Python求均值，方差，標准差

import numpy as np
arr = [1,2,3,4,5,6]
#求均值
arr_mean = np.mean(arr)
#求方差
arr_var = np.var(arr)
#求標准差
arr_std = np.std(arr,ddof=1)
print("平均值為：%f" % arr_mean)
print("方差為：%f" % arr_var)
print("標准差為:%f" % arr_std)