Parameters : 
n     : [int] n * n维的输出数组
dtype : [可选, float(by Default)] 返回数组的数据类型。

# Python Programming illustrating
# numpy.identity method
 
import numpy as geek
 
# 2x2 matrix with 1's on main diagonal
b = geek.identity(2, dtype = float)
print("Matrix b : \n", b)
 
 
a = geek.identity(4)
print("\nMatrix a : \n", a)

Matrix b : 
 [[ 1.  0.]
 [ 0.  1.]]

Matrix a : 
 [[ 1.  0.  0.  0.]
 [ 0.  1.  0.  0.]
 [ 0.  0.  1.  0.]
 [ 0.  0.  0.  1.]]