Hi, The io module provides an open() function. It also provides an OpenWrapper which only exists to be able to store open as a method (class or instance method). In the _pyio module, pure Python implementation of the io module, OpenWrapper is implemented as: class OpenWrapper: """Wrapper for builtins.open Trick so that open won't become a bound method when stored as a class variable (as dbm.dumb does). See initstdio() in Python/pylifecycle.c. """ def __new__(cls, *args, **kwargs): return open(*args, **kwargs) I would like to remove this class which is causing troubles in the PEP 597 implementation, but I don't know how. Simplified problem: --- def func(): print("my func") class MyClass: method = func func() # A MyClass.method() # B obj = MyClass() obj.method() # C --- With this syntax, A and B work, but C fails with TypeError: func() takes 0 positional arguments but 1 was given. If I decorate func() with @staticmethod, B and C work, but A fails with TypeError: 'staticmethod' object is not callable. Is OpenWrapper the only way to have a callable object which works in the 3 variants A, B and C? A, B and C work if MyClass is modified to use staticmethod: class MyClass: method = staticmethod(func) Victor -- Night gathers, and now my watch begins. It shall not end until my death.