CODEWITHSUNDEEP
cython
Goran Milovanovic
Goran Milovanovic

Reputation: 357

Cython: Trying to wrap SFML Window; getting "ImportError: No module named 'ExprNodes'"

sfml.pxd:

cdef extern from "SFML/Window.hpp" namespace "sf":

    cdef cppclass VideoMode:
        VideoMode(unsigned int, unsigned int) except +

    cdef cppclass Window:
        Window(VideoMode, String) except + 
        void display()

display.pyx:

cimport sfml

cdef class Window:

    cdef sfml.Window* _this

    def __cinit__(self, unsigned int width, unsigned int height):

        self._this = new sfml.Window(sfml.VideoMode(width, height), "title")

    def __dealloc__(self):

        del self._this

    def display(self):

        self._this.display()

setup.py:

from distutils.core import setup
from distutils.extension import Extension
from Cython.Distutils import build_ext

setup(
    cmdclass = {'build_ext': build_ext},
    ext_modules = [
        Extension("display", ["display.pyx"],
        language='c++',
        libraries=["sfml-system", "sfml-window"])
    ]
)

The error when running python setup.py build:

running build
running build_ext
cythoning display.pyx to display.cpp
Traceback (most recent call last):
  File "setup.py", line 10, in <module>
    libraries=["sfml-system", "sfml-window"])
  File "/usr/lib/python3.3/distutils/core.py", line 148, in setup
    dist.run_commands()
  File "/usr/lib/python3.3/distutils/dist.py", line 917, in run_commands
    self.run_command(cmd)
  File "/usr/lib/python3.3/distutils/dist.py", line 936, in run_command
    cmd_obj.run()
  File "/usr/lib/python3.3/distutils/command/build.py", line 126, in run
    self.run_command(cmd_name)
  File "/usr/lib/python3.3/distutils/cmd.py", line 313, in run_command
    self.distribution.run_command(command)
  File "/usr/lib/python3.3/distutils/dist.py", line 936, in run_command
    cmd_obj.run()
  File "/usr/lib/python3.3/site-packages/Cython/Distutils/build_ext.py", line 163, in run
    _build_ext.build_ext.run(self)
  File "/usr/lib/python3.3/distutils/command/build_ext.py", line 354, in run
    self.build_extensions()
  File "/usr/lib/python3.3/site-packages/Cython/Distutils/build_ext.py", line 170, in build_extensions
    ext.sources = self.cython_sources(ext.sources, ext)
  File "/usr/lib/python3.3/site-packages/Cython/Distutils/build_ext.py", line 317, in cython_sources
    full_module_name=module_name)
  File "/usr/lib/python3.3/site-packages/Cython/Compiler/Main.py", line 608, in compile
    return compile_single(source, options, full_module_name)
  File "/usr/lib/python3.3/site-packages/Cython/Compiler/Main.py", line 549, in compile_single
    return run_pipeline(source, options, full_module_name)
  File "/usr/lib/python3.3/site-packages/Cython/Compiler/Main.py", line 386, in run_pipeline
    from . import Pipeline
  File "/usr/lib/python3.3/site-packages/Cython/Compiler/Pipeline.py", line 7, in <module>
    from .Visitor import CythonTransform
  File "Visitor.py", line 10, in init Cython.Compiler.Visitor (/build/src/Cython-0.19/Cython/Compiler/Visitor.c:15987)
ImportError: No module named 'ExprNodes'

Apparently, it can't find something called 'ExprNodes', but I don't think that my Cython installation is broken, because I managed to successfully wrap a different C++ library some time ago, and I didn't run into this problem.

I'm using Cython 0.19.

I would appreciate any help/insight that you could offer.

Thanks.

Upvotes: 0

Views: 662

Answers (1)

Nikita Nemkin
Nikita Nemkin

Reputation: 2820

Looking more closely at the traceback, I see that Cython fails inside it's own compiled code. It may be a bug indeed, sorry for missing it the first time.

What can you do:

  • Create a clean virtualenv, install Cython there and check if it works. (Version 0.19.1 is the latest).
  • Create another virtualenv, but this time install Cython using python setup.py install --no-cython-compile.

If either of these fails, please post your detailed configuration (linux distro and version, python version, gcc version, etc.) to the cython-devel mailing list.

BTW does your old successful project still compile?

Upvotes: 1

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