Mercurial > cpython-lru_cache-weakref
diff Doc/lib/libfuncs.tex @ 26366:08b720cd387e legacy-trunk
Patch #642500 with slight modifications: allow keyword arguments in
dict() constructor. Example:
>>> dict(a=1, b=2)
{'a': 1, 'b': 2}
>>>
| author | Just van Rossum <just@letterror.com> |
|---|---|
| date | Sat, 23 Nov 2002 09:45:04 +0000 |
| parents | d31ddc66b1b5 |
| children | 3d0e02976bc3 |
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--- a/Doc/lib/libfuncs.tex Sat Nov 23 09:16:19 2002 +0000 +++ b/Doc/lib/libfuncs.tex Sat Nov 23 09:45:04 2002 +0000 @@ -189,27 +189,34 @@ \end{funcdesc} \begin{funcdesc}{dict}{\optional{mapping-or-sequence}} - Return a new dictionary initialized from the optional argument. - If an argument is not specified, return a new empty dictionary. - If the argument is a mapping object, return a dictionary mapping the - same keys to the same values as does the mapping object. - Else the argument must be a sequence, a container that supports - iteration, or an iterator object. The elements of the argument must - each also be of one of those kinds, and each must in turn contain + Return a new dictionary initialized from an optional positional + argument or from a set of keyword arguments. + If no arguments are given, return a new empty dictionary. + If the positional argument is a mapping object, return a dictionary + mapping the same keys to the same values as does the mapping object. + Otherwise the positional argument must be a sequence, a container that + supports iteration, or an iterator object. The elements of the argument + must each also be of one of those kinds, and each must in turn contain exactly two objects. The first is used as a key in the new dictionary, and the second as the key's value. If a given key is seen more than once, the last value associated with it is retained in the new dictionary. + + If keyword arguments are given, the keywords themselves with their + associated values are added as items to the dictionary. If a key + is specified both in the positional argument and as a keyword argument, + the value associated with the keyword is retained in the dictionary. For example, these all return a dictionary equal to - \code{\{1: 2, 2: 3\}}: + \code{\{"one": 2, "two": 3\}}: \begin{itemize} - \item \code{dict(\{1: 2, 2: 3\})} - \item \code{dict(\{1: 2, 2: 3\}.items())} - \item \code{dict(\{1: 2, 2: 3\}.iteritems())} - \item \code{dict(zip((1, 2), (2, 3)))} - \item \code{dict([[2, 3], [1, 2]])} - \item \code{dict([(i-1, i) for i in (2, 3)])} + \item \code{dict(\{'one': 2, 'two': 3\})} + \item \code{dict(\{'one': 2, 'two': 3\}.items())} + \item \code{dict(\{'one': 2, 'two': 3\}.iteritems())} + \item \code{dict(zip(('one', 'two'), (2, 3)))} + \item \code{dict([['two', 3], ['one', 2]])} + \item \code{dict(one=2, two=3)} + \item \code{dict([(['one', 'two'][i-2], i) for i in (2, 3)])} \end{itemize} \versionadded{2.2}
