Python - 取消排队

双端队列或 deque 支持在任一端添加和删除元素。更常用的 stacks 和 queues 是 deques 的退化形式，其中 inputs 和 output 被限制在单个端。

例

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)

输出

执行上述代码时，它会产生以下结果 -