diff options
Diffstat (limited to 'Doc')
| -rw-r--r-- | Doc/whatsnew/whatsnew24.tex | 47 |
1 files changed, 34 insertions, 13 deletions
diff --git a/Doc/whatsnew/whatsnew24.tex b/Doc/whatsnew/whatsnew24.tex index 45315cb..23c0430 100644 --- a/Doc/whatsnew/whatsnew24.tex +++ b/Doc/whatsnew/whatsnew24.tex @@ -756,11 +756,13 @@ language. \item The \method{dict.update()} method now accepts the same argument forms as the \class{dict} constructor. This includes any -mapping, any iterable of key/value pairs, and keyword arguments. +mapping, any iterable of key/value pairs, and keyword arguments. +(Contributed by Raymond Hettinger.) \item The string methods \method{ljust()}, \method{rjust()}, and \method{center()} now take an optional argument for specifying a fill character other than a space. +(Contributed by Raymond Hettinger.) \item Strings also gained an \method{rsplit()} method that works like the \method{split()} method but splits from the end of @@ -776,6 +778,7 @@ the string. \item The \method{sort()} method of lists gained three keyword arguments: \var{cmp}, \var{key}, and \var{reverse}. These arguments make some common usages of \method{sort()} simpler. All are optional. +(Contributed by Raymond Hettinger.) \var{cmp} is the same as the previous single argument to \method{sort()}; if provided, the value should be a comparison @@ -860,6 +863,8 @@ red 1 yellow 5 \end{verbatim} +(Contributed by Raymond Hettinger.) + \item Integer operations will no longer trigger an \exception{OverflowWarning}. The \exception{OverflowWarning} warning will disappear in Python 2.5. @@ -884,7 +889,8 @@ Python dictionary. (Contributed by Raymond Hettinger.) >>> transpose([]) [] \end{verbatim} - +(Contributed by Raymond Hettinger.) + \item Encountering a failure while importing a module no longer leaves a partially-initialized module object in \code{sys.modules}. The incomplete module object left behind would fool further imports of the @@ -892,6 +898,7 @@ same module into succeeding, leading to confusing errors. \item \constant{None} is now a constant; code that binds a new value to the name \samp{None} is now a syntax error. +(Contributed by Raymond Hettinger.) \end{itemize} @@ -906,6 +913,7 @@ the name \samp{None} is now a syntax error. were also optimized for dictionaries, resulting in performance boosts for \method{keys()}, \method{values()}, \method{items()}, \method{iterkeys()}, \method{itervalues()}, and \method{iteritems()}. + (Contributed by Raymond Hettinger.) \item The machinery for growing and shrinking lists was optimized for speed and for space efficiency. Appending and popping from lists now @@ -913,12 +921,12 @@ the name \samp{None} is now a syntax error. the underlying system \cfunction{realloc()}. List comprehensions also benefit. \method{list.extend()} was also optimized and no longer converts its argument into a temporary list before extending - the base list. + the base list. (Contributed by Raymond Hettinger.) \item \function{list()}, \function{tuple()}, \function{map()}, \function{filter()}, and \function{zip()} now run several times faster with non-sequence arguments that supply a \method{__len__()} - method. + method. (Contributed by Raymond Hettinger.) \item The methods \method{list.__getitem__()}, \method{dict.__getitem__()}, and \method{dict.__contains__()} are @@ -927,10 +935,11 @@ the name \samp{None} is now a syntax error. access doubles their performance and makes them more suitable for use as arguments to functionals: \samp{map(mydict.__getitem__, keylist)}. + (Contributed by Raymond Hettinger.) \item Added a new opcode, \code{LIST_APPEND}, that simplifies the generated bytecode for list comprehensions and speeds them up - by about a third. + by about a third. (Contributed by Raymond Hettinger.) \item String concatenations in statements of the form \code{s = s + "abc"} and \code{s += "abc"} are now performed more efficiently in @@ -938,6 +947,7 @@ certain circumstances. This optimization won't be present in other Python implementations such as Jython, so you shouldn't rely on it; using the \method{join()} method of strings is still recommended when you want to efficiently glue a large number of strings together. +(Contributed by Armin Rigo.) \end{itemize} @@ -1015,7 +1025,7 @@ True Several modules now take advantage of \class{collections.deque} for improved performance, such as the \module{Queue} and -\module{threading} modules. +\module{threading} modules. (Contributed by Raymond Hettinger.) \item The \module{ConfigParser} classes have been enhanced slightly. The \method{read()} method now returns a list of the files that @@ -1044,7 +1054,7 @@ any problems as a \member{defect} attribute of the message. high volumes of data. In addition, the module has two new functions \function{nlargest()} and \function{nsmallest()} that use heaps to find the N largest or smallest values in a dataset without the - expense of a full sort. + expense of a full sort. (Contributed by