Python: Password descriptor

password_descriptor.py

class Password(str):
    def __eq__(self, other):
        if not isinstance(other, self.__class__):
            other = bcrypt.hashpw(other, self)
        return str.__eq__(self, other)

    def __ne__(self, other):
        return not self.__eq__(other)

    def __get__(self, obj, type=None):
        # that's pretty sick :D
        return self.__class__(obj._password_hash)

    def __set__(self, obj, plain):
        # Hash a password for the first time, with a randomly-generated salt
        # gensalt's log_rounds parameter determines the complexity.
        # The work factor is 2**log_rounds, and the default is 12
        obj._password_hash = bcrypt.hashpw(plain, bcrypt.gensalt())

    def __delete__(self, obj):
        del obj._password_hash

usage_example.py

import mongoengine as me

class User(me.Document):
    email = me.StringField(required=True)
    password = Password()
    _password_hash = me.StringField()
    
>>> user = User(email='[email protected]')
>>> user.password = 'example'
>>> user.password == 'example'
True
>>> user.password == 'Something else'
False