Using __repr__ or __str__ for own printable class?

Greg Ewing (using news.cis.dfn.de) ckea25d02 at sneakemail.com
Tue Apr 15 04:53:00 CEST 2003


Mads Orbesen Troest wrote:
> But then one wouldn't be able to do a standard "print" of the class, would 
> one?

No, you'd have to say

   print myStringRep(someInstanceOfMyClass)

But this is only an issue if you're printing a built-in
container such as a list. You could just as well make
the __str__ of MyClass do whatever myStringRep does.
However, if any of the instance variables of MyClass
are built-in containers, you would have to not simply
str() them, but treat them more carefully.

 > I would like to be able to  do this ...
 >
> 	print someInstanceOfMyClass
> 
> This works with __str__ but 
> I was/am afraid if this overriding of __str__ will conflict with other uses 
> of __str__ and/or __repr__.

If it works for you, then that's fine. The only other
built-in use of __str__ that I can think of is the
str() function. If you're happy for anyone who calls
str() on your class to get the same result, then
you don't need to worry.

-- 
Greg Ewing, Computer Science Dept,
University of Canterbury,	
Christchurch, New Zealand
http://www.cosc.canterbury.ac.nz/~greg





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