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An "Object" class?


Thank you! Will give the "types" module a whirl.

Otherwise, the whole idea behind building a rigorous taxonomical hierarchy
("taxonomy") is to provide a simpler management of the wealth of features
objects have. And that is because entities belonging to the same
taxonomical class ("clade") have common features, and also inherit the
features of the taxonomical parent. A kosher type hierarchy (or class
taxonomy) is thus meant to answer precisely your concern about
entity/object behavior. Now, it may be that this was not the intention of
Python developers when they came up with the breakdown of the class of
objects into types/classes, in which case the term "type" and derivatives
(subtype, supertype etc.) used in this context is nothing but a regrettable
misnomer. Then maybe I should re-direct my quest away from studying the
type hierarchy, toward asking for built-in-object inheritance: Is there a
diagram of built-in-object inheritance available anywhere?

Many thanks for the clarifications,

C

On Fri, Aug 30, 2019 at 3:47 AM Gregory Ewing <greg.ewing at canterbury.ac.nz>
wrote:

> Cristian Cocos wrote:
>
> >>>>type(print)
> >
> > <class 'builtin_function_or_method'>
> >
> >>>>isinstance(print, builtin_function_or_method)
> >
> > Traceback (most recent call last):
> >   File "<stdin>", line 1, in <module>
> > NameError: name 'builtin_function_or_method' is not defined
> >
> > Just curious why builtin_function_or_method doesn't work as an argument
> of
> > isinstance().
>
> Because the type object in question is not bound to the name
> 'builtin_function_or_method' in the builtin namespace. There
> is a way to get at it, though:
>
>  >>> import types
>  >>> types.BuiltinFunctionType
> <class 'builtin_function_or_method'>
>  >>> isinstance(print, types.BuiltinFunctionType)
> True
>
> When it comes to objects that form part of the interpreter's
> internal machinery, the names shown when you print their types
> are often just suggestive and aren't meant to be taken literally.
> Most of them are available in the 'types' module, however,
> possibly under different names. The reasons for all this are
> buried in a lot of messy history.
>
> > The bottom line is that I am trying to figure out where exactly the world
> > of Python types _diverges from_ what I would expect as a mathematician.
> It
> > makes it easier for me to learn Python this way.
>
> I'm not sure that focusing on classes as mathematical sets is all
> that useful. In Python, what class an object belongs to isn't
> usually very important. Much more relevant is how the object
> *behaves*. We call this "duck typing" -- if it walks like a duck
> and quacks like a duck then it might as well be a duck, even if
> it doesn't belong to a class called "Duck".
>
> This is why Python doesn't have e.g. an elaborate tower of
> numeric types as is seen in some other languages. It just isn't
> necessary for getting things done, and Python, being a very
> pragmatic language, is all about getting things done.
>
> --
> Greg
> --
> https://mail.python.org/mailman/listinfo/python-list
>


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