Don't Call Us, We'll Call You: Callback Patterns and Idioms in Python
This was a typical, high-quality, interesting talk by Alex Martelli.
Using the "key" argument of the ".sort" function is far more efficient than using the "cmp" argument because the key only needs to be calculated once.
There are all sorts of uses for callbacks.
Callbacks come from a functional programming mindset.
The template method design pattern is more rigid than simply passing a callback. (2 points for Mike Cheponis if he's reading this.)
Callbacks can be used to customize a function's behavior.
Callbacks can be used for event handling.
Use "functools.partial(callable, *args, **kw)" for partial function application.
Twisted error callbacks are awesome.