Taken from

  https://gitlab.archlinux.org/archlinux/packaging/packages/python-pyliblo

diff -ruN a/src/liblo.pyx b/src/liblo.pyx
--- a/src/liblo.pyx	2015-04-14 09:02:22.000000000 +0200
+++ b/src/liblo.pyx	2023-04-06 19:51:56.042679208 +0200
@@ -258,9 +258,9 @@
                  cb.user_data)
 
     # call function
-    if _inspect.getargspec(func)[1] == None:
+    if _inspect.getfullargspec(func)[1] == None:
         # determine number of arguments to call the function with
-        n = len(_inspect.getargspec(func)[0])
+        n = len(_inspect.getfullargspec(func)[0])
         if _inspect.ismethod(func):
             n -= 1  # self doesn't count
         r = cb.func(*func_args[0:n])