獲取關於SystemError：父模塊'不加載，試圖在用Cython擴展

Question

我有一個封裝內的用Cython擴展，它的結構像這樣導入numpy的時候不能進行相對進口：

packagename 
├── MANIFEST.in 
├── packagename 
│   ├── __init__.py 
│   ├── packagename.py 
│   ├── subpackage1 
│   │   ├── __init__.py 
│   │   ├── subpackage1.py 
│   │   └── cythonExt1.pyx 
│   ├── subpackage2 
│   │   ├── __init__.py 
│   │   ├── subpackage2.py 
│   │   └── cythonExt2.pyx 
│   └── VERSION 
├── requirements.txt 
└── setup.py 

當我嘗試添加在cythonExt2.pyx一個線，進口與NumPy我得到以下錯誤：

------------------------------------------------------------- 
SystemError     Traceback (most recent call last) 
<ipython-input-5-5c4ef4d8efd3> in <module>() 
     1 # Calling Functions of Interest 
----> 2 import pacakge.subpackage2 as thingy 
     3 import numpy as np 
     4 import matplotlib.pyplot as plt 

/home/user/anaconda2/envs/python3/lib/python3.5/site-packages/pacakage-0.0.3-py3.5-linux-x86_64.egg/package/__init__.py in <module>() 
    18 
    19 # the following line imports all the functions from package.py 
---> 20 from .package import * 
    21 import package.subpackage1 
    22 import package.subpackage2 

/home/user/anaconda2/envs/python3/lib/python3.5/site-packages/package-0.0.3-py3.5-linux-x86_64.egg/package/package.py in <module>() 
     1 from package.subpackage1 import thingy1 
----> 2 from package.subpackage2 import thingy2 
     3 import numpy as _np 
     4 from multiprocessing import Pool as _Pool 

/home/user/anaconda2/envs/python3/lib/python3.5/site-packages/package-0.0.3-py3.5-linux-x86_64.egg/package/subpackage2/subpackage2.py in <module>() 
     3 import os 
----> 4 from cythonExt2 import solve as solve_cython 
     5 from frange import frange 
     6 
/home/user/anaconda2/envs/python3/lib/python3.5/site-packages/package-0.0.3-py3.5-linux-x86_64.egg/package/subpackage2/cythonExt2.pyx in init package.subpackge2.cythonExt2 (package/subpackage2/cythonExt2.c:6158)() 
     1 cimport numpy 
----> 2 import numpy 
     3 cimport cython 
     4 
     5 def get_z_n(n, z): 

SystemError: Parent module '' not loaded, cannot perform relative import 

如果我只是cimport numpy的這個作品，我有機會獲得numpy的C API，但我不能導入numpy的Python函數我需要解決一個特定的問題。

這是爲什麼，我該如何解決？

我想知道是否存在導致此問題無法解決的安裝文件問題。我的setup.py文件的cython部分是這樣的：

from setuptools import setup                  
from setuptools.extension import Extension 
from Cython.Build import cythonize                
from Cython.Build import build_ext 
extensions = [Extension(                   
    name="cythonExt1",                    
    sources=["package/subpackage1/cythonExt1.pyx"],             
    include_dirs=[numpy.get_include()],               
    ),                        
    Extension(                     
    name="cythonExt2",                   
    sources=["package/subpackage2/cythonExt2.pyx"],           
    include_dirs=[numpy.get_include()],               
    )                        
] 

setup(name='package',                    
     ... 
     include_package_data=True,                 
     packages=['package',                   
       'package.subpackage1',                
       'package.subpackage2',               
     ],                       
     ext_modules = cythonize(extensions),               
     install_requires=requirements,                
) 

Answer 1

問題是numpy沒有被包含在這個setup.py文件和工作流中。我通過修改它來解決這個問題，使得cython擴展在它自己的目錄中被cython化，並將它自己的setup.py文件放到一個.c文件中，然後該文件作爲C擴展名添加到該包的setup.py文件中。這也有一個好處，即安裝你的模塊的人不需要使用cython，因爲你可以將生成的.c文件與包一起分發。

我已經創建了我的github上here這個完整的，但簡單，例如。