Re: Handling C structs in python

From: daveh-lists_at_[hidden]
Date: 2001-10-01 13:11:04

Unfortunately this type of use of pointers is not going to work. You 
are most likely going to have to wrap this particular struct up in a 
class and deal with the pointers in a similar way to a previous post 
( http://groups.yahoo.com/group/boost/message/18015 )

What you could do is make the wrapper class (as described above) for 
the void pointer look like a python file object by providing 
read/write methods. The union will also require access functions 
because of the const char * type, though this is usually easily dealt 
with by using an STL string.

Dave Hawkes

--- In boost_at_y..., "Ivan A. Vigasin" <vig_at_P...> wrote:
> On Mon, 1 Oct 2001 daveh-lists_at_c... wrote:
> 
> > The simple solution is to just declare the members as read-write 
(see
> > http://www.boost.org/libs/python/doc/special.html and look for
> > def_read_write), unless they are pointers,
> Thanks !
> 
> > then the solution will
> > depend upon the context in which they are used.
> I have C function, that accepts following struct as argument:
> struct Field
> {
>   unsigned id;
>   union
>   {
>     unsigned num;
>     const char *name;
>   };
>   unsigned type;
>   void *value; // pointer to data
>   unsigned MFSize; // size of data
>   unsigned flags;
> };
> 
> I want to be able to use it from python.
> 
> What it is possible to do with union and pointers. Compiler want's 
accept it.
> 
> Regards, Ivan <vig_at_p...>
> ICQ: 22181170