Day 6 Collections系列

counter:对字典进行处理，用于计算元素出现的个数

#！/usr/bin/env python# -*- coding: utf-8 -*-# Author: wanghuafeng

import collections#计数器,Counterobj = collections.Counter("asdfghjgioccvbnjrtubvg6782bnsh2bn")print(obj)#取前4个数，排序按照从多到少ret = obj.most_common(4)print(ret)#obj:处理完的数据for k,v in obj.items():    print(k, v)

#elements：原生的值，未经过加工处理的for i in obj.elements():    print(i)

#！/usr/bin/env python# -*- coding: utf-8 -*-# Author: wanghuafeng

import collectionsobj = collections.Counter([‘11‘, ‘22‘, ‘33‘, ‘44‘, ‘55‘])print(obj)#增加obj.update([‘eric‘, ‘11‘, ‘11‘])print(obj)#删除obj.subtract([‘eric‘, ‘11‘, ‘11‘])print(obj)

有序字典

#！/usr/bin/env python# -*- coding: utf-8 -*-# Author: wanghuafeng

import collections#列表+字典=有序字典，key取列表中的元素dic = collections.OrderedDict()dic[‘k1‘] = ‘v1‘dic[‘k2‘] = ‘v2‘dic[‘k3‘] = ‘v3‘dic[‘k4‘] = ‘v4‘dic[‘k5‘] = ‘v5‘dic[‘k6‘] = ‘v6‘dic[‘k7‘] = ‘v7‘dic[‘k8‘] = ‘v8‘print(dic)

#！/usr/bin/env python# -*- coding: utf-8 -*-# Author: wanghuafeng

import collections#列表+字典=有序字典，key取列表中的元素dic = collections.OrderedDict()dic[‘k1‘] = ‘v1‘dic[‘k2‘] = ‘v2‘dic[‘k3‘] = ‘v3‘dic[‘k4‘] = ‘v4‘dic[‘k5‘] = ‘v5‘dic[‘k6‘] = ‘v6‘dic[‘k7‘] = ‘v7‘dic[‘k8‘] = ‘v8‘print(dic)#移动到最后dic.move_to_end(‘k1‘)print(dic)#后进先出dic.popitem()print(dic)#指定取数，pop将取出的数据为己有ret = dic.pop(‘k3‘)print(dic)print(ret)#设置默认值,如果存在不做任何操作，如果不存在则增加dic.setdefault(‘k9‘,‘22‘)print(dic)#更新dic.update({‘k1‘:‘v1‘, ‘k10‘:‘v10‘})print(dic)

默认字典

#！/usr/bin/env python# -*- coding: utf-8 -*-# Author: wanghuafeng

import collectionsvalues = [11, 22, 33, 44, 55, 66, 77, 88]my_dict = collections.defaultdict(list)

for value in values:    if value > 33:        my_dict[‘k1‘].append(value)    else:        my_dict[‘k2‘].append(value)

print(my_dict)

可命名元祖

#创建类,defaultdictMytupleClass = collections.namedtuple(‘MytupleClass‘,[‘x‘, ‘y‘, ‘z‘])print(help(MytupleClass))obj = MytupleClass(11, 22, 33)print(obj.x)print(obj.y)print(obj.z)

双向队列

#！/usr/bin/env python# -*- coding: utf-8 -*-# Author: wanghuafeng

import collections

d = collections.deque()#增加一个d.append(‘1‘)#往左增加d.appendleft(‘10‘)d.appendleft(‘1‘)print(d)#统计个数ret = d.count(‘1‘)print(ret)#扩展，右边增加d.extend([‘yy‘, ‘qq‘, ‘11‘])print(d)#扩展，左边增加d.extendleft([‘y1y‘, ‘q2q‘, ‘131‘])

print(d)

#从右取数插入左边d.rotate(3)print(d)

单向队列

import queue

#创建单向队列q = queue.Queue()#增加数据q.put(‘123‘)q.put(‘456‘)print(q.qsize())#按顺序取数据print(q.get())