text: from collections import deque
  
  class Queue:
      def __init__(self):
          self.items = deque()
          
      def is_empty(self):
          return not self.items
      
      def enqueue(self, item):
          self.items.append(item)
      
      def dequeue(self):
          if self.is_empty():
              print('Queue empty...')
              raise SystemExit
          return self.items.popleft()
      
      def size(self):
          return len(self.items)
      
      def peek(self):
          if self.is_empty():
              print('Queue empty...')
              raise SystemExit
          return self.items[0]
      
      def __str__(self):
          return str(self.items)
      
  if __name__ == '__main__':
      q = Queue()
      print(q)
      print(q.is_empty())
      q.enqueue(1)
      q.enqueue(2)
      print(q)
      print(q.dequeue())
      print(q.peek())
      print(q)
      print(q.dequeue())
      print(q.dequeue())