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  • Python学习之路10——Python常用模块

      一、模块介绍

       1、模块定义

        用来从逻辑上组织python代码(变量,函数,类,逻辑:实现一个功能),本质上就是.py结尾python文件。

        分类:内置模块、开源模块、自定义模块。

       2、导入模块

        本质:导入模块的本质就是把python文件解释一遍;导入包的本质就是把包文件下面的init.py文件运行一遍。

        1. 同目录下的模块导入

    1 #同级目录间import
    2  
    3 import module_name              #直接导入模块
    4 import module_name,module2_name     #导入多个模块     使用:模块名.加函数名
    5 from module_name import *           #导入模块中所有函数和变量等。。不建议使用
    6 from module_name import m1,m2,m3        #只导入模块中函数m1,m2,m3  使用:直接使用m1,m2,m3即可
    7 from module_name import m1 as m   #导入module_name模块中m1函数并且重新赋值给m  使用:直接输入m即可

        2.不同目录下的模块导入

     1 #不同目录之间import  当前文件main.py
     2  
     3 #目录结构
     4 # ├── Credit_card
     5 #
     6 # ├── core  #
     7 # │   ├── __init__.py
     8 # │   └── main.py  # 当前文件
     9 # ├── conf  #
    10 # │   ├── __init__.py
    11 # │   └── setting.py
    12 # │   └── lzl.py
    13  
    14 import sys,os
    15  
    16 creditcard_path=os.path.dirname(os.path.dirname(os.path.abspath(__file__))) #当前目录的上上级目录绝对路径,即Creditcard目录
    17 sys.path.insert(0,creditcard_path)    #把Creditcard目录加入到系统路径列表第0个
    18  
    19 print(sys.path)                      #打印系统环境路径
    20 #['C:\Users\L\PycharmProjects\s14\Day5\Creditcard,.......]
    21  
    22 #import settings.py                   #无法直接import
    23 #ImportError: No module named 'settings'
    24  
    25 from conf import settings           #from目录import模块
    26  
    27 settings.set()                        #执行settings下的函数
    28 #in the settings

             3.不同目录下模块连坏导入

    目录结构
    ├── Credit_card
    ├── core  #
    │   ├── __init__.py
    │   └── main.py  # 当前文件
    ├── conf  #
    │   ├── __init__.py
    │   └── setting.py
     │   └── lzl.py
    
     目录结构

        conf目录下的文件:

        lzl.py

    1 #!/usr/bin/env python
    2 # -*- coding:utf-8 -*-
    3 #-Author-Lian
    4 
    5 #当前文件lzl.py
    6 def name():
    7     print("name is lzl")
    8 
    9 lzl.py

        setting.py

     1 #当前文件settings,调用lzl.py模块
     2 import lzl              #导入模块lzl
     3 
     4 def set():
     5     print("in the settings")
     6     lzl.name()              #运行lzl模块下的函数
     7 
     8 set()                       #执行函数set
     9 #in the settings
    10 #name is lzl

        此时执行settings.py文件没有任何问题,就是同一目录下的模块之间的导入,关键来了,此刻croe目录下的main.py导入模块settings会出现什么状况呢??!

        core目录下的文件:

        main.py

     1 #不同目录之间连环import 当前文件main.py
     2 import sys,os
     3  
     4 creditcard_path=os.path.dirname(os.path.dirname(os.path.abspath(__file__))) #当前目录的上上级目录绝对路径,即Creditcard目录
     5 sys.path.insert(0,creditcard_path)    #把Creditcard目录加入到系统路径
     6  
     7 from conf import settings
     8  
     9 settings.set()                        #执行settings下的函数
    10 #    import lzl              #导入模块lzl
    11 #ImportError: No module named 'lzl'

        可以看到直接报错:ImportError: No module named 'lzl',想想什么会报错类?!

        刚才已经说到了,导入模块的本质就是把模块里的内容执行一遍,当main.py导入settings模块时,也会把settings里的内容执行一遍,即执行import lzl;

        但是对于main.py来说,不能直接import lzl,所有就出现了刚才的报错,那有什么办法可以解决?!

        对conf目录下settings.py文件进行修改

     1 #当前文件settings,调用lzl.py模块
     2 from . import lzl              #通过相对路径导入模块lzl
     3 
     4 def set():
     5     print("in the settings")
     6     lzl.name()              #运行lzl模块下的函数
     7 
     8 set()                       #执行函数set
     9 #in the settings
    10 #name is lzl

        此时执行main.py文件

     1 #不同目录之间连环import 当前文件main.py
     2 import sys,os
     3  
     4 creditcard_path=os.path.dirname(os.path.dirname(os.path.abspath(__file__))) #当前目录的上上级目录绝对路径,即Creditcard目录
     5 sys.path.insert(0,creditcard_path)    #把Creditcard目录加入到系统路径
     6  
     7 from conf import settings
     8  
     9 settings.set()                        #执行settings下的函数
    10 # in the settings
    11 # name is lzl

       没有任何报错,我们只对settings修改了lzl模块的调用方式,结果就完全不同,此时的from . import lzl 用到的是相对路径,这就是相对路径的优点所在。

       4、不同目录多个模块互相导入,用相对路径

       目录结构:

    Day5
        ├── Credit_card
                ├── README.md
                ├── core 
                │   ├── __init__.py
                │   └── main.py 
                ├── conf 
                │   ├── __init__.py
                │   └── setting.py
                │   └── lzl.py        
    
    目录结构

        conf目录下的文件:

        lzl.py

    1 #!/usr/bin/env python
    2 # -*- coding:utf-8 -*-
    3 #-Author-Lian
    4 
    5 #当前文件lzl.py  相对路径
    6 def name():
    7     print("name is lzl")

        setting.py

     1 #!/usr/bin/env python
     2 # -*- coding:utf-8 -*-
     3 #-Author-Lian
     4 
     5 #当前文件settings,调用lzl.py模块  相对路径
     6 from . import lzl              #通过相对路径导入模块lzl
     7 
     8 def set():
     9     print("in the settings")
    10     lzl.name()              #运行lzl模块下的函数
    11 
    12 set()                       #执行函数set
    13 #in the settings
    14 #name is lzl
    15 
    16 settings

        core目录下的文件:

        main.py

    1 #不同目录之间连环import 当前文件main.py  相对路径
    2  
    3 from Day5.Credit_card.conf import settings
    4  
    5  
    6 settings.set()                        #执行settings下的函数
    7 # in the settings
    8 # name is lzl

       lzl.py以及settings.py文件未变,main.py文件去掉了繁杂的sys.path添加的过程,直接执行from Day5.Credit_card.conf import settings,使用相对路径,更加简洁方便!

