title: Error: TypeError: can only concatenate str (not "NoneType") to str
body: <p>I'm doing a vocal assistant in Python 3.8 and I use a maps url to create an itinerary.
  The problem is that I have an error and I have no idea how to fix it:
  this is my code</p>
  
  <pre><code>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)
  </code></pre>
  
  <p>And the error</p>
  
  <pre><code>  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
  </code></pre>