def user_exists(form, field):
'''check if user exists, if it does raise error'''
if Classmate.select().where(Classmate.username == field.data).exists():
raise ValidationError('User with that name already exists.')
def email_exists(form, field):
'''check if email exists, if it does raise error'''
if Classmate.select().where(Classmate.email == field.data).exists():
raise ValidationError('User with that email already exists.')
