从2D列表中获取2个唯一的子列表，这两个列表都包含变量

import random

def get_unique_sublists(matrix):
    variables = []
    for sublist in matrix:
        for variable in sublist:
            variables.append(variable)
    
    unique_variables = list(set(variables))
    random.shuffle(unique_variables)
    
    sublist1 = [unique_variables[0]]
    sublist2 = [unique_variables[1]]
    
    result = [sublist1, sublist2]
    return result

# 示例用法
matrix = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
unique_sublists = get_unique_sublists(matrix)
print(unique_sublists)