Data Structures Using Python: Single linked list program using python in data structures

This is python program for single linked list concept. This code covers the following functions of single linked list.
1.Insertion at the beginning of the list
2. Insertion at the end of list
3. Insertion at intermediate position in the list
4. Deletion from the beginning of the list
5. Deletion at the end of the list
6.Deletion from intermediate position of the list
7.Count nodes of a list
8.Display the list
9.Creation of the list

source code:

class Node:

def __init__(self,data):

self.data = data

self.next = None

class Sll:

def __init__(self):

self.start = None

def createlist(self):

n=int(input("enter no of nodes"))

for i in range(n):
data = int(input("enter value"))

newnode = Node(data)

if self.start == None:

self.start = newnode

else:

temp=self.start

while temp.next != None:

temp=temp.next

temp.next=newnode

def insertend(self):

data=int(input("enter value"))

newnode = Node(data)
if self.start == None:
self.start = newnode
else:

temp=self.start

while temp.next != None:

temp=temp.next

temp.next=newnode

def insertmid(self):

data=int(input("enter value"))

newnode = Node(data)

pos=int(input("enter position"))

c=self.count()
if self.start == None:
self.start = newnode
else:

if pos>1 and pos<=c:

temp=self.start

prev=temp

i=1

while i<pos:

prev=temp

temp=temp.next

i=i+1

prev.next=newnode

newnode.next=temp

def count(self):

nc=0

temp=self.start

while temp!=None:

nc=nc+1

temp=temp.next

print("number of nodes :%d" %nc)

return nc

def deletemid(self):

count=1

if self.start==None:

print("empty")

else:

position=int(input("enter position"))

c=self.count()

if position>c:

print("check position")

if position>1 and position<c:

temp=prev=self.start

while count<position:

prev=temp

temp=temp.next

count=count+1

prev.next=temp.next

del temp

print("node deleted")

else:

print("check position")

def deleteend(self):

global prev

if self.start == None:

print('empty')

else:

temp=self.start

prev=self.start

while temp.next != None:

prev=temp

temp=temp.next

prev.next=None

del temp

def insertbegin(self):

data=int(input("enter value"))

newnode = Node(data)
if self.start == None:
self.start = newnode
else:

temp=self.start

newnode.next=temp

self.start=newnode

def deletebegin(self):

global prev

if self.start == None:

print('empty')

else:

temp=self.start

newstart=self.start.next

del temp

self.start=newstart

def display(self):

print("elements in single linked list are:")

if self.start == None:

print("empty")

else:

temp=self.start

print ("%d" %(temp.data))

while temp.next != None:

temp=temp.next

print ("%d" %(temp.data))

def menu():

print("1.createlist\n2.insertbegin\n3.insertend\n4.insertmid")

print("5.deletebegin\n6.deleteend\n7.deletemid\n8.count\n9.display\n10.exit")

def stop():

print("you are about to terminate the program")

exit(0)

s=Sll()

def default():

print("check your input")

menu()

while True:

menu= {

1: s.createlist,

2: s.insertbegin,

3: s.insertend,

4: s.insertmid,

5: s.deletebegin,

6: s.deleteend,

7: s.deletemid,

8: s.count,

9: s.display,

10: stop}

option = int(input("Please enter your choice"))

menu.get(option,default)()

Output:

Python 3.4.0 (v3.4.0:04f714765c13, Mar 16 2014, 19:24:06) [MSC v.1600 32 bit (Intel)] on win32

Type "copyright", "credits" or "license()" for more information.

>>> ================================ RESTART ================================

>>>

1.createlist

2.insertbegin

3.insertend

4.insertmid

5.deletebegin

6.deleteend

7.deletemid

8.count

9.display

10.exit

Please enter your choice1

enter no of nodes3

enter value1

enter value2

enter value3

Please enter your choice9