diff options
| -rw-r--r-- | Doc/whatsnew/whatsnew25.tex | 50 |
1 files changed, 44 insertions, 6 deletions
diff --git a/Doc/whatsnew/whatsnew25.tex b/Doc/whatsnew/whatsnew25.tex index c1ff374..3d5a32a 100644 --- a/Doc/whatsnew/whatsnew25.tex +++ b/Doc/whatsnew/whatsnew25.tex @@ -41,7 +41,7 @@ language. \item The \function{min()} and \function{max()} built-in functions gained a \code{key} keyword argument analogous to the \code{key} -argument for \function{sort()}. This argument supplies a function +argument for \method{sort()}. This argument supplies a function that takes a single argument and is called for every value in the list; \function{min()}/\function{max()} will return the element with the smallest/largest return value from this function. @@ -55,10 +55,17 @@ print max(L, key=len) print max(L) \end{verbatim} -% XXX also supported by heapq.nsmallest() and heapq.nlargest(). - (Contributed by Steven Bethard and Raymond Hettinger.) +\item The list of base classes in a class definition can now be empty. +As an example, this is now legal: + +\begin{verbatim} +class C(): + pass +\end{verbatim} +(Implemented by Brett Cannon.) + \end{itemize} @@ -95,17 +102,48 @@ details. % datetime.datetime() now has a strptime class method which can be used to % create datetime object using a string and format. +\item The \function{nsmallest()} and +\function{nlargest()} functions in the \module{heapq} module +now support a \code{key} keyword argument similar to the one +provided by the \function{min()}/\function{max()} functions +and the \method{sort()} methods. For example: +Example: + +\begin{verbatim} +>>> import heapq +>>> L = ["short", 'medium', 'longest', 'longer still'] +>>> heapq.nsmallest(2, L) # Return two lowest elements, lexicographically +['longer still', 'longest'] +>>> heapq.nsmallest(2, L, key=len) # Return two shortest elements +['short', 'medium'] +\end{verbatim} + +(Contributed by Raymond Hettinger.) + % itertools.islice() now accepts None for the start and step arguments. \item New module: \module{spwd} provides functions for accessing the shadow password database on systems that support it. % XXX give example -% XXX os.stat_float_times is now True +\item The \module{os} module underwent a number of changes. The +\member{stat_float_times} variable now defaults to true, meaning that +\function{os.stat()} will now return time values as floats. (This +doesn't necessarily mean that \function{os.stat()} will return times +that are precise to fractions of a second; not all systems support +such precision.) + +Also, constants named \member{os.SEEK_SET}, \member{os.SEEK_CUR}, and +\member{os.SEEK_END} have been added; these are the parameters to the +\function{os.lseek()} function. + +\item The \class{TarFile} class in the \module{tarfile} module now has +a \method{extractall()} method that extracts all members from the +archive into the current working directory. It's also possible to set +a different directory as the extraction target, and to unpack only a +subset of the archive's members. (Contributed by Lars Gust\"abel.) -% os.{SEEK_SET, SEEK_CUR, SEEK_END} have been added for convenience. -\end{itemize} %====================================================================== |