Rooba
/
cpython
mirror of https://github.com/python/cpython.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Merged revisions 82899 via svnmerge from 

svn+ssh://pythondev@svn.python.org/python/branches/py3k

........
  r82899 | senthil.kumaran | 2010-07-15 02:00:02 +0530 (Thu, 15 Jul 2010) | 2 lines

  Fix issue9132 - Documentation for comparing dictionaries is out of date
........
This commit is contained in:
Senthil Kumaran 2010-07-14 20:32:56 +00:00
parent 1ea57a6c5f
commit 09cfa890d2
1 changed files with 3 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
Doc/reference/expressions.rst
View File

@ -1026,9 +1026,9 @@ Comparison of objects of the same type depends on the type:
``x <= y``. If the corresponding element does not exist, the shorter
sequence is ordered first (for example, ``[1,2] < [1,2,3]``).
* Mappings (dictionaries) compare equal if and only if their sorted ``(key,
value)`` lists compare equal. [#]_ Outcomes other than equality are resolved
consistently, but are not otherwise defined. [#]_
* Mappings (dictionaries) compare equal if and only if they have the same
``(key, value)`` pairs. Order comparisons ``('<', '<=', '>=', '>')``
raise :exc:`TypeError`.
* Sets and frozensets define comparison operators to mean subset and superset
tests. Those relations do not define total orderings (the two sets ``{1,2}``
@ -1310,15 +1310,6 @@ groups from right to left).
strings in a human recognizable way, compare using
:func:`unicodedata.normalize`.
.. [#] The implementation computes this efficiently, without constructing lists
or sorting.
.. [#] Earlier versions of Python used lexicographic comparison of the sorted (key,
value) lists, but this was very expensive for the common case of comparing
for equality. An even earlier version of Python compared dictionaries by
identity only, but this caused surprises because people expected to be able
to test a dictionary for emptiness by comparing it to ``{}``.
.. [#] Due to automatic garbage-collection, free lists, and the dynamic nature of
descriptors, you may notice seemingly unusual behaviour in certain uses of
the :keyword:`is` operator, like those involving comparisons between instance