如何在Cython模块中将#defined C值暴露给Python？

Question

我想在这里定义整数常量(ACTIVE_TAG等):

//island management, m_activationState1
#define ACTIVE_TAG 1
#define ISLAND_SLEEPING 2
#define WANTS_DEACTIVATION 3
#define DISABLE_DEACTIVATION 4
#define DISABLE_SIMULATION 5

可用作我正在处理的Cython定义模块的普通属性,以便Python应用程序代码可以访问它们(将它们传递给根据它们定义的包装API).

我已经看过用cdef定义这些作为整数或枚举,但这些方法实际上都没有将值绑定到Cython模块中的属性.还有哪些其他选择？

Answer 1

这是一种方式,虽然看似乏味,但可以为任何给定的.h文件自动化作为输入:

步骤1.将所需的所有常量放入一个文件中,例如bulletdefs.h,其中包含#defines带有前导下划线的文件,例如:

#define _ACTIVE_TAG 1
#define _ISLAND_SLEEPING 2
#define _WANTS_DEACTIVATION 3
#define _DISABLE_DEACTIVATION 4
#define _DISABLE_SIMULATION 5

步骤2.将一个部分插入模块的pyx文件中,例如bullet.pyx:

cdef extern from "bulletdefs.h":
    cdef int _ACTIVE_TAG
    cdef int _ISLAND_SLEEPING
    cdef int _WANTS_DEACTIVATION
    cdef int _DISABLE_DEACTIVATION
    cdef int _DISABLE_SIMULATION

ACTIVE_TAG = _ACTIVE_TAG
ISLAND_SLEEPING = _ISLAND_SLEEPING
WANTS_DEACTIVATION = _WANTS_DEACTIVATION
DISABLE_DEACTIVATION = _DISABLE_DEACTIVATION
DISABLE_SIMULATION = _DISABLE_SIMULATION

然后,当您编译模块时,您应该获得预期的效果:

Python 2.7.1+ (r271:86832, Apr 11 2011, 18:05:24) 
[GCC 4.5.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import bullet
>>> bullet.ACTIVE_TAG
1
>>> bullet.DISABLE_SIMULATION
5
>>>

Answer 2

它对我来说有效。也许对某人也有帮助：

#define就我而言，我需要从 Linux 内核库中导出。它对我有用：

# your_pxd_file.pxd
cdef extern from "sched.h": #here are lots of `#define`'s clauses. something like the link: https://github.com/spotify/linux/blob/master/include/linux/sched.h
    cdef enum:
        CLONE_NEWNS

在你的.pyx文件中：

from your_compiled_cython_package cimport CLONE_NEWNS

print(CLONE_NEWNS)

我希望这对某人有帮助，就像对我一样=）