priority queue might be usedfor exampleby search engine to ensure it refreshes the content of the most popular web pages before crawling sites that are less likely to be searched for product recommendation tool might use one to display information about the most highly ranked products while still loading data for the lower ranks note that priority queue will always return the most important element currently in the queue the get(method will block (by defaultif the queue is emptybut it will not block and wait for higher priority element to be added if there is already something in the queue the queue knows nothing about elements that have not been added yet (or even about elements that have been previously extracted)and only makes decisions based on the current contents of the queue this interactive session shows priority queue in actionusing tuples as weights to determine what order items are processed inheap put(( "three")heap put(( "four")heap put(( "one"heap put(( "two")heap put(( "five")block=falsetraceback (most recent call last)file ""line in heap put(( "five")block=falsefile "/usr/lib /python /queue py"line in put raise full full while not heap empty()print(heap get()( 'one'( 'two'( 'three'( 'four'priority queues are almost universally implemented using the heap data structure python' implementation utilizes the heapq module to effectively store heap inside normal list direct you to an algorithm and data-structure' textbook for more information on heapsnot to mention many other fascinating structures we haven' covered here no matter what the data structureyou can use object-oriented principles to wrap relevant algorithms (behaviors)such as those supplied in the heapq modulearound the data they are structuring in the computer' memoryjust as the queue module has done on our behalf in the standard library