代码
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))
输出
-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]