Order of elements in a dict

[Leif K-Brooks]

Marcio Rosa da Silva wrote:

> So, my question is: if I use keys() and values() it will give me the 
> keys and values in the same order?

It should work fine with the current implementation of dictionaries, but 
(AFAIK) it's not guaranteed to work by the mapping protocol. So 
theoretically, it could break under Python 2.5 or with a user-made 
mapping type.

> Also, if someone has a better way to exchange keys and values in a dict, 
> I would like to learn. :-)

I would do it like this:

 >>> d = {1: 2, 2: 3, 3: 4}
 >>> d = dict([(value, key) for key, value in d.iteritems()])
 >>> d
{2: 1, 3: 2, 4: 3}