[Python-Dev] peps: And now for something completely different.

Antoine Pitrou solipsis at pitrou.net
Sun Nov 13 22:47:26 CET 2011

On Sun, 13 Nov 2011 22:33:28 +0100
barry.warsaw <python-checkins at python.org> wrote:
> +And Now For Something Completely Different
> +==========================================

So, is the release manager a man with two noses?

> +Strings and bytes
> +-----------------
> +
> +Python 2's basic original string type are called 8-bit strings, and
> +they play a dual role in Python 2 as both ASCII text and as byte
> +arrays.  While Python 2 also has a unicode string type, the
> +fundamental ambiguity of the core string type, coupled with Python 2's
> +default behavior of supporting automatic coercion from 8-bit strings
> +to unicodes when the two are combined, often leads to `UnicodeError`s.
> +Python 3's standard string type is a unicode, and Python 3 adds a
> +bytes type, but critically, no automatic coercion between bytes and
> +unicodes is provided.  Thus, the core interpreter, its I/O libraries,
> +module names, etc. are clear in their distinction between unicode
> +strings and bytes.  This clarity is often a source of difficulty in
> +transitioning existing code to Python 3, because many third party
> +libraries and applications are themselves ambiguous in this
> +distinction.  Once migrated though, most `UnicodeError`s can be
> +eliminated.

First class unicode (*) support also makes Python much friendlier to
non-ASCII natives when it comes to things like filesystem access or
error reporting.

(*) even though Tom Christiansen would disagree, but perhaps we can
settle on first and a half

> +Imports
> +-------
> +
> +In Python 3, star imports (e.g. ``from x import *``) are only
> +premitted in module level code.




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