6.2.1.15 i 6.2.1.16.py

#6.2.1.15

print("6.2.1.15\n")

class QueueError(IndexError):
    pass


class Queue:
    def __init__(self):
        self.queue=[]

    def put(self, elem):
        self.queue.insert(0,elem)

    def get(self):
        if len(self.queue)>0:
            elem=self.queue[-1]
            del self.queue[-1]
            return elem
        else:
            raise QueueError


que = Queue()
que.put(1)
que.put("dog")
que.put(False)
try:
    for i in range(4):
        print(que.get())
except:
    print("Queue error")

#6.2.1.16

print("6.2.1.16\n")

class QueueError(IndexError):
    pass


class Queue:
    def __init__(self):
        self.queue=[]

    def put(self, elem):
        self.queue.insert(0,elem)

    def get(self):
        if len(self.queue)>0:
            elem=self.queue[-1]
            del self.queue[-1]
            return elem
        else:
            raise QueueError


class SuperQueue(Queue):
    def isempty(self):
        return len(self.queue)==0


que = SuperQueue()
que.put(1)
que.put("dog")
que.put(False)
for i in range(4):
    if not que.isempty():
        print(que.get())
    else:
        print("Queue empty")