Deletion and Searching in Doubly Linked List in DSA Python

Program 1

# Implementation of Doubly Linked List

class Node:
    def __init__(self):
        self.ladd=None
        self.data=None
        self.radd=None

class DoubleLinkedList:        
      def __init__(self):
           self.start=None
           self.count=0

      # Create method of list
      def createList(self):
           n=int(input("Enter an element"))
           self.start=Node()
           self.start.ladd=None
           self.start.data=n
           self.start.radd=None
           temp=self.start
           self.count=self.count+1
           choice=input("Want to continue")
           while(choice=="Y" or choice=="y"):
                n=int(input("Enter next element"))
                newnode=Node()
                newnode.ladd=None
                newnode.data=n
                newnode.radd=None
                temp.radd=newnode
                newnode.ladd=temp
                temp=temp.radd
                self.count=self.count+1
                choice=input("Want to continue")

         # Display method of list
      def displayList(self):
           if(self.start==None):
                print("List not found")
           else:
                temp=self.start
                while(temp!=None):
                     print(temp.data,end=" ")
                     temp=temp.radd
                print("\nTotal Node is : ",self.count)                     

      # Method for insert first
      def insertFirst(self):
           if(self.start==None):
                print("List not found")
           else:
                n=int(input("Enter an element for insert"))     
                newnode=Node()
                newnode.ladd=None
                newnode.data=n
                newnode.radd=None
                newnode.radd=self.start
                self.start.ladd=newnode
                self.start=newnode
                self.count=self.count+1


      # Method for insert node at last position
      def insertLast(self):
             if(self.start==None):
                  print("List not found")
             else:
                  n=int(input("Enter an element for insert at last"))     
                  newnode=Node()
                  newnode.ladd=None
                  newnode.data=n
                  newnode.radd=None
                  last=self.start
                  while(last.radd!=None):
                       last=last.radd

                  last.radd=newnode
                  newnode.ladd=last     
                  self.count=self.count+1

      #Method for insert middle position
      def insertMiddle(self):
           if(self.start==None):
                print("List not found")
           else:
                n=int(input("Enter an element for insert at middle"))     
                newnode=Node()
                newnode.ladd=None
                newnode.data=n
                newnode.radd=None
                pos=int(input("Enter middle position"))
                if(pos>self.count):
                     print("Invalid position total node only: ",self.count)
                else:
                     i=1
                     next=self.start
                     while(i<pos):
                          prev=next
                          next=next.radd
                          i=i+1

                     prev.radd=newnode
                     newnode.ladd=prev
                     newnode.radd=next
                     next.ladd=newnode
                     self.count=self.count+1

     # Method for delete First element
      def deleteFirst(self):
           if(self.start==None):
                print("List not found")
           else:
                temp=self.start
                self.start=self.start.radd
                print("Deleted node is : ",temp.data)     
                temp.ladd=None
                temp.radd=None 
                temp=None
                self.count=self.count-1


       # Method for delete Last element
      def deleteLast(self):
           if(self.start==None):
                print("List not found")
           else:
                last=self.start
                while(last.radd!=None):
                     last=last.radd

                temp=last.ladd
                print("Deleted node is: ",last.data)  
                self.count=self.count-1
                temp.radd=None
                last.ladd=None
                last.radd=None
                last=None



         # Method for delete middle node
      def deleteMiddle(self):
           if(self.start==None):
                print("List not found")
           else:
                pos=int(input("Enter middle position for delete"))
                if(pos>self.count):
                     print("Invalid postion total node is: ",self.count)
                else:
                     i=1
                     temp=self.start
                     while(i<pos):
                        temp=temp.radd     
                        i=i+1
                     prev=temp.ladd
                     next=temp.radd   
                     prev.radd=next
                     next.ladd=prev     
                     print("Deleted node is:",temp.data)
                     temp.radd=None
                     temp.ladd=None
                     temp=None
                     self.count=self.count-1


       # Method for search in list
      def searchData(self):     
           if(self.start==None):
                print("List not found")
           else:
                n=int(input("Enter an element for search"))     
                temp=self.start
                flag=0
                while(temp!=None):
                    if(n==temp.data):
                         flag=1
                         break
                    temp=temp.radd   
                if(flag==1):
                     print("Searching success")
                else:    
                     print("Searching not success")
                
                          

        #Method for reverse display          
      def reverseDisplay(self):
           if(self.start==None):
                print("List not found")
           else:
                temp=self.start
                while(temp.radd!=None):
                     temp=temp.radd

                while(temp!=None): 
                     print(temp.data,end=" ")
                     temp=temp.ladd
                print("\nTotal Node is : ",self.count)                      

#Main Menu
mylist=DoubleLinkedList()
while(1):
    print("\n-------------------------Doubly Linked List-----------------------")                        
    print("1. Create")
    print("2. Display")
    print("3. Reverse Display")
    print("4. Insert First")
    print("5. Insert Middle")
    print("6. Insert Last")
    print("7. Delete First")
    print("8. Delete Middle")
    print("9. Delete Last")
    print("10.Serching")
    print("11. Exit")
    print("-------------------------------------------------------------------")
    choice=int(input("Enter your choice"))
    if(choice==1):
         mylist.createList()
    elif(choice==2):
         mylist.displayList()
    elif(choice==3):
         mylist.reverseDisplay()     
    elif(choice==4):
         mylist.insertFirst() 
    elif(choice==5):
         mylist.insertMiddle()      
    elif(choice==6):
         mylist.insertLast() 
    elif(choice==7):
         mylist.deleteFirst()   
    elif(choice==8):
         mylist.deleteMiddle()          
    elif(choice==9):
         mylist.deleteLast()
    elif(choice==10):
         mylist.searchData()    
    else:
         break