beam_to_global_window.py

import apache_beam as beam
from apache_beam.transforms.window import FixedWindows, GlobalWindows

events = [
    ("k1", {"a": 1, "b":2}),
    ("k1", {"a": 1, "b":2}),
    ("k2", {"a": 1, "b":2}),
    ("k2", {"a": 1, "b":2}),
    ("k3", {"a": 1, "b":2}),
    ("k4", {"a": 1, "b":2}),
]

class ToGlobalWindow(beam.DoFn):
    def process(self, element):
        yield GlobalWindows.windowed_value(element)

def main():

    with beam.Pipeline() as p:
        (
            p | beam.Create(events) | beam.WindowInto(windowfn=FixedWindows(size=60)) | beam.GroupByKey() | beam.ParDo(ToGlobalWindow()) | beam.Map(print)
        )

    p.run()

main()