python练手_76-做函数

# -*- coding:utf-8 -*-
# @Author: CH
"""
@project: python study
@time:2019/1/9-19:46
@file_name:【程序76】做函数.py
@IDE:PyCharm 
@else: DO NOT STOP STUDYING!!!
"""
# 题目 编写一个函数，输入n为偶数时，调用函数求1/2+1/4+…+1/n,当输入n为奇数时，调用函数1/1+1/3+…+1/n
# 程序分析 无。
def peven(n):
    i = 0
    s = 0.0
    for i in range(2, n + 1, 2):
        s += 1.0 / i
    return s


def podd(n):
    s = 0.0
    for i in range(1, n + 1, 2):
        s += 1.0 / i
    return s


def dcall(fp, n):
    s = fp(n)
    return s


if __name__ == '__main__':
    n = int(input('input a number: '))
    if n % 2 == 0:
        sum = dcall(peven, n)
    else:
        sum = dcall(podd, n)
    print(sum)