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More doc tweaks.

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Raymond Hettinger 2009-01-22 05:27:37 +00:00
parent c8b4ceceee
commit 94adc8e4b5
1 changed files with 12 additions and 15 deletions
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Doc/library/collections.rst
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@ -179,18 +179,15 @@ For example::
Counter objects have a dictionary interface except that they return a zero Counter objects have a dictionary interface except that they return a zero
count for missing items instead of raising a :exc:`KeyError`:: count for missing items instead of raising a :exc:`KeyError`::
>>> c = Counter(['egg', 'ham']) >>> c = Counter(['eggs', 'ham'])
>>> c['bacon'] # count of a missing element is zero >>> c['bacon'] # count of a missing element is zero
0 0
Setting a count to zero still leaves an element in the dictionary. Use Setting a count to zero does not remove an element from a counter.
``del`` to remove it entirely: Use ``del`` to remove it entirely:
>>> c = Counter(['arthur', 'gwain']) >>> c['sausage'] = 0 # counter entry with a zero count
>>> c['arthur'] = 0 # set the count of 'arthur' to zero >>> del c['sausage'] # del actually removes the entry
>>> 'arthur' in c # but 'arthur' is still in the counter
True
>>> del c['arthur'] # del will completely remove the entry
.. versionadded:: 2.7 .. versionadded:: 2.7
@ -272,19 +269,19 @@ counts less than one::
.. seealso:: .. seealso::
* `Counter class <http://code.activestate.com/recipes/576611/>`_
adapted for Python 2.5 and an early `Bag recipe
<http://code.activestate.com/recipes/259174/>`_ for Python 2.4.
* `Bag class <http://www.gnu.org/software/smalltalk/manual-base/html_node/Bag.html>`_ * `Bag class <http://www.gnu.org/software/smalltalk/manual-base/html_node/Bag.html>`_
in Smalltalk. in Smalltalk.
* A `Counter <http://code.activestate.com/recipes/576611/>`_ conformant
recipe for Python 2.5 and an early Python `Bag recipe
<http://code.activestate.com/recipes/259174/>`_ for Python 2.4.
* Wikipedia entry for `Multisets <http://en.wikipedia.org/wiki/Multiset>`_\. * Wikipedia entry for `Multisets <http://en.wikipedia.org/wiki/Multiset>`_\.
* `C++ multisets <http://www.demo2s.com/Tutorial/Cpp/0380__set-multiset/Catalog0380__set-multiset.htm>`_ * `C++ multisets <http://www.demo2s.com/Tutorial/Cpp/0380__set-multiset/Catalog0380__set-multiset.htm>`_
tutorial with standalone examples. tutorial with examples.
* For use cases for multisets and mathematical operations on multisets, see * For mathematical operations on multisets and their use cases, see
*Knuth, Donald. The Art of Computer Programming Volume II, *Knuth, Donald. The Art of Computer Programming Volume II,
Section 4.6.3, Exercise 19*\. Section 4.6.3, Exercise 19*\.
@ -292,7 +289,7 @@ counts less than one::
elements, see the :func:`combinations_with_replacement` function in the elements, see the :func:`combinations_with_replacement` function in the
:ref:`itertools-recipes` for itertools:: :ref:`itertools-recipes` for itertools::
map(Counter, combinations_with_replacement('abc', 2)) --> AA AB AC BB BC CC map(Counter, combinations_with_replacement('ABC', 2)) --> AA AB AC BB BC CC
:class:`deque` objects :class:`deque` objects