Python双端队列(Dequeue)

双端队列(Dequeue)支持从任一端添加和删除元素，更常用的堆栈和队列是双端队列的退化形式，其中输入和输出限制为单端。

import collections

DoubleEnded=collections.deque(["Mon","Tue","Wed"])

DoubleEnded.append("Thu")

print ("Appended at right- ")
print (DoubleEnded)

DoubleEnded.appendleft("Sun")

print ("Appended at right at left is- ")
print (DoubleEnded)

DoubleEnded.pop()

print ("Deleting from right- ")
print (DoubleEnded)

DoubleEnded.popleft()

print ("Deleting from left- ")
print (DoubleEnded)

Appended at right - 
deque(['Mon', 'Tue', 'Wed', 'Thu'])
Appended at right at left is - 
deque(['Sun', 'Mon', 'Tue', 'Wed', 'Thu'])
Deleting from right - 
deque(['Sun', 'Mon', 'Tue', 'Wed'])
Deleting from left - 
deque(['Mon', 'Tue', 'Wed'])