Python 循环缓冲区

class Buffer:
    def __init__(self, size):
        self.data = [None for i in range(size)]
    def append(self, x):
        self.data.pop(0)
        self.data.append(x)
    def get(self):
        return self.data
buf = Buffer(4)
for i in range(10):
    buf.append(i)
    print(buf.get())

# implememting circular queue in python
class CircularQueue():
    def __init__(collections, k):
        collections.k = k
        collections.queue = [None] * k
        collections.head = collections.tail = -1
    # this function will insert (Enqueue) an element into the circular queue
    def enqueue1(collections, data):
        if ((collections.tail + 1) % collections.k == collections.head):
            print("The queue is full\n")
        elif (collections.head == -1):
            collections.head = 0
            collections.tail = 0
            collections.queue[collections.tail] = data
        else:
            collections.tail = (collections.tail + 1) % collections.k
            collections.queue[collections.tail] = data
    # this function will delete (dequeue) an element from the circular
    def dequeue1(collections):
        if (collections.head == -1):
            print("The circular queue is empty\n")
        elif (collections.head == collections.tail):
            temp = collections.queue[collections.head]
            collections.head = -1
            collections.tail = -1
            return temp
        else:
            temp = collections.queue[collections.head]
            collections.head = (collections.head + 1) % collections.k
            return temp
     # This function is used to print the queue
    def printCQueue1(collections):
        if(collections.head == -1):
            print("Circular queue is empty")
        elif (collections.tail >= collections.head):
            for i in range(collections.head, collections.tail + 1):
                print(collections.queue[i], end=" ")
            print()
        else:
            for i in range(collections.head, collections.k):
                print(collections.queue[i], end=" ")
            for i in range(0, collections.tail + 1):
                print(collections.queue[i], end=" ")
            print()
obj = CircularQueue(5)
# adding data to the queue
for i in range(1, 6):
    obj.enqueue1(i)
print("Display queue")
obj.printCQueue1()
# removing data from the queue
print("\nDelete Value:", obj.dequeue1())
print("Delete Value:", obj.dequeue1())
print("\nTwo values were deleted from the queue")
print("The new queue has 3 values now")
obj.printCQueue1()