Python and generic programming

Roman Suzi rnd at
Fri Oct 22 10:05:41 CEST 2004

On Thu, 21 Oct 2004, Josiah Carlson wrote:

> Roman Suzi <rnd at> wrote:
> > Most Python programs are already kinda generic, yes. But generic
> > programming adds multi-sorted types control and constraints to ensure type
> > safety...
> "kinda generic"?  That is quite the understatement.
> As for "type safety", Python has runtime type checking, and as a
> programmer, if you want to have varying dispatch based on type, you are
> free to do so:
> foo_dispatch = {(int, int):foo_int_int, #some defined function
>                 ...}
> def foo(arg1, arg2):
>     foo_dispatch[(type(arg1), type(arg2))](arg1, arg2)
> With decorator syntax, the above becomes even easier.
> Your arguments claiming Python is not generic, and your suggestions that
> Python is not type safe while being generic are unfounded.  One likely
> reason why you don't find many examples of what I show above, is because
> it is usually not necessary; even for production applications.

The essense of my question was not to proof or dis-proof Python's
genericity capabilities! But I'd liked to know from those who know ;-)
can Python be called as supporting GP or not, and if not, what is missing.

C++ doesn't support GP in full, but it seems, its heading to that

As byside, type-safety is a good thing sometimes, especially in moderately
large projects. So probably interfaces or concepts is a good idea for a
PEP. And I think GPs concepts are even better than just interfaces as they
add constraints.

Right now concepts in Python are vaguely expressed like
file objects must have this, this and this.

>  - Josiah

Sincerely yours, Roman A.Suzi
 - Petrozavodsk - Karelia - Russia - mailto:rnd at -

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