BaseException, which has an

added message attribute compared to the previous version of Exception.  It is
also a new-style class, making all exceptions now new-style.  KeyboardInterrupt
and SystemExit inherit from BaseException directly.  String exceptions now
raise DeprecationWarning.

Applies patch 1104669, and closes bugs 1012952 and 518846.

Lib/test/test_exceptions.py

@@ -29,10 +29,7 @@ def test_raise_catch(exc):
 
 def r(thing):
     test_raise_catch(thing)
-    if isinstance(thing, ClassType):
-        print thing.__name__
-    else:
-        print thing
+    print getattr(thing, '__name__', thing)
 
 r(AttributeError)
 import sys