tools.py 文件源码

def _convert(node):
        if isinstance(node, ast.Str):
            return node.s
        elif isinstance(node, ast.Num):
            return node.n
        elif isinstance(node, ast.Tuple):
            return tuple(map(_convert, node.elts))
        elif isinstance(node, ast.List):
            return list(map(_convert, node.elts))
        elif isinstance(node, ast.Dict):
            return dict((_convert(k), _convert(v)) for k, v
                        in zip(node.keys, node.values))
        elif isinstance(node, ast.Name):
            if node.id in SAFE_CONSTANTS:
                return SAFE_CONSTANTS[node.id]
        raise ValueError('malformed or disallowed expression')