a strange question in it.comp.lang...

holger krekel pyth at devel.trillke.net
Wed Jan 8 20:17:05 CET 2003


6e6op wrote:
> this is (more or less) the translation
> 
> From: "Matteo Bertini" <m.bertini at tin.it>
> Newsgroups: it.comp.lang
> Sent: Sunday, January 05, 2003 11:26 PM
> Subject: [PYTHON] estendere tipi di base
> 
> 
> > I can build a class in this way:
> >
> > class mystring(str):
> >      def is_email(self):
> >          return self.find("@")
> >
> > use it in:
> >
> > mystring("pippo at pippo.it").is_email()
> >
> > the answer is, can i define mystring to be the default string class?
> > can i ''validate''  "pippo".is_email() ?
> > maybe is not goot, but is only curiosity.
> >
> > thanks,
> > Matteo
> 
> ok, then one answer jump in my brain:
> there's a "place" where the interpreter load the __builtins__  package?
> obviously __builtins__.str cannot be substitute with a customized one after
> the __builtins__ load ,
> but before load?

This wouldn't help (and you probably mean __builtin__, btw.). 

The construction of a string object doesn't involve a lookup
of the builtin namespace.  'str' is just a convenient (builtin) 
way to get to the string type.  

> if the interpreter load __builtins__ in some place i can translate
> __builtins__.str
> with a __builtins__.mystr before that interpreter load __builtins__
> 
> is it possible?

no. 

cheers,

    holger





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