How do we Write a Apache beam pipeline output to a variable instead of a file?

I need to process some values in a data pipeline and need to use the value later somewhere in the program.

Here is a simple example

import apache_beam as beam

p = beam.Pipeline()

resu=(
    p
    | beam.Create([1,3,5,3,5,3])
    | beam.CombineGlobally(beam.combiners.MeanCombineFn())
    | beam.io.WriteToText("result.txt")
)

p.run()

Now the mean value is calculated and put into the file "result.txt". If I need to use the mean value later in the program I need to do a file io operation. I want to have the result come in memory as a variable instead. How do I achieve this?

something like

mean_value=resu.values()
# use mean_value as a regular variable
some_other_value=mean_value/2