请帮我解决这个奇怪的 UnboundLocalError

Question

我尝试制作一个 Alexa Vitual Assistant，但代码抛出一个 UnboundLocalError。请帮助

import speech_recognition as sr
import pyttsx3
import datetime


listener = sr.Recognizer()
engine = pyttsx3.init()
voices = engine.getProperty("voices")
engine.setProperty('voice', voices[1].id)
def talk(text):
    engine.say(text)
    engine.runAndWait()
talk("Hi i'm Alexa ,your assistant")
talk("How can i help you ?")
print("Hi i'm Alexa")

def take_request():
    try:
        with sr.Microphone() as source:
            talk("i am listening")
            print("listening ....")
            voice = listener.listen(source)
            command = listener.recognize_google(voice)
            print(command)
            #command = input("say sth : ")
            commands= command.lower()
            if "a" in commands:
                print(commands)

    except:
        pass
    return commands


def run_alexa():
    #global commands
    cm = take_request()
    if "play" in cm:
        print("playing music")
        talk("playing music")
    elif "time" in cm:
        time = datetime.datetime.now().strftime("%H:%M")
        print(time)
        talk("your current time is "+time)
    else:
        talk('Please say the command again.')
        print("pls talk again !!!")


while True:
    run_alexa()

和错误

Hi i'm Alexa
listening ....
Traceback (most recent call last):
  File "C:\Users\USER\Desktop\autobot\Hana assistant.py", line 50, in <module>
    run_alexa()
  File "C:\Users\USER\Desktop\autobot\Hana assistant.py", line 36, in run_alexa
    cm = take_request()
  File "C:\Users\USER\Desktop\autobot\Hana assistant.py", line 32, in take_request
    return commands
UnboundLocalError: local variable 'commands' referenced before assignment

我可以手写命令而且没有错误！我尝试 global commands 但它不起作用

Answer 1

如果出现异常，您将不会分配 commands。您可以在 try 块之前分配默认值。

def take_request():
    commands = ""
    try:
        with sr.Microphone() as source:
            talk("i am listening")
            print("listening ....")
            voice = listener.listen(source)
            command = listener.recognize_google(voice)
            print(command)
            #command = input("say sth : ")
            commands= command.lower()
            if "a" in commands:
                print(commands)

    except:
        pass
    return commands

请帮我解决这个奇怪的 UnboundLocalError

pls help me fix this weird UnboundLocalError

python

closures

scope

global-variables