如何用python计算基本统计值？

def getNum(): #从控制台获取多个不确定数据的方法 nums = []; iNumStr = input("请输入数字(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:{:.2f},中位数:{}.".format(m, dev(n,m),median(n))); #运行结果 #请输入数字(回车退出):10 #请输入数字(回车退出):20 #请输入数字(回车退出):30 #请输入数字(回车退出): #平均值:20.0,方差:10.00,中位数:20.