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pythondllctypesattributeerror

Python: accessing DLL function using ctypes -- access by function *name* fails

myPythonClient (below) wants to invoke a ringBell function (loaded from a DLL using ctypes). However, attempting to access ringBell via its name results in an AttributeError. Why?

RingBell.h contains

namespace MyNamespace
    {
    class MyClass
        {
        public:
            static __declspec(dllexport) int ringBell ( void ) ;
        } ;
    }

RingBell.cpp contains

#include <iostream>
#include "RingBell.h"
namespace MyNamespace
    {
    int __cdecl MyClass::ringBell ( void )
        {
        std::cout << "\a" ;
        return 0 ;
        }
    }

myPythonClient.py contains

from ctypes import *
cdll.RingBell[1]() # this invocation works fine
cdll.RingBell.ringBell() # however, this invocation errors out
# AttributeError: function 'ringBell' not found
Solution

  • Perhaps because the C++ name is mangled by the compiler and not exported from the DLL as RingBell. Have you checked that it appears in the exported names exactly like that?