Python Productivity over C++

[Gordon McMillan]

Neurocrat wrote:

>gmcm at hypernet.com (Gordon McMillan) writes:
>
>[snip]
>
>> One point worth reiterating is that where the app (in a C++ design)
>> calls for lots of related classes, you will probably only have a
>> handful in Python. Of course, this means discarding classical "OOP"
>> thinking, and desinging more in the "component" style. But this can
>> yield an order of magnitude all by itself.
>
>If it's worth reiterating, would you mind elaborating on this
>somewhat?

Simply that in Python, inheritance doesn't necessarily have anything to do 
with runtime behavior. (You can, of course, introduce that dependency, but 
you'd be well advised not to.)

The classic example would be 2 base classes (say Event and View), and you 
want view->process(event) to get to both the right overload and the right 
override. In C++ (or Java) that takes spelling out the whole num(View 
derived classes) x num(Event derived classes) matrix, and bouncing the 
message back and forth (first to get the overload and then to get the 
override). In Python, it takes view.process(event).

That is, it's the interface that matters (not the derivation), and you 
don't even have to get formal about that.

Not that you should throw out everything you know about pre-condions and 
post-conditions and substitutability; but you don't have to spend all week 
convincing the compiler you know what you're doing.

- Gordon