' UnboundLocalError: local variable 'command' referenced before assignment '

Question

我正在制作一个可以识别用户语音的麦克风 class。它给了我一个 UnboundLocalError。当我将 return command 添加到 mic_config() 方法时会发生这种情况。

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

是的，正如 Carcigenicate 所说，这是因为命令仅在 try 块中定义。这意味着如果出现错误，则未定义命令。我不知道它是否只是在你在这里发布的代码中，但是 with 语句中有一个缩进错误

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

' UnboundLocalError: local variable 'command' referenced before assignment '

' UnboundLocalError: local variable 'command' referenced before assignment '

python

speech-recognition

python-3.x