__declspec(dllexport) int sum(int a, int b) {
    return a + b;
}

from ctypes import cdll

mydll = cdll.LoadLibrary('libTest.dll')


if __name__ == '__main__':
    pass

Traceback (most recent call last):
  File "C:Usersrobertodg.p2poolpluginsorg.python.pydev.core_6.4.3.201807050139pysrc_pydev_runfilespydev_runfiles.py", line 468, in __get_module_from_str
    mod = __import__(modname)
  File "C:Usersrobertodgeclipse-workspaceLetsHopeHope.py", line 8, in <module>
    mydll = cdll.LoadLibrary('libTest.dll')
  File "C:UsersrobertodgAppDataLocalProgramsPythonPython37-32libctypes__init__.py", line 434, in LoadLibrary
    return self._dlltype(name)
  File "C:UsersrobertodgAppDataLocalProgramsPythonPython37-32libctypes__init__.py", line 356, in __init__
    self._handle = _dlopen(self._name, mode)
OSError: [WinError 193] %1 is not a valid win32 application