    def __repr__(self) -> str:
        """
        String representation of the DataCollection.

        Examples:
            >>> from towhee.runtime.data_queue import DataQueue, ColumnType
            >>> from towhee.datacollection.data_collection import DataCollection
            >>> dq = DataQueue([('a', ColumnType.SCALAR), ('b', ColumnType.QUEUE)])
            >>> dc = DataCollection(dq)
            >>> repr(dc)
            '<DataCollection Schema[a: ColumnType.SCALAR, b: ColumnType.QUEUE] SIZE 0>'
        """
        names = self._schema
        types = self._type_schema
        content = ', '.join([i + ': ' + str(j) for i, j in zip(names, types)])
        return f'<{self.__class__.__name__} Schema[{content}] SIZE {len(self)}>'
String representation of the DataCollection.

Examples:
>>> from towhee.runtime.data_queue import DataQueue, ColumnType
>>> from towhee.datacollection.data_collection import DataCollection
>>> dq = DataQueue([('a', ColumnType.SCALAR), ('b', ColumnType.QUEUE)])
>>> dc = DataCollection(dq)
>>> repr(dc)
'<DataCollection Schema[a: ColumnType.SCALAR, b: ColumnType.QUEUE] SIZE 0>'
towhee/datacollection/data_collection.py