[Python-Dev] Toowtdi: Datatype conversions

[Robert Brewer]

Raymond Hettinger wrote:
> Choosing between:
> 
>     list(d)  or   d.keys()
> 
> Which is the one obvious way of turning a dictionary into a list?  
> IMO, list(d) is it.

Except that, "turning a dictionary into a list" as an English phrase is
indeterminate--do you want the keys or the values or both? list(d)
happens to choose the keys, but that doesn't make it the "one obvious
way". If I were being introduced to list() for the first time, I would
probably expect/desire it to be lossless, producing something like
d.items() instead.

> So, one question is whether set() and frozenset() should grow an
> analogue to the keys() method:
> >>> set('banana').elements()
> ['a', 'b', 'n']

I don't think so, for the reason that .keys() is effectively a
disambiguator as I just described. With sets, there is no mapping, and
therefore no ambiguity.


Robert Brewer
MIS
Amor Ministries
fumanchu at amor.org