from flask_wtf import FlaskForm
    from wtforms import StringField, PasswordField, SubmitField, BooleanField,SelectField
    from wtforms.validators import InputRequired, Length, Email, EqualTo,ValidationError

    class RegistrationForm(FlaskForm):
        username = StringField('Username',validators=
                   [DataRequired(),Length(min=2,max=20)])
        email = StringField('Email',validators=[DataRequired(),Email()])
        branches = SelectField('',[validators.input_required("Please choose your branch")],choices=[('-1','-- select --'),('0','cse'),('1','ece'),('2','mech'),('3','chem'),('4','mme'),('5','civil')])
        password = PasswordField('Password',validators=[DataRequired()])
        confirm_password = PasswordField('Confirm Password',validators=[DataRequired(),EqualTo('password')])
        submit = SubmitField('Sign Up')

<form method="POST" action="/register">
    {{ form.hidden_tag() }}
    {{ form.csrf_token }}
    {{ form.username.errors }}
    {{ form.username(class="form-control form-control-lg") }}
    {{ form.email(class="form-control form-control-lg") }}
    {{ form.password(class="form-control form-control-lg") }}
    {{ form.confirm_password(class="form-control form-control-lg") }}
    </form>