python - 将 Python 对象转换为 C void 类型

Question

如何使用 Cython 将 Python 对象转换为 C void 类型？

目前，当我尝试投射时收到此消息

将临时 Python 对象转换为非数字非 Python 类型

Answer 1

这可以这样做：

1. 从 Python 转换为 C

如果你真的是void *这个意思：

some_pyobj = "abc"
cdef void *ptr
ptr = <void *>some_pyobj

如果您的意思PyObject *是：

cdef PyObject *ptr
ptr = <PyObject *>some_pyobj           # Cast from Python object to C pointer

然后，从 C 端，PyObject struct可以通过包含Python.h.

这是参考（来自object.hPython 包含文件）：

/* Nothing is actually declared to be a PyObject, but every pointer to
 * a Python object can be cast to a PyObject*.  This is inheritance built
 * by hand.  Similarly every pointer to a variable-size Python object can,
 * in addition, be cast to PyVarObject*.
 */
typedef struct _object {
    PyObject_HEAD
} PyObject;

2. 从 C 转换为 Python

它以两种方式工作，这意味着以下也是可能的：

cdef PyObject *ptr
ptr = <PyObject *>some_pyobj
cdef object some_other_pyobj
some_other_pyobj = <object>ptr          # Cast from C pointer to Python object

Answer 2

你可以：

def run():
   pyobj = 'abc'
   pyobj_void_star = <void *>pyobj