old_contents: from wtforms import Form, TextAreaField, validators
  
  
  class NanoTtsForm(Form):
      text = TextAreaField(
          u'Text',
          [validators.InputRequired(), validators.length(max=200)],
          default=u"Nano T T S service.")
  
new_contents: from wtforms import Form, validators, TextAreaField, SelectField
  from libnanotts import NanoTts
  
  
  class NanoTtsForm(Form):
      text = TextAreaField(
          u'Text',
          [validators.InputRequired(), validators.length(max=200)],
          default=u"Nano T T S service.")
      voice = SelectField(
          choices=[(voice, voice) for voice in NanoTts.get_voices()])
  
subject: Update forms.py