save and restore the tstate, but explicitly calling
PyEval_SaveThread() does reset it! While I think about how to fix
this for real, here's a fix that avoids getting a fatal error.
set_completer(function)
parse_and_bind(string)
read_init_file(filename)
The first is the most exciting feature: with an appropriate Python
completer function, it can do dynamic completion based on the contents
of your namespace!
Guido van Rossum