[Zope3-dev] Re: What does python 3000 mean for zope?

[Christian Theune]

Am Freitag, den 31.08.2007, 23:35 -0400 schrieb Fred Drake:
> On 8/31/07, Stephan Richter <srichter at cosmos.phy.tufts.edu> wrote:
> > That's is what I am most worried about. I really need to look into this to see
> > how much things changed. Maybe not as much as we tend to think.
> 
> I think the changes will be substantial, both for Python code and for
> C extensions.
> 
> A biggie is going to be the replacement of immutable str for binary
> data; that gets replaced with a mutable bytes object.  It'll be good
> to have, but the loss of an immutable sequence-of-bytes type seems
> like a problem to me.
> 
> On the other hand, we gain ordinary string literals being Unicode.
> 
> I'm not sure what will happen with the standard library; it's just too
> early to say.  I don't actually expect huge changes there, aside from
> changes required by the str->bytes replacement.

I think the byte/text change is excellent.

The worrysome part is that Python 2.6 is going to introduce information
about code that won't run in Python 3. However, Guido said there won't
be any substantially useful common subset of Python that runs both in 2
and 3. 

He imagines users to write code compatible to 2.6 and use the 2to3
conversion tool to automatically migrate. He envisioned an iterative
process where you keep tuning your Python 2 code until the converter
does the right thing. Which means you can by some means run the code in
2 and 3.

In general our small eggs are a good start for being able to tackle the
problem slowly. Above point might make the effort futile again though.