def test_dll_string():
test_dll = DLL()
test_dll.add_tail(1)
test_dll.add_tail(2)
test_dll.add_tail("test")
test_string = "[1, 2, test]"
assert str(test_dll) == test_string
def test_query_position():
test_dll = DLL()
test_dll.add_tail(1)
test_dll.add_tail(2)
test_dll.add_tail("test")
assert test_dll.query_position(0) == 1
assert test_dll.query_position(1) == 2
assert test_dll.query_position(2) == "test"
def test_find_data():
test_dll = DLL()
test_dll.add_tail(1)
test_dll.add_tail(2)
test_dll.add_tail("test")
assert test_dll.query_position(0) == 1
assert test_dll.query_position(1) == 2
assert test_dll.query_position(2) == "test"
assert test_dll.query_position(3) is None
def test_update_position():
test_dll = DLL()
test_dll.add_tail(1)
test_dll.add_tail(2)
test_dll.add_tail("test")
test_dll.update_position(0, 3)
test_dll.update_position(1, 2)
test_dll.update_position(2, 1)
assert test_dll.query_position(0) == 3
assert test_dll.query_position(1) == 2
assert test_dll.query_position(2) == 1
assert test_dll.update_position(3, 1) == -1
def test_remove_position():
test_dll = DLL()
test_dll.add_tail(1)
test_dll.add_tail(2)
test_dll.add_tail("test")
test_dll.remove_position(1)
assert test_dll.head == 1
assert test_dll.tail == "test"
test_dll.remove_position(0)
assert test_dll.head == "test"
assert test_dll.tail == "test"
test_dll.remove_position(0)
assert test_dll.head is None
assert test_dll.tail is None
def test_remove_data():
test_dll = DLL()
test_dll.add_tail(1)
test_dll.add_tail(2)
test_dll.add_tail("test")
test_dll.remove_data(2)
assert test_dll.head == 1
assert test_dll.tail == "test"
test_dll.remove_data(1)
assert test_dll.head == "test"
assert test_dll.tail == "test"
test_dll.remove_data("test")
assert test_dll.head is None
assert test_dll.tail is None
def test_ddl_add_tail():
test_dll = DLL()
test_dll.add_tail(1)
assert test_dll.head.data == 1
assert test_dll.tail.data == 1
test_dll.add_tail(2)
assert test_dll.head.data == 1
assert test_dll.tail.data == 2
test_dll.add_tail("test")
assert test_dll.head.data == 1
assert test_dll.tail.data == "test"
def test_len():
test_dll = DLL()
len_now = test_dll.len()
assert len_now == 0
test_dll.add_tail(1)
len_now = test_dll.len()
assert len_now == 1
test_dll.add_tail(2)
len_now = test_dll.len()
assert len_now == 2
test_dll.add_tail("test")
len_now = test_dll.len()
assert len_now == 3
