str(bytes) in Python 3.0

[Kay Schluehr]

On 12 Apr., 14:44, Christian Heimes <li... at cheimes.de> wrote:
> Gabriel Genellina schrieb:
>
> > On the last line, str(x), I would expect 'abc' - same as str(x, 'ascii')
> > above. But I get the same as repr(x) - is this on purpose?
>
> Yes, it's on purpose but it's a bug in your application to call str() on
> a bytes object or to compare bytes and unicode directly. Several months
> ago I added a bytes warning option to Python. Start Python as  "python
> -bb" and try it again. ;)
>
> Christian

And making an utf-8 encoding default is not possible without writing a
new function?