Kaydet (Commit) 1a420251 authored tarafından Andrew M. Kuchling's avatar Andrew M. Kuchling

Add some recent changes

üst af28e4b6
...@@ -27,8 +27,33 @@ rationale, refer to the PEP for a particular new feature. ...@@ -27,8 +27,33 @@ rationale, refer to the PEP for a particular new feature.
%====================================================================== %======================================================================
\section{PEP 322: Reverse Iteration}
% Large, PEP-level features and changes should be described here. A new built-in function, \function{reversed(seq)}, takes a sequence
and returns an iterator that returns the elements of the sequence
in reverse order.
\begin{verbatim}
>>> for i in reversed([1,2,3]):
... print i
...
3
2
1
\end{verbatim}
Note that \function{reversed()} only accepts sequences, not arbitrary
iterators. If you want to reverse an iterator, convert it to
a list or tuple with \function{list()} or \function{tuple()}.
\begin{verbatim}
>>> input = open('/etc/passwd', 'r')
>>> for line in reversed(list(input)):
... print line
...
root:*:0:0:System Administrator:/var/root:/bin/tcsh
...
\end{verbatim}
%====================================================================== %======================================================================
...@@ -76,6 +101,23 @@ The \var{reverse} parameter should have a Boolean value. If the value is ...@@ -76,6 +101,23 @@ The \var{reverse} parameter should have a Boolean value. If the value is
of \code{L.sort() ; L.reverse()}, you can now write of \code{L.sort() ; L.reverse()}, you can now write
\code{L.sort(reverse=True)}. \code{L.sort(reverse=True)}.
\item The list type gained a \method{sorted(iterable)} method that
returns the elements of the iterable as a sorted list. It also accepts
the \var{cmp}, \var{key}, and \var{reverse} keyword arguments, same as
the \method{sort()} method. An example usage:
\begin{verbatim}
>>> L = [9,7,8,3,2,4,1,6,5]
>>> list.sorted(L)
[1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> L
[9, 7, 8, 3, 2, 4, 1, 6, 5]
>>>
\end{verbatim}
Note that the original list is unchanged; the list returned by
\method{sorted()} is a newly-created one.
\item The \function{zip()} built-in function and \function{itertools.izip()} now return an empty list \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 instead of raising a \exception{TypeError} exception if called
with no arguments. with no arguments.
...@@ -114,6 +156,9 @@ details. ...@@ -114,6 +156,9 @@ details.
supports transparency, this makes it possible to use a transparent background. supports transparency, this makes it possible to use a transparent background.
(Contributed by J\"org Lehmann.) (Contributed by J\"org Lehmann.)
\item The \module{heapq} module is no longer implemented in Python,
having been converted into C.
\item The \module{random} module has a new method called \method{getrandbits(N)} \item The \module{random} module has a new method called \method{getrandbits(N)}
which returns an N-bit long integer. which returns an N-bit long integer.
......
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