pydoc.help (aliased to the builtin help) uses the values of sys.stdout and sys.stdin that were in use when the pydoc module was imported.  This means that if sys.stdout and/or sys.stdin are later modified, subsequent calls to pydoc.help (or help) use the wrong stdout and stdin.

Instead, help should use the current values of sys.stdout and sys.stdin each time it is called.

Reported against Python 2.4.4.