       二、内置模块

      1、time和datatime模块    

    时间相关的操作,时间有三种表示方式:

      • 时间戳               1970年1月1日之后的秒,即:time.time()
      • 格式化的字符串    2014-11-11 11:11,    即:time.strftime('%Y-%m-%d')
      • 结构化时间          元组包含了:年、日、星期等... time.struct_time    即:time.localtime()
     1 Python 3.6.2 (v3.6.2:5fd33b5, Jul  8 2017, 04:14:34) [MSC v.1900 32 bit (Intel)] on win32
     2 Type "copyright", "credits" or "license()" for more information.
     3 >>> 
     4 >>> import time
     5 >>> 
     6 >>> print("time stamp:", time.time())       #时间戳
     7 time stamp: 1525852970.2903516
     8 
     9 >>> print("local time:", time.localtime())    # struct_time类型的本地时间
    10 local time: time.struct_time(tm_year=2018, tm_mon=5, tm_mday=9, tm_hour=16, tm_min=3, tm_sec=10, tm_wday=2, tm_yday=129, tm_isdst=0)
    11 
    12 >>> print("utc time:", time.gmtime())         # struct_time类型的utc时间
    13 utc time: time.struct_time(tm_year=2018, tm_mon=5, tm_mday=9, tm_hour=8, tm_min=4, tm_sec=4, tm_wday=2, tm_yday=129, tm_isdst=0)

        可以看出,当地时间(北京时间)比 UTC时间早8个小时。

        各种时间形式的转换。

     1 #!/user/bin/env ptyhon
     2 # -*- coding:utf-8 -*-
     3 # Author: VisonWong
     4 
     5 import  time,calendar
     6 
     7 # time模块中,三种时间形式之间的转换
     8 time_stamp = time.time()               # 时间戳
     9 local_time = time.localtime(time_stamp)# 时间戳转struct_time类型的本地时间
    10 utc_time = time.gmtime(time_stamp)     # 时间戳转struct_time类型的utc时间
    11 
    12 time_stamp_1 = time.mktime(local_time) # struct_time类型的本地时间转时间戳
    13 time_stamp_2 = calendar.timegm(utc_time)# struct_time类型的utc时间转时间戳
    14 
    15 print('time_stamp:',time_stamp)
    16 print('local_time:',local_time)
    17 print('utc_time:',utc_time)
    18 print('time_stamp_local:',time_stamp_1)
    19 print('time_stamp_utc:',time_stamp_2)

        输出结果:

    1 E:PythonPythonLearingvenvScriptspython.exe E:/Python/PythonLearing/time.py
    2 time_stamp: 1525857093.0751617
    3 local_time: time.struct_time(tm_year=2018, tm_mon=5, tm_mday=9, tm_hour=17, tm_min=11, tm_sec=33, tm_wday=2, tm_yday=129, tm_isdst=0)
    4 utc_time: time.struct_time(tm_year=2018, tm_mon=5, tm_mday=9, tm_hour=9, tm_min=11, tm_sec=33, tm_wday=2, tm_yday=129, tm_isdst=0)
    5 time_stamp_local: 1525857093.0
    6 time_stamp_utc: 1525857093
    7 
    8 Process finished with exit code 0

        各种时间形式与字符串之间的转换。

     1 #!/user/bin/env ptyhon
     2 # -*- coding:utf-8 -*-
     3 # Author: VisonWong
     4 
     5 import  time
     6 
     7 time_stamp = time.time()               # 时间戳
     8 local_time = time.localtime(time_stamp)# 时间戳转struct_time类型的本地时间
     9 utc_time = time.gmtime(time_stamp)     # 时间戳转struct_time类型的utc时间
    10 
    11 # time模块中,三种时间形式和字符串之间的转换
    12 print(time.ctime(time_stamp))           # 时间戳转字符串(本地时间字符串)
    13 
    14 print(time.asctime(local_time))         # struct_time类型的本地时间转字符串
    15 print(time.asctime(utc_time))           # struct_time类型的utc时间转字符串
    16 
    17 print(time.strftime("%Y-%m-%d, %H:%M:%S, %w", local_time))      # struct_time类型的本地时间转字符串:自定义格式
    18 print(time.strftime("%Y-%m-%d, %H:%M:%S, %w", utc_time))        # struct_time类型的utc时间转字符串:自定义格式
    19 
    20 struct_time = time.strptime("2016-11-15, 15:32:12, 2", "%Y-%m-%d, %H:%M:%S, %w")       # 字符串转struct_time类型
    21 
    22 print(struct_time)

        输出结果:

    1 E:PythonPythonLearingvenvScriptspython.exe E:/Python/PythonLearing/time.py
    2 Wed May  9 17:16:05 2018
    3 Wed May  9 17:16:05 2018
    4 Wed May  9 09:16:05 2018
    5 2018-05-09, 17:16:05, 3
    6 2018-05-09, 09:16:05, 3
    7 time.struct_time(tm_year=2016, tm_mon=11, tm_mday=15, tm_hour=15, tm_min=32, tm_sec=12, tm_wday=1, tm_yday=320, tm_isdst=-1)
    8 
    9 Process finished with exit code 0

        结构化时间:

      

        时间戳、格式化字符串、机构化时间相互转换:

     

        datatime模块:

    接下来再看datetime模块。该模块中包含4个主要的类:

        • datetime.time:时间类,只包含时、分、秒、微秒等时间信息。
        • datetime.date:日期类,只包含年、月、日、星期等日期信息。
        • datetime.datetime:日期时间类,包含以上两者的全部信息。
        • datetime.timedelta:时间日期差值类,用来表示两个datetime之间的差值。
     1 #!/user/bin/env ptyhon
     2 # -*- coding:utf-8 -*-
     3 # Author: VisonWong
     4 
     5 import  datetime
     6 
     7 # datetime模块中datetime类的用法
     8 a_datetime_local = datetime.datetime.now()                      # 获取datetime.datetime类型的本地时间
     9 a_datetime_utc = datetime.datetime.utcnow()                     # 获取datetime.datetime类型的utc时间
    10 
    11 print('local_time:',a_datetime_local)
    12 print('utc_time:',a_datetime_utc)
    13 print('format_local:',a_datetime_local.strftime("%Y-%m-%d, %H:%M:%S, %w"))      # datetime.datetime类型转字符串
    14 print('format_utc:',a_datetime_utc.strftime("%Y-%m-%d, %H:%M:%S, %w"))        # datetime.datetime类型转字符串
    15 
    16 a_datetime = datetime.datetime.strptime("2016-11-15, 15:32:12, 2", "%Y-%m-%d, %H:%M:%S, %w")    # 字符串转datetime.datetime格式
    17 
    18 print('a_datetime:',a_datetime)

