Detect if a python module changes and then reload

So I’m developing a rather large python project with a number of modules. The “main” (runnable) module is a daemon (a Thrift daemon, actually) which calls off to other modules for its actual functionality. Starting up the daemon takes a long time because some of the modules have a rather lengthy and involved initialization processes.

So when I start the daemon, I wait… let’s say… 2 minutes for everything to load, which isn’t too bad in the grand scheme of things. However for development it becomes a major pain because I need to restart the daemon EVERY TIME which has been wasting a lot of my time.

Most modules only takes a few seconds to load. Ideally what I’d like to do is detect when any of the files in a particular module have changed, and reload that particular module. I’ve already figured out how to reload a module, but at this point I can’t figure out how to watch a particular module for changes. Keep in mind that a module isn’t a single .py file in this case, but rather a directory with __init__.py and 5-10 .py files, so I need to detect when any of them have changed.

Here is the project layout (if it makes any difference at all)

project
| -- daemonize.py
| -- main.py
| -- moduleA
|    | -- __init__.py
|    | -- happy_panda.py
|    ` -- sad_panda.py
| -- moduleB
|    | -- __init__.py
|    | -- takes_forever_to_load.py
|    ` -- seriously_get_some_coffee.py
| -- moduleC
|    | -- __init__.py
|    | -- frequently_changes.py
|    | -- reasons_i_hate_my_job.txt
|    ` -- home_address_of_moduleB_developer.txt
` -- service.py <-- uses modules A, B, and C

Any ideas or suggestions are appreciated.

EDIT

Thanks for the great feedback. Here is the code I created based on the suggestions. There’s a small bug where pyinotify seems to be getting more than one notification, but it’s a very small problem for me so I’m not going to fix it.

https://gist.github.com/1013122