Error: TypeError: can only concatenate str (not "NoneType") to str

Error: TypeError: can only concatenate str (not "NoneType") to str

我在 Python 3.8 中做语音助手,我使用地图 url 创建行程。 问题是我有一个错误,我不知道如何修复它: 这是我的代码

def RecordAudio(ask = False):
    print("micro on")
    voice_data = ''
    r = sr.Recognizer()
    with sr.Microphone() as source:
        r.adjust_for_ambient_noise(source)
        if ask:
            print(ask)
        audio = r.listen(source)
        try:
            voice_data = r.recognize_google(audio, language="en-EN")
            print(voice_data)
            respond(voice_data)
        except sr.UnknownValueError:
            if "" in voice_data.lower():
                RecordAudio()
            else:
                print("Sorry, I did not understand, could you repeat ?")
                RecordAudio()
        except sr.RequestError:
            print("I can't answer for the moment")

def respond(voice_data):
    if "itineraire" in voice_data:
        frommaps = RecordAudio('Where do you go from?')
        tomaps = RecordAudio("Where do you go to?")
        print("Calculating...")
        time.sleep(1)
        itineraireurl = "https://www.google.fr/maps/dir/" +frommaps +'/'+tomaps
        webbrowser.get().open(itineraireurl)

错误

  File "main.py", line 86, in respond
    itineraireurl = "https://www.google.fr/maps/dir/" +frommaps +'/'+tomaps
TypeError: can only concatenate str (not "NoneType") to str

我只需要在 record_audio() 函数中写入 return voice_data

itineraireurl = "https://www.google.fr/maps/dir/" +frommaps +'/'+tomaps
    webbrowser.get().open(itineraireurl)

将上面的代码行以字符串的形式放在下面:

itineraireurl = f"https://www.google.fr/maps/dir/ {frommaps} +'/'+tomaps.webbrowser.get().open(itineraireurl)"

PS : 尝试使用 python f string.