[Numpy-discussion] Record arrays
Fri Jun 27 19:10:57 CDT 2008
On Fri, Jun 27, 2008 at 7:10 AM, Fernando Perez <email@example.com> wrote:
> On Thu, Jun 26, 2008 at 1:25 PM, Robert Kern <firstname.lastname@example.org> wrote:
>> One downside of this is that the attribute access feature slows down
>> all field accesses, even the r['foo'] form, because it sticks a bunch
>> of pure Python code in the middle. Much code won't notice this, but if
>> you end up having to iterate over an array of records (as I have),
>> this will be a hotspot for you.
> I wonder if it wouldn't be useful for *all* numpy arrays to have a .f
> attribute that would provide attribute access to fields for complex
> In : r['foo']
> Out: array([1, 1, 1])
> In : r.f.foo
> -> Hypothetically, same as  above
> This object would be in general an empty namespace, thus avoiding the
> potential for collisions that recarrays have, could normalize field
> names to be valid python identifiers (spaces to _, etc) and could
> provide name TAB completion. Since the .f object would be a *separate*
> object, the main array wouldn't need to have complex python code in
> the fast path and there would be no speed penalty for other uses of
> the top level object.
> I've never quite liked recarrays because of the fact that they blend
> the named fields with the main namespace, and because they don't tab
> complete. I'd happily pay the price of accessing a sub-object for a
> cleaner and more useful access to fields (I could always do xf=x.f if
> I am really going to use the field object a lot).
> Just an idea, perhaps it's already been shut down in the past.
-- Sebastian Haase
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