def __eq__(self, other):
        """'Deep, sparse compare.

        Deeply compare two entities, following the non-None attributes of the
        non-persisted object, if possible.

        """
        if other is self:
            return True
        elif not self.__class__ == other.__class__:
            return False

        if id(self) in _recursion_stack:
            return True
        _recursion_stack.add(id(self))

        try:
            # pick the entity that's not SA persisted as the source
            try:
                self_key = sa.orm.attributes.instance_state(self).key
            except sa.orm.exc.NO_STATE:
                self_key = None

            if other is None:
                a = self
                b = other
            elif self_key is not None:
                a = other
                b = self
            else:
                a = self
                b = other

            for attr in list(a.__dict__):
                if attr.startswith('_'):
                    continue
                value = getattr(a, attr)

                try:
                    # handle lazy loader errors
                    battr = getattr(b, attr)
                except (__HOLE__, sa_exc.UnboundExecutionError):
                    return False

                if hasattr(value, '__iter__'):
                    if hasattr(value, '__getitem__') and not hasattr(
                            value, 'keys'):
                        if list(value) != list(battr):
                            return False
                    else:
                        if set(value) != set(battr):
                            return False
                else:
                    if value is not None and value != battr:
                        return False
            return True
        finally:
            _recursion_stack.remove(id(self))
dataset/ETHPy150Open RoseOu/flasky/venv/lib/python2.7/site-packages/sqlalchemy/testing/entities.py/ComparableEntity.__eq__