Dear Sir, Thank you for your effort in developing a wonderful module pythonnet so that I can easily interface the C# assembly (https://www.kgifutures.com.tw/content/images_D8/QuoteCom%20API-20170425.zip ) offered by my futures dealer. A working simple code is as follows, using the supplied assembly in bin\release\QuoteCom.dll: # File name: Test.py import clr clr.AddReference("QuoteCom") import Intelligence QC = Intelligence.QuoteCom("211.20.186.12", 8000, "API", "b6eb") However, it caused an error importing "Intelligence" module when I converted .py to .pyd. Conversion was done using: # setup.py from distutils.core import setup from distutils.extension import Extension from Cython.Distutils import build_ext ext_modules = [ Extension("Test", sources=["Test.py"]), ] setup( name = 'My Program', cmdclass = {'build_ext': build_ext}, ext_modules = ext_modules ) # DOS command: Python setup.py build_ext -inplace Is there any step I've done wrong? Any response is appreciated. Thank you very much! Best regards, Weichen Lin