def add(self, data):
"""Create a new Node containing 'data' and add it to
the end of the list.
Example:
>>> my_list = LinkedList()
>>> my_list.add(1)
>>> my_list.head.data
1
>>> my_list.add(2)
>>> my_list.head.next.data
2
"""
new_node = LinkedListNode(data)
if self.head is None:
# If the list is empty, point the head attribute to the new node.
self.head = new_node
else:
# If the list is not empty, traverse the list
# and place the new_node at the end.
current_node = self.head
while current_node.next is not None:
# This moves the current node to the next node if it is not
# empty. Then when we break out of the loop, current_node
# points to the last node in the list.
current_node = current_node.next
current_node.next = new_node
def insert_node(self, new_data, old_data):
#check to see if it's empty
if self.head is None:
return
#if inserting at the front of the list
new_node = LinkedListNode(new_data)
if old_data == self.head.data:
new_node.next = self.head
self.head = new_node
return
else:
current_node = self.head
while current_node.next.data != old_data:
current_node = current_node.next
if current_node.next is None:
print "Node not in list"
return
new_node.next = current_node.next
current_node.next = new_node
def __init__(self, data):
Node.__init__(self, data)
self.prev = None
def __init__(self, data): Node.__init__(self, data) self.prev = None