C hotreload/figwheel in Python

run.py

#!/usr/bin/env python
import ctypes
from ctypes import cdll

cur_x = 10
libpath = "./some_lib.so"
lib = cdll.LoadLibrary(libpath)
print(f"loaded {lib}")

# https://stackoverflow.com/a/62021495/1420489
def ctypesCloseLibrary(lib):
    dlclose_func = ctypes.CDLL(None).dlclose
    dlclose_func.argtypes = [ctypes.c_void_p]
    dlclose_func.restype = ctypes.c_int
    dlclose_func(lib._handle)
    
def reloadLibrary(lib):
    name = lib._name
    ctypesCloseLibrary(lib)
    return cdll.LoadLibrary(name)

while True:
    inp = input("> ")
    inp = inp.strip().upper()

    if inp == "X":
        x = lib.foo(cur_x)
        print(x)

    elif inp == "L":
        lib = reloadLibrary(lib)
        print(f"reloaded {lib}")

    else:
        print(f"unknown input {inp}")

just to write it down:

# Makefile
%.o: %.c
	gcc -c -fPIC $< -o $@

%.so: %.o
	gcc $< -shared -o $@