might want to issue a warning when a program uses an obsolete module.
Python programmers issue warnings by calling the :func:`warn` function defined
-in this module. (C programmers use :cfunc:`PyErr_Warn`; see
+in this module. (C programmers use :cfunc:`PyErr_Warn`; see
:ref:`exceptionhandling` for details).
Warning messages are normally written to ``sys.stderr``, but their disposition