Run filename
        args: command line arguments (string)

def runfile(self, filename, args=None):
        """
        Run filename
        args: command line arguments (string)
        """
        if args is not None and not is_text_string(args):
            raise TypeError("expected a character buffer object")
        self.namespace['__file__'] = filename
        sys.argv = [filename]
        if args is not None:
            for arg in args.split():
                sys.argv.append(arg)
        self.execfile(filename)
        sys.argv = ['']
        self.namespace.pop('__file__')