pool.py 文件源码

def checkout(cls, pool):
        rec = pool._do_get()
        try:
            dbapi_connection = rec.get_connection()
        except:
            with util.safe_reraise():
                rec.checkin()
        echo = pool._should_log_debug()
        fairy = _ConnectionFairy(dbapi_connection, rec, echo)
        rec.fairy_ref = weakref.ref(
            fairy,
            lambda ref: _finalize_fairy and
            _finalize_fairy(
                dbapi_connection,
                rec, pool, ref, echo)
        )
        _refs.add(rec)
        if echo:
            pool.logger.debug("Connection %r checked out from pool",
                              dbapi_connection)
        return fairy