Python之路,Day2

本节内容

列表、元组操作
字符串操作
字典操作
集合操作
文件操作
字符编码与转码

1. 列表、元组操作

列表是我们最以后最常用的数据类型之一，通过列表可以对数据实现最方便的存储、修改等操作

定义列表

1	`names` `=` `['Alex',"Tenglan",'Eric']`

通过下标访问列表中的元素，下标从0开始计数

>>> names[0]
'Alex'

>>> names[2]
'Eric'

>>> names[-1]
'Eric'

>>> names[-2] #还可以倒着取
'Tenglan'

切片:取多个元素

>>> names = ["Alex","Tenglan","Eric","Rain","Tom","Amy"]
>>> names[1:4]  #取下标1至下标4之间的数字，包括1，不包括4
['Tenglan', 'Eric', 'Rain']
>>> names[1:-1] #取下标1至-1的值，不包括-1
['Tenglan', 'Eric', 'Rain', 'Tom']
>>> names[0:3] 
['Alex', 'Tenglan', 'Eric']
>>> names[:3] #如果是从头开始取，0可以忽略，跟上句效果一样
['Alex', 'Tenglan', 'Eric']
>>> names[3:] #如果想取最后一个，必须不能写-1，只能这么写
['Rain', 'Tom', 'Amy'] 
>>> names[3:-1] #这样-1就不会被包含了
['Rain', 'Tom']
>>> names[0::2] #后面的2是代表，每隔一个元素，就取一个
['Alex', 'Eric', 'Tom'] 
>>> names[::2] #和上句效果一样
['Alex', 'Eric', 'Tom']

View Code

1 >>> names 2 ['Alex', 'Tenglan', 'Eric', 'Rain', 'Tom', 'Amy', '我是新来的'] 3 >>> names.insert(2,"强行从Eric前面插入") 4 >>> names 5 ['Alex', 'Tenglan', '强行从Eric前面插入', 'Eric', 'Rain', 'Tom', 'Amy', '我是新来的'] 6 7 >>> names.insert(5,"从eric后面插入试试新姿势") 8 >>> names 9 ['Alex', 'Tenglan', '强行从Eric前面插入', 'Eric', 'Rain', '从eric后面插入试试新姿势', 'Tom', 'Amy', '我是新来的']

1 >>> del names[2] 2 >>> names 3 ['Alex', 'Tenglan', 'Eric', 'Rain', '从eric后面插入试试新姿势', 'Tom', 'Amy', '我是新来的'] 4 >>> del names[4] 5 >>> names 6 ['Alex', 'Tenglan', 'Eric', 'Rain', 'Tom', 'Amy', '我是新来的'] 7 >>> 8 >>> names.remove("Eric") #删除指定元素 9 >>> names 10 ['Alex', 'Tenglan', 'Rain', 'Tom', 'Amy', '我是新来的'] 11 >>> names.pop() #删除列表最后一个值 12 '我是新来的' 13 >>> names 14 ['Alex', 'Tenglan', 'Rain', 'Tom', 'Amy']

1 >>> names 2 ['Alex', 'Tenglan', 'Amy', 'Tom', 'Amy', 1, 2, 3] 3 >>> names.sort() #排序 4 Traceback (most recent call last): 5 File "<stdin>", line 1, in <module> 6 TypeError: unorderable types: int() < str() #3.0里不同数据类型不能放在一起排序了，擦 7 >>> names[-3] = '1' 8 >>> names[-2] = '2' 9 >>> names[-1] = '3' 10 >>> names 11 ['Alex', 'Amy', 'Amy', 'Tenglan', 'Tom', '1', '2', '3'] 12 >>> names.sort() 13 >>> names 14 ['1', '2', '3', 'Alex', 'Amy', 'Amy', 'Tenglan', 'Tom'] 15 16 >>> names.reverse() #反转 17 >>> names 18 ['Tom', 'Tenglan', 'Amy', 'Amy', 'Alex', '3', '2', '1']

