def report_invalid_syntax(self):
        """Check if the syntax is valid."""
        (exc_type, exc) = sys.exc_info()[:2]
        if len(exc.args) > 1:
            offset = exc.args[1]
            if len(offset) > 2:
                offset = offset[1:3]
        else:
            offset = (1, 0)
        self.report_error(offset[0], offset[1] or 0,
                          'E901 %s: %s' % (exc_type.__name__, exc.args[0]),
                          self.report_invalid_syntax)
Check if the syntax is valid.