类型错误：“NoneType”类型的参数不可迭代回溯（最近一次调用最后一次）：类型错误：“NoneType”类型的参数不可迭代

Question

我正在用 python 制作 alexa 并且我收到这个错误我不知道如何解决这个我正在尝试解决这个错误但我不知道如何解决这里是完整的错误如果你不明白是什么我想说这是我在 python 中制作 alexa 的完整错误，我收到了这个错误 我不知道如何解决这个问题 我正在尝试解决这个错误，但我不知道如何解决如果您不明白我想说的内容，请修复这里的完整错误修复此错误，但我不知道如何修复此错误 如果您不明白我在说什么，这是完整错误

抱歉，stackoverflow 要求添加更多详细信息，但我没有更多详细信息

完整错误：

None
Traceback (most recent call last):
  File "alexa.py", line 60, in <module>
    run_alexa()
  File "alexa.py", line 37, in run_alexa
    if 'play' in command:
TypeError: argument of type 'NoneType' is not iterable

完整代码：

import speech_recognition as sr
import pyttsx3
import pywhatkit
import datetime
import wikipedia
import pyjokes

listener = sr.Recognizer()
engine = pyttsx3.init()
voices = engine.getProperty('voices')
engine.setProperty('voice', voices[1].id)


def talk(text):
    engine.say(text)
    engine.runAndWait()


def take_command():
    command = None  # (<-- !!!)
    try:
        with sr.Microphone() as source:
            print('listening...')
            voice = listener.listen(source)
            command = listener.recognize_google(voice)
            command = command.lower()
            if 'alexa' in command:
                command = command.replace('alexa', '')
                print(command)
    except:
        pass
    return command

def run_alexa():
    command = take_command()
    print(command)
    if 'play' in command:
        song = command.replace('play', '')
        talk('playing ' + song)
        pywhatkit.playonyt(song)
    elif 'time' in command:
        time = datetime.datetime.now().strftime('%I:%M %p')
        talk('Current time is ' + time)
    elif 'who the heck is' in command:
        person = command.replace('who the heck is', '')
        info = wikipedia.summary(person, 1)
        print(info)
        talk(info)
    elif 'date' in command:
        talk('sorry, I have a headache')
    elif 'are you single' in command:
        talk('I am in a relationship with wifi')
    elif 'joke' in command:
        talk(pyjokes.get_joke())
    else:
        talk('Please say the command again.')


while True:
    run_alexa()