pyflink.datastream.data_stream.DataStream.key_by

DataStream.key_by(key_selector: Union[Callable, pyflink.datastream.functions.KeySelector], key_type: Optional[pyflink.common.typeinfo.TypeInformation] = None) → pyflink.datastream.data_stream.KeyedStream

Creates a new KeyedStream that uses the provided key for partitioning its operator states.

Parameters

• key_selector – The KeySelector to be used for extracting the key for partitioning.

• key_type – The type information describing the key type.

Returns

The DataStream with partitioned state(i.e. KeyedStream).