pyflink.datastream.data_stream.DataStream.flat_map#
- DataStream.flat_map(func: Callable | FlatMapFunction, output_type: TypeInformation | None = None) DataStream[source]#
Applies a FlatMap transformation on a DataStream. 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.