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Various corrections

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Andrew M. Kuchling 2008-09-06 12:50:05 +00:00
parent ad2a9e72f1
commit 48a937ab41
1 changed files with 15 additions and 15 deletions
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Doc/whatsnew/2.6.rst
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@ -63,7 +63,7 @@ what it can, adding compatibility functions in a
usages that will become unsupported in 3.0.
Some significant new packages have been added to the standard library,
such as the :mod:`multiprocessing` and :mod:`jsonlib` modules, but
such as the :mod:`multiprocessing` and :mod:`json` modules, but
there aren't many new features that aren't related to Python 3.0 in
some way.
@ -2014,16 +2014,16 @@ changes, or look through the Subversion logs for all the details.
others, the missing values are set to *fillvalue*. For example::
itertools.izip_longest([1,2,3], [1,2,3,4,5]) ->
[(1, 1), (2, 2), (3, 3), (None, 4), (None, 5)]
(1, 1), (2, 2), (3, 3), (None, 4), (None, 5)
``product(iter1, iter2, ..., [repeat=N])`` returns the Cartesian product
of the supplied iterables, a set of tuples containing
every possible combination of the elements returned from each iterable. ::
itertools.product([1,2,3], [4,5,6]) ->
[(1, 4), (1, 5), (1, 6),
(1, 4), (1, 5), (1, 6),
(2, 4), (2, 5), (2, 6),
(3, 4), (3, 5), (3, 6)]
(3, 4), (3, 5), (3, 6)
The optional *repeat* keyword argument is used for taking the
product of an iterable or a set of iterables with themselves,
@ -2031,39 +2031,39 @@ changes, or look through the Subversion logs for all the details.
are returned::
itertools.product([1,2], repeat=3) ->
[(1, 1, 1), (1, 1, 2), (1, 2, 1), (1, 2, 2),
(2, 1, 1), (2, 1, 2), (2, 2, 1), (2, 2, 2)]
(1, 1, 1), (1, 1, 2), (1, 2, 1), (1, 2, 2),
(2, 1, 1), (2, 1, 2), (2, 2, 1), (2, 2, 2)
With two iterables, *2N*-tuples are returned. ::
itertools.product([1,2], [3,4], repeat=2) ->
[(1, 3, 1, 3), (1, 3, 1, 4), (1, 3, 2, 3), (1, 3, 2, 4),
(1, 3, 1, 3), (1, 3, 1, 4), (1, 3, 2, 3), (1, 3, 2, 4),
(1, 4, 1, 3), (1, 4, 1, 4), (1, 4, 2, 3), (1, 4, 2, 4),
(2, 3, 1, 3), (2, 3, 1, 4), (2, 3, 2, 3), (2, 3, 2, 4),
(2, 4, 1, 3), (2, 4, 1, 4), (2, 4, 2, 3), (2, 4, 2, 4)]
(2, 4, 1, 3), (2, 4, 1, 4), (2, 4, 2, 3), (2, 4, 2, 4)
``combinations(iterable, r)`` returns sub-sequences of length *r* from
the elements of *iterable*. ::
itertools.combinations('123', 2) ->
[('1', '2'), ('1', '3'), ('2', '3')]
('1', '2'), ('1', '3'), ('2', '3')
itertools.combinations('123', 3) ->
[('1', '2', '3')]
('1', '2', '3')
itertools.combinations('1234', 3) ->
[('1', '2', '3'), ('1', '2', '4'), ('1', '3', '4'),
('2', '3', '4')]
('1', '2', '3'), ('1', '2', '4'), ('1', '3', '4'),
('2', '3', '4')
``permutations(iter[, r])`` returns all the permutations of length *r* of
the iterable's elements. If *r* is not specified, it will default to the
number of elements produced by the iterable. ::
itertools.permutations([1,2,3,4], 2) ->
[(1, 2), (1, 3), (1, 4),
(1, 2), (1, 3), (1, 4),
(2, 1), (2, 3), (2, 4),
(3, 1), (3, 2), (3, 4),
(4, 1), (4, 2), (4, 3)]
(4, 1), (4, 2), (4, 3)
``itertools.chain(*iterables)`` is an existing function in
:mod:`itertools` that gained a new constructor in Python 2.6.
@ -2073,7 +2073,7 @@ changes, or look through the Subversion logs for all the details.
all the elements of the second, and so on. ::
chain.from_iterable([[1,2,3], [4,5,6]]) ->
[1, 2, 3, 4, 5, 6]
1, 2, 3, 4, 5, 6
(All contributed by Raymond Hettinger.)