Re: [Pytables-users] Unbound nodes.

[Ivan V. i B. <iv...@ca...>]

On Thu, Jan 27, 2005 at 12:17:01PM +0100, Norbert Nemec wrote:
> Am Donnerstag 27 Januar 2005 10:16 schrieb Ivan Vilata i Balaguer:
> > Actually, it is possible for Group to use _f_create* methods and have no
> > knowledge of which kinds of nodes it supports.  One could register and
> > deregister new Node classes into Group in this way:
> >
> > class MyNewLeaf(Leaf):
> >   ... class definition ...
> > Group._f_registerNode(MyNewLeaf)
> >
> > The _f_create* method would be created on-the-fly....
>=20
> Maybe it is just me personally, but I find this kind of library-design=20
> extremely confusing. Of course, Python allows an extremely flexible desig=
n of=20
> libraries that would never be possible in other languages (my personal=20
> background is mostly C++). This flexibility calls for a lot of=20
> self-discipline.

If I may say, I only see one text line of self-discipline. ;)  For me,
it is not confusing at all, and it leverages the power of Python
introspection and dynamic binding.
>=20
> My usual idea of a library is, that it is a fixed set of modules, contain=
ing a=20
> fixed set of classes offering a fixed set of methods. Any departure from =
this=20
> static picture means an additional step in understanding the library. It =
may=20
> be justified in many cases, but should still be avoided if there is no go=
od=20
> reason for it.

Yes, you are completely right.  However, when *extending* the library we
are changing the library =E2=80=9Cblack-box=E2=80=9D approach (which is sti=
ll valid for
users) for a framework =E2=80=9Cwhite-box=E2=80=9D approach (where develope=
rs have
access to some internal aspects).  Registering new classes in a
framework is not that strange (and believe me, it could have been *much*
worse).
>=20
> Anyway: this is just my personal view as someone relatively new to Python=
=2E..

And it is a very interesting one.  Please, don't hesitate to show your
opinions about PyTables (that goes for everyone).  They are very
valuable to us.

Regards,
    Ivan

--=20
Ivan Vilata i Balaguer   >qo<   http://www.carabos.com/
       C=C3=A1rabos Coop. V.  V  V   Enjoy Data
                          ""