app\main\forms(5).py

from flask_login import current_user
from flask_wtf import FlaskForm
from wtforms import StringField, TextAreaField
from wtforms.validators import Length, Regexp
from wtforms import ValidationError
from ..models import User


class EditProfileForm(FlaskForm):
    class Meta:
        csrf = False

    name = StringField('name', validators=[Length(0, 64)])
    username = StringField('username', validators=[Length(1, 64),
        Regexp('^[A-Za-z][A-Za-z0-9_.]*$', 0,
               'Usernames must have only letters, numbers, dots or '
               'underscores')])
    about_me = TextAreaField('about_me')

    def validate_username(self, field):
        if field.data and field.data != current_user.username:
            if User.query.filter_by(username=field.data).first():
                raise ValidationError('Username already in use.')