如何用cython包装参数为wchar_t指针的C函数 [英] How to wrap a C function whose parameter is wchar_t pointer with cython
本文介绍了如何用cython包装参数为wchar_t指针的C函数的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我想用cython包装一个C库.库中的一个功能就像
I want to use cython to wrap a C library. One function in the library is like
int hid_get_manufacturer_string(hid_device *device, wchar_t *string, size_t maxlen);
有两个问题:
-
如何在cython中使用
wchar_t
?
如何在我的.pyx文件中转换字符串指针.
How to convert the string pointer in my .pyx file.
推荐答案
声明wchar_t:
cdef extern from "stddef.h":
ctypedef void wchar_t
或从libc模块导入:
Or import from libc module:
from libc.stddef cimport wchar_t
使用WideCharToMultiByte将wchar_t转换为python字符串的函数(请参见 CefStringToPyString ):
A function to convert wchar_t to python string by using WideCharToMultiByte (see CefStringToPyString):
# Declare these in .pxd file:
#
# cdef extern from "Windows.h":
# cdef int CP_UTF8
# cdef int WideCharToMultiByte(int, int, wchar_t*, int, char*, int, char*, int*)
cdef object WideCharToPyString(wchar_t *wcharstr):
cdef int charstr_bytes = WideCharToMultiByte(CP_UTF8, 0, wcharstr, -1, NULL, 0, NULL, NULL)
# Do not use malloc, otherwise you get trash data when string is empty.
cdef char* charstr = <char*>calloc(charstr_bytes, sizeof(char))
cdef int copied_bytes = WideCharToMultiByte(CP_UTF8, 0, wcharstr, -1, charstr, charstr_bytes, NULL, NULL)
if bytes == str:
pystring = "" + charstr # Python 2.7
else:
pystring = (b"" + charstr).decode("utf-8", "ignore") # Python 3
free(charstr)
return pystring
从Python 3.2开始,您可以使用PyUnicode_FromWideChar(wcharstr,-1)进行此操作,请参见compostus的注释.
Since Python 3.2 you can do this with the use of PyUnicode_FromWideChar(wcharstr, -1), see the comment by compostus.
这篇关于如何用cython包装参数为wchar_t指针的C函数的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
查看全文