def __getitem__(self, key):
    if (key in HEADERS):
        return tuple(self._get_col(key))
    elif isinstance(key, int):
        return self._rows[key]
    else:
        return self._rows[self._get_index_by_id(key)]
def __getitem__(self, key):
    if (key in HEADERS):
        return tuple(self._get_col(key))
    elif isinstance(key, int):
        return self._rows[key]
    else:
        return self._rows[self._get_index_by_id(key)]