mem_usage.py

#! /usr/bin/python

from __future__ import print_function
import subprocess
import sys
import time

if (len(sys.argv)) != 2:
    print("usage:", sys.argv[0], "<pid>")
    sys.exit(1)

pid = sys.argv[1]

peak_rss = 0

try:
    while True:
        # Use -p because --pid doesn't work on Mac.
        # Also, have to split the output because --no-headers doesn't work on
        # Mac.
        cmd = ["ps", "-o", "rss", "-p", pid];
        heading, rss = (subprocess.check_output(cmd).rstrip()).split('\n');
        rss = int(rss)
        print("{0:.2f} MiB".format(rss / 1024.0))
        if (rss > peak_rss):
            peak_rss = rss
        time.sleep(0.05)

except:
    print("\npeak: {0:.2f} MiB".format(peak_rss / 1024.0))