interactiveshell.py 文件源码

 复制代码def transform_ast(self, node):
        """Apply the AST transformations from self.ast_transformers

        Parameters
        ----------
        node : ast.Node
          The root node to be transformed. Typically called with the ast.Module
          produced by parsing user input.

        Returns
        -------
        An ast.Node corresponding to the node it was called with. Note that it
        may also modify the passed object, so don't rely on references to the
        original AST.
        """
        for transformer in self.ast_transformers:
            try:
                node = transformer.visit(node)
            except InputRejected:
                # User-supplied AST transformers can reject an input by raising
                # an InputRejected.  Short-circuit in this case so that we
                # don't unregister the transform.
                raise
            except Exception:
                warn("AST transformer %r threw an error. It will be unregistered." % transformer)
                self.ast_transformers.remove(transformer)

        if self.ast_transformers:
            ast.fix_missing_locations(node)
        return node