[Python-3000] A plea for anonymous functions

[Antoine]

>> The problem is not merely related to the number of lines of code. It is
>> a
>> readibility problem. Having the callback enclosed in a the function call
>> which registers it makes the code more readable than defining the
>> callback
>> beforehand.
>
> And, unless I'm missing something, much harder to unit test.

Not harder than any nested function, or am I missing something?