Unicode

[leam hall]

Matt wrote:

Hi Leam-
>
> Targeting Python 2.6 for deployment on RHEL/CentOS 6 is a perfectly
> valid use case, and after the recent discussions in multiple threads
> (your "Design: method in class or general function?" and INADA Naoki's
> "People choosing Python 3"), I doubt it would be very useful to
> reiterate the same points.
>
> I can't speak for Peter Otten, but I suspect he was making a very narrow
> statement about one of the large backwards-incompatible changes in
> Python 3: strict separation between text (str) and binary data (bytes).
> This stricter distinction eliminates the conceptual problems you
> described, in terms of ensuring that you need to use the right type at
> the right time in the right place, and would probably have prevented
> your problem entirely.
>
> Additionally, your note of "this works in Python 2 but fails in Python
> 3" shows some text-related confusion that is quite common when dealing
> with the text model in Python 2. It is always the case that the
> `__str__` method should return a `str` object under whichever version of
> Python you're using, and your attempt of `self.name.encode("utf-8")`
> returns the wrong type under Python 3. *Encoding* Unicode text (class
> `unicode` under Python 2, `str` under 3) produces binary data (class
> `str` under Python 2, `bytes` under 3). As such, you're returning a
> `bytes` object from `__str__` in Python 3, which is incorrect. It would
> be appropriate to do something like
>
> """
> def __str__(self):
>     if sys.version_info[0] < 3:
>         return self.name.encode("utf-8")
>     return self.name
> """
>
> Django provides a `python_2_unicode_compatible` decorator that allows
> always returning text (class `unicode` under Python 2, `str` under 3)
> from `__str__`, and automatically rewrites a class' methods under Python
> 2. That decorator renames `__str__` to `__unicode__`, and creates a new
> `__str__` method that essentially returns
> `self.__unicode__().encode('utf-8')`.
>
> (Hopefully this is clear enough, but I intended this message to be
> practical advice for your current task and mental model of what's going
> on, *not* as Python 3 evangelism.)
>
> MMR...
>
>
Matt, thanks! I figured there was a way to get the python major version,
just hadn't gotten there yet. Your code passes user typing and testing.

Peter has earned a lot of leeway due to his expert help and reasonable
manner. I took his comment as a friendly note and, like yours, not Py3
evangelism.

Most of my frustration isn't with the community though I think it has come
off that way. I'm not a good enough coder to get a job with pay close to
what I make as a Linux guy. I just have to deal with the pay check coming
from where I am and not where the rest of the gang is.  :(

Leam