import math
import csv
with open('data.csv',newline='')as f:
reader=csv.read(f)
file_data=list(reader)

data=file_data[0]
 def mean(data):
n= len(data)
    total =0
    for x in data:
        total += int(x)

    mean = total / n
    return mean

squared_list=[]
for number in data:
    a=int(number)-mean(data)
a=a**2
 squared_list.append(a)
 sum=0
 for i in squared_list:
    sum =sum + i

#dividing the sum by the total values
result = sum/ (len(data)-1)

# getting the deviation by taking square root of the result
std_deviation = math.sqrt(result)
print(std_deviation)
# print("derived using predefined function ",statistics.stdev(data))


















