Mutable and immutable args for functions in Python3

mutable_immutable.py

class AutoInc:
    current_index = 0

    def __call__(self):
        self.current_index += 1
        return self.current_index


def append_to_list(alist: list):
    alist.append(7)


def del_var(v):
    del v


def set_var(v):
    v = 5


def append_by_yeild(alist: list):
    alist.append(8)
    yield
    alist.append(9)


if __name__ == '__main__':
    list_ = [1, 2]
    int_ = 10
    list2_ = list_

    append_to_list(list_)
    del_var(int_)
    del_var(list_)
    set_var(int_)

    i = AutoInc()
    print(f'{i()}: {list_=}')
    print(f'{i()}: {int_=}')
    print(f'{i()}: {list2_=}')

    saved_func = append_by_yeild(list2_)
    print(f'{i()}: {list_=}')
    del list_
    next(saved_func)
    print(f'{i()}: {list2_=}')
    print(f'{i()}: {list_=}')