text: from app.models import User
  from flask_wtf import FlaskForm
  from wtforms import StringField, PasswordField, BooleanField, SubmitField, TextAreaField
  from wtforms.validators import DataRequired, Email, EqualTo, ValidationError, Length
  
  
  class LoginForm(FlaskForm):
      username = StringField('Username', validators=[DataRequired()])
      password = PasswordField('Password', validators=[DataRequired()])
      remember_me = BooleanField('Remember Me')
      submit = SubmitField('Sign In')
  
  
  class RegistrationForm(FlaskForm):
      username = StringField('Username', validators=[DataRequired()])
      email = StringField('Email', validators=[DataRequired(), Email()])
      password = PasswordField('Password', validators=[DataRequired()])
      confirm = PasswordField('Confirm',
                              validators=[DataRequired(),
                                          EqualTo('password')])
      submit = SubmitField('Register')
  
      def validate_username(self, username):
          user = User.query.filter_by(username=username.data).first()
          if user is not None:
              raise ValidationError('Please use a different username.')
  
      def validate_email(self, email):
          user = User.query.filter_by(email=email.data).first()
          if user is not None:
              raise ValidationError('Please use a different email address.')
  
  
  class EditProfileForm(FlaskForm):
      username = StringField('Username', validators=[DataRequired()])
      about_me = TextAreaField('About me', validators=[Length(min=0, max=140)])
      submit = SubmitField('Submit')
  