数据处理（python）

#shuji.py
def getnums():
     nums=[]
     inumstr=input("输入数字（回车退出）：")
     while inumstr!="":
          nums.append(eval(inumstr))
          inumstr=input("输入数字（回车退出）：")
     return nums
def mean(numbers):
     s=0
     for i in numbers:
          s+=i
     m=s/len(numbers)
     return m
def f(numbers,mean):
     sdev=0
     for i in numbers:
          sdev=sdev+(i-mean)**2
     return pow(sdev/(len(numbers)-1),0.5)
def z(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 med
n=getnums()
m=mean(n)
print("平均值：{}\n方差：{:.2f}\n中位数：{}".format(m,f(n,m),z(n)))