Queue using deque from collections


examples/lists/queue_with_deque.py
from collections import deque

fruits = deque()

print(type(fruits))  # <type 'collections.deque'>
print(fruits)        # deque([])
print(len(fruits))   # 0

fruits.append('Apple')
print(fruits)        # deque(['Apple'])
print(len(fruits))   # 1

fruits.append('Banana')
fruits.append('Peach')
print(fruits)        # deque(['Apple', 'Banane', 'Peach'])
print(len(fruits))   # 3

nxt = fruits.popleft()
print(nxt)           # 'Apple'
print(fruits)        # deque(['Banana', 'Peach'])
print(len(fruits))   # 2

if fruits:
    print("The queue has items")
else:
    print("The queue is empty")

nxt = fruits.popleft()
nxt = fruits.popleft()

if fruits:
    print("The queue has items")
else:
    print("The queue is empty")





<class 'collections.deque'>
deque([])
0
deque(['Apple'])
1
deque(['Apple', 'Banana', 'Peach'])
3
Apple
deque(['Banana', 'Peach'])
2
The queue has items
The queue is empty