Asp Forum - Re: Python UML Metamodel

Gabriel Genellina

1/31/2008 2:23:00 AM

--- sccs cscs <zorg724@yahoo.fr> escribió:
> Gabriel Genellina <gagsl-py2@yahoo.com.ar> a écrit :
> En Tue, 29 Jan 2008 21:25:26 -0200, sccs cscs
> escribió:
>
> > I find an OPEN SOURCE tool
> (http://boum...) that Recently
> > generates Python code from UML model.
>
> Does it keep the model synchronized when you modify
> the Python code?
>
> =>No, not for the moment because the Python code
> generator is brand new, but the tool's author and
> i are specifying the reverse tool for a next
> version. I do not have found another Open Source
> Tool that generates Python code from UML better like
> that.

Ok, that's important. If the model cannot reflect
changes in the code it becomes less and less useful.

> > I like to model the Python language metamodel
> himself, with it, e.g the
> > model of the language: I need that to better
> understand the language
> > constraint of the language.
> > [...]
> > -a class "class" has 0..n attributes and 0..n
> method
>
> Just attributes. Methods are created on-the-fly when
> the corresponding
> function attribute is retrieved from the instance.
> And remember that instances are not restricted to
> what their class define.
> You can add or remove any attribute (even methods!)
> to any instance of a
> user-defined class at any time. (This doesn't apply
> to most builtin types,
> but *does* apply if you inherit from it)
>
>
> =>You're Right but I will also model that dynamic
> aspect . However i think it is possible and the
> relevant to make a static metamodel of Python, as
> if there was no possibility of changing dynamic an
> instance.

But Python *is* a dynamic language. You have to
capture that into the model somehow.

> A lot of person do not understand nothing
> to Python on many aspects, because there is no
> graphical representation of the relation of concepts
> : may a module have more than on class definition ?
> a mix of class and global fonction? etc...

A graphical representation may be useful, but it must
be acurate too - else people may incorrectly deduce
that something can't be done because it's not
expressed in the graph.

> > Does anyone know a document that describes it
> already, because I think
> > it is complicated to find this information in the
> documentation of
> > Python.
>
> See section 2 "Data Model" and section 3 "Execution
> Model" in the Python
> Language Reference http://docs.pytho...
>
> =>
> Thank you, it's pretty standard but somewhat
> indigestible. However, by studying line by line, I
> would have to be filled into a UML model

Yes, sure, it's hard to follow. As the subtitle says,
it's "for language lawyers" :)

> > - a class "method" can contains nested "method",
> but what is the way to
> > get a list of internal methods, without use ? Can
> i just write:
> > "myNestedMethodList = method.nestedMethodList"
>
> Are you talking about nested functions?
> => Yes
>
> You can't enumerate them from outside the container
> function: Python is a
> dynamic language, those inner functions are created
> when the def statement
> is *executed*. If you have an if statement around
> the def, the function
> may not even exist.
>
> => OK, it is diffcult to model: but possible: for
> example, by using a composition (a method may have
> 0..n inner function). The dynamic aspect may be
> described into a UML note or constraints for example

Anyway it doesn't look right. Inner functions are not
attributes of the enclosing one, like local variables
are not attributes of the enclosing function.

--
Gabriel Genellina

Los referentes más importantes en compra/ venta de autos se juntaron:
Demotores y Yahoo!
Ahora comprar o vender tu auto es más fácil. Vistá ar.autos.yahoo.com/

comp.lang.python

Re: Python UML Metamodel

Gabriel Genellina

x Login to ForumsZone