ctypes 操作 python 与 c++ dll 互传结构体指针

Posted 2020-07-30 佩雷尔曼的信徒

CMakeLists.txt

# project(工程名)
project(blog-3123958139-1)

# add_library(链接库名称 SHARED 链接库代码)
add_library(dll_ SHARED dll_.cpp)

dll_.cpp

#include <iostream>

using namespace std;

// c++ 结构体定义
struct cpp_struck_ {

    // 股票代码，字符串
    char *stock_name_;

    // 日期，字符串数组
    char *stock_date_[];

    // 开高低收四组价格，浮点型数组
    double stock_open_[];
    double stock_high_[];
    double stock_low_[];
    double stock_close_[];

    // 成交量，浮点型数组
    double stock_volume_[];

    // 长度，整型
    int stock_len_;
    int ma_len_;
};

// 声明为标准 C 格式导出的函数
extern "C" {

// 传入结构体指针，传出结构体指针
cpp_struck_ *dll_function_1(cpp_struck_ *py_struck_pointer_) {
    /*
     * 数据处理部分...
     *
     *
     *
     */
    cpp_struck_ *cpp_struck_pointer_;
    cpp_struck_pointer_ = py_struck_pointer_;
    return cpp_struck_pointer_;
}
}

test_dll_.py

import tushare
from ctypes import *

# 下载测试数据
sh_data_frame_ = tushare.get_hist_data(\'sh\')
stock_name_ = \'sh\'
stock_date_ = sh_data_frame_.index.values
stock_open_ = sh_data_frame_[\'open\'].values
stock_high_ = sh_data_frame_[\'high\'].values
stock_low_ = sh_data_frame_[\'low\'].values
stock_close_ = sh_data_frame_[\'close\'].values
stock_volume_ = sh_data_frame_[\'volume\'].values
stock_len_ = len(sh_data_frame_)
ma_len_ = 2

# 打印旧数据作为比较
print("old_date_ = ", list(stock_date_))
print("old_open_ = ", list(stock_open_))

# python 结构体定义
class py_struct_(Structure):
    _fields_ = [("stock_name_", c_wchar_p),

                # 注意字符串格式要用 c_wchar_p 而不是 c_char_p
                ("stock_date_", c_wchar_p * stock_len_),
                ("stock_open_", c_double * stock_len_),
                ("stock_high_", c_double * stock_len_),
                ("stock_low_", c_double * stock_len_),
                ("stock_close_", c_double * stock_len_),
                ("stock_volume_", c_double * stock_len_),
                ("stock_len_", c_int),
                ("ma_len_", c_int)]


# python 结构体实例化，初始化
py_struct_1 = py_struct_()
py_struct_1.stock_name_ = stock_name_
py_struct_1.stock_date_ = (c_wchar_p * stock_len_)(*stock_date_)
py_struct_1.stock_open_ = (c_double * stock_len_)(*stock_open_)

# 传入指针实例
py_struct_1_pointer_ = byref(py_struct_1)

# 获取 dll 句柄
h_dll_ = CDLL(
    \'C:\\\\Users\\\\Perelman\\\\.CLion2016.1\\\\system\\\\cmake\\\\generated\\\\blog-3123958139-1-6c04ac5e\\\\6c04ac5e\\\\Debug\\\\libdll_.dll\')

# 定义 dll 返回值类型为 python 结构体指针
h_dll_.dll_function_1.restype = POINTER(py_struct_)

# 返回 dll 结构体指针
cpp_struct_pointer_ = h_dll_.dll_function_1(py_struct_1_pointer_)

# 结构体指针取内容
cpp_struct_contents_ = cpp_struct_pointer_.contents

# 保存结果为 python list 格式
new_date_ = []
for value in cpp_struct_contents_.stock_date_:
    new_date_.append(value)
print("new_date_ = ", new_date_)

# 保存结果为 python list 格式
new_open_ = []
for value in cpp_struct_contents_.stock_open_:
    new_open_.append(value)
print("new_open_ = ", new_open_)