Run winpdb to debug current file

def run_winpdb(self):
        """Run winpdb to debug current file"""
        if self.save():
            fname = self.get_current_filename()
            runconf = get_run_configuration(fname)
            if runconf is None:
                args = []
                wdir = None
            else:
                args = runconf.get_arguments().split()
                wdir = runconf.get_working_directory()
            # Handle the case where wdir comes back as an empty string
            # when the working directory dialog checkbox is unchecked.
            # (subprocess "cwd" default is None, so empty str
            # must be changed to None in this case.)
            programs.run_program(WINPDB_PATH, [fname] + args, cwd=wdir or None)