[Python-3000] bytes & Py_TPFLAGS_BASETYPE

[Guido van Rossum]

On 9/17/07, Greg Ewing <greg.ewing at canterbury.ac.nz> wrote:
> Guido van Rossum wrote:
> > I understand. But bytes are still in flux (see the repeated requests
> > for immutable bytes)
>
> Moreover, my feeling is that immutable byte should be
> the *default*, and if you want mutable bytes you
> should have to ask for it.
>
> This would make bytes more symmetrical with strings,
> where immutability is the default, and if you want
> mutability you use an array.array('c') or whatever
> the equivalent will be in py3k.
>
> It would also help to settle the question of
> whether b"xyz" should be mutable -- clearly not,
> for symmetry with strings.

I'm considering the following option -- it would help if someone
explored creating a patch to implement this, just to see the minimum
amount of code that would need to change compared to 3.0a1: bytes are
always immutable, and for the few places where a mutable bytes buffer
would be handy, we use the array module. Then it would also make sense
to make b[0] return a bytes array of length 1 instead of a small int
-- bytes would be more similar to str in 2.x, albeit completely
incompatible with str in terms of mixed operations.

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