def __delitem__(self, key):
    self.changed = True
    if isinstance(key, int):
        del self._rows[key]
    else:
        del self._rows[self._get_index_by_id(key)]
def __delitem__(self, key):
    self.changed = True
    if isinstance(key, int):
        del self._rows[key]
    else:
        del self._rows[self._get_index_by_id(key)]