Python：ctypes.cdll无法加载c ++编译的共享.dll文件

Question

.dll

我已经检查了这条路，甚至使用了全路，从未工作过，一整天都在尝试，一次又一次地以不同的方式和方法来编译

Traceback (most recent call last):
  File "e:\My Apps\Python\Telegram_Bots\Calculator\main.py", line 6, in <module>
    lib = CDLL("E:\My Apps\Python\Telegram_Bots\Calculator\lib.dll")
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "c:\Users\KHATAM_PC\AppData\Local\Programs\Python\Python311\Lib\ctypes\__init__.py", line 376, in __init__
    self._handle = _dlopen(self._name, mode)
                   ^^^^^^^^^^^^^^^^^^^^^^^^^
FileNotFoundError: Could not find module 'E:\My Apps\Python\Telegram_Bots\Calculator\lib.dll' (or one of its dependencies). Try using the full path with constructor syntax.

，但没有任何东西，但它们都在C ++

中工作。

.dll

出口命令：

.dll

g++ -DMATH_DLL_EXPORTS -shared -std=c++17 -o lib.dll lib.cpp

：

lib.hpp

// #pragma once

#ifndef MATH_DLL_API
#define MATH_DLL_API

#ifdef _WIN32
#define DLL_EXPORT __declspec(dllexport)
#else
#define DLL_EXPORT
#endif

#include <iostream>
#include <vector>
extern "C" {
    DLL_EXPORT int precedence(char o);
    DLL_EXPORT float calc(float a, float b, char o);
    DLL_EXPORT void calculate(std::vector<float>& values, std::vector<char>& ops);
    DLL_EXPORT float evaluate(std::string e);
}
#endif // MATH_DLL_API

：

lib.cpp

最后，python脚本：

#include "lib.hpp"
#include <iostream>
#include <vector>
extern "C" {
    DLL_EXPORT int precedence(char o) { ... }
    DLL_EXPORT float calc(float a, float b, char o) { ... }
    DLL_EXPORT void calculate(std::vector<float>& values, std::vector<char>& ops) { ... }
    DLL_EXPORT float evaluate(std::string e) { ... }
}

有人可以帮助吗？

here是一个可以加载它的DLL和Python脚本的简单示例。这是使用Microsoft的C ++编译器而不是GNU版本构建的。

from ctypes import c_char, c_int, c_float, c_char_p, c_void_p, CDLL, cdll, POINTER

lib = CDLL("E:\My Apps\Python\Telegram_Bots\Calculator\lib.dll")

lib.evaluate.argtypes = [c_char_p]
lib.evaluate.restype = c_float

lib.calculate.argtypes = [POINTER(c_float), POINTER(c_char)]
lib.calculate.restype = c_void_p

lib.calc.argtypes = [c_float, c_float, c_char]
lib.calc.restype = c_float

lib.precedence.argtypes = [c_char]
lib.precedence.restype = c_int

//
// zzdll.h header 
//
#pragma once

#ifdef ZZDLL
#define DLL_EXPORT __declspec(dllexport)
#else
#define DLL_EXPORT
#endif

extern "C" {
    DLL_EXPORT int precedence(char o);
    DLL_EXPORT float calculate(float a, float b);
}

//
// zzdll.cpp implementation file
//
#include <iostream>

#define ZZDLL
#include "zzdll.h"

int precedence(char o)
{
    std::cout << "zzdll::precedence('" << o << "')\n";
    
    return 137;
}

float calculate(float a, float b)
{
    std::cout << "zzdll::calc(" << a << ", " << b << ")\n";
    
    return float(a * b);
}

Answer 1