markers.py 文件源码

def visit(self, node):
        """Ensure statement only contains allowed nodes."""
        if not isinstance(node, self.ALLOWED):
            raise SyntaxError('Not allowed in environment markers.\n%s\n%s' %
                               (self.statement,
                               (' ' * node.col_offset) + '^'))
        return ast.NodeTransformer.visit(self, node)