The Python Software Foundation releases Python 3.0, the latest version of the Python dynamic language for application development. Python 3.0 is incompatible with past versions and introduces several new features and ways of doing things.
The Python Software Foundation released Python 3.0, the latest version of
the Python language, on Dec. 3.
Python 3.0, also known as Python 3000 or Py3k, is a new version of the
language that is incompatible with the 2.x line of releases, Python Software
Foundation officials said.
According to the PSF, with Version 3.0 the Python language is mostly the
same, but many details, especially how built-in objects such as dictionaries
and strings work, have changed considerably, and a lot of deprecated features
have finally been removed. Also, the standard library has been reorganized in a
few prominent places, foundation officials said.
In response to a query from eWEEK, Guido van Rossum, the creator of the
Python language, said the standout features in Python 3.0 are, "Much
better Unicode support, and cleanup of collected 'cruft.'"
In a Dec. 4 blog post
about Python 3.0, Van Rossum said
Compared to 2.6, Python 3.0 is the first-ever
intentionally backwards-incompatible Python release. There are more changes
than in a typical release, and more that are important for all Python users.
Nevertheless, after digesting the changes, you'll find that Python really
hasn't changed all that much-by and large, we're mostly fixing well-known
annoyances and warts, and removing a lot of old cruft.
Indeed, "Python 3.0 uses the concepts of text and [binary] data instead
of Unicode strings and 8-bit strings," Van Rossum said. "All text is
Unicode; however, encoded Unicode is represented as binary data ... As a
consequence of this change in philosophy, pretty much all code that uses
Unicode, encodings or binary data most likely has to change. The change is for
the better, as in the 2.x world there were numerous bugs having to do with
mixing encoded and unencoded text."
In a blog post from March, Van Rossum
warned Python developers
: "Don't change your APIs incompatibly when
porting to Py3k."
Yes, you heard that right: even though
Python 3.0 is changing incompatibly, I implore you (especially if you're
maintaining a library that's used by others) not to make incompatible changes
to your API. If you have make API changes, do them before you port to
3.0-release a version with the new API for
Python 2.5, or 2.6 if you must. (Or do it later, after you've released a port
to 3.0 without adding new features.)
Explaining a bit further, Van Rossum said, "Why? Think of your users.
Suppose Ima Lumberjack has implemented a Web 2.0 app for managing his sawmill.
Ima is a happy user of your most excellent Web 2.0 framework. Now Ima wants to
upgrade his app to Py3k. He waits until you have ported your framework to Py3k.
He does everything by the books, runs his source code through the 2to3 tool,
and starts testing. Imagine his despair when the tests fail: How is he going to
tell whether the breakage is due to your API
changes or due to his own code not being Py3k-ready?"
Yet, "On the other hand, if [you] port your Web 2.0 framework to Py3k
without making API changes, Ima's task is
much more focused: The bugs he is left with after running 2to3 are definitely
in his own code, which (presumably) he knows how to debug and fix," Van
Incidentally, despite the fact that many believe the language's name, Python,
is derived from the snake by the same name, it is not. The Python language is
so named in homage to the "Monty Python" comic team.
According to a Wikipedia
entry on the subject
: "An important goal of the Python developers is
making Python fun to use. This is reflected in the origin of the name (based on
the television series "Monty Python's Flying Circus"), in the common
practice of using Monty Python references in example code, and in an
occasionally playful approach to tutorials and reference materials. For
example, the metasyntactic variables often used in Python literature are spam
and eggs, instead of the traditional foo and bar."