watch_pythonista_forum.py

#!/usr/bin/env python
"""
recent_entries() will print out info on all posts to the Pythonista forum
in the past 24 hours. watch_feed() will print out info on the last
post to the Pythonista forum Sleeps for 15 minutes then check
to see if there is a newer post.
If so, prints out info on it and opens its URL in the webbrowser.  Repeat.
"""

import datetime
import sys
import time
import webbrowser

import feedparser

FEED_URL = 'http://omz-forums.appspot.com/pythonista/rss'
FEED_FMT = '''{title} -- {published}
>>> {link}
>>> {summary}'''


def get_latest_entry(in_url=FEED_URL):
    """
    Return the latest entry from the RSS feed in_url.
    """
    rss_entry = feedparser.parse(FEED_URL).entries
    return rss_entry[0] if rss_entry else None


def watch_feed(in_url=FEED_URL, in_sleep_minutes=15):
    """
    Watch the RSS feed in_url, and open the link in the webbrowser if there is a new post.
    """
    prev_post = get_latest_entry(in_url)
    if prev_post:
        # import pprint ; pprint.pprint(prev_post)
        print(FEED_FMT.format(**prev_post))
    while prev_post:
        curr_post = get_latest_entry(in_url)
        if curr_post and curr_post != prev_post:
            print(FEED_FMT.format(**curr_post))
            webbrowser.open(curr_post.link)  # open new post in browser
            prev_post = curr_post
        print('{} --- sleeping... {}'.format(time.ctime(), '-' * 20))
        for i in xrange(in_sleep_minutes * 6):  # in Pythonista, allow the
            time.sleep(10)  # user to halt the script once every 10 seconds
        # probably add nodoze.py here to wake up device if it goes to sleep


def hours_ago(in_hours_ago=24):
    """
    Return the number of seconds since the epoch, in the past hours.
    """
    delta_t = datetime.timedelta(hours=in_hours_ago)
    return time.time() - delta_t.total_seconds()


def recent_entries(in_url=FEED_URL, in_hours_ago=24):
    """
    Return a list of entries from the RSS feed in_url, in the past in hours.
    """
    cutoff_time = hours_ago(in_hours_ago)
    print('=' * 40)
    print('Cutoff time is: {}'.format(time.ctime(cutoff_time)))
    cutoff_time = time.gmtime(cutoff_time)  # struct_time
    rss_entries = feedparser.parse(in_url).entries
    # import pprint ; pprint.pprint(rss_entries[0])
    for i, post in enumerate(rss_entries):
        post_time = time.strptime(post['published'], '%a, %d %b %Y %H:%M:%S')
        if post_time < cutoff_time:  # this post is too old
            return rss_entries[:i]   # return entries before cutoff_time
    return rss_entries  # ALL entries are before cutoff_time


def main(argv):
    """
    Main function.
    """
    rss_entries = recent_entries(FEED_URL, 24)
    if not rss_entries:
        print('No new entries in the past 24 hours!!')
    for the_post in rss_entries:
        print('-' * 20)
        # import pprint ; pprint.pprint(the_post)
        print(FEED_FMT.format(**the_post))
    for i in xrange(2):
        print('=' * 40)
    watch_feed(FEED_URL)


if __name__ == '__main__':
    sys.exit(main(sys.argv))