         输出结果:

    1 E:PythonPythonLearingvenvScriptspython.exe E:/Python/PythonLearing/time.py
    2 local_time: 2018-05-09 18:58:24.620881
    3 utc_time: 2018-05-09 10:58:24.620881
    4 format_local: 2018-05-09, 18:58:24, 3
    5 format_utc: 2018-05-09, 10:58:24, 3
    6 a_datetime: 2016-11-15 15:32:12
    7 
    8 Process finished with exit code 0

        datetime.datetime类和时间戳、struct_time类型之间的转换。

     1 #!/user/bin/env ptyhon
     2 # -*- coding:utf-8 -*-
     3 # Author: VisonWong
     4 
     5 import  time,datetime
     6 
     7 # datetime模块中datetime类的用法
     8 a_datetime_local = datetime.datetime.now()                      # 获取datetime.datetime类型的本地时间
     9 a_datetime_utc = datetime.datetime.utcnow()                     # 获取datetime.datetime类型的utc时间
    10 
    11 # datetime.datetime类和时间戳、struct_time类型之间的转换
    12 time_stamp = a_datetime_local.timestamp()                           # datetime类型转时间戳
    13 print('time_stamp:',time_stamp)
    14 
    15 a_datetime_local = datetime.datetime.fromtimestamp(time.time())     # 时间戳转datetime.datetime类型的本地时间
    16 a_datetime_utc = datetime.datetime.utcfromtimestamp(time.time())    # 时间戳转datetime.datetime类型的utc时间
    17 print('a_datetime_local:',a_datetime_local)
    18 print('a_datetime_utc:',a_datetime_utc)
    19 
    20 print(a_datetime_local.timetuple())                 # datetime类型转struct_time类型
    21 print(a_datetime_utc.utctimetuple())                # datetime类型转struct_time类型

        输出结果:

    1 E:PythonPythonLearingvenvScriptspython.exe E:/Python/PythonLearing/time.py
    2 time_stamp: 1525863948.894291
    3 a_datetime_local: 2018-05-09 19:05:48.894292
    4 a_datetime_utc: 2018-05-09 11:05:48.894292
    5 time.struct_time(tm_year=2018, tm_mon=5, tm_mday=9, tm_hour=19, tm_min=5, tm_sec=48, tm_wday=2, tm_yday=129, tm_isdst=-1)
    6 time.struct_time(tm_year=2018, tm_mon=5, tm_mday=9, tm_hour=11, tm_min=5, tm_sec=48, tm_wday=2, tm_yday=129, tm_isdst=0)
    7 
    8 Process finished with exit code 0

        2、random模块

        生成随机数。

     1 #random随机数模块
     2 import random
     3  
     4 print(random.random())      #生成0到1的随机数
     5 #0.7308387398872364
     6  
     7 print(random.randint(1,3))  #生成1-3随机数
     8 #3
     9  
    10 print(random.randrange(1,3)) #生成1-2随机数,不包含3
    11 #2
    12  
    13 print(random.choice("hello"))  #随机选取字符串
    14 #e
    15  
    16 print(random.sample("hello",2))     #随机选取特定的字符
    17 #['l', 'h']
    18  
    19 items = [1,2,3,4,5,6,7]
    20 random.shuffle(items)
    21 print(items)
    22 #[2, 3, 1, 6, 4, 7, 5]

        验证码。

     1 #!/user/bin/env ptyhon
     2 # -*- coding:utf-8 -*-
     3 # Author: VisonWong
     4 
     5 import random
     6 
     7 checkcode = ''
     8 for i in range(4):
     9     current = random.randrange(0, 4)
    10     if current != i:
    11         temp = chr(random.randint(65, 90))    #生成随机字母
    12     else:
    13         temp = random.randint(0, 9)
    14     checkcode += str(temp)
    15 
    16 print(checkcode)

        输出结果:

    1 E:PythonPythonLearingvenvScriptspython.exe E:/Python/PythonLearing/time.py
    2 GNU1
    3 
    4 Process finished with exit code 0

        3、os模块

        用于提供系统级别的操作。

     1 #os模块
     2 import os
     3  
     4 os.getcwd() #获取当前工作目录,即当前python脚本工作的目录路径
     5 os.chdir("dirname")  #改变当前脚本工作目录;相当于shell下cd
     6 os.curdir  #返回当前目录: ('.')
     7 os.pardir  #获取当前目录的父目录字符串名:('..')
     8 os.makedirs('dirname1/dirname2')    #可生成多层递归目录
     9 os.removedirs('dirname1')   # 若目录为空,则删除,并递归到上一级目录,如若也为空,则删除,依此类推
    10 os.mkdir('dirname')   # 生成单级目录;相当于shell中mkdir dirname
    11 os.rmdir('dirname')    #删除单级空目录,若目录不为空则无法删除,报错;相当于shell中rmdir dirname
    12 os.listdir('dirname')    #列出指定目录下的所有文件和子目录,包括隐藏文件,并以列表方式打印
    13 os.remove() # 删除一个文件
    14 os.rename("oldname","newname") # 重命名文件/目录
    15 os.stat('path/filename') # 获取文件/目录信息
    16 os.sep    #输出操作系统特定的路径分隔符,win下为"\",Linux下为"/"
    17 os.linesep    #输出当前平台使用的行终止符,win下为"	
    ",Linux下为"
    "
    18 os.pathsep    #输出用于分割文件路径的字符串
    19 os.name    #输出字符串指示当前使用平台。win->'nt'; Linux->'posix'
    20 os.system("bash command")  #运行shell命令,直接显示 commans可以获取返回值
    21 os.environ  #获取系统环境变量
    22 os.path.abspath(path)  #返回path规范化的绝对路径
    23 os.path.split(path)  #将path分割成目录和文件名二元组返回
    24 os.path.dirname(path) # 返回path的目录。其实就是os.path.split(path)的第一个元素
    25 os.path.basename(path) # 返回path最后的文件名。如何path以/或结尾,那么就会返回空值。即os.path.split(path)的第二个元素
    26 os.path.exists(path)  #如果path存在,返回True;如果path不存在,返回False
    27 os.path.isabs(path)  #如果path是绝对路径,返回True
    28 os.path.isfile(path)  #如果path是一个存在的文件,返回True。否则返回False
    29 os.path.isdir(path)  #如果path是一个存在的目录,则返回True。否则返回False
    30 os.path.join(path1[, path2[, ...]]) # 将多个路径组合后返回,第一个绝对路径之前的参数将被忽略
    31 os.path.getatime(path)  #返回path所指向的文件或者目录的最后存取时间
    32 os.path.getmtime(path)  #返回path所指向的文件或者目录的最后修改时间

