[Haskell-cafe] Python?

[Quinn Dunkan]

On 5/10/05, Daniel Carrera <dcarrera at digitaldistribution.com> wrote:
> Hello,
> 
> This might be a strange question to ask on a Haskell list, but I do want
> to hear your opinions. What do you think of Python?

Python has first class functions and lexical scoping, and encourages
higher-order functions, though to a much lesser degree than a real
functional language.  It has list comprehensions which it stole
directly from haskell, and a tab oriented syntax that is somewhat
similar to haskell's offside rule but simpler.  It is very natural to
write in a somewhat functional style, especially in regards to
sequence processing: higher order functions and listcomps provide the
processing and its built in generators and iterator protocol provide
some of the benefits of laziness.  Its elementary pattern matching
encourages you to return as many values from a function as you need
and use zip() (another haskell steal) to iterate over parallel
sequences (all pattern matches are irrefutable, though).

However, python is definately an imperative language.  How much
mutable state your objects have depends entirely on programmer
discipline.  Some built in types are mutable, and it's up to you
whether you copy or mutate.  Python's "lists" are actually arrays, and
recursive car/cdr type stuff is not a natural fit.  Python loves a for
loop.

All that said, it "feels" haskellish to me for some reason.  I think
teaching python is a reasonable approach.  If you are used to using
the REPL, writing small functions, and using listcomps and HOFs and
not engaging in gratuitous mutation then I don't think haskell will be
such a huge jump.  Dynamic typing -> static typing and "why do you
have to use do {}" is likely to be a bigger issue.  I went from
haskell to python so my perspective is all backwards though :)