Re: [boost] How can I switch a PyObject into a void*

From: David Abrahams (david.abrahams_at_[hidden])
Date: 2001-10-02 20:12:28

Mike,

I don't see what the problem is. Your code below looks fine. What do you
mean by "it returns PyObject*'s out of the function call"? What is "it"?
What function call?

Are you perhaps saying that you want to get a pointer to the base address of
the memory held by the buffer? If there is a function to do that in the
Python 'C' API, then use it, I guess. Otherwise, there's a struct in the
Python source associated with instances of Buffer (let's imagine it's called
PyBuffer). Find that struct, cast the PyObject* to a PyBuffer*, and fondle
its private data until you find what you're looking for.

Does that help?

-Dave

P.S. I'm happy to answer questions, but it will be easier for me if you can
spend the time to eliminate vagaries.

===================================================
  David Abrahams, C++ library designer for hire
 resume: http://users.rcn.com/abrahams/resume.html

        C++ Booster (http://www.boost.org)
          email: david.abrahams_at_[hidden]
===================================================

----- Original Message -----
From: "Mike Ensor" <MikeEnsor_at_[hidden]>
To: <boost_at_[hidden]>
Sent: Tuesday, October 02, 2001 8:45 PM
Subject: [boost] How can I switch a PyObject into a void*

> How can I switch a PyObject* in C into a void* varible?  Is that possible?
> if not, can I convert it into a char*?  I am trying to get a "Buffer"
object
> in python and convert it into a void* type.  I have no problem telling how
> long it is, and extracting elements out of the "Buffer", but it returns
> PyObject*'s out of the function call.  I can print them out, but that does
> nothing for me.
>
> void ListAddEntry_Binary(e5_List&l, PyObject* pyObjRef)
> {
>   int size = PySequence_Size(pyObjRef);
>   if(!PyBuffer_Check(pyObjRef))
>   {
>     std::cout << "PyObject is not a Buffer Object" << std::endl;
>     return;
>   }
>   for(int i=0; i< size; i++)
>   {
>     std::cout << PySequence_GetItem(pyObjRef, i) << std::endl;
>   }
> }
>
>
> that is the code I am currently working with.
>
> Thank you,
> Mike Ensor
>
> Info: http://www.boost.org  Unsubscribe:
<mailto:boost-unsubscribe_at_[hidden]>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>