threadlocal.py 文件源码

def contextual_connect(self, **kw):
        if not hasattr(self._connections, 'conn'):
            connection = None
        else:
            connection = self._connections.conn()

        if connection is None or connection.closed:
            # guards against pool-level reapers, if desired.
            # or not connection.connection.is_valid:
            connection = self._tl_connection_cls(
                self,
                self._wrap_pool_connect(
                    self.pool.connect, connection),
                **kw)
            self._connections.conn = weakref.ref(connection)

        return connection._increment_connect()