R: R: [Pytables-users] Re: [ pytables-Patches-1192700 ] Multi-dimensional HDF5 attributes

[Valentino A. <val...@co...>]

> -----Messaggio originale-----
> Da: Francesc Altet [mailto:fa...@ca...]
> Inviato: giovedì 12 maggio 2005 11.05
> A: Valentino Antonio
> Cc: pyt...@li...
> Oggetto: Re: R: [Pytables-users] Re: [ pytables-Patches-1192700 ]
> Multi-dimensional HDF5 attributes
>
>
> A Dijous 12 Maig 2005 09:16, vàreu escriure:
> > No. The contrary. In my opinion, python integers and float should be
> > pickled.
> > Numarray objects, including scalars, should be saved as numeric HDF5
> > attributes.
> > In this way numeric HDF5 attributes will be *always* loaded
> into pytables
> > as numarray objects, and numarray objects will be *always*
> saved on file as
> > numeric
> > HDF5 attributes (H5T_NATIVE_INT, H5T_NATIVE_FLOAT and so on).
> > Python objects, including int, float, complex, decimal.Decimal, list,
> > tuple, dict, etc, should be saved as cpickle strings in order
> to not have
> > ambiguities with
> > numeric attributes.
> > In this way you can write code like this
> >
> > leaf.attrs.uchar = na.array(1, type=na.UInt8)   # --> H5T_NATIVE_UCHAR
> > integet = 1
> > leaf.attrs.int = integer   # --> cpickle string
> > leaf.attrs.int32 = na.asarray(integer)  # --> H5T_NATIVE_INT
> >
> > and then retrieve them back unambiguously.
> > Stated that extra code is needed in order to preserve the compatibility
> > with old pytables version, I don't know if this approach can
> araise other
> > problems.
> > I hope I have not been too much confusing.
>
> No, I understand clearly now.

:)))

> Well, after discussing this issue with
> Ivan, we think that your suggestion is very consistent. And, as we can
> distinguish between files made with PyTables 1.0 and earlier from
> those made with PyTables 1.1 and after, I think there will be no
> problem in implementing that.

I'm happy to hear this.

> May you provide the necessary patch based on the latest snapshot? If
> you can't, I can do it my self.

Of course I can.
I will make it available this weekend (I hope).

> Thanks,
>
> --
> >0,0<   Francesc Altet     http://www.carabos.com/
> V   V   Cárabos Coop. V.   Enjoy Data
>  "-"
>

ciao

--
Antonio Valentino