python调用c/c++时传递结构体参数

时间:2021-06-13 05:47:38

背景:使用python调用linux的动态库SO文件,并调用里边的c函数,向里边传递结构体参数。直接上代码

//test1.c

# include <stdio.h>
# include <stdlib.h> //创建一个Student结构体
struct Student
{
char name[];
float fScore[];
}; void Display(struct Student su)
{
printf("-----Information------\n");
printf("Name:%s\n",su.name);
printf("Chinese:%.2f\n",su.fScore[]);
printf("Math:%.2f\n",su.fScore[]);
printf("English:%.2f\n",su.fScore[]);
printf("总分数为:%f\n", su.fScore[]+su.fScore[]+su.fScore[]);
printf("平均分数为:%.2f\n",((su.fScore[]+su.fScore[]+su.fScore[]))/);
}

生成libpycall.so文件:

gcc -o libpycall.so -shared -fPIC test1.c

python调用,给Display传递结构体参数:

#pycall.py

import ctypes
from ctypes import * class Student(Structure):
_fields_ = [("name",c_char * 30),
("fScore", c_float * 3)
] su = Student()
su.name = b"test-sdk"
PARAM = c_float * 3
fScore = PARAM()
fScore[0] = 55.1
fScore[1] = 33.2
fScore[2] = 51.3 su.fScore = fScore if __name__ == '__main__': ll = ctypes.cdll.LoadLibrary
lib = ll("./libpycall.so")
# lib.Display.restype = c_float
lib.Display.argtypes = [Student] #这一行很重要
lib.Display(su)
print('----- finish -----')

输出Display函数调用结果:

-----Information------
Name:test-sdk
Chinese:55.10
Math:33.20
English:51.30
总分数为:139.600006
平均分数为:46.53
----- finish -----