Using assert raises unit testing in python

Currently I'm writing a unittest for my class function.

def test_getitem(self):
    test1 = List(3)
    for i in range(3):
        test1.append(i)
    self.assertEqual(test1[2], 2)

    test1 = List(3)
    for i in range(3):
        test1.append(i)
    self.assertRaises(IndexError, test1[4])

the problem I'm having now is at the self.assertRaises part of my code. I'm not sure if that is how it's done but when I run the unittest, it produces an error Index out of range. By right, it should be "OK".

List is my class and List(3) creates an array based list. so when i test1.append(i), it is now [0,1,2].

test1[2] is a method of calling the getitem function in my class similar to self[index].

I'm wondering if I'm assert raising correctly? self.assertEqual is fine.