1 >>> n3_arg 2 {'name': 'alex', 'age': 33} 3 >>> n3 4 'my name is {name} and age is {age}' 5 >>> n3.format_map(n3_arg) 6 'my name is alex and age is 33' 7 8 9 >>> n4.ljust(40,"-") 10 'Hello 2orld-----------------------------' 11 >>> n4.rjust(40,"-") 12 '-----------------------------Hello 2orld' 13 14 15 >>> s = "Hello World!" 16 >>> p = str.maketrans("abcdefg","3!@#$%^") 17 >>> s.translate(p) 18 'H$llo Worl#! 19 20 21 >>> b="ddefdsdff_哈哈" 22 >>> b.isidentifier() #检测一段字符串可否被当作标志符，即是否符合变量命名规则 23 True

1 >>> info 2 {'stu1102': 'LongZe Luola', 'stu1103': 'XiaoZe Maliya', 'stu1101': '武藤兰'} 3 >>> info.pop("stu1101") #标准删除姿势 4 '武藤兰' 5 >>> info 6 {'stu1102': 'LongZe Luola', 'stu1103': 'XiaoZe Maliya'} 7 >>> del info['stu1103'] #换个姿势删除 8 >>> info 9 {'stu1102': 'LongZe Luola'} 10 >>> 11 >>> 12 >>> 13 >>> info = {'stu1102': 'LongZe Luola', 'stu1103': 'XiaoZe Maliya'} 14 >>> info 15 {'stu1102': 'LongZe Luola', 'stu1103': 'XiaoZe Maliya'} #随机删除 16 >>> info.popitem() 17 ('stu1102', 'LongZe Luola') 18 >>> info 19 {'stu1103': 'XiaoZe Maliya'}

1 >>> info = {'stu1102': 'LongZe Luola', 'stu1103': 'XiaoZe Maliya'} 2 >>> 3 >>> "stu1102" in info #标准用法 4 True 5 >>> info.get("stu1102") #获取 6 'LongZe Luola' 7 >>> info["stu1102"] #同上，但是看下面 8 'LongZe Luola' 9 >>> info["stu1105"] #如果一个key不存在，就报错，get不会，不存在只返回None 10 Traceback (most recent call last): 11 File "<stdin>", line 1, in <module> 12 KeyError: 'stu1105'

1 av_catalog = { 2 "欧美":{ 3 "www.youporn.com": ["很多免费的,世界最大的","质量一般"], 4 "www.pornhub.com": ["很多免费的,也很大","质量比yourporn高点"], 5 "letmedothistoyou.com": ["多是自拍,高质量图片很多","资源不多,更新慢"], 6 "x-art.com":["质量很高,真的很高","全部收费,屌比请绕过"] 7 }, 8 "日韩":{ 9 "tokyo-hot":["质量怎样不清楚,个人已经不喜欢日韩范了","听说是收费的"] 10 }, 11 "大陆":{ 12 "1024":["全部免费,真好,好人一生平安","服务器在国外,慢"] 13 } 14 } 15 16 av_catalog["大陆"]["1024"][1] += ",可以用爬虫爬下来" 17 print(av_catalog["大陆"]["1024"]) 18 #ouput 19 ['全部免费,真好,好人一生平安', '服务器在国外,慢,可以用爬虫爬下来']

1 #values 2 >>> info.values() 3 dict_values(['LongZe Luola', 'XiaoZe Maliya']) 4 5 #keys 6 >>> info.keys() 7 dict_keys(['stu1102', 'stu1103']) 8 9 10 #setdefault 11 >>> info.setdefault("stu1106","Alex") 12 'Alex' 13 >>> info 14 {'stu1102': 'LongZe Luola', 'stu1103': 'XiaoZe Maliya', 'stu1106': 'Alex'} 15 >>> info.setdefault("stu1102","龙泽萝拉") 16 'LongZe Luola' 17 >>> info 18 {'stu1102': 'LongZe Luola', 'stu1103': 'XiaoZe Maliya', 'stu1106': 'Alex'} 19 20 21 #update 22 >>> info 23 {'stu1102': 'LongZe Luola', 'stu1103': 'XiaoZe Maliya', 'stu1106': 'Alex'} 24 >>> b = {1:2,3:4, "stu1102":"龙泽萝拉"} 25 >>> info.update(b) 26 >>> info 27 {'stu1102': '龙泽萝拉', 1: 2, 3: 4, 'stu1103': 'XiaoZe Maliya', 'stu1106': 'Alex'} 28 29 #items 30 info.items() 31 dict_items([('stu1102', '龙泽萝拉'), (1, 2), (3, 4), ('stu1103', 'XiaoZe Maliya'), ('stu1106', 'Alex')]) 32 33 34 #通过一个列表生成默认dict,有个没办法解释的坑，少用吧这个 35 >>> dict.fromkeys([1,2,3],'testd') 36 {1: 'testd', 2: 'testd', 3: 'testd'}

