What's the best dispatcher/callback library in Python?
I need to allow other Python applications to register callback functions for events in my application. These need to have priorities associated with them (so a callback with a priority of 10 runs before a callback with a priority of 1) and callback functions need to be able to signal errors to the dispatcher.
These are all lightweight callbacks running in the same process, so I don't need to send signals across process boundaries.
Is there a good Python library to handle this, or do I need to write my own?
Are these other applications running in another address space? If so, you'll need to use an interprocess communication library like D-BUS.
If you're just sending signals in the same process, try PyDispatcher
What platform are you running under? GObject is the basis of the GTK GUI that's widely-used under Linux, and it supports event loops with prioritizable events like this.
Try Twisted for anything network-related. Its perspective broker is quite nice to use.
Try python-callbacks - http://code.google.com/p/python-callbacks/.