hupper is an integrated process monitor that will track changes to any imported Python files in sys.modules as well as custom paths. When files are changed the process is restarted.

Hupper can load any Python code similar to python -m <module> by using the hupper -m <module> program.

$ hupper -m myapp
Starting monitor for PID 23982.

Start by defining an entry point for your process. This must be an importable path in string format. For example, myapp.scripts.serve.main.

# myapp/scripts/serve.py
import sys
import hupper
import waitress
def wsgi_app(environ, start_response):
    start_response('200 OK', [('Content-Type', 'text/plain')])
    yield b'hello'
def main(args=sys.argv[1:]):
    if '--reload' in args:
        # start_reloader will only return in a monitored subprocess
        reloader = hupper.start_reloader('myapp.scripts.serve.main')
        # monitor an extra file
        reloader.watch_files(['foo.ini'])
    waitress.serve(wsgi_app)

hupper is inspired by initial work done by Carl J Meyer and David Glick during a Pycon sprint and is built to be a more robust and generic version of Ian Bicking's excellent PasteScript paste serve --reload and Pyramid's pserve --reload.