enumerate 函数用于遍历序列中的元素以及它们的下标：
>>> for i,j in enumerate(('a','b','c')):
print i,j
0 a
1 b
2 c
>>> for i,j in enumerate([1,2,3]):
print i,j
0 1
1 2
2 3
>>> for i,j in enumerate({'a':1,'b':2}):
print i,j
0 a
1 b
>>> for i,j in enumerate('abc'):
print i,j
0 a
1 b
2 c
集合、有序字典、可命名元祖、计数
1 #!/usr/bin/env python3.5 2 # -*-coding:utf8-*- 3 # s1 = set() # 集合 是一个无序且不重复的元素集合 4 # s1.add("alex") 5 # print("s1") 6 # s1.add("alex") 7 # print("s1") 8 # set() # 访问速度快，天生解决了重复问题 # 用于爬虫等s2 = 9 # s2 = set(["alex", "eric", "tony"]) 10 #print(s2) 11 # s3 = s2.difference(["alex", "eric"]) # difference 没有改变原来的元数，生成了一个生的元素（集合） 12 # print(s3) 13 # # {'tony', 'alex', 'eric'} 14 # # {'tony'} 15 # s4 = s2.difference_update(["alex", "eric"]) # 不生成新的内容，而是改变原有集合的内容 ，删除当前SET中的所有包含在参数集合里的元素 16 # print(s2) 17 # print(s4) 18 # s5 = s2.intersection(["alex", "eric"]) # 新建一个取相同的部分 19 # print(s5) 20 # s6 = s2.intersection_update(["alex", "eric"]) # 更新原来的取相同部分 21 # print(s2) 22 23 # b = {"1":"2","2":5} 24 # c = {"1":"2","2":6} 25 # c.update(b) 26 # print(b) 27 # print(c) 28 29 # import collections 30 # obj = collections.Counter(["afad", "adfas"]) 31 # print(obj) # 字典 32 # obj.update(["afad", "ad2adf"]) # 更新计数 33 # print(obj) 34 # obj.subtract(["afad", "adfa"]) # 删除计数 35 # print(obj) 36 # ret = obj.most_common(4) 37 # print(ret) 38 # for k in obj.elements(): 39 # elements =>原生值 40 # print(k) # 循环取出从多到少的各个元素 41 # for k, v in obj.items(): 42 # print(k, v) # 取字典键与值 43 # import collections 44 # # 有序字典 45 # dic = collections.OrderedDict() 46 # dic['k1'] = 'v1' 47 # dic['k2'] = 'v2' 48 # dic['k3'] = 'v3' 49 # print(dic) 50 # dic.popitem() # 后进先出 51 # print(dic) 52 # dic.pop('k2') 53 # print(dic) 54 # help(collections.OrderedDict()) 55 # 内部用列表来维护有序字典 56 # dic = {"k1": []} 57 # dic["k1"].append("alex") 58 # import collections 59 # dic = collections.defaultdict(list) # 设置字典默认值为空列表 60 # dic["k1"].append("alex") 61 # print(dic) 62 63 # 可命名元祖 意思是 对元祖的元素命名 以后可以直接调名字 64 # import collections 65 # mytupleclass = collections.namedtuple('mytupleclass', ['x', 'y', 'z']) # 创建类等同于 defaultdict 66 # print(help(mytupleclass)) 67 # obj = mytupleclass(11, 22, 33) 68 # print(obj.x) 69 # print(obj.y) 70 # print(obj.z) 71 # # 主要用于坐标 72 73 # 队列 分双向队列与单向队列 74 # import collections 75 # d = collections.deque() # 创建双向队列 76 # d.append("1") 77 # d.append("10") 78 # d.append("1") 79 # d.append("10") 80 # r = d.count("1") 81 # # print(r) 82 # d.extend(["yy", "uu", "ii"]) 83 # d.appendleft("ad") 84 # d.appendleft("12") 85 # d.extendleft(["adf", "1111", "222"]) 86 # print(d) 87 # #print(help(d)) 88 89 # 单向队列FIFO 90 # 生产者消费者模型 91 # import queue 92 # q = queue.Queue() # 创建单向队列 93 # # print(help(q)) 94 # q.put('123') 95 # q.put("678") 96 # print(q.qsize()) # 获取队列大小 97 # print(q.get()) # 获取队列值