``````

In [1]:

import numpy as np

``````
``````

In [2]:

# https://docs.scipy.org/doc/numpy/reference/generated/numpy.eye.html

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``````

In [3]:

e = np.eye(4)
print(type(e))
print(e)
print(e.dtype)

``````
``````

<class 'numpy.ndarray'>
[[ 1.  0.  0.  0.]
[ 0.  1.  0.  0.]
[ 0.  0.  1.  0.]
[ 0.  0.  0.  1.]]
float64

``````
``````

In [4]:

e = np.eye(4, M=3, k=1, dtype=np.int8)
print(e)
print(e.dtype)

``````
``````

[[0 1 0]
[0 0 1]
[0 0 0]
[0 0 0]]
int8

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``````

In [5]:

# https://docs.scipy.org/doc/numpy/reference/generated/numpy.identity.html

``````
``````

In [6]:

i = np.identity(4)
print(i)
print(i.dtype)

``````
``````

[[ 1.  0.  0.  0.]
[ 0.  1.  0.  0.]
[ 0.  0.  1.  0.]
[ 0.  0.  0.  1.]]
float64

``````
``````

In [7]:

i = np.identity(4, dtype=np.uint8)
print(i)
print(i.dtype)

``````
``````

[[1 0 0 0]
[0 1 0 0]
[0 0 1 0]
[0 0 0 1]]
uint8

``````
``````

In [8]:

a = [3, 0, 8, 1, 9]
a_one_hot = np.identity(10)[a]
print(a)
print(a_one_hot)

``````
``````

[3, 0, 8, 1, 9]
[[ 0.  0.  0.  1.  0.  0.  0.  0.  0.  0.]
[ 1.  0.  0.  0.  0.  0.  0.  0.  0.  0.]
[ 0.  0.  0.  0.  0.  0.  0.  0.  1.  0.]
[ 0.  1.  0.  0.  0.  0.  0.  0.  0.  0.]
[ 0.  0.  0.  0.  0.  0.  0.  0.  0.  1.]]

``````
``````

In [9]:

a = [2, 2, 0, 1, 0]
a_one_hot = np.identity(3)[a]
print(a)
print(a_one_hot)

``````
``````

[2, 2, 0, 1, 0]
[[ 0.  0.  1.]
[ 0.  0.  1.]
[ 1.  0.  0.]
[ 0.  1.  0.]
[ 1.  0.  0.]]

``````