Returns timestamp of most recently modified file under given path

newest_mtime.py

#!/usr/bin/env python

import sys, os, time

def newest_mtime(path):
    """Returns timestamp of newest file under path."""
    newest_time = 0
    for root, dirs, files in os.walk(path):
        for fname in files:
            mtime = os.stat(os.path.join(root, fname)).st_mtime
            if mtime > newest_time:
                newest_time = mtime
    return newest_time

def newest_timestamp(path, format="%Y%m%d%H%M"):
    return time.strftime(format, time.localtime(newest_mtime(path)))

if __name__ == "__main__":
    print(newest_timestamp(sys.argv[1]))

This script returns the timestamp of the file that has been changed most recently under the given directory path. It's useful to e.g. generate a URL timestamp for a website's static file root directory.

Use it in Django like so:

local_settings.py:

from newest_mtime import newest_timestamp
ts = newest_timestamp('./static/')
STATIC_URL = '/static/v%/' % ts

nginx.conf:

location ~ ^/static/v\d+/(.*)$ {
    alias /home/django/site/static/$1;
    expires max;
}

For more Django tips & tricks see my presentation at http://www.wombatsoftware.com/mpug2016.