Comments on: Compiling Python extensions with distutils and MinGW

By: Tejovathi

Tejovathi — Tue, 19 Jan 2010 17:28:05 +0000

HI All,

I am trying to do the same thing i.e I have a C++ DLL and C++ header file. Now I am trying to build a SWIG extension so that I can use it in Python. Now, I create a .i file and passed it to swig. I successfully got the .cxx file. I passes this file as source in distutils. But when I run setup.py, I am getting a undefined refence error. How to solve this? Please reply asap

By: Vishwajeet

Vishwajeet — Fri, 13 Nov 2009 09:41:09 +0000

you saved my day thank you so much.

By: Jacobo

Jacobo — Thu, 26 Mar 2009 15:03:14 +0000

Thanks for the guide! Helped alot.

By: Anish

Anish — Tue, 05 Aug 2008 06:29:29 +0000

Hi,,thank’s for lot’s of information
but i’m having one problem again..i have created .pyd file using gcc from mingw for one sample example but when called from python as
>>import sample
>>print sample.cal(2,3)
it’s not showing anyvalue or error, I used SWIG for creating wrap and .o file.

By: eliben

eliben — Sun, 27 Jul 2008 18:52:11 +0000

Basil,
I’m glad you’ve found the solution. I’ve actually linked to this page in the post itself.

By: Basil

Basil — Sat, 26 Jul 2008 16:44:46 +0000

I figured it out! If interested, please see this page.

By: Basil

Basil — Fri, 25 Jul 2008 12:15:15 +0000

Hi Eli,

It is possibly one of the few million compiler/linker/project options in VS, but I am not an expert in that either.. or quite possibly my best guess at the project’s composition of files is wrong.

Both the VS problem and the mingw32 problem have answers floating around the net, though nothing definitive; but I’ll keep looking. After all, I only stumbled on your page after two days of shooting in the Google dark

The other excellent resource is frank’s “Building Python extensions for Windows with only free tools” that you link to. I also have Cygwin. The libmcrypt library compiles successfully only with default (i.e., Cygwin-dependent) settings during ./configure. I had no success in using frank’s recipe with the “-mno-cygwin” switches; but then again, I know very very little about the *POSIX environment.

I’ll keep looking.
Keep up the good work!
Basil

By: eliben

eliben — Fri, 25 Jul 2008 04:53:04 +0000

Hi Basil,

Could it be a problem with VS’s C/C++ standard compatibility ? Although that probably doesn’t explain the problem with mingw32. However, ‘initializer element is not constant’ should be simple enough to diagnose.

I’m not really an expert on these matters, so you might consider asking in the distutils mailing list.

Eli

By: Basil

Basil — Fri, 25 Jul 2008 04:31:28 +0000

This is a very cool and useful example, thanks for posting it!

I followed your tutorial and it worked perfectly (only had to clean up the ampersand HTML from your C code).

I will just mention that the binary win32 distribution of Python 2.5 ships with the ‘libpython25.a’ file, so users such as myself can skip the pexports step.

The reason I am here is that I am looking for a solution to building the mcrypt library (libmcrypt) on win32 so that I can then build its extension, python-mcrypt. I am stuck in several ways:

1. Problem compiling libmcrypt in VS 2003 because the __declspec(dllexport) issue causes a bunch of syntax errors during compile.

2. Using distutils with “-c mingw32″, I get the error “initializer element is not constant”

3. Using Cygwin to build libmcrypt works perfectly in Cygwin; unfortunately, I cannot for the life of me figure out how to carry over whatever is built there to the Windows side so I can built python-mcrypt.

Do you have any clues?

Thanks,
Basil