        ①os.dir、os.popen调用当前系统命令

    1 #!/user/bin/env ptyhon
    2 # -*- coding:utf-8 -*-
    3 # Author: VisonWong
    4 
    5 import os
    6 
    7 res = os.system('dir')          #只执行dir命令,不保存结果
    8 
    9 print(res)         #res只返会执行命令的成功与否,成功为0 反之为1

        执行结果:

     1 E:PythonPythonLearingvenvScriptspython.exe 
     2  ������ E �еľ��� �ĵ�
     3  �������� 0000-5431
     4 
     5  E:PythonPythonLearing ��Ŀ¼
     6 
     7 2018/05/09  20:46    <DIR>          .
     8 2018/05/09  20:46    <DIR>          ..
     9 2018/05/09  20:45    <DIR>          .idea
    10 2018/04/01  01:32               378 changefile.py
    11 2018/05/02  02:13               306 copy.py
    12 2018/04/10  21:08               204 decorater.py
    13 2018/04/01  00:28               722 File.py
    14 2018/05/01  19:45               842 file_op.py
    15 2018/05/05  22:58             1,253 func.py
    16 2018/05/07  22:35               674 generater.py
    17 2018/04/12  21:38               209 generator.py
    18 2017/12/25  12:02               638 GuessAge.py
    19 2018/03/16  00:47                95 HelloWorld.py
    20 2017/12/25  02:38               671 Interaction.py
    21 2018/05/09  02:51                73 module.py
    22 2018/04/01  01:11               162 test.py
    23 2018/05/09  20:46               122 time.py
    24 2018/04/01  00:56    <DIR>          venv
    25 2018/05/01  19:42               649 yesterday
    26 2018/03/31  23:49               643 yesterday.txt
    27 2018/04/01  00:15                26 yesterday1.txt
    28 2018/05/01  19:00               649 yesterday2
    29 2018/04/01  01:33               639 yesterday_bak.txt
    30 2018/05/02  02:13    <DIR>          __pycache__
    31 2018/04/01  00:40               181 ������.py
    32               20 ���ļ�          9,136 �ֽ�
    33                5 ��Ŀ¼ 46,039,920,640 �����ֽ�
    34 0

        os.popen

     1 #!/user/bin/env ptyhon
     2 # -*- coding:utf-8 -*-
     3 # Author: VisonWong
     4 
     5 import os
     6 
     7 res = os.popen("dir")               #不打印输出,保存执行结果
     8 print(res)                           #打印res内存地址信息
     9 
    10 res = os.popen("dir").read()        #通过read去读取内存地址记录的信息
    11 print(res)

        执行结果:

     1 E:PythonPythonLearingvenvScriptspython.exe 
     2 <os._wrap_close object at 0x015DB3F0>
     3  驱动器 E 中的卷是 文档
     4  卷的序列号是 0000-5431
     5 
     6  E:PythonPythonLearing 的目录
     7 
     8 2018/05/09  20:54    <DIR>          .
     9 2018/05/09  20:54    <DIR>          ..
    10 2018/05/09  20:52    <DIR>          .idea
    11 2018/04/01  01:32               378 changefile.py
    12 2018/05/02  02:13               306 copy.py
    13 2018/04/10  21:08               204 decorater.py
    14 2018/04/01  00:28               722 File.py
    15 2018/05/01  19:45               842 file_op.py
    16 2018/05/05  22:58             1,253 func.py
    17 2018/05/07  22:35               674 generater.py
    18 2018/04/12  21:38               209 generator.py
    19 2017/12/25  12:02               638 GuessAge.py
    20 2018/03/16  00:47                95 HelloWorld.py
    21 2017/12/25  02:38               671 Interaction.py
    22 2018/05/09  02:51                73 module.py
    23 2018/04/01  01:11               162 test.py
    24 2018/05/09  20:54               325 time.py
    25 2018/04/01  00:56    <DIR>          venv
    26 2018/05/01  19:42               649 yesterday
    27 2018/03/31  23:49               643 yesterday.txt
    28 2018/04/01  00:15                26 yesterday1.txt
    29 2018/05/01  19:00               649 yesterday2
    30 2018/04/01  01:33               639 yesterday_bak.txt
    31 2018/05/02  02:13    <DIR>          __pycache__
    32 2018/04/01  00:40               181 进度条.py
    33               20 个文件          9,339 字节
    34                5 个目录 46,039,887,872 可用字节

        两者结合使用:

    1 import os,sys
    2   
    3 os.system(''.join(sys.argv[1:])) #把用户的输入的参数当作一条命令交给os.system来执行

        4、sys模块

        用于提供对解释器相关的操作。

     1 #sys模块
     2 import sys
     3  
     4 sys.argv           #命令行参数List,第一个元素是程序本身路径
     5 sys.exit(n)        #退出程序,正常退出时exit(0)
     6 sys.version       # 获取Python解释程序的版本信息
     7 sys.maxint         #最大的Int值
     8 sys.path           #返回模块的搜索路径,初始化时使用PYTHONPATH环境变量的值
     9 sys.platform      #返回操作系统平台名称
    10 sys.stdout.write('please:')
    11 val = sys.stdin.readline()[:-1]

        ① 其中的 sys.argv 用来捕获执行执行python脚本时传入的参数:

