python代码入门练习1

# -*- coding: utf-8 -*-
"""
Created on Sat Feb 22 18:35:05 2020

@author: 15389
"""
#CalStatisticsV1.py
def getNum():           #获取用户不定长度的输入
	nums = []
	iNumStr = input("请输入数值（回车退出）：")
	while iNumStr != "":
		nums.append(eval(iNumStr))
		iNumStr = input("请输入数字（回车退出）：")
	return nums

def mean(numbers):      #计算平均值
	s = 0.0
	for num in numbers:
		s = s + num
	return s / len(numbers)

def dev(numbers, mean):     #计算方差
	sdev = 0.0
	for num in numbers:
		sdev = sdev + (num - mean)**2
	return pow(sdev / (len(numbers)-1), 0.5)

def median(numbers):        #计算中位数
	sorted(numbers)
	size = len(numbers)
	if size % 2 == 0:
		med = (numbers[size//2-1] + numbers[size//2])/2
	else:
		med = numbers[size//2]
	return med

n = getNum()
m = mean(n)
print("平均值：{},方差：{},中位数:{}.".format(m,dev(n ,m),median(n)))