如何在 Cython 中正确包含头文件（setup.py）？答案

【问题标题】：How to include header file in Cython correctly (setup.py)?如何在 Cython 中正确包含头文件（setup.py）？
【发布时间】：2017-08-27 01:28:34
【问题描述】：

如何在 my_math 包中正确包含 my_math/clog.h 以让 tox 通过 py.test 套件？

项目文件结构：

my_math/__init__.py
my_math/clog.h
my_math/clog.pxd
my_math/integrate.pyx
setup.py
tests/__init__.py
tests/test_log.py
tox.ini

my_math/clog.h

#include <python.h>
#include <math.h>

#if PY_VERSION_HEX < 0x3050000 && (defined(_WIN32) || defined(_WIN64))
// Calculates log2 of number
double log2(double n);
{
    // log(n)/log(2) is log2
    double log_2 = 0.693147180559945309417232121458176568075500134360255254120680;
    return log(n) / log_2;
}
#endif

my_math/integrate.pyx

def extern from "clog.h":
    double log2(double)

def call_log2(n):
    return log2(n)

setup.py

import os

from setuptools import setup, Extension
from setuptools.dist import Distribution
from Cython.Distutils import build_ext

Distribution(dict(setup_requires='Cython'))

ext_modules = [
    Extension("my_math.integrate", ["my_math/integrate.pyx"],
              include_dirs=['my_math'],  # path to .h file(s)
              library_dirs=['my_math'],  # path to .a or .so file(s)
              # libraries=['clog'],
              extra_compile_args = ['-I/usr/local/include',
                                    '-L/usr/local/lib'],
              depends=['my_math/clog.h']
            )
]

setup(
    name='my_math',
    package_dir={'my_math': 'my_math'},
    packages=['my_math'],
    include_package_data=True,
    package_data={'': ['*.pyx', '*.pxd', '*.h', '*.c']},
    cmdclass = {'build_ext': build_ext},
    ext_modules=ext_modules
)

测试/test_log.py

from pytest import approx

from my_math.integrate import call_log2

def test_call_log2():
    assert approx(call_log2(100)) == 6.64386

tox.ini

[tox]
envlist = py36

[testenv]
deps = cython
       pytest
commands = python setup.py build_ext --inplace
           py.test tests

my_math/__init__.py 和 tests/__init__.py 为空。

我运行python3 setup.py build_ext --inplace 没有任何故障。

我可以直接调用函数call_log2：

python3 -c 'from my_math.integrate import call_log2; print(call_log2(100))'
6.643856189774724

但不是tox：

clang -Wno-unused-result -Wsign-compare -Wunreachable-code -fno-common -dynamic -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -Imy_math -I/usr/local/Cellar/python3/3.6.0/Frameworks/Python.framework/Versions/3.6/include/python3.6m -c my_math/integrate.c -o build/temp.macosx-10.11-x86_64-3.6/my_math/integrate.o -I/usr/local/include -L/usr/local/lib
clang: warning: argument unused during compilation: '-L/usr/local/lib'
my_math/integrate.c:432:10: fatal error: 'clog.h' file not found
#include "clog.h"
         ^
1 error generated.
error: command 'clang' failed with exit status 1

如果我取消注释 # libraries = ['clog'], 一个新的 python3 setup.py build_ext --inplace 将产生一个 ld: library not found for -lclog 错误。

【问题讨论】：

标签： cython setuptools

【解决方案1】：

通过更正MANIFEST.in解决：

global-include *.txt *.rst *.pyx *.pxd *.c *.h

setup.py:

'': ['data/*', '*.pyx', '*.pxd', '*.c', '*.h']

MANIFEST.in 和 setup.py 必须同时覆盖所有文件模式以支持 bdist 和 sdist。

【讨论】：