Is This Code Ok? How Can I Avoid Using Global Variables?

[DeaD_EyE]

def test():
 return [1, 2, 3, 4, 5]
 
 
def test2():
    return [6, 7, 8, 9, 10]
 

def test3():
    return [11, 12, 13, 14, 15]


final_list = test1() + test2() + test3()
print()
print(final_list)