constant_folding.py 文件源码

def fold(self, node):
        self._has_names.append(False)
        node = self.generic_visit(node)
        if not self._has_names.pop():
            try:
                node = self.convert(node)
            except TypeError as exc:
                if  not isinstance(node, ast.Expression) \
                and str(exc).startswith('expected Expression node, got'):
                    try:
                        node = self.convert(ast.Expression(body=node))
                    except:
                        pass
            except:
                pass
        return node