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author | Raymond Hettinger <python@rcn.com> | 2003-11-26 17:52:45 (GMT) |
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committer | Raymond Hettinger <python@rcn.com> | 2003-11-26 17:52:45 (GMT) |
commit | d4462300db217c357108e9618190b2f92ae8522f (patch) | |
tree | f5e575e717f0011281953908583b8d43169cdb6d /Doc/whatsnew | |
parent | 72452650af812d06796995a25e939e0534bfa0b8 (diff) | |
download | cpython-d4462300db217c357108e9618190b2f92ae8522f.zip cpython-d4462300db217c357108e9618190b2f92ae8522f.tar.gz cpython-d4462300db217c357108e9618190b2f92ae8522f.tar.bz2 |
Nits from a review of the documentation update.
Diffstat (limited to 'Doc/whatsnew')
-rw-r--r-- | Doc/whatsnew/whatsnew24.tex | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/Doc/whatsnew/whatsnew24.tex b/Doc/whatsnew/whatsnew24.tex index 0f5e546..2e573b5 100644 --- a/Doc/whatsnew/whatsnew24.tex +++ b/Doc/whatsnew/whatsnew24.tex @@ -12,7 +12,7 @@ \tableofcontents This article explains the new features in Python 2.4. No release date -for Python 2.4 has been set; expect that this will happen in 2004. +for Python 2.4 has been set; expect that this will happen mid-2004. While Python 2.3 was primarily a library development release, Python 2.4 may extend the core language and interpreter in @@ -42,6 +42,7 @@ False set(['a', 'r', 'b', 'c', 'd']) >>> ''.join(a) # convert back into a string 'arbcd' + >>> b = set('alacazam') # form a second set >>> a - b # letters in a but not in b set(['r', 'd', 'b']) @@ -51,6 +52,7 @@ set(['a', 'c', 'r', 'd', 'b', 'm', 'z', 'l']) set(['a', 'c']) >>> a ^ b # letters in a or b but not both set(['r', 'd', 'b', 'm', 'z', 'l']) + >>> a.add('z') # add a new element >>> a.update('wxy') # add multiple new elements >>> a @@ -115,6 +117,11 @@ Here are all of the changes that Python 2.4 makes to the core Python language. \begin{itemize} + +\item The string methods, \method{ljust()}, \method{rjust()}, and +\method{center()} now take a optional argument for specifying a +fill character other than a space. + \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. @@ -185,10 +192,12 @@ use in expressions. The differences are: [11, 12, 13, 14, 15, 16, 17, 18, 19] >>> L = [9,7,8,3,2,4,1,6,5] # original is left unchanged [9,7,8,3,2,4,1,6,5] + >>> list.sorted('Monte Python') # any iterable may be an input [' ', 'M', 'P', 'e', 'h', 'n', 'n', 'o', 'o', 't', 't', 'y'] + +>>> # List the contents of a dict sorted by key values >>> colormap = dict(red=1, blue=2, green=3, black=4, yellow=5) ->>> # Lists the contents of the dict sorted by key values >>> for k, v in list.sorted(colormap.iteritems()): ... print k, v ... @@ -202,7 +211,7 @@ yellow 5 \item The \function{zip()} built-in function and \function{itertools.izip()} - now return an empty list instead of raising a \exception{TypeError} + now returns an empty list instead of raising a \exception{TypeError} exception if called with no arguments. This makes the functions more suitable for use with variable length argument lists: @@ -297,6 +306,12 @@ Changes to Python's build process and to the C API include: objN)}, constructs tuples from a variable length argument list of Python objects. + \item A new function, \function{PyDict_Contains(d, k)}, implements + fast dictionary lookups without masking exceptions raised during + the loop-up process (compare with \function{PySequence_Contains()} + which is slower or \function{PyMapping_HasKey()} which clears all + exceptions). + \end{itemize} |