Dynamic Bookmark in Pythonista

#! /usr/bin/env python

import webbrowser
import datetime
import sys

today = datetime.datetime.today()

two_months_ago = today + datetime.timedelta(weeks = -6)

year = two_months_ago.year
month = two_months_ago.month

safari_prefix = ''
if sys.platform != 'darwin':
    safari_prefix = 'safari-'

url = safari_prefix + 'http://n8henrie.com/{0}/{1}'.format(year, month)

webbrowser.open(url)