编写函数，计算数列

m(n) = 1/2 + 2/3 + ... +n/n+1

def sljisuan():
    s = 0
    n = int(input("请输入需要求和的数："))
    for i in range(1,n+1):
        s += i/(i+1)

    print("前{0}项和为{1}".format(n,s))


sljisuan()