[Python-Dev] inheriting basic types more efficiently

[Guido van Rossum]

I still don't understand what you are asking for. However there's one
problem with your code:

On 4/26/06, Dennis Heuer <dh at triple-media.com> wrote:
>
> class bitarray(long):
> ...
>     def __setitem__(self, key, value):
>         [...]
>         long.__add__(2**key * value) # Should actually overwrite the [...]

What on earth are you trying to do here? There are at least two bugs
in this line: (a) long.__add__ is an unbound method so requires two
arguments; (b) __setitem__ suggests that you're creating a mutable
object; but long is immutable and even if your subclass isn't
immutable, it still can't modify the immutable underlying long.

You probably want to write a class that *has* a long (I agree that it
is a good type to implement a bit array) instead of one that *is* a
long. Subclassing is overrated!

I don't understand at all what you're saying about decimal.

You should take this to comp.lang.python; python-dev is about
developing Python, not about programming questions.

Even if you believe that your problem can only be solved by changes to
Python, I gurantee you that it's much better to discuss this on
c.l.py; most likely there's a solution to your problem (once you
understand it) that does not involve changing the language or its
implementation.

--
--Guido van Rossum (home page: http://www.python.org/~guido/)