queue program in python code example
Example 1: queue python
from queue import Queue
q = Queue()
q.size() # returns the current lenght of queue
q.empty() # returns True if empty, False otherwise
q.put(item)
q.get()
Example 2: queues in python
class Queue:
def __init__(self, capacity):
self.front = self.size = 0
self.rear = capacity - 1
self.Q = [None] * capacity
self.capacity = capacity
def isFull(self):
return self.size == self.capacity
def isEmpty(self):
return self.size == 0
def EnQueue(self, item):
if self.isFull():
print("Full")
return
self.rear = (self.rear + 1) % (self.capacity)
self.Q[self.rear] = item
self.size = self.size + 1
print("%s enqueue to queue" %str(item))
def DeQueue(self):
if self.isEmpty():
return "Empty"
print("%s dequeued from queue" %str(self.Q[self.front]))
self.front = (self.front + 1) % (self.capacity)
self.size = self.size - 1
def que_front(self):
if self.isEmpty():
print("The Queue is empty")
print("Front item is ", self.Q[self.front])
def que_rear(self):
if self.isEmpty():
print("Queue is Empty")
print("The rear item is ", self.Q[self.rear])
queue = Queue(30)
queue.EnQueue(10)
queue.EnQueue(20)
queue.EnQueue(30)
queue.EnQueue(40)
queue.EnQueue(50)
queue.que_front()
print()
queue.DeQueue()
queue.que_front()
queue.que_rear()
print()
queue.DeQueue()
queue.que_front()
queue.que_rear()
Example 3: python list as queue
# Demonstrate queue implementation using list
# Initializing a queue
queue = []
# Adding elements to the queue
queue.append('a')
queue.append('b')
print(queue)
# Removing elements from the queue
print("\nElements dequeued from queue")
print(queue.pop(0))
print(queue.pop(0))
print("\nQueue after removing elements")
print(queue)
# print(queue.pop(0)) will raise and IndexError as the queue is now empty