Comment

Peter Bengtsson

From https://docs.python.org/3/library/concurrent.futures.html#concurrent.futures.ProcessPoolExecutor
"If max_workers is None or not given, it will default to the number of processors on the machine."

So by default, it will use as many CPUs as your computer possibly has.

Parent comment

Viola

How should I increase the instance number or thread number?because I have many zip file to extract.