pyflink.datastream.data_stream.KeyedStream.flat_map

KeyedStream.flat_map(func: Union[Callable, FlatMapFunction], output_type: Optional[TypeInformation] = None) → DataStream

Applies a FlatMap transformation on a KeyedStream. The transformation calls a FlatMapFunction for each element of the DataStream. Each FlatMapFunction call can return any number of elements including none.

Parameters

• func – The FlatMapFunction that is called for each element of the DataStream.

• output_type – The type information of output data.

Returns

The transformed DataStream.