python 求数组标准差 python如何求标准差

import math
 lst=[] 

 str=input("输入：") 

 lst1 = str.split(" ") 

 i = 0  

 t=len(lst1)  

 while i <= t+1: 

     if len(lst1)==0: 

         break 

     else: 

         lst.append(float(lst1.pop()))#将lst1的数据转换为整型并赋值给lst   

         i += 1 

 def sum1(list):   

     "对列表的数值求和"   

     s = 0 

        

     for x in list:   

         s += x   

     return s   

 def average(list):   

     "对列表数据求平均值"   

     avg = 0   

     avg = sum1(lst)/float(len(lst)*1.0) #调用sum函数求和   

     return avg  

 def var(list,avg): 

     """利用list 和均值计算方差""" 

     var1=0 

     for i in list: 

         var1+=float((i-avg)**2*1.0) 

     var2=(math.sqrt(var1/(len(lst)-1)*1.0)) 

     return var2 



 print("sum= %f"%sum1(lst)) 

 print("avg = %f"%average(lst))  

 print("s = %f"%var(lst,average(list)))