Raymond Hettinger.) \item The \module{imaplib} module now supports IMAP's THREAD command (contributed by Yves Dionne) and new \method{deleteacl()} and @@ -1103,6 +1113,8 @@ r ['r', 'r'] [('a', 5), ('b', 2), ('c', 1), ('d', 1), ('r', 2)] \end{verbatim} +(Contributed by Hye-Shik Chang.) + \item \module{itertools} also gained a function named \function{tee(\var{iterator}, \var{N})} that returns \var{N} independent iterators that replicate \var{iterator}. If \var{N} is omitted, the @@ -1127,6 +1139,7 @@ If the separation is large, then you might as well use \function{list()} instead. When the iterators track closely with one another, \function{tee()} is ideal. Possible applications include bookmarking, windowing, or lookahead iterators. +(Contributed by Raymond Hettinger.) \item A number of functions were added to the \module{locale} module, such as \function{bind_textdomain_codeset()} to specify a @@ -1176,6 +1189,8 @@ data extractors when used with \function{map()} or [('d', 1), ('c', 2), ('b', 3), ('a', 4)] \end{verbatim} +(Contributed by Raymond Hettinger.) + \item The \module{optparse} module was updated. The module now passes its messages through \function{gettext.gettext()}, making it possible to internationalize Optik's help and error messages. Help messages @@ -1203,12 +1218,14 @@ not it's a symbolic link. This differs from the existing \item The \module{poplib} module now supports POP over SSL. \item The \module{profile} module can now profile C extension functions. -% XXX more to say about this? +% XXX more to say about this? +(Contributed by Nick Bastin.) \item The \module{random} module has a new method called \method{getrandbits(N)} which returns an N-bit long integer. This method supports the existing \method{randrange()} method, making it possible to efficiently generate arbitrarily large random numbers. + (Contributed by Raymond Hettinger.) \item The regular expression language accepted by the \module{re} module was extended with simple conditional expressions, written as @@ -1261,11 +1278,12 @@ Other threads can assign and retrieve their own values for the \item The \module{timeit} module now automatically disables periodic garbarge collection during the timing loop. This change makes - consecutive timings more comparable. + consecutive timings more comparable. (Contributed by Raymond Hettinger.) \item The \module{weakref} module now supports a wider variety of objects including Python functions, class instances, sets, frozensets, deques, arrays, files, sockets, and regular expression pattern objects. + (Contributed by Raymond Hettinger.) \item The \module{xmlrpclib} module now supports a multi-call extension for transmitting multiple XML-RPC calls in a single HTTP operation. @@ -1315,18 +1333,19 @@ Changes to Python's build process and to the C API include: \item Three new convenience macros were added for common return values from extension functions: \csimplemacro{Py_RETURN_NONE}, \csimplemacro{Py_RETURN_TRUE}, and \csimplemacro{Py_RETURN_FALSE}. + (Contributed by Brett Cannon.) \item Another new macro, \csimplemacro{Py_CLEAR(\var{obj})}, decreases the reference count of \var{obj} and sets \var{obj} to the - null pointer. + null pointer. (Contributed by Jim Fulton.) \item A new function, \cfunction{PyTuple_Pack(\var{N}, \var{obj1}, \var{obj2}, ..., \var{objN})}, constructs tuples from a variable - length argument list of Python objects. + length argument list of Python objects. (Contributed by Raymond Hettinger.) \item A new function, \cfunction{PyDict_Contains(\var{d}, \var{k})}, implements fast dictionary lookups without masking exceptions raised - during the look-up process. + during the look-up process. (Contributed by Raymond Hettinger.) \item A new function, \cfunction{PyArg_VaParseTupleAndKeywords()}, is the same as \cfunction{PyArg_ParseTupleAndKeywords()} but takes a @@ -1336,7 +1355,7 @@ Changes to Python's build process and to the C API include: \item A new method flag, \constant{METH_COEXISTS}, allows a function defined in slots to co-exist with a \ctype{PyCFunction} having the same name. This can halve the access time for a method such as - \method{set.__contains__()}. + \method{set.__contains__()}. (Contributed by Raymond Hettinger.) \item Python can now be built with additional profiling for the interpreter itself. This is intended for people developing on the @@ -1359,6 +1378,7 @@ Changes to Python's build process and to the C API include: \begin{itemize} \item The Windows port now builds under MSVC++ 7.1 as well as version 6. + (Contributed by Martin von Loewis.) \end{itemize} @@ -1375,6 +1395,7 @@ changes to your code: \item The \function{zip()} built-in function and \function{itertools.izip()} now return an empty list instead of raising a \exception{TypeError} exception if called with no arguments. + (Contributed by Raymond Hettinger.) \item \function{dircache.listdir()} now passes exceptions to the caller instead of returning empty lists. |