Datastore access using apache_beam sdk

class PrintQuery(beam.DoFn):
  def process(self, context):
    yield (context.element.get("language")) # Yielding the language of each user

def datastoreQuery():
    client = datastore.Client(project="projectidhere")
    query = client.query(kind='User').fetch() # User is my user table with over 2lac entries

    pipeline_options = PipelineOptions()
    start_time = time.time()
    p = beam.Pipeline(options=pipeline_options)
    (p
        | beam.Create(query)
        | beam.ParDo(PrintQuery())
        | beam.Map(lambda x: (x, 1)) | beam.combiners.Count.PerKey()   # Counting the frequency of each language
        | beam.io.Write(beam.io.TextFileSink("languageFrequency"))) # writing it to a file

    p.run()
    print("--- %s seconds ---" % (time.time() - start_time))
    return 200