Cython to build a python script

Question

Trying to get cython to run and I get this issue after following the quick start guide:

$ ~/midt $ ./setup.py build_ext --inplace
running build_ext
building 'proc' extension
x86_64-linux-gnu-gcc -pthread -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fPIC -I/usr/include/python2.7 -c proc.c -o build/temp.linux-x86_64-2.7/proc.o
proc.c:2511:16: error: ‘initproc’ redeclared as different kind of symbol
 PyMODINIT_FUNC initproc(void); /*proto*/
                ^
In file included from /usr/include/python2.7/Python.h:80:0,
                 from proc.c:16:
/usr/include/python2.7/object.h:320:15: note: previous declaration of ‘initproc’ was here
 typedef int (*initproc)(PyObject *, PyObject *, PyObject *);
               ^
error: command 'x86_64-linux-gnu-gcc' failed with exit status 1

Here are my version numbers and stuff:

$ ~/midt $ python --version
Python 2.7.6
$ ~/midt $ cython --version
Cython version 0.23.5
$ ~/midt $ uname -a
Linux xxxxx 3.13.0-37-generic #64-Ubuntu SMP Mon Sep 22 21:28:38 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

DavidW · Accepted Answer · 2016-03-30 17:22:34Z

2

I believe the issue is:

Python requires the function to initialise a C module initialisation to be called init<module_name> (where you substitute your module name). (Python 3 uses a slightly different form).
You've called your module proc.
Cython has thus created a function called initproc to be defined when your module is imported.
Python defines a typedef called initproc internally, which conflicts with the Cython generated initproc used to initialise your module.

The solution is to call your module something other than proc. It isn't an ideal solution, but there aren't too many other options.

One of the reasons Python 3 picked a different form PyInit_<module_name> was that the Python 2 form was known to cause a few conflicts (see https://www.python.org/dev/peps/pep-3121/#entry-point-name-conflicts).

edited Mar 30, 2016 at 17:22

answered Mar 30, 2016 at 17:07

DavidW

31.2k7 gold badges64 silver badges99 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Cython to build a python script

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related