test_cancel.py 文件源码

def setUp(self):
        # create a closed serial port
        self.s = serial.serial_for_url(PORT, baudrate=300)  # extra slow ~30B/s => 1kb ~ 34s
        self.assertTrue(hasattr(self.s, 'cancel_write'), "serial instance has no cancel_write")
        self.s.write_timeout = 10
        self.cancel_called = 0