字符串转码python

字符串转码python

文件操作

对文件操作流程

打开文件，得到文件句柄并赋值给一个变量

通过句柄对文件进行操作

关闭文件

现有文件如下

1 Somehow, it seems the love I knew was always the most destructive kind2 不知为何，我经历的爱情总是最具毁灭性的的那种3 Yesterday when I was young4 昨日当我年少轻狂5 The taste of life was sweet6 生命的滋味是甜的7 As rain upon my tongue8 就如舌尖上的雨露9 I teased at life as ifit were a foolish game10 我戏弄生命 视其为愚蠢的游戏11 The way the evening breeze12 就如夜晚的微风13 May tease the candle flame14 逗弄蜡烛的火苗15 The thousand dreams I dreamed16 我曾千万次梦见17 The splendid things I planned18 那些我计划的绚丽蓝图19 I always built to last on weak andshifting sand20 但我总是将之建筑在易逝的流沙上21 I lived by night andshunned the naked light of day22 我夜夜笙歌 逃避白昼赤裸的阳光23 And only now I see how the time ran away24 事到如今我才看清岁月是如何匆匆流逝25 Yesterday when I was young26 昨日当我年少轻狂27 So many lovely songs were waiting to be sung28 有那么多甜美的曲儿等我歌唱29 So many wild pleasures lay in store forme30 有那么多肆意的快乐等我享受31 And so much pain my eyes refused to see32 还有那么多痛苦 我的双眼却视而不见33 I ran so fast that time andyouth at last ran out34 我飞快地奔走 最终时光与青春消逝殆尽35 I never stopped to think what life was all about36 我从未停下脚步去思考生命的意义37 And every conversation that I can now recall38 如今回想起的所有对话39 Concerned itself with me and nothing elseat all40 除了和我相关的 什么都记不得了41 The game of love I played with arrogance andpride42 我用自负和傲慢玩着爱情的游戏43 And every flame I lit too quickly, quickly died44 所有我点燃的火焰都熄灭得太快45 The friends I made all somehow seemed to slip away46 所有我交的朋友似乎都不知不觉地离开了47 And only now I‘m left alone to end the play, yeah

48 只剩我一个人在台上来结束这场闹剧49 Oh, yesterday when I was young50 噢 昨日当我年少轻狂51 So many, many songs were waiting to be sung52 有那么那么多甜美的曲儿等我歌唱53 So many wild pleasures lay in store forme54 有那么多肆意的快乐等我享受55 And so much pain my eyes refused to see56 还有那么多痛苦 我的双眼却视而不见57 There are so many songs in me that won‘t be sung

58 我有太多歌曲永远不会被唱起59 I feel the bitter taste of tears upon my tongue60 我尝到了舌尖泪水的苦涩滋味61 The time has come for me to pay foryesterday62 终于到了付出代价的时间 为了昨日63 When I was young64 当我年少轻狂

待处理文件内容

基本操作

1 f = open(‘lyrics‘) #打开文件

2 first_line &#adline()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

打开文件的模式有：

r，只读模式(默认)。

w，只写模式。【不可读；不存在则创建；存在则删除内容；】

a，追加模式。【可读；   不存在则创建；存在则只追加内容；】

"+" 表示可以同时读写某个文件

r+，可读写文件。【可读；可写；可追加】

w+，写读

a+，同a

"U"表示在读取时，可以将 r n rn自动转换成 n (与 r 或 r+ 模式同使用)

rU

r+U

"b"表示处理二进制文件(如：FTP发送上传ISO镜像文件，linux可忽略，windows处理二进制文件时需标注)

rb

wb

ab

其它语法

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 be6 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 _ad

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 adinto()."""

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 to51 SEEK_SET or 0 (offset from start of file, offset should be >= 0); other values52 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, although54 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

View Code

with语句

为了避免打开文件后忘记关闭，可以通过管理上下文，即：

1 with open(‘log‘,‘r‘) as f:2

3 ...

如此方式，当with代码块执行完毕时，内部会自动关闭并释放文件资源。

在Python 2.7 后，with又支持同时对多个文件的上下文进行管理，即：

1 with open(‘log1‘) as obj1, open(‘log2‘) as obj2:2 pass

程序练习

程序1: 实现简单的shell sed替换功能

程序2:修改haproxy配置文件

需求：

1 1、查2 输入：www.oldboy3 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‘,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‘,20 ‘record‘:{21 ‘server‘: ‘100.1.7.9‘,22 ‘weight‘: 20,23 ‘maxconn‘: 30

24 }25 }

需求

1 global

2 log 127.0.0.1local23 daemon4 maxconn 256

5 log 127.0.0.1local2 info6 defaults7 log global

8 mode http9 timeout connect 5000ms10 timeout client 50000ms11 timeout server 50000ms12 option dontlognull13

14 listen stats :8888

15 stats enable16 stats uri /admin17 stats auth admin:1234

18

19 frontend oldboy20 bind 0.0.0.0:80

21 option httplog22 option httpclose23 option forwardfor24 log global

25 acl www hdr_reg(host) -i www.oldboy26 use_backend www.oldboy ifwww27

28 backend www.oldboy29 server 100.1.7.9 100.1.7.9 weight 20 maxconn 3000

原配置文件

字符编码与转码

详细文章:

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原文：.html