【Python】Statistics

x = 0 #loop variable 
ls = [] #create list 
while x == 0:　
    shuru = input() 
    if shuru == '': 
        x = 1 #interrupt while 
    else: 
        ls.append(eval(shuru)) #increase Element 
he = 0 
#and fangchahe = 0 
#variance zhongweishu = 0 
#median zhongweils = [] #sorted list 
geshu = len(ls) #number of elements 
for i in ls: 
    he += i 
pingjun = he / geshu 
for j in ls: 
    fangchahe += pow(2,j-pingjun) #variance = ((the subtraction of each element and the average) squared)/number of elements 
fangcha = fangchahe / geshu 
zhongweils = sorted(ls) #sorted The function can sort 
midgeshu = len(zhongweils) 
if midgeshu % 2 == 1: 
    zhongweishu = zhongweils[midgeshu//2] 
else:
    zhongweishu = (zhongweils[midgeshu//2]+zhongweils[midgeshu//2 - 1])//2 
print(geshu,pingjun,'{0:.3}'.format(fangcha),zhongweishu) 
print(zhongweils)