How can I unload a DLL using ctypes in Python?

Question

I\'m using ctypes to load a DLL in Python. This works great.

Now we\'d like to be able to reload that DLL at runtime.

The straightforward approach would s

Answer 1

Piotr's answer helped me, but I did run into one issue on 64-bit Windows:

Traceback (most recent call last):
...
ctypes.ArgumentError: argument 1: : int too long to convert

Adjusting the argument type of the FreeLibrary call as suggested in this answer solved this for me.

Thus we arrive at the following complete solution:

import ctypes, ctypes.windll

def free_library(handle):
    kernel32 = ctypes.WinDLL('kernel32', use_last_error=True)
    kernel32.FreeLibrary.argtypes = [ctypes.wintypes.HMODULE]
    kernel32.FreeLibrary(handle)

Usage:

lib = ctypes.CDLL("foobar.dll")
free_library(lib._handle)