double_linked_list.py

class node:
    def __init__(self,data):
        self.data=data
        self.prev=None
        
class sll():  
    def __init__(self,n):
        self.head=None
        num=n
        print(num)    
    def display(self):
        if self.head==None:
            print('empty linked list...')
        else:
            temp=self.head
            while temp:
                print(temp.data,end=' ')
                temp=temp.next


print('PRINTING DEFAULT NUMBER IN SLL')
l=sll('WELCOME TO THE SINGLE LINKED LIST...')
n1=node(10)
n2=node(20)
n3=node(30)
n4=node(40)
'''
l.head=n1
n1.next=n2
n2.next=n3
n3.next=n4
'''

l.head=n1
n1.next=n2
n2.next=n3
n3.next=n4
n4.next=None
n1.prev=None
n2.prev=n1
n3.prev=n2
n4.prev=n3

l.display()


print('\n')
print('PRINTING KEYS FROM USER & GETTING VALUES FROM DICTIONARY')
l=sll('WELCOME TO THE SINGLE LINKED LIST...')     
ll={'16':'charan','58':'prabhu','a0':'shree','52':'nikhil'}
n1=node(ll[input('enter : ')])
n2=node(ll[input('enter : ')])
n3=node(ll[input('enter : ')])
n4=node(ll[input('enter : ')])
l.head=n1
n1.next=n2
n2.next=n3
n3.next=n4
n4.next=None
n1.prev=None
n2.prev=n1
n3.prev=n2
n4.prev=n3
l.display()

class nodee:
    def __init__(self,data):
        self.data=data
        self.prev=None
        
class dll():  
    def __init__(self,n):
        self.head=None
        num=n
        print(num)    
    def display(self):
        n=''
        n+=temp.data
        if self.head==None:
            print('empty linked list...')
        else:
            print(temp.data,end='-->')

"""            
print('\n.........................DOUT ON THE PROCESS.........................................')        
  
print('PRINTING N VALUES INPUT FROM USER OF MONTHS ')
l=dll('WELCOME TO THE SINGLE LINKED LIST...')    
n=int(input('''PRINTING VALUES TAKING KEYS FROM USER AND GETTING VALUES
FROM DICTIONARY : '''))
for i in range(1,n+1):
    z={1:'january',
       2:'february',
       3:'march',
       4:'april',
       5:'may',
       6:'june',
       7:'july',
       8:'august',
       9:'september',
       10:'october',
       11:'november',
       12:'december'}
    l.display()
print('\n.....................................................................')
    
"""
'''
for i in range(3):
    a=i
    n='n'+str(i)
    print(n)

'''