     1 import sys
     2  
     3 strings = sys.argv
     4 print(strings)   # 所有参数 类型为列表
     5 # ['start.py', 'hello', 'world']
     6 print(strings[0])   # 脚本名本身
     7 # start.py
     8 print(strings[1])   # 第一个参数
     9 # hello
    10 print(strings[2])   # 第二个参数
    11 # world
    12 print(strings[-1])  # 倒数第一个参数
    13 # world
    14  
    15 $ python test.py helo world   执行脚本

        ② sys.stdin信息输入:

     1 #!/user/bin/env ptyhon
     2 # -*- coding:utf-8 -*-
     3 # Author: VisonWong
     4 
     5 import sys
     6 li = []
     7 file = sys.stdin
     8 # <_io.TextIOWrapper name='<stdin>' mode='r' encoding='cp936'>  file
     9 for line in file:
    10     li.append(line)
    11     print(li)
    12     print(line.strip())    # 这个很重要 strip去除末尾的换行符 本身print跟print直接回产生换行符
    13                            # 如果不进去去除末尾的换行符的话 会再多打印一行换行符

        执行结果:

     1 E:PythonPythonLearingvenvScriptspython.exe E:/Python/PythonLearing/time.py
     2  3 ['']
     4  5  6 ['', '']
     7  8 python
     9 ['', '', 'python
    ']
    10 python
    11 
    12 Process finished with exit code 1

        ③ sys.stdout 重定向输出

    1 import sys
    2  
    3 sys.stdout.write("asdgf") # 当我们在 Python 中打印对象调用 print obj 时候,事实上是调用了 sys.stdout.write(obj+'
    ')
    4 # asdgf

        5、shutil模块

        高级的 文件、文件夹、压缩包 处理模块。

        ① shutil.copyfileobj 将文件内容拷贝到另一个文件中,可以部分内容 

     1 #shutil 文件拷贝
     2 import shutil
     3  
     4 f1 = open("fsrc",encoding="utf-8")
     5  
     6 f2 = open("fdst",encoding="utf-8")
     7  
     8 shutil.copyfile(f1,f2)
     9  
    10 #把文件f1里的内容拷贝到f2当中

        函数源码 

    def copyfileobj(fsrc, fdst, length=16*1024):
        """copy data from file-like object fsrc to file-like object fdst"""
        while 1:
            buf = fsrc.read(length)
            if not buf:
                break
            fdst.write(buf)
    
    shutil.copyfileobj
    shutil.copyfileobj 

        ② shutil.copyfile 文件拷贝

    1 #shutil.copyfile 文件拷贝
    2 import shutil
    3  
    4 shutil.copyfile("f1","f2")
    5 #把文件f1里的内容拷贝到f2当中

        函数源码

    def copyfile(src, dst):
        """Copy data from src to dst"""
        if _samefile(src, dst):
            raise Error("`%s` and `%s` are the same file" % (src, dst))
    
        for fn in [src, dst]:
            try:
                st = os.stat(fn)
            except OSError:
                # File most likely does not exist
                pass
            else:
                # XXX What about other special files? (sockets, devices...)
                if stat.S_ISFIFO(st.st_mode):
                    raise SpecialFileError("`%s` is a named pipe" % fn)
    
        with open(src, 'rb') as fsrc:
            with open(dst, 'wb') as fdst:
                copyfileobj(fsrc, fdst)
    
    shutil.copyfile
    shutil.copyfile

        ③ shutil.copymode(src, dst) 仅拷贝权限。内容、组、用户均不变

    def copymode(src, dst):
        """Copy mode bits from src to dst"""
        if hasattr(os, 'chmod'):
            st = os.stat(src)
            mode = stat.S_IMODE(st.st_mode)
            os.chmod(dst, mode)
    
    shutil.copymode
    shutil.copymode

        ④ shutil.copystat(src, dst) 拷贝状态的信息,包括:mode bits, atime, mtime, flags

    def copystat(src, dst):
        """Copy all stat info (mode bits, atime, mtime, flags) from src to dst"""
        st = os.stat(src)
        mode = stat.S_IMODE(st.st_mode)
        if hasattr(os, 'utime'):
            os.utime(dst, (st.st_atime, st.st_mtime))
        if hasattr(os, 'chmod'):
            os.chmod(dst, mode)
        if hasattr(os, 'chflags') and hasattr(st, 'st_flags'):
            try:
                os.chflags(dst, st.st_flags)
            except OSError, why:
                for err in 'EOPNOTSUPP', 'ENOTSUP':
                    if hasattr(errno, err) and why.errno == getattr(errno, err):
                        break
                else:
                    raise
    
    shutil.copystat
    shutil.copystat

        ⑤ shutil.copy(src, dst) 拷贝文件和权限

    def copy(src, dst):
        """Copy data and mode bits ("cp src dst").
    
        The destination may be a directory.
    
        """
        if os.path.isdir(dst):
            dst = os.path.join(dst, os.path.basename(src))
        copyfile(src, dst)
        copymode(src, dst)
    
    shutil.copy
    shutil.copy

        ⑥ shutil.copy2(src, dst) 拷贝文件和状态信息

    def copy2(src, dst):
        """Copy data and all stat info ("cp -p src dst").
    
        The destination may be a directory.
    
        """
        if os.path.isdir(dst):
            dst = os.path.join(dst, os.path.basename(src))
        copyfile(src, dst)
        copystat(src, dst)
    
    shutil.copy2
    shutil.copy2

        ⑦ shutil.copytree(src, dst, symlinks=False, ignore=None) 递归的去拷贝文件 拷贝多层目录

    def ignore_patterns(*patterns):
        """Function that can be used as copytree() ignore parameter.
    
        Patterns is a sequence of glob-style patterns
        that are used to exclude files"""
        def _ignore_patterns(path, names):
            ignored_names = []
            for pattern in patterns:
                ignored_names.extend(fnmatch.filter(names, pattern))
            return set(ignored_names)
        return _ignore_patterns
    
    def copytree(src, dst, symlinks=False, ignore=None):
        """Recursively copy a directory tree using copy2().
    
        The destination directory must not already exist.
        If exception(s) occur, an Error is raised with a list of reasons.
    
        If the optional symlinks flag is true, symbolic links in the
        source tree result in symbolic links in the destination tree; if
        it is false, the contents of the files pointed to by symbolic
        links are copied.
    
