merits of Lisp vs Python

[Robert Brown]

Paul Rubin <http://phr.cx@NOSPAM.invalid> writes:
> Espen Vestre <espen at vestre.net> writes:
>> > Can you redefine CLOS methods without calling CLOS functions that tell
>> > the object system what to expect (so it can do things like update the
>> > MRO cache)?  I.e. can you redefine them by poking some random
>> > dictionary?  You can in Python.  I don't claim that's a good thing.
>> 
>> Just as I said: Less managable, but not more dynamic.
>
> I'm not getting through to you.  Yes, you could create a Python-like
> object system in Lisp that's separate from CLOS, but nobody would use
> it ....

I think you are not understanding the point that Espen is trying to make.
He is not suggesting a different object system for Lisp.

Espen is saying that Common Lisp often offers the same dynamic feature as
Python has, such as the ability to redefining a method at runtime.  Lisp,
however, forces you to call a CLOS function or use an well defined interface
when redefining a method.  You can't just change a value in a hash table.
Does this make Lisp "less dynamic" than Python?  Espen would say it's not
less dynamic, but rather that a similar level of dynamism is achieved in
Common Lisp via well defined interfaces.  The compiler knows the interfaces,
so it can do a better job optimizing the code.