Building an extension module with SWIG

[garyr]

"garyr" <garyr at fidalgo.net> wrote in message 
news:mkco9p$gf8$1 at speranza.aioe.org...
> I'm trying to create an extension module using SWIG. I've
> succeeded in generating a pyd file but when I import the module I get the
> error message: "SystemError: dynamic module not initialized properly." I
> added an initfoo() function but that didn't solve the problem. Below are 
> the
> various files, a slightly modified version of a SWIG exmaple.
> I'm using Python 2.7
>
> What am I missing?
>
> //foo.c:
> #include "foo.h"
> double Foo;
> void initfoo()
> {
>    Foo = 3.0;
> }
> int gcd(int x, int y) {
>  int g;
>  g = y;
>  while (x > 0) {
>    g = x;
>    x = y % x;
>    y = g;
>  }
>  return g;
> }
>
> #foo.h:
> extern void initfoo();
> extern double Foo;
> extern int gcd(int x, int y);
>
> #foo.i:
> %module example
> %inline %{
> extern int    gcd(int x, int y);
> extern double Foo;
> %}
>
> #setup.py
> from setuptools import setup, Extension
> setup(name='foo',
>    version='0.1',
>    ext_modules=[Extension('foo', ['foo.c', 'foo.i'],
>                    include_dirs=['.'],
>                    depends=['foo.h', 'foo.i'],
>                    swig_opts=['-modern', '-I../include'],
>                    )],
>    )
>
It's working! The first character of the name of the extension must be an 
underscore; e.g.,

>    ext_modules=[Extension('_foo', ['foo.c', 'foo.i'],
and the initfoo() function is not needed.

Thanks to all that replied to my post.