def getNum():
    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):
    s = 0.0
    for num in numbers:
        s +=num
    return s/len(numbers)
def dev(numbers,mean):
    sdev =0.0
    for num in numbers:
        sdev +=(num-mean)**2
    return pow(sdev/(len(numbers)-1),0.5)
def median(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= getNum()
m = mean(n)
print(f"平均值:{m}, 方差:{dev(n,m):.2}, 中位数:{median(n)}")