How to use ctypes, c++ and python?

Question

Python

Understanding the ctypes tool to call dll from python code. It is not possible to call functions from a dll compiled from C ++, although the same source code, but already in C, compiled into a dll, works fine, all functions are called.
C/C++ code:
int test(int x)
{
return x;
}
Python code:
from ctypes import *
c_testlib = cdll.LoadLibrary('libtest.dll')
c_test=c_testlib.test
Error:
AttributeError: function 'test' not found
Are Ctypes and C++ not friends? What are the options for calling functions from already written dlls in C++?

Answer 1

extern "C"it is necessary to write before the functions so that the compiler in the dll calls them according to C, and not according to C ++