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python - TypeError：尝试将参数传递给循环内的函数时，“NoneType”对象不可下标

问题描述

我正在尝试将字典值传递给函数，但出现此错误：

Traceback (most recent call last):
  File "check_alarm_status.py", line 33, in <module>
    main()
  File "check_alarm_status.py", line 18, in main
    alarmStatus = read_digital_input.main("i1", adams_ips[n])[0]
TypeError: 'NoneType' object is not subscriptable

我已经在其他脚本中使用了相同的函数，但它在循环内的这个函数中不起作用。这是我的代码：

import read_digital_input
import change_terminal_light
import time

terminales_ips = { "1":"10.102.12.87", "2":"10.102.12.88", "3":"10.102.12.89", "4":"10.102.12.90", "5":"10.107.12.80"}
adams_ips = {"1":"10.102.12.91", "2":"10.102.12.92", "3":"10.102.12.93", "4":"10.102.12.94", "5":"10.107.12.82"}
previous_state = [0, 0, 0, 0, 0]
state = [False, False, False, False, False]

APAGADO = 0
ENCENDIDO = 5
aux = 0

def main():
        while True:
                for n in adams_ips:
                        alarmStatus = read_digital_input.main("i1", adams_ips[n])[0]
                        state[int(n)-1] = alarmStatus
                        print("Alarm status ", n, " = ", alarmStatus)
                        if state[int(n)-1] is not previous_state[int(n)-1]:
                                print("Terminal ", n, " changed")
                                if state[int(n)-1] == True:
                                        print("Encendiendo el terminal", n)
                                        change_terminal_light.main(ENCENDIDO, terminales_ips[n])
                                elif state[int(n)-1] == False:
                                        print("Apagando el terminal", n)
                                        change_terminal_light.main(APAGADO, terminales_ips[n])
                        previous_state[int(n)-1] = state[int(n)-1]
                        time.sleep(0.5)

if __name__ == "__main__":
        main()

我见过类似的错误，但我无法解决这个问题。

编辑 这里是 read_digital_input.py （我正在使用它与其他脚本一起使用）：

import time
from pyModbusTCP.client import ModbusClient

port = "502"

coil_dictionary = {
    "i0": 0,
    "i1": 1,
    "i2": 2,
    "i3": 3,
    "i4": 4
}


def main(coil, host):
    print(host)
    try:
        c = ModbusClient(host, port)
        c.open()
        state = c.read_coils(coil_dictionary[coil])
        return state

    except ValueError:
        print("Error with host or port params")


if __name__ == '__main__':
    main()

标签： pythontypeerror

解决方案

回溯告诉你这一行有错误

alarmStatus = read_digital_input.main("i1", adams_ips[n])[0]

'NoneType' object is not subscriptable表示您已下标（通过调用 []）一个对象None，因此很可能

read_digital_input.main("i1", adams_ips[n])

调用返回一个None。也许你需要检查这是否是一个无，像这样

def main():
        while True:
                for n in adams_ips:
                        input = read_digital_input.main("i1", adams_ips[n])
                        if input is None:
                            continue
                            # you may want to do something else than simply skipping here
                        alarmStatus = alarm[0]
                        state[int(n)-1] = alarmStatus
                        print("Alarm status ", n, " = ", alarmStatus)
                        if state[int(n)-1] is not previous_state[int(n)-1]:
                                print("Terminal ", n, " changed")
                                if state[int(n)-1] == True:
                                        print("Encendiendo el terminal", n)
                                        change_terminal_light.main(ENCENDIDO, terminales_ips[n])
                                elif state[int(n)-1] == False:
                                        print("Apagando el terminal", n)
                                        change_terminal_light.main(APAGADO, terminales_ips[n])
                        previous_state[int(n)-1] = state[int(n)-1]
                        time.sleep(0.5)

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