        The optional ignore argument is a callable. If given, it
        is called with the `src` parameter, which is the directory
        being visited by copytree(), and `names` which is the list of
        `src` contents, as returned by os.listdir():
    
            callable(src, names) -> ignored_names
    
        Since copytree() is called recursively, the callable will be
        called once for each directory that is copied. It returns a
        list of names relative to the `src` directory that should
        not be copied.
    
        XXX Consider this example code rather than the ultimate tool.
    
        """
        names = os.listdir(src)
        if ignore is not None:
            ignored_names = ignore(src, names)
        else:
            ignored_names = set()
    
        os.makedirs(dst)
        errors = []
        for name in names:
            if name in ignored_names:
                continue
            srcname = os.path.join(src, name)
            dstname = os.path.join(dst, name)
            try:
                if symlinks and os.path.islink(srcname):
                    linkto = os.readlink(srcname)
                    os.symlink(linkto, dstname)
                elif os.path.isdir(srcname):
                    copytree(srcname, dstname, symlinks, ignore)
                else:
                    # Will raise a SpecialFileError for unsupported file types
                    copy2(srcname, dstname)
            # catch the Error from the recursive copytree so that we can
            # continue with other files
            except Error, err:
                errors.extend(err.args[0])
            except EnvironmentError, why:
                errors.append((srcname, dstname, str(why)))
        try:
            copystat(src, dst)
        except OSError, why:
            if WindowsError is not None and isinstance(why, WindowsError):
                # Copying file access times may fail on Windows
                pass
            else:
                errors.append((src, dst, str(why)))
        if errors:
            raise Error, errors
    
    shutil.copytree
    shutil.cpoytree

        ⑧ shutil.rmtree(path[, ignore_errors[, onerror]]) 递归的去删除文件

    def rmtree(path, ignore_errors=False, onerror=None):
        """Recursively delete a directory tree.
    
        If ignore_errors is set, errors are ignored; otherwise, if onerror
        is set, it is called to handle the error with arguments (func,
        path, exc_info) where func is os.listdir, os.remove, or os.rmdir;
        path is the argument to that function that caused it to fail; and
        exc_info is a tuple returned by sys.exc_info().  If ignore_errors
        is false and onerror is None, an exception is raised.
    
        """
        if ignore_errors:
            def onerror(*args):
                pass
        elif onerror is None:
            def onerror(*args):
                raise
        try:
            if os.path.islink(path):
                # symlinks to directories are forbidden, see bug #1669
                raise OSError("Cannot call rmtree on a symbolic link")
        except OSError:
            onerror(os.path.islink, path, sys.exc_info())
            # can't continue even if onerror hook returns
            return
        names = []
        try:
            names = os.listdir(path)
        except os.error, err:
            onerror(os.listdir, path, sys.exc_info())
        for name in names:
            fullname = os.path.join(path, name)
            try:
                mode = os.lstat(fullname).st_mode
            except os.error:
                mode = 0
            if stat.S_ISDIR(mode):
                rmtree(fullname, ignore_errors, onerror)
            else:
                try:
                    os.remove(fullname)
                except os.error, err:
                    onerror(os.remove, fullname, sys.exc_info())
        try:
            os.rmdir(path)
        except os.error:
            onerror(os.rmdir, path, sys.exc_info())
    
    shutil.rmtree
    shutil.rmtree

        ⑨ shutil.move(src, dst) 递归的去移动文件

    def move(src, dst):
        """Recursively move a file or directory to another location. This is
        similar to the Unix "mv" command.
    
        If the destination is a directory or a symlink to a directory, the source
        is moved inside the directory. The destination path must not already
        exist.
    
        If the destination already exists but is not a directory, it may be
        overwritten depending on os.rename() semantics.
    
        If the destination is on our current filesystem, then rename() is used.
        Otherwise, src is copied to the destination and then removed.
        A lot more could be done here...  A look at a mv.c shows a lot of
        the issues this implementation glosses over.
    
        """
        real_dst = dst
        if os.path.isdir(dst):
            if _samefile(src, dst):
                # We might be on a case insensitive filesystem,
                # perform the rename anyway.
                os.rename(src, dst)
                return
    
            real_dst = os.path.join(dst, _basename(src))
            if os.path.exists(real_dst):
                raise Error, "Destination path '%s' already exists" % real_dst
        try:
            os.rename(src, real_dst)
        except OSError:
            if os.path.isdir(src):
                if _destinsrc(src, dst):
                    raise Error, "Cannot move a directory '%s' into itself '%s'." % (src, dst)
                copytree(src, real_dst, symlinks=True)
                rmtree(src)
            else:
                copy2(src, real_dst)
                os.unlink(src)
    
    shutil.move
    shutil.move

    ⑩ shutil.make_archive(base_name, format,...) 创建压缩包并返回文件路径,例如:zip、tar

      • base_name: 压缩包的文件名,也可以是压缩包的路径。只是文件名时,则保存至当前目录,否则保存至指定路径,

            如:www                        =>保存至当前路径

            如:/Users/wupeiqi/www =>保存至/Users/wupeiqi/

      • format: 压缩包种类,“zip”, “tar”, “bztar”,“gztar”
      • root_dir: 要压缩的文件夹路径(默认当前目录)
      • owner: 用户,默认当前用户
      • group: 组,默认当前组
      • logger: 用于记录日志,通常是logging.Logger对象
    def make_archive(base_name, format, root_dir=None, base_dir=None, verbose=0,
                     dry_run=0, owner=None, group=None, logger=None):
        """Create an archive file (eg. zip or tar).
    
        'base_name' is the name of the file to create, minus any format-specific
        extension; 'format' is the archive format: one of "zip", "tar", "bztar"
        or "gztar".
    
        'root_dir' is a directory that will be the root directory of the
        archive; ie. we typically chdir into 'root_dir' before creating the
        archive.  'base_dir' is the directory where we start archiving from;
        ie. 'base_dir' will be the common prefix of all files and
        directories in the archive.  'root_dir' and 'base_dir' both default
        to the current directory.  Returns the name of the archive file.
    
