How to create a copy of a python function [duplicate]

In Python3:

import typesimport functoolsdef copy_func(f):    """Based on http://stackoverflow.com/a/6528148/190597 (Glenn Maynard)"""    g = types.FunctionType(f.__code__, f.__globals__, name=f.__name__,                           argdefs=f.__defaults__,                           closure=f.__closure__)    g = functools.update_wrapper(g, f)    g.__kwdefaults__ = f.__kwdefaults__    return gdef f(arg1, arg2, arg3, kwarg1="FOO", *args, kwarg2="BAR", kwarg3="BAZ"):    return (arg1, arg2, arg3, args, kwarg1, kwarg2, kwarg3)f.cache = [1,2,3]g = copy_func(f)print(f(1,2,3,4,5))print(g(1,2,3,4,5))print(g.cache)assert f is not g

yields

(1, 2, 3, (5,), 4, 'BAR', 'BAZ')(1, 2, 3, (5,), 4, 'BAR', 'BAZ')[1, 2, 3]

In Python2:

import typesimport functoolsdef copy_func(f):    """Based on http://stackoverflow.com/a/6528148/190597 (Glenn Maynard)"""    g = types.FunctionType(f.func_code, f.func_globals, name=f.func_name,                           argdefs=f.func_defaults,                           closure=f.func_closure)    g = functools.update_wrapper(g, f)    return gdef f(x, y=2):    return x,yf.cache = [1,2,3]g = copy_func(f)print(f(1))print(g(1))print(g.cache)assert f is not g

yields

(1, 2)(1, 2)[1, 2, 3]