帮儿子问一下,python

python中 利用递归求1-1/2+1/3-....+1/99-1/100+1/(n-1)-1/n


def func(n):
    ret = 0
    if n == 1:
        return 1

    if (n % 2) == 0:
        ret = func(n - 1) - 1 / n
    else:
        ret = func(n - 1) + 1 / n

    return ret

func(4)