        'owner' and 'group' are used when creating a tar archive. By default,
        uses the current owner and group.
        """
        save_cwd = os.getcwd()
        if root_dir is not None:
            if logger is not None:
                logger.debug("changing into '%s'", root_dir)
            base_name = os.path.abspath(base_name)
            if not dry_run:
                os.chdir(root_dir)
    
        if base_dir is None:
            base_dir = os.curdir
    
        kwargs = {'dry_run': dry_run, 'logger': logger}
    
        try:
            format_info = _ARCHIVE_FORMATS[format]
        except KeyError:
            raise ValueError, "unknown archive format '%s'" % format
    
        func = format_info[0]
        for arg, val in format_info[1]:
            kwargs[arg] = val
    
        if format != 'zip':
            kwargs['owner'] = owner
            kwargs['group'] = group
    
        try:
            filename = func(base_name, base_dir, **kwargs)
        finally:
            if root_dir is not None:
                if logger is not None:
                    logger.debug("changing back to '%s'", save_cwd)
                os.chdir(save_cwd)
    
        return filename
    
    源码
    shutil.make_archive

         shutil 对压缩包的处理是调用 ZipFile 和 TarFile 两个模块来进行的,详细:

    import zipfile
    
    # 压缩
    z = zipfile.ZipFile('laxi.zip', 'w')
    z.write('a.log')
    z.write('data.data')
    z.close()
    
    # 解压
    z = zipfile.ZipFile('laxi.zip', 'r')
    z.extractall()
    z.close()
    
    zipfile 压缩解压
    
    zipfile 压缩解压
    zipfile 压缩解压
    import tarfile
    
    # 压缩
    tar = tarfile.open('your.tar','w')
    tar.add('/Users/wupeiqi/PycharmProjects/bbs2.zip', arcname='bbs2.zip')
    tar.add('/Users/wupeiqi/PycharmProjects/cmdb.zip', arcname='cmdb.zip')
    tar.close()
    
    # 解压
    tar = tarfile.open('your.tar','r')
    tar.extractall()  # 可设置解压地址
    tar.close()
    
    tarfile 压缩解压
    tarfile 压缩解压
    class ZipFile(object):
        """ Class with methods to open, read, write, close, list zip files.
    
        z = ZipFile(file, mode="r", compression=ZIP_STORED, allowZip64=False)
    
        file: Either the path to the file, or a file-like object.
              If it is a path, the file will be opened and closed by ZipFile.
        mode: The mode can be either read "r", write "w" or append "a".
        compression: ZIP_STORED (no compression) or ZIP_DEFLATED (requires zlib).
        allowZip64: if True ZipFile will create files with ZIP64 extensions when
                    needed, otherwise it will raise an exception when this would
                    be necessary.
    
        """
    
        fp = None                   # Set here since __del__ checks it
    
        def __init__(self, file, mode="r", compression=ZIP_STORED, allowZip64=False):
            """Open the ZIP file with mode read "r", write "w" or append "a"."""
            if mode not in ("r", "w", "a"):
                raise RuntimeError('ZipFile() requires mode "r", "w", or "a"')
    
            if compression == ZIP_STORED:
                pass
            elif compression == ZIP_DEFLATED:
                if not zlib:
                    raise RuntimeError,
                          "Compression requires the (missing) zlib module"
            else:
                raise RuntimeError, "That compression method is not supported"
    
            self._allowZip64 = allowZip64
            self._didModify = False
            self.debug = 0  # Level of printing: 0 through 3
            self.NameToInfo = {}    # Find file info given name
            self.filelist = []      # List of ZipInfo instances for archive
            self.compression = compression  # Method of compression
            self.mode = key = mode.replace('b', '')[0]
            self.pwd = None
            self._comment = ''
    
            # Check if we were passed a file-like object
            if isinstance(file, basestring):
                self._filePassed = 0
                self.filename = file
                modeDict = {'r' : 'rb', 'w': 'wb', 'a' : 'r+b'}
                try:
                    self.fp = open(file, modeDict[mode])
                except IOError:
                    if mode == 'a':
                        mode = key = 'w'
                        self.fp = open(file, modeDict[mode])
                    else:
                        raise
            else:
                self._filePassed = 1
                self.fp = file
                self.filename = getattr(file, 'name', None)
    
            try:
                if key == 'r':
                    self._RealGetContents()
                elif key == 'w':
                    # set the modified flag so central directory gets written
                    # even if no files are added to the archive
                    self._didModify = True
                elif key == 'a':
                    try:
                        # See if file is a zip file
                        self._RealGetContents()
                        # seek to start of directory and overwrite
                        self.fp.seek(self.start_dir, 0)
                    except BadZipfile:
                        # file is not a zip file, just append
                        self.fp.seek(0, 2)
    
                        # set the modified flag so central directory gets written
                        # even if no files are added to the archive
                        self._didModify = True
                else:
                    raise RuntimeError('Mode must be "r", "w" or "a"')
            except:
                fp = self.fp
                self.fp = None
                if not self._filePassed:
                    fp.close()
                raise
    
        def __enter__(self):
            return self
    
        def __exit__(self, type, value, traceback):
            self.close()
    
        def _RealGetContents(self):
            """Read in the table of contents for the ZIP file."""
            fp = self.fp
            try:
                endrec = _EndRecData(fp)
            except IOError:
                raise BadZipfile("File is not a zip file")
            if not endrec:
                raise BadZipfile, "File is not a zip file"
            if self.debug > 1:
                print endrec
            size_cd = endrec[_ECD_SIZE]             # bytes in central directory
            offset_cd = endrec[_ECD_OFFSET]         # offset of central directory
            self._comment = endrec[_ECD_COMMENT]    # archive comment
    
            # "concat" is zero, unless zip was concatenated to another file
            concat = endrec[_ECD_LOCATION] - size_cd - offset_cd
            if endrec[_ECD_SIGNATURE] == stringEndArchive64:
                # If Zip64 extension structures are present, account for them
                concat -= (sizeEndCentDir64 + sizeEndCentDir64Locator)
    
