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