larry-discuss team mailing list archive

[Keith Goodman <kwgoodman@xxxxxxxxx>]

On Tue, Feb 9, 2010 at 7:23 AM, Keith Goodman <kwgoodman@xxxxxxxxx> wrote:
> On Mon, Feb 8, 2010 at 8:42 PM,  <josef.pktd@xxxxxxxxx> wrote:

>> I'm just reading the new lix
>>
>> For this case  lar.lix[['a']:['b']:2]
>>
>> why do you need the list check? you raise a ValueError if it's not a
>> list. this and the fact that slicing start and stop need to be valid
>> labels, seems to indicate that the list is not necessary, i.e.
>> lar.lix['a':'b':2] , and lar.lix['a':'b':2,...]  should be unambiguous
>> for any label type.
>> Do you have an example where this would break? I don't see one right now.
>
> Yes, good point, removing the list requirement for slices should work.
> If, however, we keep the list requirement, then by adding one if
> statement to lix we can also index with integers:
>
> lar.lix[0, ['a', 'b']]
> lar.lix[1:[date1]]
> lar.lix[5, [date1]:-1]
>
> That might make it easier to loop:
>
> for i in range(lar.shape[0]):
>    date = datetime.date(2010,1,1) + datetime.timedelta(i)
>    y = lar.lix[i, [date]]
>
> And I could even eventually add some tuple support in the form:
>
> lar.lix[([date] - 10):[date]]
>
> Yes, I think  that woul be powerful. And the integer support comes for
> free if we keep the list requirement.
>
> What do you think?

To add integer indexing (float too if I wrap the scalar in
int(scalar)) I only need to add these lines:

                        elif isscalar(idx):
                            index2.append([idx])

                elif isscalar(index):
                    # Example: lar.lix[0]
                    return y[index]