如何基于numpy的矩阵中的值获取列，行号

Question

如何根据矩阵中的值返回列和行号？

import numpy as np

matrix = np.random.randint(9, size=(3,3))
#matrix
#[[2 3 3]
# [6 2 4]
# [1 8 4]]

类似

matrix.where(2,[]) => (0,0), (1,1)
matrix.where(4,[]) => (1,2), (2,2)

Answer 1

使用np.argwhere功能

import numpy as np

matrix = np.random.randint(9, size=(3,3))
print(matrix)
# array([[2, 1, 3],
#        [7, 2, 4],
#        [1, 7, 7]])

np.argwhere(matrix == 7)

输出：

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

Answer 2

使用np.where功能。

matrix = np.random.randint(9, size=(3,3))
np.where(matrix == 2)