[Python-Dev] adding a bytes sequence type to Python

[Skip Montanaro]

    Guido> Anyway, if we really do have enough use cases for byte array
    Guido> literals, we might add them.  I still think that would be
    Guido> confusing though, because byte arrays are most useful if they are
    Guido> mutable: and then we'd have mutable literals -- blechhhh!

Today I can initialize mutable objects from immutable strings:

    >>> print list("abc")
    ['a', 'b', 'c']
    >>> print set("abc")
    set(['a', 'c', 'b'])

I see no reason that mutable bytes objects couldn't be created from
otherwise immutable sequences either.  Would it be a problem to ensure that

    a = b"abc"
    b = b"abc"
    print a is b

prints False?

The main difference as I see it is that byte literals would be completely
devoid of any sort of interpretation as unicode sequences.  It would be nice
if this was possible:

    # -*- coding: utf-8 -*-
    b = b"â"

though that would probably wreak havoc with editors and hex escapes would
have to be used in most situations.

Skip