如何组合不匹配的三维数组？

import numpy as np

def combine_3d_arrays(arr1, arr2):
    # 获取数组1和数组2的维度和大小
    rows1, cols1, depth1 = arr1.shape
    rows2, cols2, depth2 = arr2.shape
    
    # 创建一个新的三维数组，大小与要组合的数组相同
    combined_arr = np.zeros((max(rows1, rows2), max(cols1, cols2), max(depth1, depth2)))
    
    # 遍历数组1，将其复制到新的三维数组中对应的位置
    for i in range(rows1):
        for j in range(cols1):
            for k in range(depth1):
                combined_arr[i, j, k] = arr1[i, j, k]
    
    # 遍历数组2，将其复制到新的三维数组中对应的位置
    for i in range(rows2):
        for j in range(cols2):
            for k in range(depth2):
                combined_arr[i, j, k] = arr2[i, j, k]
    
    return combined_arr

# 示例用法
arr1 = np.array([[[1, 2], [3, 4]], [[5, 6], [7, 8]]])
arr2 = np.array([[[9, 10], [11, 12]], [[13, 14], [15, 16]], [[17, 18], [19, 20]]])

combined_arr = combine_3d_arrays(arr1, arr2)
print(combined_arr)