def test_get_by_next(self):
dll = DoubleLinkedList()
dll.add(12)
dll.add(99)
dll.add(37)
dll.add(66)
link = dll.get_by_next(37)
self.assertEqual(99, link.value)
self.assertEqual(37, link.next)
self.assertEqual(12, link.prev)
self.assertEqual(4, dll.count_links())
def main():
"""
print("### Node")
node1 = Node(12)
node2 = Node(99)
node3 = Node(37)
node4 = Node(66)
node1.next = node2
node2.next = node3
node3.next = node4
node1.traverse()
print("### DoubleNode")
dnode1 = DoubleNode(12)
dnode2 = DoubleNode(99)
dnode3 = DoubleNode(37)
dnode1.next = dnode2
dnode2.prev = dnode1
dnode2.next = dnode3
dnode3.prev = dnode2
dnode1.traverse()
dnode3.traverse_back()
"""
"""
#items = [12, 99, 37, 66]
#sll = SingleLinkedList(items)
sll = SingleLinkedList()
sll.add(12)
sll.add(99)
sll.add(37)
sll.add(66)
sll.traverse()
sll.add(44)
link66 = sll.get_link(66)
print("link66: value=%s next=%s" % (link66.value, link66.next))
print("links: %s" % (sll.links))
link_last = sll.get_last()
print("link_last: value=%s next=%s" % (link_last.value, link_last.next))
sll.traverse(37)
print("get_position 99")
print(sll.get_position(99))
#link37 = sll.get_by_next(37)
#print("link37:", link37.value)
print("update 99 - 88")
sll.update(99, 88)
print("links: %s" % (sll.links))
sll.traverse()
print("delete 66")
sll.delete(66)
print("links: %s" % (sll.links))
sll.traverse()
"""
dll = DoubleLinkedList()
dll.add(12)
dll.add(99)
dll.add(37)
dll.add(66)
dll.add(44)
print("links: %s" % (dll.links))
dll.traverse()
dll.traverse(99)
dll.traverse_back()
dll.traverse_back(37)
link_by66 = dll.get_link(66)
print("link_by66: value=%s next=%s prev=%s" % (link_by66.value, link_by66.next, link_by66.prev))
link_next66 = dll.get_by_next(66)
print("link_next66: value=%s next=%s prev=%s" % (link_next66.value, link_next66.next, link_next66.prev))
link_prev66 = dll.get_by_prev(66)
print("link_prev66: value=%s next=%s prev=%s" % (link_prev66.value, link_prev66.next, link_prev66.prev))