Python collections中的双向队列deque简单介绍详解

from collections import deque
q = deque(maxlen=4)#有固定长度的双向队列
qq = deque() #无固定长度
print(dir(q))#看看有哪些可用方法或属性

In [1]: from collections import deque
…: q = deque(maxlen=4)#有固定长度的双向队列
…: qq = deque() #无固定长度
…: print(dir(q))#看看有哪些可用方法或属性
[‘add', ‘bool', ‘class', ‘contains', ‘copy', ‘delattr', ‘delitem', ‘dir', ‘doc', ‘eq', ‘format', ‘ge', ‘getattribute', ‘getitem', ‘gt', ‘hash', ‘iadd', ‘imul', ‘init', ‘init_subclass', ‘iter', ‘le', ‘len', ‘lt', ‘mul', ‘ne', ‘new', ‘reduce', ‘reduce_ex', ‘repr', ‘reversed', ‘rmul', ‘setattr', ‘setitem', ‘sizeof', ‘str', ‘subclasshook', ‘append', ‘appendleft', ‘clear', ‘copy', ‘count', ‘extend', ‘extendleft', ‘index', ‘insert', ‘maxlen', ‘pop', ‘popleft', ‘remove', ‘reverse', ‘rotate']
In [2]: q
Out[2]: deque([])
In [3]: q.append(1)
In [4]: q.insert(0,33)
In [6]: q
Out[6]: deque([33, 1])
In [8]: q.appendleft(44)
In [9]: q
Out[9]: deque([44, 33, 1])
In [10]: q.pop()
Out[10]: 1
In [12]: q[1]
Out[12]: 33
In [13]: q
Out[13]: deque([44, 33])
In [14]: q.reverse()
In [15]: q
Out[15]: deque([33, 44])
In [17]: q.clear()
In [18]: q
Out[18]: deque([])

#coding:utf8
import datetime,time
from collections import deque
D = deque()
L=[]
def calcTime(func):  
  def doCalcTime():
    sst = int(time.time()*1000)
    func()
    eed = int(time.time()*1000)
    print(func,'cost time:',eed-sst,'ms')
  return doCalcTime

@calcTime
def didDeque():
  for i in range(0,10000000):
    D.append(i)
  while D:
    D.pop()

@calcTime
def didList():
  for i in range(0,10000000):
    L.append(i)
  while L:
    L.pop()
    
if __name__=='__main__':
  didDeque()
  print("------------")
  didList()

#coding:utf8
import datetime,time
from collections import deque
D = deque()
L=[]
def calcTime(func):  
  def doCalcTime():
    sst = int(time.time()*1000)
    func()
    eed = int(time.time()*1000)
    print(func,'cost time:',eed-sst,'ms')
  return doCalcTime

@calcTime
def didDeque():
  for i in range(0,100000):
    D.insert(5,i)
    
@calcTime
def didList():
  for i in range(0,100000):
    L.insert(5,i)

if __name__=='__main__':
  didDeque()
  print("------------")
  didList()

>>> import numpy as np
>>> from collections import deque
>>> q=deque(maxlen=5)
>>> q.append(1)
>>> q.append(2)
>>> q.append(3)
>>> q.append(4)
>>> q.append(5)
>>> q.append(6)
>>> q
deque([2, 3, 4, 5, 6], maxlen=5)
>>> np.array(q).mean()
4.0