[Python-checkins] r64306 - peps/trunk/pep-0372.txt

[Nick Coghlan]

georg.brandl wrote:
> Author: georg.brandl
> Date: Mon Jun 16 12:15:48 2008
> New Revision: 64306
> 
> Log:
> Updates and fixes from Armin.
> 
> 
> Modified:
>    peps/trunk/pep-0372.txt
> 
> Modified: peps/trunk/pep-0372.txt
> ==============================================================================
> --- peps/trunk/pep-0372.txt	(original)
> +++ peps/trunk/pep-0372.txt	Mon Jun 16 12:15:48 2008
> @@ -31,8 +31,8 @@
>  Some dynamic programming languages like PHP and Ruby 1.9 guarantee a
>  certain order on iteration.  In those languages, and existing Python
>  ordered-dict implementations, the ordering of items is defined by the
> -time of insertion of the key.  New keys are appended at the end, keys
> -that are overwritten and not moved.
> +time of insertion of the key.  New keys are appended at the end, but
> +keys that are overwritten are not moved to the end.
>  
>  The following example shows the behavior for simple assignments:
>  
> @@ -67,6 +67,11 @@
>    Django currently uses an ugly hack to restore the ordering of
>    members in database models.
>  
> +- The RawConfigParser class accepts a ``dict_type`` argument that
> +  allows an application to set the type of dictionary used internally.
> +  The motivation for this addition was expressly to allow users to
> +  provide an ordered dictionary. [1]_
> +  
>  - Code ported from other programming languages such as PHP often
>    depends on a ordered dict.  Having an implementation of an
>    ordering-preserving dictionary in the standard library could ease
> @@ -106,34 +111,37 @@
>  
>  New methods not available on dict:
>  
> -    ``odict.byindex(index)``
> +``odict.byindex(index)``
>  
> -        Index-based lookup is supported by ``byindex()`` which returns
> -        the key/value pair for an index, that is, the "position" of a
> -        key in the ordered dict.  0 is the first key/value pair, -1
> -        the last.
> +    Returns the key/value pair for an index, that is, the "position" of a key in
> +    the ordered dict.  0 is the first key/value pair, -1 the last.
>  
> -        >>> d.byindex(2)
> -        ('foo', 'bar')
> +    >>> d.byindex(2)
> +    ('foo', 'bar')
>  
> -    ``odict.sort(cmp=None, key=None, reverse=False)``
> +    If there is no key for index an `IndexError` is raised.
>  
> -        Sorts the odict in place by cmp or key.  This works exactly
> -        like ``list.sort()``, but the comparison functions are passed
> -        a key/value tuple, not only the value.
> +``odict.index(key)``
>  
> -        >>> d = odict([(42, 1), (1, 4), (23, 7)])
> -        >>> d.sort()
> -        >>> d
> -        collections.odict([(1, 4), (23, 7), (42, 1)])
> +    Returns the index of a key.  If the key does not exist, a `ValueError` is
> +    raised.

Hmm, while I can see the rationale for suggesting ValueError here for 
the symmetry with list, KeyError is probably more intuitive.

Cheers,
Nick.

-- 
Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia
---------------------------------------------------------------
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