1 menu = { 2 '北京':{ 3 '海淀':{ 4 '五道口':{ 5 'soho':{}, 6 '网易':{}, 7 'google':{} 8 }, 9 '中关村':{ 10 '爱奇艺':{}, 11 '汽车之家':{}, 12 'youku':{}, 13 }, 14 '上地':{ 15 '百度':{}, 16 }, 17 }, 18 '昌平':{ 19 '沙河':{ 20 '老男孩':{}, 21 '北航':{}, 22 }, 23 '天通苑':{}, 24 '回龙观':{}, 25 }, 26 '朝阳':{}, 27 '东城':{}, 28 }, 29 '上海':{ 30 '闵行':{ 31 "人民广场":{ 32 '炸鸡店':{} 33 } 34 }, 35 '闸北':{ 36 '火车战':{ 37 '携程':{} 38 } 39 }, 40 '浦东':{}, 41 }, 42 '山东':{}, 43 } 44 45 46 exit_flag = False 47 current_layer = menu 48 49 layers = [menu] 50 51 while not exit_flag: 52 for k in current_layer: 53 print(k) 54 choice = input(">>:").strip() 55 if choice == "b": 56 current_layer = layers[-1] 57 #print("change to laster", current_layer) 58 layers.pop() 59 elif choice not in current_layer:continue 60 else: 61 layers.append(current_layer) 62 current_layer = current_layer[choice] 63 64 三年菜单文艺青年版

1 s = set([3,5,9,10]) #创建一个数值集合 2 3 t = set("Hello") #创建一个唯一字符的集合 4 5 6 a = t | s # t 和 s的并集 7 8 b = t & s # t 和 s的交集 9 10 c = t – s # 求差集（项在t中，但不在s中） 11 12 d = t ^ s # 对称差集（项在t或s中，但不会同时出现在二者中） 13 14 15 16 基本操作： 17 18 t.add('x') # 添加一项 19 20 s.update([10,37,42]) # 在s中添加多项 21 22 23 24 使用remove()可以删除一项： 25 26 t.remove('H') 27 28 29 len(s) 30 set 的长度 31 32 x in s 33 测试 x 是否是 s 的成员 34 35 x not in s 36 测试 x 是否不是 s 的成员 37 38 s.issubset(t) 39 s <= t 40 测试是否 s 中的每一个元素都在 t 中 41 42 s.issuperset(t) 43 s >= t 44 测试是否 t 中的每一个元素都在 s 中 45 46 s.union(t) 47 s | t 48 返回一个新的 set 包含 s 和 t 中的每一个元素 49 50 s.intersection(t) 51 s & t 52 返回一个新的 set 包含 s 和 t 中的公共元素 53 54 s.difference(t) 55 s - t 56 返回一个新的 set 包含 s 中有但是 t 中没有的元素 57 58 s.symmetric_difference(t) 59 s ^ t 60 返回一个新的 set 包含 s 和 t 中不重复的元素 61 62 s.copy() 63 返回 set “s”的一个浅复制

