Python 双端队列

from collections import deque

q = deque()
q.append(1)
q.append(2)
q.append(3)
len(q) # 3
print(q) # deque([1, 2, 3])
print(q.popleft()) # 1
print(q) # deque([2, 3])
print(q.pop()) # 3
print(q) # deque([2])