def append(self,item):
q = NodeInfo(item)
if self.head == 0:
self.head = q
else:
p = self.head
while p.nextnode != 0:
p = p.nextnode
p.nextnode = q
q.prevnode = p
def initlist(self,data):
self.head = NodeInfo(data[0])
p = self.head
for i in data[1:]:
node = NodeInfo(i)
p.nextnode = node
node.prevnode = p
p = p.nextnode
def insert(self,index,item):
if self.is_empty() or index < 0 or index > self.getlength():
print 'Linklist is empty.'
return
if index == 0:
q = NodeInfo(item,self.head)
self.head = q
p = self.head
post = self.head
j = 0
while p.nextnode != 0 and j < index:
post = p
p = p.nextnode
j += 1
if index == j:
q = NodeInfo(item,p)
post.nextnode = q#?
q.prevnode = post
q.nextnode = p
p.prevnode = q