1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10 11 11 12 12 13 13 14 14 15 15 16 16 17 17 18 18 19 19 20 20 21 21 22 22 23 23 24 24 25 25 26 26 27 27 28 28 29 29 30 30 31 31 32 32 33 33 34 34 35 35 36 36 37 37 38 38 39 39 40 40 41 41 42 42 43 43 44 44 45 45 46 46 47 47 48 48 49 49 50 50 51 51 52 52 53 53 54 54 55 55 56 56 57 57 58 58 59 59 60 60 61 61 62 62 63 63 64 64 65 Somehow, it seems the love I knew was always the most destructive kind 66 不知为何，我经历的爱情总是最具毁灭性的的那种 67 Yesterday when I was young 68 昨日当我年少轻狂 69 The taste of life was sweet 70 生命的滋味是甜的 71 As rain upon my tongue 72 就如舌尖上的雨露 73 I teased at life as if it were a foolish game 74 我戏弄生命视其为愚蠢的游戏 75 The way the evening breeze 76 就如夜晚的微风 77 May tease the candle flame 78 逗弄蜡烛的火苗 79 The thousand dreams I dreamed 80 我曾千万次梦见 81 The splendid things I planned 82 那些我计划的绚丽蓝图 83 I always built to last on weak and shifting sand 84 但我总是将之建筑在易逝的流沙上 85 I lived by night and shunned the naked light of day 86 我夜夜笙歌逃避白昼赤裸的阳光 87 And only now I see how the time ran away 88 事到如今我才看清岁月是如何匆匆流逝 89 Yesterday when I was young 90 昨日当我年少轻狂 91 So many lovely songs were waiting to be sung 92 有那么多甜美的曲儿等我歌唱 93 So many wild pleasures lay in store for me 94 有那么多肆意的快乐等我享受 95 And so much pain my eyes refused to see 96 还有那么多痛苦我的双眼却视而不见 97 I ran so fast that time and youth at last ran out 98 我飞快地奔走最终时光与青春消逝殆尽 99 I never stopped to think what life was all about 100 我从未停下脚步去思考生命的意义 101 And every conversation that I can now recall 102 如今回想起的所有对话 103 Concerned itself with me and nothing else at all 104 除了和我相关的什么都记不得了 105 The game of love I played with arrogance and pride 106 我用自负和傲慢玩着爱情的游戏 107 And every flame I lit too quickly, quickly died 108 所有我点燃的火焰都熄灭得太快 109 The friends I made all somehow seemed to slip away 110 所有我交的朋友似乎都不知不觉地离开了 111 And only now I'm left alone to end the play, yeah 112 只剩我一个人在台上来结束这场闹剧 113 Oh, yesterday when I was young 114 噢昨日当我年少轻狂 115 So many, many songs were waiting to be sung 116 有那么那么多甜美的曲儿等我歌唱 117 So many wild pleasures lay in store for me 118 有那么多肆意的快乐等我享受 119 And so much pain my eyes refused to see 120 还有那么多痛苦我的双眼却视而不见 121 There are so many songs in me that won't be sung 122 我有太多歌曲永远不会被唱起 123 I feel the bitter taste of tears upon my tongue 124 我尝到了舌尖泪水的苦涩滋味 125 The time has come for me to pay for yesterday 126 终于到了付出代价的时间为了昨日 127 When I was young 128 当我年少轻狂

1 f = open('lyrics') #打开文件 2 first_line = f.readline() 3 print('first line:',first_line) #读一行 4 print('我是分隔线'.center(50,'-')) 5 data = f.read()# 读取剩下的所有内容,文件大时不要用 6 print(data) #打印文件 7 8 f.close() #关闭文件

