pyflink.datastream.data_stream.WindowedStream.apply#
- WindowedStream.apply(window_function: pyflink.datastream.functions.WindowFunction, result_type: Optional[pyflink.common.typeinfo.TypeInformation] = None) pyflink.datastream.data_stream.DataStream [source]#
Applies the given window function to each window. The window function is called for each evaluation of the window for each key individually. The output of the window function is interpreted as a regular non-windowed stream.
Note that this function requires that all data in the windows is buffered until the window is evaluated, as the function provides no means of incremental aggregation.
- Parameters
window_function – The window function.
result_type – Type information for the result type of the window function.
- Returns
The data stream that is the result of applying the window function to the window.