[Python-checkins] r61919 - python/trunk/Doc/whatsnew/2.6.rst
andrew.kuchling
python-checkins at python.org
Wed Mar 26 01:30:02 CET 2008
Author: andrew.kuchling
Date: Wed Mar 26 01:30:02 2008
New Revision: 61919
Modified:
python/trunk/Doc/whatsnew/2.6.rst
Log:
Add various items
Modified: python/trunk/Doc/whatsnew/2.6.rst
==============================================================================
--- python/trunk/Doc/whatsnew/2.6.rst (original)
+++ python/trunk/Doc/whatsnew/2.6.rst Wed Mar 26 01:30:02 2008
@@ -555,10 +555,11 @@
Format specifiers can reference other fields through nesting::
fmt = '{0:{1}}'
- fmt.format('Invoice #1234', width) ->
- 'Invoice #1234 '
fmt.format('Invoice #1234', 15) ->
'Invoice #1234 '
+ width = 35
+ fmt.format('Invoice #1234', width) ->
+ 'Invoice #1234 '
The alignment of a field within the desired width can be specified:
@@ -571,11 +572,38 @@
= (For numeric types only) Pad after the sign.
================ ============================================
-Format data types::
-
- ... XXX take table from PEP 3101
+Format specifiers can also include a presentation type, which
+controls how the value is formatted. For example, floating-point numbers
+can be formatted as a general number or in exponential notation:
+
+ >>> '{0:g}'.format(3.75)
+ '3.75'
+ >>> '{0:e}'.format(3.75)
+ '3.750000e+00'
+
+A variety of presentation types are available. Consult the 2.6
+documentation for a complete list (XXX add link, once it's in the 2.6
+docs), but here's a sample::
+
+ 'b' - Binary. Outputs the number in base 2.
+ 'c' - Character. Converts the integer to the corresponding
+ Unicode character before printing.
+ 'd' - Decimal Integer. Outputs the number in base 10.
+ 'o' - Octal format. Outputs the number in base 8.
+ 'x' - Hex format. Outputs the number in base 16, using lower-
+ case letters for the digits above 9.
+ 'e' - Exponent notation. Prints the number in scientific
+ notation using the letter 'e' to indicate the exponent.
+ 'g' - General format. This prints the number as a fixed-point
+ number, unless the number is too large, in which case
+ it switches to 'e' exponent notation.
+ 'n' - Number. This is the same as 'g', except that it uses the
+ current locale setting to insert the appropriate
+ number separator characters.
+ '%' - Percentage. Multiplies the number by 100 and displays
+ in fixed ('f') format, followed by a percent sign.
-Classes and types can define a __format__ method to control how it's
+Classes and types can define a __format__ method to control how they're
formatted. It receives a single argument, the format specifier::
def __format__(self, format_spec):
@@ -610,7 +638,6 @@
Python 2.6 has a ``__future__`` import that removes ``print`` as language
syntax, letting you use the functional form instead. For example::
- XXX need to check
from __future__ import print_function
print('# of entries', len(dictionary), file=sys.stderr)
@@ -701,6 +728,21 @@
.. ======================================================================
+.. _pep-3118:
+
+PEP 3118: Revised Buffer Protocol
+=====================================================
+
+The buffer protocol is a C-level API that lets Python extensions
+XXX
+
+.. seealso::
+
+ :pep:`3118` - Revising the buffer protocol
+ PEP written by Travis Oliphant and Carl Banks.
+
+.. ======================================================================
+
.. _pep-3119:
PEP 3119: Abstract Base Classes
@@ -1082,7 +1124,7 @@
by using pymalloc for the Unicode string's data.
* The ``with`` statement now stores the :meth:`__exit__` method on the stack,
- producing a small speedup. (Implemented by Nick Coghlan.)
+ producing a small speedup. (Implemented by Jeffrey Yasskin.)
* To reduce memory usage, the garbage collector will now clear internal
free lists when garbage-collecting the highest generation of objects.
@@ -1361,10 +1403,8 @@
the forward search.
(Contributed by John Lenton.)
-* The :mod:`new` module has been removed from Python 3.0.
- Importing it therefore
- triggers a warning message when Python is running in 3.0-warning
- mode.
+* (3.0-warning mode) The :mod:`new` module has been removed from
+ Python 3.0. Importing it therefore triggers a warning message.
* The :mod:`operator` module gained a
:func:`methodcaller` function that takes a name and an optional
@@ -1483,6 +1523,14 @@
.. Issue 1727780
+ The new ``triangular(low, high, mode)`` function returns random
+ numbers following a triangular distribution. The returned values
+ are between *low* and *high*, not including *high* itself, and
+ with *mode* as the mode, the most frequently occurring value
+ in the distribution. (Contributed by Raymond Hettinger. XXX check)
+
+ .. Patch 1681432
+
* Long regular expression searches carried out by the :mod:`re`
module will now check for signals being delivered, so especially
long searches can now be interrupted.
@@ -1500,6 +1548,16 @@
.. Patch 1861
+* The :mod:`select` module now has wrapper functions
+ for the Linux :cfunc:`epoll` and BSD :cfunc:`kqueue` system calls.
+ Also, a :meth:`modify` method was added to the existing :class:`poll`
+ objects; ``pollobj.modify(fd, eventmask)`` takes a file descriptor
+ or file object and an event mask,
+
+ (Contributed by XXX.)
+
+ .. Patch 1657
+
* The :mod:`sets` module has been deprecated; it's better to
use the built-in :class:`set` and :class:`frozenset` types.
@@ -1948,9 +2006,8 @@
Porting to Python 2.6
=====================
-This section lists previously described changes, and a few
-esoteric bugfixes, that may require changes to your
-code:
+This section lists previously described changes and other bugfixes
+that may require changes to your code:
* The :meth:`__init__` method of :class:`collections.deque`
now clears any existing contents of the deque
@@ -1986,7 +2043,11 @@
.. Issue 1330538
-* In 3.0-warning mode, inequality comparisons between two dictionaries
+* (3.0-warning mode) The :class:`Exception` class now warns
+ when accessed using slicing or index access; having
+ :class:`Exception` behave like a tuple is being phased out.
+
+* (3.0-warning mode) inequality comparisons between two dictionaries
or two objects that don't implement comparison methods are reported
as warnings. ``dict1 == dict2`` still works, but ``dict1 < dict2``
is being phased out.
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