Cython dynamic library problem

[Tommy Grav]

I am trying to learn how to use cython, and while I am following the
cython-dev
mailing list I didn't feel like this question was totally appropriate
for its audience
so I am trying here first.

I am on a max os x 10.5.4 running

drtgrav% python
ActivePython 2.5.2.2 (ActiveState Software Inc.) based on
Python 2.5.2 (r252:60911, Mar 27 2008, 17:40:23)
[GCC 4.0.1 (Apple Computer, Inc. build 5250)] on darwin
Type "help", "copyright" , "credits" or "license" for more information.

>>>

I have a pure python file that I am wanting to try to speed up some,
so I ran the file through cython, compiled it with gcc and tried to
call it from a python file

cython integrations.py x
gcc -arch ppc -shared -c -fPIC -I/usr/include/python2.5

integration.c -o pyx_integration .so

python integration_tes t.py

Traceback (most recent call last):
File "integration_te st.py", line 1, in <module>
from astroPyX import pyx_integration
ImportError: dlopen(/Users/drtgrav/Work/myCode/Python/astroPyX/
pyx_integration .so, 2): no suitable image found. Did find:
/Users/drtgrav/Work/myCode/Python/astroPyX/pyx_integration .so: can't
map

where integration_tes t.py is

from astroPyX import pyx_integration

pyx_integration .test(0)
pyx_integration .test(100)

Does anyone know what the ImportError means and how to correct it?

Cheers
Tommy

[Rob Wolfe]

Re: Cython dynamic library problem

Tommy Grav <tgrav@mac.comw rites:

I am trying to learn how to use cython, and while I am following the
cython-dev
mailing list I didn't feel like this question was totally appropriate
for its audience
so I am trying here first.

[...]

Does anyone know what the ImportError means and how to correct it?

I would try to use `distutils` because this package is much wiser
than me and knows all necessary switches for gcc. ;)

# test_cython.pyx
def test(x):
return x * x

# test_cython.py
from pyx_test import test

print test(0)
print test(10)

# setup.py
from distutils.core import setup
from distutils.exten sion import Extension
from Cython.Distutil s import build_ext as build_pyx

setup(name = 'pyx_test',
ext_modules=[Extension('pyx_ test', ['test_cython.py x'])],
cmdclass = { 'build_ext': build_pyx })


$ python2.5 setup.py build_ext -i
running build_ext
cythoning test_cython.pyx to test_cython.c
building 'pyx_test' extension
creating build/temp.linux-i686-2.5
gcc -pthread -fno-strict-aliasing -DNDEBUG -g -O2 -Wall -Wstrict-prototypes -fPIC -I/usr/include/python2.5 -c test_cython.c -o build/temp.linux-i686-2.5/test_cython.o
test_cython.c:8 6: warning: function declaration isnft a prototype
test_cython.c:2 41: warning: function declaration isnft a prototype
test_cython.c:5 9: warning: e__pyx_skip_di spatchf defined but not used
gcc -pthread -shared -Wl,-O1 build/temp.linux-i686-2.5/test_cython.o -o pyx_test.so
$ python2.5 test_cython.py
0
100


HTH,
Rob

[bearophileHUGS@lycos.com]

Re: Cython dynamic library problem

Rob Wolfe:

# setup.py
from distutils.core import setup
from distutils.exten sion import Extension
from Cython.Distutil s import build_ext as build_pyx
>
setup(name = 'pyx_test',
ext_modules=[Extension('pyx_ test', ['test_cython.py x'])],
cmdclass = { 'build_ext': build_pyx })
>
$ python2.5 setup.py build_ext -i
running build_ext
cythoning test_cython.pyx to test_cython.c
building 'pyx_test' extension
creating build/temp.linux-i686-2.5
gcc -pthread -fno-strict-aliasing -DNDEBUG -g -O2 -Wall -Wstrict-prototypes -fPIC -I/usr/include/python2.5 -c test_cython.c -o build/temp.linux-i686-2.5/test_cython.o
test_cython.c:8 6: warning: function declaration isn’t a prototype
test_cython.c:2 41: warning: function declaration isn’t a prototype
test_cython.c:5 9: warning: ‘__pyx_skip_dis patch’ defined but not used
gcc -pthread -shared -Wl,-O1 build/temp.linux-i686-2.5/test_cython.o -o pyx_test.so
$ python2.5 test_cython.py
0
100

With some intelligence added to Cython, probably there are ways to
reduce all this, and most of the times avoid any setup.py module too.

Bye,
bearophile

[Tommy Grav]

Re: Cython dynamic library problem

On Sep 18, 2008, at 12:35 PM, Rob Wolfe wrote:

I would try to use `distutils` because this package is much wiser
than me and knows all necessary switches for gcc. ;)

That worked! Thanks

Cheers
Tommy

[Tommy Grav]

Re: Cython dynamic library problem


On Sep 18, 2008, at 12:35 PM, Rob Wolfe wrote:

>
I would try to use `distutils` because this package is much wiser
than me and knows all necessary switches for gcc. ;)

That worked! Thanks

Cheers
Tommy