ast24.py 文件源码

def visit_Stmt(self, node):
        def _check_del(n):
            # del x is just AssName('x', 'OP_DELETE')
            # we want to transform it to Delete([Name('x', Del())])
            dcls = (_ast.Name, _ast.List, _ast.Subscript, _ast.Attribute)
            if isinstance(n, dcls) and isinstance(n.ctx, _ast.Del):
                return self._new(_ast.Delete, [n])
            elif isinstance(n, _ast.Tuple) and isinstance(n.ctx, _ast.Del):
                # unpack last tuple to avoid making del (x, y, z,);
                # out of del x, y, z; (there's no difference between
                # this two in compiler.ast)
                return self._new(_ast.Delete, n.elts)
            else:
                return n
        def _keep(n):
            if isinstance(n, _ast.Expr) and n.value is None:
                return False
            else:
                return True
        return [s for s in [_check_del(self.visit(n)) for n in node.nodes]
                if _keep(s)]