(更新中)NumPy – 进阶函数和自测题

Contents

1 Numpy-进阶函数和自测题
- 1.1 np.repeat和np.tile
- 1.2 如何获得两个 Python NumPy 数组中共同的项？
2 101道numpy自测题链接

Numpy-进阶函数和自测题

　　首先我们会学习以下函数，然后在101道自测题中检测学习效果。

函数	作用
np.repeat(a,r)	将a中的每个元素重复r次
np.tile(a,r)	将a整体重复r次(铺地砖)
np.intersect1d(A,B)	返回A、B中的共同项

np.repeat和np.tile

import numpy as np

a = [1, 2, 3]

c = np.repeat(a, 3)
print(c)
'''
[1 1 1 2 2 2 3 3 3]
'''

c = np.tile(a, 3)
print(c)
'''
[1 2 3 1 2 3 1 2 3]
'''

c = np.tile(a, [3, 2])  # 用3×2个a来铺地砖
print(c)
'''
[[1 2 3 1 2 3]
 [1 2 3 1 2 3]
 [1 2 3 1 2 3]]
'''

import numpy as np

a = [1, 2, 3]

c = np.repeat(a, 3)

print(c)

'''

[1 1 1 2 2 2 3 3 3]

'''

c = np.tile(a, 3)

print(c)

'''

[1 2 3 1 2 3 1 2 3]

'''

c = np.tile(a, [3, 2]) # 用3×2个a来铺地砖

print(c)

'''

[[1 2 3 1 2 3]

[1 2 3 1 2 3]

[1 2 3 1 2 3]]

'''

如何获得两个 Python NumPy 数组中共同的项？

难度：L2

输入：

a = np.array([1,2,3,2,3,4,3,4,5,6])
b = np.array([7,2,10,2,7,4,9,4,9,8])

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

b = np.array([7,2,10,2,7,4,9,4,9,8])

期望输出：

array([2, 4])

1 2	array([2, 4])

答案:

a = np.array([1,2,3,2,3,4,3,4,5,6])
b = np.array([7,2,10,2,7,4,9,4,9,8])
np.intersect1d(a,b)

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

b = np.array([7,2,10,2,7,4,9,4,9,8])

np.intersect1d(a,b)

101道numpy自测题链接

中文:
https://www.jiqizhixin.com/articles/030201

英文(含答案):
https://www.machinelearningplus.com/101-numpy-exercises-python/