Cythonize instance method of Python class

basic.py

import numpy as np
from scipy.special import gammaln


class MyClass(object):
    def __init__(self, n, x):
        self.n = n
        self.x = np.abs(x)

    def fun(self):
        return (np.random.rand(self.n), gammaln(self.x))

if __name__ == '__main__':
    np.random.seed(8675309)
    mc = MyClass(5, 12)
    (r, gx) = mc.fun()
    print r
    print gx

cy1.py

import types
import numpy as np
import cy1fun


class MyClass(object):
    def __init__(self, n, x):
        self.n = n
        self.x = np.abs(x)

# Add the cython implementation of fun to the class as an instance method
# Want to do this, but it doesn't work
# MyClass.fun = cy1fun.fun

# Need to do this instead
MyClass.fun = types.MethodType(cy1fun.fun, None, MyClass)


if __name__ == '__main__':
    np.random.seed(8675309)
    mc = MyClass(5, 12)
    (r, gx) = mc.fun()
    print r
    print gx

cy1fun.pyx

# build with: python setup.py build_ext --inplace
# see setup.py below

import numpy as np
cimport numpy as np

from scipy.special import gammaln

def fun(object self):
    return (np.random.rand(self.n), gammaln(self.x))

cy2.py

import types
import numpy as np
import cy2fun


class MyClass(object):
    def __init__(self, n, x):
        self.n = n
        self.x = np.abs(x)

# Add the cython implementation of fun to the class as an instance method
# Want to do this, but it doesn't work
# MyClass.fun = cy2fun.fun

# Need to do this instead
MyClass.fun = types.MethodType(cy2fun.fun, None, MyClass)


if __name__ == '__main__':
    np.random.seed(8675309)
    mc = MyClass(5, 12)
    (r, gx) = mc.fun()
    print r
    print gx

cy2fun.pyx

# build with: python setup.py build_ext --inplace
# see setup.py below

import numpy as np
cimport numpy as np

cdef extern from "gsl/gsl_sf_gamma.h":
    double gsl_sf_lngamma(double x)


cdef gammaln(double x):
     return gsl_sf_lngamma(x)


def fun(object self):
    return (np.random.rand(self.n), gammaln(self.x))

setup.py

import numpy as np

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

cy1fun = Extension("cy1fun", ["cy1fun.pyx"],
                   include_dirs=[np.get_include()],
                  )

gsl_include_dir = "/usr/local/include"
gsl_lib_dir = "/usr/local/lib"

cy2fun = Extension("cy2fun", ["cy2fun.pyx"],
                   include_dirs=[np.get_include(),
                                 gsl_include_dir],
                   library_dirs=[gsl_lib_dir],
                   libraries=["gsl"],
                  )

setup(cmdclass={'build_ext': build_ext},
      ext_modules=[cy1fun, cy2fun]
     )