How to Watch webpages for Changes

Today, I encountered a webpage for which there is no rss feed, nor atom feed. I whipped up something to watch the page myself and report on any changes in python. Hey, Guido, if you integrate requests, I won't have any non-stdlib requirements to the script. What do you say? please? Not that the BDFL reads my blog but anyway, here's the code:

#!/Users/hdiwan/.virtualenvs/globetrekker/bin/python
import argparse
import hashlib
import json
import logging
import pprint
import requests
import smtplib


def send_mail(msg, user, password):
    server = smtplib.SMTP('smtp.gmail.com', 587)
    server.ehlo()
    server.starttls()
    server.ehlo()
    server.login(user, password)
    server.sendmail(user, user, msg)

if __name__ == '__main__':
    argparser = argparse.ArgumentParser(description='Check a website for changes')
    argparser.add_argument('-n', '--url', type=str, default=None, help='Add URL to watcher',  action='store')
    argparser.add_argument('-l', '--list', action='store_true')
    argparser.add_argument('-u', '--user', type=str, default='hd1@jsc.d8u.us', help='Your username',  action='store')
    argparser.add_argument('-p', '--password', type=str, help='Your password', action='store')
    argparser.add_argument('-v', '--verbose', action='store_false')
    parsed = argparser.parse_args()

    if not parsed.verbose:
        logging.basicConfig(level=logging.DEBUG)
    else:
        logging.basicConfig(level=logging.FATAL)

    if parsed.url:
        new_hash = {parsed.url: 0}
        output = json.dumps(new_hash)
        logging.debug(output)
        try:
            with open('/var/tmp/.globetrekker.txt', 'a') as fin:
                data = json.load(fin)
                data[parsed.url] = 0
                logging.debug(data)
                json.dump(data, fin)
        except:
            with open('/var/tmp/.globetrekker.txt', 'w') as fout:
                json.dump(new_hash, fout)
        exit()

    with open('/var/tmp/.globetrekker.txt', 'r') as fin:
        stored_hash_json = json.load(fin)
        logging.debug(stored_hash_json)
        if parsed.list:
            for k in stored_hash_json:
                print(k)
            exit()
    new_hashes = []
    stored_hash = stored_hash_json
    logging.debug(stored_hash)
    for url in stored_hash:
        logging.debug('{} is our URL'.format(url))
        browser = requests.get(url)
        encoding = 'utf-8'
        logging.debug('page retrieved -- {}'.format(url[0]))
        text = browser.content
        encoded = text.encode(encoding, errors='xmlcharrefreplace')
        logging.debug(encoded)
        decoded = encoded.decode(encoding, errors='xmlcharrefreplace')
        logging.debug(decoded)
        new_hash = hashlib.sha1(decoded).hexdigest()
        logging.debug('Calculated hash code: {}'.format(new_hash))
        logging.debug('Stored hash: {}'.format(stored_hash[url]))
        if new_hash != stored_hash[url]:
            logging.debug('{} changed'.format(url))
            if stored_hash[url] != 0:
                send_mail(u'Subject: {} Change detected\r\n\r\n--H'.format(url), parsed.user, parsed.password)

            stored_hash[url] = new_hash
    with open('/var/tmp/.globetrekker.txt', 'w') as fout:
        json.dump(stored_hash, fout)