The philosophy is hardcoded in the design of the language. For example, the BDFL has explicitly stated he doesn't want macros because it will hurt the readability (1), and he rejected support for multi-line anonymous functions because he didn't find a syntax which he thought was clear and readable enough. Clearly this is a very different philosophy than the one behind Lisp.
(1) The quote from Guido:
Programmable syntax is not in Python's
future -- or at least it's not for Python 3000. The problem IMO is
that everybody will abuse it to define their own language. And the
problem with that is that it will fracture the Python community
because nobody can read each other's code any more.
(http://mail.python.org/pipermail/python-3000/2006-April/0002...)
Well it's easy to disagree with him on many points.
The use of macros that I've seen in CL source doesn't indicate that people are creating other programming languages out of Lisp. In fact, it makes the source easier to read by allowing a natural level of terseness by way of abstraction.
Python's method of abstraction is via encapsulation in it's class/meta-class/object model.
However, this is an argument for another post.
Funny how these Lisp posts continue to flame across the net.
Programmable syntax is not in Python's future -- or at least it's not for Python 3000. The problem IMO is that everybody will abuse it to define their own language. And the problem with that is that it will fracture the Python community because nobody can read each other's code any more
I like Python and use it everyday, and I this is simply FUD. Sadly it's the kind of argument I hear coming too often from people in the Python community unfamiliar with Lisp when attempting to critique powerful Lisps.
Is it really FUD though? Having gone through a few bruising experiences with different libraries having incompatible object systems built in Javascript, I have come to appreciate the advantages of only having one way to implement certain types of structures.
It doesn't need to be hard-coded into the language though - a decent Standard Library showing how things should be done, and a culture maintained by the community would be enough. That would allow everyone the freedom to do what they want if they say a definate advantage in breaking with convention, whilst making it easy for people to generate libraries that are interoperable...
I think macros do have certain disadvantages (they make debugging seem to look harder, more syntax, etc, ...).
But I find things like extensive use of MOP also make maintenance of programming more challenging.
Common Lisp has never tried to take away 'power' from users.
Scheme had a different philosophy: reduce everything to the most basic and pleasing constructs. But that approach has its own disadvantages - if one arrives at the bottom of programming language constructs, working 'upwards' is a problem.
Take for example the argument lists: Common Lisp has things like keywords, optional and rest arguments. Plain Scheme only has rest arguments. Adding other argument interpretation is possible, but is only really use if the language would support it and would make use of it.
>Clearly this is a very different philosophy than the one behind Lisp.
Depends on which lisp you mean. There are many dialects of lisp and each have their own philosophies and ideals. Scheme, for example, is a minimalist lisp whose philosophy is probably not too different from python - although python has a far bigger standard library (but that is a separate issue).
I actually wound up in an email discussion about that with Guido. He made it clear that it wasn't just that he didn't find a syntax he liked, but that he didn't try hard because he's not convinced that code that makes heavy use of anonymous functions is a good idea. And the latter seems to me to be his real objection.
