python之二维数组中的查找

# 实现方式一
def find_num(matrix, num):
    """二维数组中的查找"""
    tmp = [i for j in matrix for i in j if i == num]
    return tmp is not None


# 实现方式二
def find_num2(matrix, num):
    """二维数组中的查找"""
    for i in matrix:
        for j in i:
            if j == num:
                return True
    return False

if __name__ == '__main__':

    list2 = [[12, 3, 4], [4, 6, 7, 8]]
    print(find_num2(list2, 6))