def find_nearby_devices(self):
    print("Detecting nearby Bluetooth devices...")
    # 可传参数 duration--持续时间 lookup-name=true 显示设备名
    # 大概查询10s左右
    # 循环查找次数
    loop_num = 3
    i = 0
    try:
        self.nearby_devices = bluetooth.discover_devices(lookup_names=True, duration=5)
        while self.nearby_devices.__len__() == 0 and i < loop_num:
            self.nearby_devices = bluetooth.discover_devices(lookup_names=True, duration=5)
            if self.nearby_devices.__len__() > 0:
                break
            i = i + 1
            time.sleep(2)
            print("No Bluetooth device around here! trying again {}...".format(str(i)))
        if not self.nearby_devices:
            print("There's no Bluetooth device around here. Program stop!")
        else:
            print("{} nearby Bluetooth device(s) has(have) been found:".format(self.nearby_devices.__len__()), self.nearby_devices)  # 附近所有可连的蓝牙设备s
    except Exception as e:
        # print(traceback.format_exc())
        # 不知是不是Windows的原因，当附近没有蓝牙设备时，bluetooth.discover_devices会报错。
        print("There's no Bluetooth device around here. Program stop(2)!")

def find_target_device(self, target_name, target_address):
    self.find_nearby_devices()
    if self.nearby_devices:
        for addr, name in self.nearby_devices:
            if target_name == name and target_address == addr:
                print("Found target bluetooth device with address:{} name:{}".format(target_address, target_name))
                self.find = True
                break
        if not self.find:
            print("could not find target bluetooth device nearby. "
                  "Please turn on the Bluetooth of the target device.")

def connect_target_device(self, target_name, target_address):
    self.find_target_device(target_name=target_name, target_address=target_address)
    if self.find:
        print("Ready to connect")
        self.sock = bluetooth.BluetoothSocket(bluetooth.RFCOMM)
        try:
            self.sock.connect((target_address, 1))
            print("Connection successful. Now ready to get the data")
            data_dtr = ""
            # 以下代码根据需求更改
            while True:
                data = self.sock.recv(1024)
                data_dtr += data.decode()
                if '\n' in data.decode():
                    # data_dtr[:-2] 截断"\t\n",只输出数据
                    print(datetime.datetime.now().strftime("%H:%M:%S")+"->"+data_dtr[:-2])
                    data_dtr = ""
        except Exception as e:
            print("connection fail\n", e)
            self.sock.close()

def close_target_device(self):
    print("Ready to close")
    self.sock.close()