larry-discuss team mailing list archive

[josef.pktd@xxxxxxxxx]

On Sun, Feb 7, 2010 at 10:23 PM, Keith Goodman <kwgoodman@xxxxxxxxx> wrote:
> On Sun, Feb 7, 2010 at 7:11 PM,  <josef.pktd@xxxxxxxxx> wrote:
>
>> If you want to go this way, you could have lixs :  lix with strings,
>> and lixr : lix with repr , ... ?
>> lix would be safe  because it uses the labels directly, the other ones
>> are only recommended in restricted cases where the string (or other)
>> representation makes sense.
>
> Too confusing with two I think.
>
>> if you want to allow slicing i.e. `:`  then I think lix would need to
>> use its __getitem__ instead of __call__ or __init__
>> lar1[1:4, lix['msft', google], lixs['2010-02-01':]   or lar1[1:4,
>> lix[['msft', google]], lixs['2010-02-01':] ?
>
> lar1[lix(date)]: will work. So will lar[lix(date1):lix(date2)]
>
> Allowing slices slows things down because now we have to look instead
> each slice object (slice.start, slice.stop) for lix object and if
> found convert them.

I wouldn't mix lix and regular array slices or indices for the same
axis. I would restrict it to if either one of (slice.start,
slice.stop) are lix then both are interpreted as labels.

either lar[lix[date1:date2],:]   or   lar[lix(date1):lix(date2), :]
but not lar[lix(date1):-3]

>
>> I don't know if lix should hold some code for conversion from label
>> representation to indices, or be just an identifier for use in
>> larry.__getitem__
>
> Yeah, a method getindex that takes label as input, perhaps. larry's
> getitem is already getting harry, so keeping the code in lix instead
> of adding yet more code to getitem might be a good idea. Or make a
> function in util.misc like a did for string indexing.
>
>> Josef
>>
>