python求平均数、方差、中位数的例子

def getNum():       #获取用户不定长度的输入  nums = []  iNumStr = input("请输入数字(回车退出):")  while iNumStr != "":    nums.append(eval(iNumStr))    iNumStr = input("请输入数学(回车退出):")  return numsdef 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  numbers = sorted(numbers)    #sorted(numbers)  size = len(numbers)  if size % 2 == 0:    med = (numbers[size//2 - 1] + numbers[size//2])/2  else:    med = numbers[size//2]  return medn = getNum()m = mean(n)print("平均值:{},方差:{:.2},中位数:{}.".format(m, dev(n,m), median(n)))