std.py

import numpy as np
def standard_deviation(array):
    mean = sum(array) / len(array)
    distances = []
    for value in array:
        # appending square of distances
        distances.append(((value - mean)**2))
    return sum(distances) / len(distances)
  

input = [1,1,1,1,1,1,1,1,1,21]
std = np.sqrt(variance(input))

# Output - 6