python:将nan分配给其他三个矩阵的给定语句的矩阵元素

下面的代码不起作用,但如果上面不清楚的话,也许至少可以说明我的雄心壮志。

import numpy as np
# Create the fake matrices A, B, C, D
A = np.full((4,5), np.nan)
A[0,0] = 2
A[1,1] = 2
A[2,2] = 2
A[3,3] = 2
A[1,3] = 2
B = np.random.rand(4,5)
C = np.arange(0.0, 0.1, 0.02)
D = np.ones([4,5])

# First loop: meant to fulfill the first statement
for i in np.arange(4):
    for j in np.arange(5):
        D[i,j][np.isnan(A[i,j])] = np.nan

# Second loop: meant to fulfill the second statement
for i in np.arange(4):
    for j in np.arange(5):
        if B[i,j] < (0.3 - C[j]) or B[i,j] > (0.7 + C[j]):
            D[i,j] = np.nan