Re: [Swig-user] redefining __repr__ for python

[Kris T. <kri...@gm...>]

Oh well. You can ignore my previous email. I forgot to %include <stl.i>,
which explains my failure with std::string. Now I'm left with problems with
builtin, see edited question below.
 
Apologies.

> From: Kris Thielemans [mailto:kri...@gm...]
> Sent: 19 September 2012 02:20
> 
> I'm trying to debug some stuff with __repr__ and __str__ (see previous
> emails if you're interested but it's irrelevant here) so went back to
basics
> and made short example. Sadly, this short example works even less than my
> complicated one, so I must be doing something very stupid. Maybe someone
> can
> help?
> 
> My simple example is as follows: define simple class, extend it with
> __repr__. Here is the code
> 
> %module testKT
>  %{
> #include <string>
>  %}
> 


%include <stl.i>

> %inline {
>   class A
>   {
>   public:
>     int _a;
>     A(int a):  _a(a) {}
>   };
> }
> 
>   %extend A {
>     std::string __repr__()
>     {  return "in repr";   }
>     #if defined(SWIGPYTHON_BUILTIN)
>     %feature("python:slot", "tp_repr", functype="reprfunc") __repr__;
>     #endif
>   }
> }
> 

Now, without builtin everything is at it should. But if I use builtin, then
A.__repr__ works, but repr(A) doesn't:

>>> from testKT import *
>>> a=A(1)
>>> a.__repr__()
'in repr'
>>> repr(a)
"<Swig Object of type 'A *' at 0x7f12e470cab0>"


 (i.e. repr(a) falls back to the default swig version). Checking the wrapped
code I see that my function is wrapped and is added as a method
(SwigPyBuiltin__A_methods), but isn't inserted into the type definition
table (SwigPyBuiltin__A_type) as the tp_repr slot.


> 
> The weird thing is that in my complicated code (too long to include here),
> the above type of lines do work, both with and without builtin (and using
a
> std::string return signature).
> 
> What am I missing here?
> 
> I'm using swig 2.0.7 and python 2.7.2. on ubuntu.
> 
> thanks for any help
> 
All this still applies :-;


Kris