python求一组数据的标准差和中位数

Question

如何用python求一组数据的平均数、标准差和中位数，并保留两位小数？

numbers=eval(input("请输入数据，并以逗号分隔:"))
sum=0
count=0
for i in numbers:
    sum=sum+i
    a=sum/len(numbers)
print(f"平均值：{a:.2f}")

接下来如何写？

Answer 1

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

def dev(numbers,mean):  #计算标准差
    sdev=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
    news_numbers=sorted(numbers)
    size=len(news_numbers)
    if size%2==0:
        med=(news_numbers[size//2-1]+news_numbers[size//2])/2
    else:
        med=news_numbers[size//2]
    return med

numbers=eval(input("请输入数据，并以逗号分隔:"))
print("平均值：%.2f,标准差：%.2f,中位数：%.2f"%(mean(numbers),dev(numbers,mean(numbers)),median(numbers)))