Question

我正在尝试使用每次发送消息时都会更新的变量（msg_no）更新字符串（MESSAGE）

我戳了一下，看起来msg_no变量正在按照我想要的方式进行更新，但是字符串（MESSAGE）没有得到更新（每次显示为0）。我不确定为什么，谢谢您的帮助。

import xbee
import time

msg_no = 0

# TODO: replace with the 64-bit address of your target device.
TARGET_64BIT_ADDR = b'\x00\x13\xA2\x00\x41\xB7\x6C\x8C'
MESSAGE = "Hello from router (Msg No. %s)" % (msg_no)

print(" +---------------------------------------+")
print(" | XBee MicroPython Transmit Data Sample |")
print(" +---------------------------------------+\n")

print("Sending data to %s >> %s" % (''.join('{:02x}'.format(x).upper() for x in TARGET_64BIT_ADDR),
                                    MESSAGE))

try:
    msg_no += 1
    xbee.transmit(TARGET_64BIT_ADDR, MESSAGE)
    print("Data sent successfully")
except Exception as e:
    print("Transmit failure: %s" % str(e))

time.sleep(5)

try:
    msg_no += 1
    MESSAGE = MESSAGE
    xbee.transmit(TARGET_64BIT_ADDR, MESSAGE)
    print("Data sent successfully")
except Exception as e:
    print("Transmit failure: %s" % str(e))

Answer 1

MESSAGE = MESSAGE没有任何效果，您可以做的是为消息创建一个模板，然后在要创建消息时使用它：

# put this line on top of the script
MESSAGE_TEMPLATE = "Hello from router (Msg No. %s)"

#some code

# use this whenever a message with number `msg_no` needs to be created
MESSAGE = MESSAGE_TEMPLATE % msg_no

字符串不随变量变化而更新

1 个答案: