Numpy multidimensional array element filtering

guide

We often use numpy in python data manipulation, it is very convenient and fast to operate arrays through numpy

Element screening

• One-dimensional array
  Filter out the array equal to a certain value in the array

import numpy as np

a = np.array([1,2,3,4,2,4,5])
#筛选出元素
print(a[a == 2])
#筛选出元素的下标
print(np.where(a == 2))

• Multidimensional array
  The target element of filtering is a multidimensional array, at this time we need to use alland anyfunction

import numpy as np

a = np.array([[0,0],[1,1],[2,2],[0,0],[3,4],[1,5]])
#目标元素
target = np.array([0,0])
#筛选出元素
print(a[(a==target).all(axis=1)])

#目标元素
target = np.array([1,2])
#筛选出第一列包含1或者第二列包含2的元素
print(a[(a==target).any(axis=1)])