Stowage/cpython
2
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-11-01 14:11:41 +00:00
Code Issues Projects Releases Packages Wiki Activity

Extend some comments on the order of values in the returns from

Browse source 
dict.items/keys/values/iteritems/iterkeys/itervalues().
This commit is contained in:
Fred Drake 2002-08-19 21:58:58 +00:00
parent 45ec02aed1
commit 017778332f
1 changed files with 14 additions and 8 deletions
Download patch file Download diff file Expand all files Collapse all files

22
Doc/lib/libstdtypes.tex
View file

@ -1049,13 +1049,13 @@ arbitrary objects):
{(6)} {(6)}
\lineiii{\var{a}.iteritems()} \lineiii{\var{a}.iteritems()}
{return an iterator over (\var{key}, \var{value}) pairs} {return an iterator over (\var{key}, \var{value}) pairs}
{(2)} {(2), (3)}
\lineiii{\var{a}.iterkeys()} \lineiii{\var{a}.iterkeys()}
{return an iterator over the mapping's keys} {return an iterator over the mapping's keys}
{(2)} {(2), (3)}
\lineiii{\var{a}.itervalues()} \lineiii{\var{a}.itervalues()}
{return an iterator over the mapping's values} {return an iterator over the mapping's values}
{(2)} {(2), (3)}
\end{tableiii} \end{tableiii}
\noindent \noindent
@ -1067,11 +1067,17 @@ in the map.
\item[(2)] \versionadded{2.2} \item[(2)] \versionadded{2.2}
\item[(3)] Keys and values are listed in random order. If \item[(3)] Keys and values are listed in random order. If
\method{keys()} and \method{values()} are called with no intervening \method{items()}, \method{keys()}, \method{values()},
modifications to the dictionary, the two lists will directly \method{iteritems()}, \method{iterkeys()}, and \method{itervalues()}
correspond. This allows the creation of \code{(\var{value}, are called with no intervening modifications to the dictionary, the
\var{key})} pairs using \function{zip()}: \samp{pairs = lists will directly correspond. This allows the creation of
zip(\var{a}.values(), \var{a}.keys())}. \code{(\var{value}, \var{key})} pairs using \function{zip()}:
\samp{pairs = zip(\var{a}.values(), \var{a}.keys())}. The same
relationship holds for the \method{iterkeys()} and
\method{itervalues()} methods: \samp{pairs = zip(\var{a}.itervalues(),
\var{a}.iterkeys())} provides the same value for \code{pairs}.
Another way to create the same list is \samp{pairs = [(v, k) for (k,
v) in \var{a}.iteritems()]}.
\item[(4)] Never raises an exception if \var{k} is not in the map, \item[(4)] Never raises an exception if \var{k} is not in the map,
instead it returns \var{x}. \var{x} is optional; when \var{x} is not instead it returns \var{x}. \var{x} is optional; when \var{x} is not