Simulating piping one command to another using Python

pipe.py

#!/usr/bin/env python3

import subprocess

# This performs the equivalent of `ps -axm -o rss,comm | sort -rn -k 1 | head -n 20`
number_of_entries = 20
cmd1 = ['/bin/ps', '-axm', '-o', 'rss,comm']
cmd2 = ['sort', '-rn', '-k', '1']
cmd3 = ['head', '-n', str(number_of_entries)]

p1 = subprocess.Popen(cmd1, stdout=subprocess.PIPE)
p2 = subprocess.Popen(cmd2, stdin=p1.stdout, stdout=subprocess.PIPE)
p3 = subprocess.Popen(cmd3, stdin=p2.stdout, stdout=subprocess.PIPE)
output = p3.stdout.read().decode()

print(output)

This specific example is using the MacOS Sequoia version of ps.