notifications-admin/app/main/validators.py

from wtforms import ValidationError
from datetime import datetime
from app.main.encryption import check_hash


class Blacklist(object):
    def __init__(self, message=None):
        if not message:
            message = 'Password is blacklisted.'
        self.message = message

    def __call__(self, form, field):
        if field.data in ['password1234', 'passw0rd1234']:
            raise ValidationError(self.message)


class CsvFileValidator(object):

    def __init__(self, message='Not a csv file'):
        self.message = message

    def __call__(self, form, field):
        if not form.file.data.mimetype == 'text/csv':
            raise ValidationError(self.message)