1 def close(self): # real signature unknown; restored from __doc__ 2 """ 3 Close the file. 4 5 A closed file cannot be used for further I/O operations. close() may be 6 called more than once without error. 7 """ 8 pass 9 10 def fileno(self, *args, **kwargs): # real signature unknown 11 """ Return the underlying file descriptor (an integer). """ 12 pass 13 14 def isatty(self, *args, **kwargs): # real signature unknown 15 """ True if the file is connected to a TTY device. """ 16 pass 17 18 def read(self, size=-1): # known case of _io.FileIO.read 19 """ 20 注意，不一定能全读回来 21 Read at most size bytes, returned as bytes. 22 23 Only makes one system call, so less data may be returned than requested. 24 In non-blocking mode, returns None if no data is available. 25 Return an empty bytes object at EOF. 26 """ 27 return "" 28 29 def readable(self, *args, **kwargs): # real signature unknown 30 """ True if file was opened in a read mode. """ 31 pass 32 33 def readall(self, *args, **kwargs): # real signature unknown 34 """ 35 Read all data from the file, returned as bytes. 36 37 In non-blocking mode, returns as much as is immediately available, 38 or None if no data is available. Return an empty bytes object at EOF. 39 """ 40 pass 41 42 def readinto(self): # real signature unknown; restored from __doc__ 43 """ Same as RawIOBase.readinto(). """ 44 pass #不要用,没人知道它是干嘛用的 45 46 def seek(self, *args, **kwargs): # real signature unknown 47 """ 48 Move to new file position and return the file position. 49 50 Argument offset is a byte count. Optional argument whence defaults to 51 SEEK_SET or 0 (offset from start of file, offset should be >= 0); other values 52 are SEEK_CUR or 1 (move relative to current position, positive or negative), 53 and SEEK_END or 2 (move relative to end of file, usually negative, although 54 many platforms allow seeking beyond the end of a file). 55 56 Note that not all file objects are seekable. 57 """ 58 pass 59 60 def seekable(self, *args, **kwargs): # real signature unknown 61 """ True if file supports random-access. """ 62 pass 63 64 def tell(self, *args, **kwargs): # real signature unknown 65 """ 66 Current file position. 67 68 Can raise OSError for non seekable files. 69 """ 70 pass 71 72 def truncate(self, *args, **kwargs): # real signature unknown 73 """ 74 Truncate the file to at most size bytes and return the truncated size. 75 76 Size defaults to the current file position, as returned by tell(). 77 The current file position is changed to the value of size. 78 """ 79 pass 80 81 def writable(self, *args, **kwargs): # real signature unknown 82 """ True if file was opened in a write mode. """ 83 pass 84 85 def write(self, *args, **kwargs): # real signature unknown 86 """ 87 Write bytes b to file, return number written. 88 89 Only makes one system call, so not all of the data may be written. 90 The number of bytes actually written is returned. In non-blocking mode, 91 returns None if the write would block. 92 """ 93 pass

1 1、查 2 输入：www.oldboy.org 3 获取当前backend下的所有记录 4 5 2、新建 6 输入： 7 arg = { 8 'bakend': 'www.oldboy.org', 9 'record':{ 10 'server': '100.1.7.9', 11 'weight': 20, 12 'maxconn': 30 13 } 14 } 15 16 3、删除 17 输入： 18 arg = { 19 'bakend': 'www.oldboy.org', 20 'record':{ 21 'server': '100.1.7.9', 22 'weight': 20, 23 'maxconn': 30 24 } 25 } 26 27 需求

1 global 2 log 127.0.0.1 local2 3 daemon 4 maxconn 256 5 log 127.0.0.1 local2 info 6 defaults 7 log global 8 mode http 9 timeout connect 5000ms 10 timeout client 50000ms 11 timeout server 50000ms 12 option dontlognull 13 14 listen stats :8888 15 stats enable 16 stats uri /admin 17 stats auth admin:1234 18 19 frontend oldboy.org 20 bind 0.0.0.0:80 21 option httplog 22 option httpclose 23 option forwardfor 24 log global 25 acl www hdr_reg(host) -i www.oldboy.org 26 use_backend www.oldboy.org if www 27 28 backend www.oldboy.org 29 server 100.1.7.9 100.1.7.9 weight 20 maxconn 3000 30 31 原配置文件

1 #-*-coding:utf-8-*- 2 __author__ = 'Alex Li' 3 4 import sys 5 print(sys.getdefaultencoding()) 6 7 8 msg = "我爱北京*" 9 msg_gb2312 = msg.decode("utf-8").encode("gb2312") 10 gb2312_to_gbk = msg_gb2312.decode("gbk").encode("gbk") 11 12 print(msg) 13 print(msg_gb2312) 14 print(gb2312_to_gbk) 15 16 in python2

1. 列表、元组操作

元组

程序练习

2. 字符串操作

3. 字典操作

4.集合操作

5. 文件操作

6. 字符编码与转码

Python之路,Day2

1. 列表、元组操作

元组

程序练习

2. 字符串操作

3. 字典操作

4.集合操作

5. 文件操作

6. 字符编码与转码

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