我一直在Python中尝试使用np.all，我看过这里的文档：https://numpy.org/doc/stable/reference/generated/numpy.all.html
我期望下面的np.all语句的计算结果为：[对，对，对]和对，但他们没有。
我错过了什么？
我试过下面的代码：

import numpy as np

NA = float("NAN")
arrNA = np.array([[NA, NA, NA], [NA, NA, NA], [NA, NA, NA]])

print(np.all(arrNA == NA, axis=0)) 
#This prints [False, False, False], but every element in the np.array is equal to NA. Why not True?

print(np.all(arr == NA)) 
#This also prints false, but every element in the np.array is NA. Why not True?