Re: [Pytables-users] __setattr__/__delattr__ for existing/nonexistant group members

[Francesc A. <fa...@ca...>]

A Dissabte 04 Desembre 2004 11:44, Norbert Nemec va escriure:
> just noticed a behavior that' just contrary to python convention:
>=20
> First the convention in python:
> ------------
> class D:
>  pass
> d=3DD()
> d.asdf=3D"asdf"
> d.asdf=3D"qwer" # this just overwrites the old attribute
> del d.asdf
> del d.asdf  # AttributeError: D instance has no attribute 'asdf'
> ------------
>=20
> You see: reassignment overwrites the old field, deletion of nonexistant f=
ields=20
> gives an exception
>=20
> Now in pytables:
> -----------------
> from tables import *
> h5file =3D openFile("dummy.h5",'w')
> h5file.root.asdf =3D Group()
> h5file.root.asdf =3D Group()  # NameError: '/' group already has=20
>                             # a child named 'asdf' in file 'dummy.h5'

Yes, I wanted to protect somewhat the attributes so that a user has to
delete it before being overwritten. But you are probably right in that we
PyTables should follow as carefully as possible the python behaviour.

> del h5file.root.asdf
> del h5file.root.asdf   # this just does nothing

Ops, this should raise AttributeError of course.

Well, I'll try to address to that in next releases

Thanks for noting this!

=2D-=20
=46rancesc Altet
Who's your data daddy? =A0PyTables