import numpy as np

array = np.array([[1,2,5],[3,4,6]])

print('-1-')

print('数组维度', array.ndim)

print('-2-')

print('', array.shape)

a = np.array([1,2,3])

print('-3-')

print(a)

a = np.array([1,2,3], dtype=np.int)

print('-4-')

print(a.dtype)

a = np.array([1,2,3], dtype=np.int64)

print('-5-')

print(a.dtype)

a = np.array([1,2,3], dtype=np.float32)

print('-6-')

print(a.dtype)

a = np.array([1,2,3], dtype=np.float64)

print('-7-')

print(a.dtype)

a = np.array([[1,2,3],

              [4,5,6]], dtype=np.float32)

print('-8-')

print(a)

# shape

a = np.zeros((3,4))

print('-9-')

print(a)

# shape

a = np.ones((3,4), dtype=np.int16)

print('-10-')

print(a)

# very close to zero

a = np.empty((3,4), dtype=np.float64)

print('-11-')

print(a)

# [)

a = np.arange(10, 20)

print('-12-')

print(a)

# [) step 2

a = np.arange(10, 20, 2)

print('-13-')

print(a)

a = np.arange(12).reshape((3,4))

print('-14-')

print(a)

# linspace,

a = np.linspace(1,10,20)

print('-15-')

print(a)

# linspace,

a = np.linspace(1,10,20).reshape((5,4))

print('-16-')

print(a)

# linspace,

a = np.arange(2, 14).reshape((3,4))

print('-17-')

print(a)

print('-18-')

print(np.argmin(a))

print('-19-')

print(np.argmax(a))

print('-20-')

print(np.mean(a))

print('-21-')

print(a.mean())

print('-22-')

print(np.average(a))

# 之前所有数的累加值

print('-23-')

print(np.cumsum(a))

# 之前所有数的累差值

print('-24-')

print(np.diff(a))

# 行序号，列序号

print('-25-')

print(np.nonzero(a))

# (array([0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2], dtype=int64), array([0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3], dtype=int64))

print('-26-')

print(np.sort(a))

a = np.arange(14, 2, -1).reshape((3,4))

print('-27-')

print(a)

print('-28-')

print(np.sort(a))

print('-29-')

print(np.transpose(a))

print('-30-')

print(a.T)

print('-31-')

print((a.T).dot(a))

# 小于5等于5，大于9等于9

print('-32-')

print(np.clip(a,5,9))

# 列平均

print('-33-')

print(np.mean(a,axis=0))

# 行平均

print('-34-')

print(np.mean(a,axis=1))

-1-

数组维度 2

-2-

 (2, 3)

-3-

[1 2 3]

-4-

int32

-5-

int64

-6-

float32

-7-

float64

-8-

[[1. 2. 3.]

 [4. 5. 6.]]

-9-

[[0. 0. 0. 0.]

 [0. 0. 0. 0.]

 [0. 0. 0. 0.]]

-10-

[[1 1 1 1]

 [1 1 1 1]

 [1 1 1 1]]

-11-

[[0. 0. 0. 0.]

 [0. 0. 0. 0.]

 [0. 0. 0. 0.]]

-12-

[10 11 12 13 14 15 16 17 18 19]

-13-

[10 12 14 16 18]

-14-

[[ 0  1  2  3]

 [ 4  5  6  7]

 [ 8  9 10 11]]

-15-

[ 1.          1.47368421  1.94736842  2.42105263  2.89473684  3.36842105

  3.84210526  4.31578947  4.78947368  5.26315789  5.73684211  6.21052632

  6.68421053  7.15789474  7.63157895  8.10526316  8.57894737  9.05263158

  9.52631579 10.        ]

-16-

[[ 1.          1.47368421  1.94736842  2.42105263]

 [ 2.89473684  3.36842105  3.84210526  4.31578947]

 [ 4.78947368  5.26315789  5.73684211  6.21052632]

 [ 6.68421053  7.15789474  7.63157895  8.10526316]

 [ 8.57894737  9.05263158  9.52631579 10.        ]]

-17-

[[ 2  3  4  5]

 [ 6  7  8  9]

 [10 11 12 13]]

-18-

0

-19-

11

-20-

7.5

-21-

7.5

-22-

7.5

-23-

[ 2  5  9 14 20 27 35 44 54 65 77 90]

-24-

[[1 1 1]

 [1 1 1]

 [1 1 1]]

-25-

(array([0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2], dtype=int64), array([0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3], dtype=int64))

-26-

[[ 2  3  4  5]

 [ 6  7  8  9]

 [10 11 12 13]]

-27-

[[14 13 12 11]

 [10  9  8  7]

 [ 6  5  4  3]]

-28-

[[11 12 13 14]

 [ 7  8  9 10]

 [ 3  4  5  6]]

-29-

[[14 10  6]

 [13  9  5]

 [12  8  4]

 [11  7  3]]

-30-

[[14 10  6]

 [13  9  5]

 [12  8  4]

 [11  7  3]]

-31-

[[332 302 272 242]

 [302 275 248 221]

 [272 248 224 200]

 [242 221 200 179]]

-32-

[[9 9 9 9]

 [9 9 8 7]

 [6 5 5 5]]

-33-

[10.  9.  8.  7.]

-34-

[12.5  8.5  4.5]