def test_delete_at_index(self):
doubly = DoublyLinkedList(
['very first', 'first', 'second', 'third', 'fourth', 'very last'])
self.assertEqual('second', doubly.get_node_by_index_from_top(2).data)
doubly.delete_at_index(2)
self.assertEqual('third', doubly.get_node_by_index_from_top(2).data)
self.assertEqual(
"DoublyLinkedList(['very first', 'first', 'third', 'fourth', 'very last'])",
doubly.__repr__())
self.assertEqual('first',
doubly.get_node_by_index_from_top(2).leftlink.data)
self.assertEqual('third',
doubly.get_node_by_index_from_top(1).rightlink.data)
doubly.delete_from_the_bottom()
doubly.delete_from_the_top()
self.assertEqual("DoublyLinkedList(['first', 'third', 'fourth'])",
doubly.__repr__())
self.assertEqual('fourth', doubly.last_node.data)
self.assertEqual(None, doubly.last_node.rightlink)
self.assertEqual('third', doubly.last_node.leftlink.data)
self.assertEqual('first', doubly.first_node.data)
self.assertEqual(None, doubly.first_node.leftlink)
self.assertEqual('third', doubly.first_node.rightlink.data)
def test_insert_in_the_middle(self):
doubly = DoublyLinkedList(['first', 'third', 'fourth'])
self.assertEqual(doubly.get_node_by_index_from_top(1).data, 'third')
doubly.insert_at_index(1, 'second')
self.assertEqual(
"DoublyLinkedList(['first', 'second', 'third', 'fourth'])",
doubly.__repr__())
self.assertEqual(doubly.get_node_by_index_from_top(1).data, 'second')
self.assertEqual(doubly.get_node_by_index_from_top(2).data, 'third')
self.assertEqual(
doubly.get_node_by_index_from_top(0).rightlink.data, 'second')
self.assertEqual(
doubly.get_node_by_index_from_top(1).leftlink.data, 'first')
self.assertEqual(
doubly.get_node_by_index_from_top(1).rightlink.data, 'third')
self.assertEqual(
doubly.get_node_by_index_from_top(2).leftlink.data, 'second')
doubly.insert_at_index(0, 'very first')
doubly.insert_at_index(5, 'very last')
self.assertEqual(None, doubly.insert_at_index(7, 'out of range'))
self.assertEqual('very first', doubly.first_node.data)
self.assertEqual('very last', doubly.last_node.data)
self.assertEqual(
"DoublyLinkedList(['very first', 'first', 'second', 'third', 'fourth', 'very last'])",
doubly.__repr__())
def test_delete_from_the_bottom(self):
doubly = DoublyLinkedList(
['very first', 'first', 'second', 'third', 'fourth', 'very last'])
doubly.delete_from_the_bottom()
self.assertEqual(
"DoublyLinkedList(['very first', 'first', 'second', 'third', 'fourth'])",
doubly.__repr__())
self.assertEqual('fourth', doubly.last_node.data)
self.assertEqual(None, doubly.last_node.rightlink)
self.assertEqual('third', doubly.last_node.leftlink.data)
def test_insert_to_the_top(self):
doubly = DoublyLinkedList(['first', 'second', 'third'])
self.assertEqual(doubly.get_node_by_index_from_top(0).data, 'first')
doubly.insert_to_the_top('very first')
self.assertEqual(
doubly.__repr__(),
"DoublyLinkedList(['very first', 'first', 'second', 'third'])")
self.assertEqual(
doubly.get_node_by_index_from_top(0).data, 'very first')
self.assertEqual(doubly.get_node_by_index_from_top(1).data, 'first')
self.assertEqual(
doubly.get_node_by_index_from_top(1).leftlink.data, 'very first')
self.assertEqual(
doubly.get_node_by_index_from_top(0).rightlink.data, 'first')
self.assertEqual(doubly.get_node_by_index_from_top(0).leftlink, None)
self.assertEqual(doubly.first_node.data, 'very first')
def test_insert_to_the_bottom(self):
doubly = DoublyLinkedList(['first', 'second', 'third'])
self.assertEqual(doubly.get_node_by_index_from_bottom(0).data, 'third')
doubly.insert_to_the_bottom('fourth')
self.assertEqual(
"DoublyLinkedList(['first', 'second', 'third', 'fourth'])",
doubly.__repr__())
self.assertEqual(
doubly.get_node_by_index_from_bottom(0).data, 'fourth')
self.assertEqual(doubly.get_node_by_index_from_bottom(1).data, 'third')
self.assertEqual(
doubly.get_node_by_index_from_bottom(1).rightlink.data, 'fourth')
self.assertEqual(
doubly.get_node_by_index_from_bottom(0).leftlink.data, 'third')
self.assertEqual(
doubly.get_node_by_index_from_bottom(0).rightlink, None)
self.assertEqual(doubly.last_node.data, 'fourth')
def test_doubly_repr(self):
doubly = DoublyLinkedList(['first', 'second', 'third'])
self.assertEqual(doubly.__repr__(),
"DoublyLinkedList(['first', 'second', 'third'])")