[Python-checkins] CVS: python/dist/src/Misc NEWS,1.52,1.53

[Guido van Rossum]

Update of /cvsroot/python/python/dist/src/Misc
In directory slayer.i.sourceforge.net:/tmp/cvs-serv3383

Modified Files:
	NEWS 
Log Message:
Added the 2.0b1 news.


Index: NEWS
===================================================================
RCS file: /cvsroot/python/python/dist/src/Misc/NEWS,v
retrieving revision 1.52
retrieving revision 1.53
diff -C2 -r1.52 -r1.53
*** NEWS	2000/09/01 22:34:33	1.52
--- NEWS	2000/09/05 04:38:34	1.53
***************
*** 1,18 ****
! What's new in this release?
  ===========================
  
  Below is a list of all relevant changes since release 1.6.  Older
! changes are in the file HISTORY.  The most recent changes are listed
! first.
  
! A note on attributions: while I have sprinkled some names throughout
! here, I'm grateful to many more people who remain unnamed.  You may
! find your name in the ACKS file.  If you believe you deserve more
! credit, let me know and I'll add you to the list!
  
  
  ======================================================================
  
! <To be done>
  
  ======================================================================
--- 1,274 ----
! What's New in Python 2.0b1?
  ===========================
  
  Below is a list of all relevant changes since release 1.6.  Older
! changes are in the file HISTORY.  If you are making the jump directly
! from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
! HISTORY file!  Many important changes listed there.
  
! Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
! the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
! http://starship.python.net/crew/amk/python/writing/new-python/.
  
