Python Data Structures and Algorithms

Dequeue operation

The dequeue operation is used to remove items from the queue. With reference to the introduction to the topic of queues, this operation captures the point where we serve the customer who joined the queue first and also waited the longest:

    def dequeue(self):        data = self.items.pop()        self.size -= 1        return data

The Python list class has a method called pop(). The pop method does the following:

1. Removes the last item from the list.
2. Returns the removed item from the list back to the user or code that called it.

The last item in the list is popped and saved in the data variable. In the last line of the method, the data is returned.

Consider the tunnel in the following figure as our queue. To perform a dequeue operation, the node ...