dictionary issue (and maybe PEP ... depending on the answer)

[Carl Banks]

dsavitsk wrote:
> (Python 2.2.1 on FreeBSD 4.7 being used via mod_python 3)
> 
> I have a dictionary at the top of a module that looks like this
> 
> _months = {1: 'January',
>           2: 'February',
>           3: 'March',
>           4: 'April',
>           5: 'May',
>           6: 'June',
>           7: 'July',
>           8: 'August',
>           9: 'September',
>           10: 'October',
>           11: 'November',
>           12: 'December'}
> 
> never mind, for now, that there are proably better ways to do what the 
> dict obviously does.  anyhow, I get a list of the months by doing this
> 
> >>> [_months[i] for i in _months.keys()]
> 
> The issue is, this consistently returns the months in order. I don't see 
> any obvious reason that it does, but I can't get it to fail. So,I am 
> wondering if there is a reason, or is it serendipity.

It's because the hash value of an int (except -1) is itself.  So the
entries are stored in the hash table in order, and thus returned in
order.


-- 
CARL BANKS