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authorRaymond Hettinger <python@rcn.com>2009-01-14 00:15:21 (GMT)
committerRaymond Hettinger <python@rcn.com>2009-01-14 00:15:21 (GMT)
commit59894127e4b64dfbf017fe488a7de19c15b01865 (patch)
tree01d350b733691c54190d1274a821ae908a587226 /Doc
parent717c083e8d78cf3814a496284c28748834f2bf91 (diff)
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Minor doc tweaks.
Diffstat (limited to 'Doc')
-rw-r--r--Doc/library/collections.rst36
1 files changed, 17 insertions, 19 deletions
diff --git a/Doc/library/collections.rst b/Doc/library/collections.rst
index 13a92c4..fc2b802 100644
--- a/Doc/library/collections.rst
+++ b/Doc/library/collections.rst
@@ -188,26 +188,24 @@ For example::
>>> c = Counter() # a new, empty counter
>>> c = Counter('gallahad') # a new counter from an iterable
- >>> c = Counter({'a': 4, 'b': 2}) # a new counter from a mapping
+ >>> c = Counter({'red': 4, 'blue': 2}) # a new counter from a mapping
The returned object has a dictionary style interface except that it returns
a zero count for missing items (instead of raising a :exc:`KeyError` like a
dictionary would)::
- >>> c = Counter(['if', 'your', 'peril', 'be'])
- >>> c['questions'] # count of a missing element is zero
+ >>> c = Counter(['egg', 'ham'])
+ >>> c['bacon'] # count of a missing element is zero
0
Assigning a count of zero or reducing the count to zero leaves the
element in the dictionary. Use ``del`` to remove the entry entirely:
>>> c = Counter(['arthur', 'gwain'])
- >>> c['arthur'] = 0 # set the count of "arthur" to zero
- >>> 'arthur' in c # but "arthur" is still in the counter
+ >>> c['arthur'] = 0 # set the count of 'arthur' to zero
+ >>> 'arthur' in c # but 'arthur' is still in the counter
True
>>> del c['arthur'] # del will completely remove the entry
- >>> 'arthur' in c
- False
.. versionadded:: 2.7
@@ -267,25 +265,25 @@ Common patterns for working with :class:`Counter` objects::
dict(c) # convert to a regular dictionary
c.items() # convert to a list of (elem, cnt) pairs
Counter(dict(list_of_pairs)) # convert from a list of (elem, cnt) pairs
- c.most_common()[-n:] # n least common elements
+ c.most_common()[:-n:-1] # n least common elements
**References**:
- * Wikipedia entry for `Multisets <http://en.wikipedia.org/wiki/Multiset>`_
+* Wikipedia entry for `Multisets <http://en.wikipedia.org/wiki/Multiset>`_
- * `Bag class <http://www.gnu.org/software/smalltalk/manual-base/html_node/Bag.html>`_
- in Smalltalk
+* `Bag class <http://www.gnu.org/software/smalltalk/manual-base/html_node/Bag.html>`_
+ in Smalltalk
+* `C++ multisets <http://www.demo2s.com/Tutorial/Cpp/0380__set-multiset/Catalog0380__set-multiset.htm>`_
+ tutorial with standalone examples
- * `C++ multisets <http://www.demo2s.com/Tutorial/Cpp/0380__set-multiset/Catalog0380__set-multiset.htm>`_
- tutorial with standalone examples
+* An early Python `Bag <http://code.activestate.com/recipes/259174/>`_ recipe
+ for Python 2.4 and a `Counter <http://code.activestate.com/recipes/576611/>`_
+ comformant recipe for Python 2.5 and later
- * An early Python `Bag <http://code.activestate.com/recipes/259174/>`_ recipe
- for Python 2.4 and a `Counter <http://code.activestate.com/recipes/576611/>`_
- comformant recipe for Python 2.5 and later
+* Use cases for multisets and mathematical operations on multisets.
+ Knuth, Donald. The Art of Computer Programming Volume II,
+ Section 4.6.3, Exercise 19
- * Use cases for multisets and mathematical operations on multisets.
- Knuth, Donald. The Art of Computer Programming Volume II,
- Section 4.6.3, Exercise 19
.. _deque-objects: