Python 3.0, also known as "Python 3000" or "Py3K", is the first ever

Due to time constraints, this document does not exhaustively cover the

very extensive changes to the standard library. :pep:`3108` is the

reference for the major changes to the library. Here's a capsule

review:

* Many old modules were removed. Some, like :mod:`gopherlib` (no

longer used) and :mod:`md5` (replaced by :mod:`hashlib`), were

already deprecated by :pep:`0004`. Others were removed as a result

of the removal of support for various platforms such as Irix, BeOS

and Mac OS 9 (see :pep:`0011`). Some modules were also selected for

removal in Python 3.0 due to lack of use or because a better

replacement exists. See :pep:`3108` for an exhaustive list.

* The :mod:`bsddb3` package was removed because its presence in the

core standard library has proved over time to be a particular burden

for the core developers due to testing instability and Berlekey DB's

release schedule. However, the package is alive and well,

externally maintained at http://www.jcea.es/programacion/pybsddb.htm.

* Some modules were renamed because their old name flaunted

:pep:`0008`, or for various other reasons:

Old Name New Name

_winreg winreg

ConfigParser configparser

copy_reg copyreg

Queue queue

SocketServer socketserver

markupbase _markupbase

repr reprlib

test.test_support test.support

* A common pattern in Python 2.x is to have one version of a module

implemented in pure Python, with an optional accelerated version

implemented as a C extension; for example, :mod:`pickle` and

:mod:`cPickle`. This places the burden of importing the accelerated

version and falling back on the pure Python version on each user of

these modules. In Python 3.0, the accelerated versions are

considered implementation details of the pure Python versions.

Users should always import the standard version, which attempts to

import the accelerated version and falls back to the pure Python

version. The :mod:`pickle` module received this treatment. The

:mod:`profile` module is on the list for 3.1. The :mod:`StringIO`

module has been turned into a class in the :mod:`io` module.

* Some related modules have been grouped into packages, and usually

the submodule names have been simplified. The resulting new

packages are:

* :mod:`dbm` (:mod:`anydbm`, :mod:`dbhash`, :mod:`dbm`,

:mod:`dumbdbm`, :mod:`gdbm`, :mod:`whichdb`).

* :mod:`html` (:mod:`HTMLParser`, :mod:`htmlentitydefs`).

* :mod:`http` (:mod:`httplib`, :mod:`BaseHTTPServer`,

:mod:`CGIHTTPServer`, :mod:`SimpleHTTPServer`, :mod:`Cookie`,

:mod:`cookielib`).

* :mod:`tkinter` (all :mod:`Tkinter`-related modules except

:mod:`turtle`). The target audience of :mod:`turtle` doesn't

really care about :mod:`tkinter`. Also note that as of Python

2.6, the functionality of :mod:`turtle` has been greatly enhanced.

* :mod:`urllib` (:mod:`urllib`, :mod:`urllib`2, :mod:`urlparse`,

:mod:`robotparse`).

* :mod:`xmlrpc` (:mod:`xmlrpclib`, :mod:`DocXMLRPCServer`,

:mod:`SimpleXMLRPCServer`).

Some other library changes (not covered by :pep:`3108`):

* Cleanup of the :mod:`sys` module: removed :func:`sys.exitfunc`,

:func:`sys.exc_clear`, :data:`sys.exc_type`, :data:`sys.exc_value`,

:data:`sys.exc_traceback`. (Note that :data:`sys.last_type`

* Cleanup of the :class:`array.array` type: the :meth:`read` and

:meth:`write` methods are gone; use :meth:`fromfile` and

:meth:`tofile` instead.

* Cleanup of the :mod:`operator` module: removed

:func:`sequenceIncludes` and :func:`isCallable`.

* Cleanup of the :mod:`thread` module: :func:`acquire_lock` and

:func:`release_lock` are gone; use :func:`acquire` and

:func:`release` instead.

* Cleanup of the :mod:`random` module: removed the :func:`jumpahead` API.

This section discusses the many changes in string XXX