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author | Andrew M. Kuchling <amk@amk.ca> | 2002-11-13 13:24:41 (GMT) |
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committer | Andrew M. Kuchling <amk@amk.ca> | 2002-11-13 13:24:41 (GMT) |
commit | 8a61f499dcb6ea90cb6f283c13e9de53485dfb47 (patch) | |
tree | de99311a1a7ed8cf331bfc4b8063d583cbc638a2 | |
parent | e1172588e608858d26e9de328309fe924c16081c (diff) | |
download | cpython-8a61f499dcb6ea90cb6f283c13e9de53485dfb47.zip cpython-8a61f499dcb6ea90cb6f283c13e9de53485dfb47.tar.gz cpython-8a61f499dcb6ea90cb6f283c13e9de53485dfb47.tar.bz2 |
Fill out the 'Porting' section
Add random.sample()
-rw-r--r-- | Doc/whatsnew/whatsnew23.tex | 64 |
1 files changed, 62 insertions, 2 deletions
diff --git a/Doc/whatsnew/whatsnew23.tex b/Doc/whatsnew/whatsnew23.tex index 244d7ca..27b67e5 100644 --- a/Doc/whatsnew/whatsnew23.tex +++ b/Doc/whatsnew/whatsnew23.tex @@ -943,7 +943,7 @@ property is O(lg~n). (See \url{http://www.nist.gov/dads/HTML/priorityque.html} for more information about the priority queue data structure.) -The Python \module{heapq} module provides \function{heappush()} and +The \module{heapq} module provides \function{heappush()} and \function{heappop()} functions for adding and removing items while maintaining the heap property on top of some other mutable Python sequence type. For example: @@ -1000,6 +1000,31 @@ your character data handler and therefore faster performance. Setting the parser object's \member{buffer_text} attribute to \constant{True} will enable buffering. +\item The \function{sample(\var{population}, \var{k})} function was +added to the \module{random} module. \var{population} is a sequence +containing the elements of a population, and \function{sample()} +chooses \var{k} elements from the population without replacing chosen +elements. \var{k} can be any value up to \code{len(\var{population})}. +For example: + +\begin{verbatim} +>>> pop = range(6) ; pop +[0, 1, 2, 3, 4, 5] +>>> random.sample(pop, 3) # Choose three elements +[0, 4, 3] +>>> random.sample(pop, 6) # Choose all six elements +[4, 5, 0, 3, 2, 1] +>>> random.sample(pop, 6) # Choose six again +[4, 2, 3, 0, 5, 1] +>>> random.sample(pop, 7) # Can't choose more than six +Traceback (most recent call last): + File ``<stdin>'', line 1, in ? + File ``/home/amk/src/sf/python/dist/src/Lib/random.py'', line 396, in sample + raise ValueError, ``sample larger than population'' +ValueError: sample larger than population +>>> +\end{verbatim} + \item The \module{readline} module also gained a number of new functions: \function{get_history_item()}, \function{get_current_history_length()}, and \function{redisplay()}. @@ -1338,7 +1363,42 @@ under ``python -O'' in earlier versions of Python. %====================================================================== \section{Porting to Python 2.3} -XXX write this +This section lists changes that may actually require changes to your code: + +\begin{itemize} + +\item \keyword{yield} is now always a keyword; if it's used as a +variable name in your code, a different name must be chosen. + +\item You can no longer disable assertions by assigning to \code{__debug__}. + +\item Using \code{None} as a variable name will now result in a +\exception{SyntaxWarning} warning. + +\item Names of extension types defined by the modules included with +Python now contain the module and a \samp{.} in front of the type +name. + +\item For strings \var{X} and \var{Y}, \code{\var{X} in \var{Y}} now works +if \var{X} is more than one character long. + +\item The Distutils \function{setup()} function has gained various new +keyword arguments such as \samp{depends}. Old versions of the +Distutils will abort if passed unknown keywords. The fix is to check +for the presence of the new \function{get_distutil_options()} function +in your \file{setup.py} if you want to only support the new keywords +with a version of the Distutils that supports them: + +\begin{verbatim} +from distutils import core + +kw = {'sources': 'foo.c', ...} +if hasattr(core, 'get_distutil_options'): + kw['depends'] = ['foo.h'] +ext = Extension(**kw) +\end{verbatim} + +\end{itemize} %====================================================================== |