Use commands inside rpdb2:
(I assume that you want to connect to process running on localhost. Otherwise you should use --host switch)
$ ./rdb2
RPDB2 - The Remote Python Debugger, version RPDB_2_4_8,
Copyright (C) 2005-2009 Nir Aides.
Type "help", "copyright", "license", "credits" for more information.
> password "debugger"
Password is set to: "debugger"
> attach
Connecting to 'localhost'...
Scripts to debug on 'localhost':
pid name
--------------------------
7772 myscript.py
> attach 7772
> *** Attaching to debuggee...
> *** Debug Channel is encrypted.
> *** Successfully attached to
> *** 'myscript.py'.
> *** Debuggee is waiting at break point for further commands.
> go