def target_func(): pass def func1(): def inner_func1(x=target_func): pass return inner_func1(target_func) def func2(): def inner_func2(x=target_func()): pass return inner_func2(target_func) def func3(x=target_func()): pass def func4(): def inner_func4(x=target_func): pass return inner_func4(target_func()) target_func()