- New function sys.exc_clear() clears the current exception. This is

rarely needed, but can sometimes be useful to release objects
  referenced by the traceback held in sys.exc_info()[2].  (SF patch
  #693195.)  Thanks to Kevin Jacobs!

Doc/lib/libsys.tex

@@ -99,6 +99,11 @@ It is always available.
   encapsulates the call stack at the point where the exception
   originally occurred.  \obindex{traceback}
 
+  If \function{exc_clear()} is called, this function will return three
+  \code{None} values until either another exception is raised in the
+  current thread or the execution stack returns to a frame where
+  another exception is being handled.
+
   \warning{Assigning the \var{traceback} return value to a
   local variable in a function that is handling an exception will
   cause a circular reference.  This will prevent anything referenced
@@ -115,6 +120,21 @@ It is always available.
   efficient to avoid creating cycles.}
 \end{funcdesc}
 
+\begin{funcdesc}{exc_clear}{}
+  This function clears all information relating to the current or last
+  exception that occured in the current thread.  After calling this
+  function, \function{exc_info()} will return three \code{None} values until
+  another exception is raised in the current thread or the execution stack
+  returns to a frame where another exception is being handled.
+  
+  This function is only needed in only a few obscure situations.  These
+  include logging and error handling systems that report information on the
+  last or current exception.  This function can also be used to try to free
+  resources and trigger object finalization, though no guarantee is made as
+  to what objects will be freed, if any.
+\versionadded{2.3}
+\end{funcdesc}
+
 \begin{datadesc}{exc_type}
 \dataline{exc_value}
 \dataline{exc_traceback}