+ --Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
  
  ======================================================================
  
! Source Incompatibilities
! ------------------------
! 
! None.  Note that 1.6 introduced several incompatibilities with 1.5.2,
! such as single-argument append(), connect() and bind(), and changes to
! str(long) and repr(float).
! 
! 
! Binary Incompatibilities
! ------------------------
! 
! - Third party extensions built for Python 1.5.x or 1.6 cannot be used
! with Python 2.0; these extensions will have to be rebuilt for Python
! 2.0.
! 
! - On Windows, attempting to import a third party extension built for
! Python 1.5.x or 1.6 results in an immediate crash; there's not much we
! can do about this.  Check your PYTHONPATH environment variable!
! 
! - Python bytecode files (*.pyc and *.pyo) are not compatible between
! releases.
! 
! 
! Overview of Changes Since 1.6
! -----------------------------
! 
! There are many new modules (including brand new XML support through
! the xml package, and i18n support through the gettext module); a list
! of all new modules is included below.  Lots of bugs have been fixed.
! 
! There are several important syntax enhancements, described in more
! detail below:
! 
!   - Augmented assignment, e.g. x += 1
! 
!   - List comprehensions, e.g. [x**2 for x in range(10)]
! 
!   - Extended import statement, e.g. import Module as Name
! 
!   - Extended print statement, e.g. print >> file, "Hello"
! 
! Other important changes:
! 
!   - Optional collection of cyclical garbage
! 
! 
! Augmented Assignment
! --------------------
! 
! This must have been the most-requested feature of the past years!
! Eleven new assignment operators were added:
! 
!     += -+ *= /= %= **= <<= >>= &= ^= |=
! 
! For example,
! 
!     A += B
! 
! is similar to
! 
!     A = A + B
! 
! except that A is evaluated only once (relevant when A is something
! like dict[index].attr).
! 
! However, if A is a mutable object, A may be modified in place.  Thus,
! if A is a number or a string, A += B has the same effect as A = A+B
! (except A is only evaluated once); but if a is a list, A += B has the
! same effect as A.extend(B)!
! 
! Classes and built-in object types can override the new operators in
! order to implement the in-place behavior; the not-in-place behavior is
! used automatically as a fallback when an object doesn't implement the
! in-place behavior.  For classes, the method name is derived from the
! method name for the corresponding not-in-place operator by inserting
! an 'i' in front of the name, e.g. __iadd__ implements in-place
! __add__.
! 
! Augmented assignment was implemented by Thomas Wouters.
! 
! 
! List Comprehensions
! -------------------
! 
! This is a flexible new notation for lists whose elements are computed
! from another list (or lists).  The simplest form is:
! 
!     [<expression> for <variable> in <sequence>]
! 
! For example, [x**2 for i in range(4)] yields the list [0, 1, 4, 9].
! This is more efficient than map() with a lambda.
! 
! You can also add a condition:
! 
!     [<expression> for <variable> in <sequence> if <condition>]
! 
! For example, [w for w in words if w == w.lower()] would yield the list
! of words that contain no uppercase characters.  This is more efficient
! than filter() with a lambda.
! 
! You can also have nested for loops and more than one 'if' clause.  For
! example, here's a function that flattens a sequence of sequences::
! 
!     def flatten(seq):
!         return [x for subseq in seq for x in subseq]
! 
!     flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
! 
! This prints
! 
!     [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
! 
! List comprehensions originated as a patch set from Greg Ewing; Skip
! Montanaro and Thomas Wouters also contributed.
! 
! 
! Extended Import Statement
! -------------------------
! 
! Many people have asked for a way to import a module under a different
! name.  This can be accomplished like this:
! 
!     import foo
!     bar = foo
!     del foo
! 
! but this common idiom gets old quickly.  A simple extension of the
! import statement now allows this to be written as follows:
! 
!     import foo as bar
! 
! There's also a variant for 'from ... import':
! 
!     from foo import bar as spam
! 
! This also works with packages; e.g. you can write this:
! 
!     import test.regrtest as regrtest
! 
! Note that 'as' is not a new keyword -- it is recognized only in this
! context (this is only possible because the syntax for the import
! statement doesn't involve expressions).
! 
! Implemented by Thomas Wouters.
! 
! 
! Extended Print Statement
! ------------------------
! 
! Easily the most controversial new feature, this extension to the print
! statement adds an option to make the output go to a different file
! than the default sys.stdout.
! 
! For example, to write an error message to sys.stderr, you can now
! write:
! 
!     print >> sys.stderr, "Error: bad dog!"
! 
! As a special feature, if the expression used to indicate the file
! evaluates to None, the current value of sys.stdout used.  Thus:
! 
!     print >> None, "Hello world"
! 
! is equivalent to
! 
!     print "Hello world"
! 
! Design and implementation by Barry Warsaw.
! 
! 
! Optional Collection of Cyclical Garbage
! ---------------------------------------
! 
! Python is now equipped with a garbage collector that can hunt down
! cyclical references between Python objects.  It's no replacement for
! reference counting; in fact, it depends on the reference counts being
! correct, and decides that a set of objects belong to a cycle if all
! their reference counts can be accounted for from their references to
! each other.  This devious scheme was first proposed by Eric Tiedemann,
! and brought to implementation by Neil Schemenauer.
! 
! There's a module "gc" that lets you control some parameters of the
! garbage collection.  There's also an option to the configure script
! that lets you enable or disable the garbage collection.  In 2.0b1,
! it's on by default, so that we (hopefully) can collect decent user
! experience with this new feature.  There are some questions about its
! performance.  if it proves to be too much of a problem, we'll turn it
! off by default in the final 2.0 release.
! 
! 
! Smaller Changes
! ---------------
! 
! A new function zip() was added.  zip(seq1, seq2, ...) is equivalent to
! map(None, seq1, seq2, ...) when the sequences have the same length;
! i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)].  When
! the lists are not all the same length, the shortest list wins:
! zip([1,2,3], [10,20]) returns [(1,10), (2,20)].
! 
! sys.version_info is a tuple (major, minor, micro, level, serial).
! 
! Dictionaries have an odd new method, setdefault(key, default).
! dict.setdefault(key, default) returns dict[key] if it exists; if not,
! it sets dict[key] to default and returns that value.  Thus:
! 
!     dict.setdefault(key, []).append(item)
! 
! does the same work as this common idiom:
! 
!     if not dict.has_key(key):
!         dict[key] = []
!     dict[key].append(item)
! 
! 
! New Modules and Packages
! ------------------------
! 
! atexit - for registering functions to be called when Python exits.
! 
! imputil - Greg Stein's alternative API for writing custom import
! hooks.
! 
! pyexpat - an interface to the Expat XML parser, contributed by Paul
! Prescod.
! 
! xml - a new package with XML support code organized (so far) in three
! subpackages: xml.dom, xml.sax, and xml.parsers.  Describing these
! would fill a volume.  There's a special feature whereby a
! user-installed package named _xmlplus overrides the standard
! xmlpackage; this is intended to give the XML SIG a hook to distribute
! backwards-compatible updates to the standard xml package.
! 
! webbrowser - a platform-independent API to launch a web browser.
! 
! 
! C-level Changes
! ---------------
! 
! Several cleanup jobs were carried out throughout the source code.
! 
! All C code was converted to ANSI C; we got rid of all uses of the
! Py_PROTO() macro, which makes the header files a lot more readable.
! 
! Most of the portability hacks were moved to a new header file,
! pyport.h; several other new header files were added and some old
! header files were removed, in an attempt to create a more rational set
! of header files.  (Few of these ever need to be included explicitly;
! they are all included by Python.h.)
! 
! Vladimir Marangozov redesigned more rational APIs for allocating
! memory.  See pymem.h.
! 
! Trent Mick ensured portability to 64-bit platforms, under both Linux
! and Win64, especially for the new Intel Itanium processor.
! 
! Numerous new APIs were added, e.g. 
  
  ======================================================================