From 7c29aaee88dab01530090a82c4cb17a506449aa1 Mon Sep 17 00:00:00 2001 From: "Andrew M. Kuchling" Date: Wed, 26 Mar 2008 00:30:02 +0000 Subject: [PATCH] Add various items --- Doc/whatsnew/2.6.rst | 91 ++++++++++++++++++++++++++++++++++++-------- 1 file changed, 76 insertions(+), 15 deletions(-) diff --git a/Doc/whatsnew/2.6.rst b/Doc/whatsnew/2.6.rst index d255c16f902..bc1487e964c 100644 --- a/Doc/whatsnew/2.6.rst +++ b/Doc/whatsnew/2.6.rst @@ -555,10 +555,11 @@ adding a colon followed by a format specifier. For example:: 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 @@ Character Effect = (For numeric types only) Pad after the sign. ================ ============================================ -Format data types:: +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: - ... XXX take table from PEP 3101 + >>> '{0:g}'.format(3.75) + '3.75' + >>> '{0:e}'.format(3.75) + '3.750000e+00' -Classes and types can define a __format__ method to control how it's +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 they're formatted. It receives a single argument, the format specifier:: def __format__(self, format_spec): @@ -610,7 +638,6 @@ function from somewhere else. 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 @@ and it also supports the ``b''`` notation. .. ====================================================================== +.. _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 @@ Optimizations 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 @@ complete list of changes, or look through the CVS logs for all the details. 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 @@ complete list of changes, or look through the CVS logs for all the details. .. 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 @@ complete list of changes, or look through the CVS logs for all the details. .. 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 @@ Some of the more notable changes are: 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 @@ code: .. 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.