[SAGA-RG] SAGA attributes as Python dictionaries?

[Manuel Franceschini]

On Wed, Nov 4, 2009 at 6:34 PM, Steve Fisher <dr.s.m.fisher at gmail.com> wrote:
> Just a note to remind people that the dictionary syntax in python is
> just a convenience - you need to implement __setitem__, __getitem__,
> __delitem__ etc. Our __setitem__   can reject requests to set fields
> whoch don't already exist for those cases where the set of attributes
> is not extensible. It just needs a private method called by the
> implementation to set the attributes with any defalt values and
> indicate whether or not it is extensible. I think it is best to try it
> and see if there are any practical problems. Also see:
> http://docs.python.org/library/userdict.html#module-UserDict which may
> be useful.

It is certainly doable from the technical point of view. My question
is what would be the advantages of having a dict-like interface? Would
that be in this form then:

1)  jobDescription["Executable"] = "/bin/hostname")

Where 'jobDescription' is an object. Why not having just class
attributes (as Mathijs showed in the first e-mail), as in:

2)  jobDescription.Executable = "/bin/hostname"


IMHO, one of the most important Pythonic properties is having exactly
_one_ way of achieving a task. In other words, having two different
ways (even if the added way is slightly simpler) is not what I would
want. Therefore, if we decide to expose one of the above ways to the
end user, it should be the _only_ one, while
jobDescription.set_attribute(...) should not be part of the API for
the end user then.

My 2 cents.

Cheers,
-- 
/Manuel