used in many applications, such as the Internet Web browsers history and the “undo” mechanism in Text editors

stack

peek() : adds a new item to the top of the stack. It needs the item and returns nothing. this definition is not true.

The order of insertion is the reverse of the order of removalqueue

Using python list , Stack ADT "push()" is implemented using append (item)

Using python list , Stack ADT "peek()"
is implemented using [len (self.item) +1]

Using python list , Stack ADT "size()" is implemented using " len (self.item) "

Deque is a hybrid linear structure, so it requires the LIFO and FIFO ordering.

deque ()
creates a new empty deque. returns an empty queue

Elements are added at one end called(front)

Elements are removed from the other end(front)

dequeue()
removes the rare item, returns the item.

A network printer is an example of a

in Queue is_empty() : tests to see whether the queue is empty. It needs no parameters and returns the item.

enqueue(item) adds a new item to the rear of the queue. It needs the item and returns nothing.

Using python list , Queue ADT "enqueue()" is implemented using pop (0 , item)

the string "bla bla bla" is a palindrome word.

Using python list , Queue ADT "size()" is implemented using len (self.item - 1 )