' UnboundLocalError: 赋值前引用的局部变量 'command' '

Question

I am making a microphone class that recognize user voice. It gives me an UnboundLocalError . That happens when I add a return command to the mic_config() method.

import speech_recognition as sr
import pyaudio
from speaker import Speaker


class Microphone:
    """Microphone class that represent mic and get user's voice..."""

    def __init__(self):
        """Initializing of class"""
        self.recognizer = sr.Recognizer()  # Voice recognizer
        self.microphone = sr.Microphone()  # Mic

    def mic_config(self):
        try:
            with self.microphone as source:  # Getting mic
            print('Listening...')
            voice = self.recognizer.listen(source)
            command = self.recognizer.recognize_google(voice, language='en-IN')  # Using google api
            print(command)  

        except: 
            pass
            return command


m1 = Microphone()  # just a test
m1.mic_config()```

Answer 1

Yeah as Carcigenicate said it is because command is only defined in the try block. This means that if there is an error then command is not defined. I don't know if it is just in the code you posted here but there is an indent error in the with statement

try:
    with self.microphone as source:
        print('Listening...')
        voice = self.recognizer.listen(source)
        command = self.recognizer.recognize_google(voice, language='en-IN')
        print(command)

except: 
    raise CustomError
    # or return None, command = None, etc just define command before the last line
    # or don't let the function reach the return command statement

return command