twitter logging example using werkzeug's reloader

gistfile1.py

import os
import sys
import signal
import json
import requests
from subprocess import call
from time import time, sleep
from itertools import chain
try:
    from urllib import urlopen
except ImportError:
    from urllib.request import urlopen
try:
    from thread import start_new_thread
except ImportError:
    from _thread import start_new_thread


def reloader_loop(extra_files=None, interval=1):
    """When this function is run from the main thread, it will force other
    threads to exit when any modules currently loaded change.

    Copyright notice.  This function is based on the autoreload.py from
    the CherryPy trac which originated from WSGIKit which is now dead.

    :param extra_files: a list of additional files it should watch.
    """
    def _iter_module_files():
        modules = list(sys.modules.values())
        for module in modules:
            filename = getattr(module, '__file__', None)
            if filename:
                old = None
                while not os.path.isfile(filename):
                    old = filename
                    filename = os.path.dirname(filename)
                    if filename == old:
                        break
                else:
                    if filename[-4:] in ('.pyc', '.pyo'):
                        filename = filename[:-1]
                    yield filename
    mtimes = {}
    while 1:
        for filename in chain(_iter_module_files(), extra_files or ()):
            try:
                mtime = os.stat(filename).st_mtime
            except OSError:
                continue

            old_time = mtimes.get(filename)
            if old_time is None:
                mtimes[filename] = mtime
                continue
            elif mtime > old_time:
                sys.exit(3)
        sleep(interval)

def restart_with_reloader():
    """Spawn a new Python interpreter with the same arguments as this one,
    but running the reloader thread.
    """
    while 1:
        print(' * Restarting with reloader')
        environ = os.environ.copy()
        environ['RUN_MAIN'] = 'true'

        exit_code = call([sys.executable] + sys.argv, env=environ)
        if exit_code != 3:
            return exit_code

def run_with_reloader(main_func, extra_files=None, interval=1, args=(), kwargs={}):
    """Run the given function in an independent python interpreter."""
    if os.environ.get('RUN_MAIN', '') == 'true':
        start_new_thread(main_func, args, kwargs)
        try:
            reloader_loop(extra_files, interval)
        except KeyboardInterrupt:
            return
    else:
        try:
            status = restart_with_reloader()
            signal.signal(signal.SIGTERM, lambda *args: sys.exit(0))
            sys.exit(status)
        except KeyboardInterrupt:
            pass

def main(auth=('foo','bar')):

    resp = requests.post('https://stream.twitter.com/1/statuses/sample.json',
               auth=auth)
    with open('%s.log'%auth[0], 'a') as f:
        f.write('running\n')
        for tweet in resp.iter_lines():
            if tweet:
                f.write('%s\n' % json.loads(tweet.decode('utf-8')).get('id', ''))
                #except ValueError: raise

if __name__ == '__main__':
    start_new_thread(main)
    run_with_reloader(main)