            if self.debug > 2:
                inferred = concat + offset_cd
                print "given, inferred, offset", offset_cd, inferred, concat
            # self.start_dir:  Position of start of central directory
            self.start_dir = offset_cd + concat
            fp.seek(self.start_dir, 0)
            data = fp.read(size_cd)
            fp = cStringIO.StringIO(data)
            total = 0
            while total < size_cd:
                centdir = fp.read(sizeCentralDir)
                if len(centdir) != sizeCentralDir:
                    raise BadZipfile("Truncated central directory")
                centdir = struct.unpack(structCentralDir, centdir)
                if centdir[_CD_SIGNATURE] != stringCentralDir:
                    raise BadZipfile("Bad magic number for central directory")
                if self.debug > 2:
                    print centdir
                filename = fp.read(centdir[_CD_FILENAME_LENGTH])
                # Create ZipInfo instance to store file information
                x = ZipInfo(filename)
                x.extra = fp.read(centdir[_CD_EXTRA_FIELD_LENGTH])
                x.comment = fp.read(centdir[_CD_COMMENT_LENGTH])
                x.header_offset = centdir[_CD_LOCAL_HEADER_OFFSET]
                (x.create_version, x.create_system, x.extract_version, x.reserved,
                    x.flag_bits, x.compress_type, t, d,
                    x.CRC, x.compress_size, x.file_size) = centdir[1:12]
                x.volume, x.internal_attr, x.external_attr = centdir[15:18]
                # Convert date/time code to (year, month, day, hour, min, sec)
                x._raw_time = t
                x.date_time = ( (d>>9)+1980, (d>>5)&0xF, d&0x1F,
                                         t>>11, (t>>5)&0x3F, (t&0x1F) * 2 )
    
                x._decodeExtra()
                x.header_offset = x.header_offset + concat
                x.filename = x._decodeFilename()
                self.filelist.append(x)
                self.NameToInfo[x.filename] = x
    
                # update total bytes read from central directory
                total = (total + sizeCentralDir + centdir[_CD_FILENAME_LENGTH]
                         + centdir[_CD_EXTRA_FIELD_LENGTH]
                         + centdir[_CD_COMMENT_LENGTH])
    
                if self.debug > 2:
                    print "total", total
    
    
        def namelist(self):
            """Return a list of file names in the archive."""
            l = []
            for data in self.filelist:
                l.append(data.filename)
            return l
    
        def infolist(self):
            """Return a list of class ZipInfo instances for files in the
            archive."""
            return self.filelist
    
        def printdir(self):
            """Print a table of contents for the zip file."""
            print "%-46s %19s %12s" % ("File Name", "Modified    ", "Size")
            for zinfo in self.filelist:
                date = "%d-%02d-%02d %02d:%02d:%02d" % zinfo.date_time[:6]
                print "%-46s %s %12d" % (zinfo.filename, date, zinfo.file_size)
    
        def testzip(self):
            """Read all the files and check the CRC."""
            chunk_size = 2 ** 20
            for zinfo in self.filelist:
                try:
                    # Read by chunks, to avoid an OverflowError or a
                    # MemoryError with very large embedded files.
                    with self.open(zinfo.filename, "r") as f:
                        while f.read(chunk_size):     # Check CRC-32
                            pass
                except BadZipfile:
                    return zinfo.filename
    
        def getinfo(self, name):
            """Return the instance of ZipInfo given 'name'."""
            info = self.NameToInfo.get(name)
            if info is None:
                raise KeyError(
                    'There is no item named %r in the archive' % name)
    
            return info
    
        def setpassword(self, pwd):
            """Set default password for encrypted files."""
            self.pwd = pwd
    
        @property
        def comment(self):
            """The comment text associated with the ZIP file."""
            return self._comment
    
        @comment.setter
        def comment(self, comment):
            # check for valid comment length
            if len(comment) > ZIP_MAX_COMMENT:
                import warnings
                warnings.warn('Archive comment is too long; truncating to %d bytes'
                              % ZIP_MAX_COMMENT, stacklevel=2)
                comment = comment[:ZIP_MAX_COMMENT]
            self._comment = comment
            self._didModify = True
    
        def read(self, name, pwd=None):
            """Return file bytes (as a string) for name."""
            return self.open(name, "r", pwd).read()
    
        def open(self, name, mode="r", pwd=None):
            """Return file-like object for 'name'."""
            if mode not in ("r", "U", "rU"):
                raise RuntimeError, 'open() requires mode "r", "U", or "rU"'
            if not self.fp:
                raise RuntimeError, 
                      "Attempt to read ZIP archive that was already closed"
    
            # Only open a new file for instances where we were not
            # given a file object in the constructor
            if self._filePassed:
                zef_file = self.fp
                should_close = False
            else:
                zef_file = open(self.filename, 'rb')
                should_close = True
    
            try:
                # Make sure we have an info object
                if isinstance(name, ZipInfo):
                    # 'name' is already an info object
                    zinfo = name
                else:
                    # Get info object for name
                    zinfo = self.getinfo(name)
    
                zef_file.seek(zinfo.header_offset, 0)
    
                # Skip the file header:
                fheader = zef_file.read(sizeFileHeader)
                if len(fheader) != sizeFileHeader:
                    raise BadZipfile("Truncated file header")
                fheader = struct.unpack(structFileHeader, fheader)
                if fheader[_FH_SIGNATURE] != stringFileHeader:
                    raise BadZipfile("Bad magic number for file header")
    
                fname = zef_file.read(fheader[_FH_FILENAME_LENGTH])
                if fheader[_FH_EXTRA_FIELD_LENGTH]:
                    zef_file.read(fheader[_FH_EXTRA_FIELD_LENGTH])
    
                if fname != zinfo.orig_filename:
                    raise BadZipfile, 
                            'File name in directory "%s" and header "%s" differ.' % (
                                zinfo.orig_filename, fname)
    
                # check for encrypted flag & handle password
                is_encrypted = zinfo.flag_bits & 0x1
                zd = None
                if is_encrypted:
                    if not pwd:
                        pwd = self.pwd
                    if not pwd:
                        raise RuntimeError, "File %s is encrypted, " 
                            "password required for extraction" % name
    
                    zd = _ZipDecrypter(pwd)
                    # The first 12 bytes in the cypher stream is an encryption header
                    #  used to strengthen the algorithm. The first 11 bytes are
                    #  completely random, while the 12th contains the MSB of the CRC,
                    #  or the MSB of the file time depending on the header type
                    #  and is used to check the correctness of the password.
                    bytes = zef_file.read(12)
                    h = map(zd, bytes[0:12])
                    if zinfo.flag_bits & 0x8:
                        # compare against the file type from extended local headers
                        check_byte = (zinfo._raw_time >> 8) & 0xff
                    else:
                        # compare against the CRC otherwise
                        check_byte = (zinfo.CRC >> 24) & 0xff
                    if ord(h[11]) != check_byte:
                        raise RuntimeError("Bad password for file", name)
    
                return ZipExtFile(zef_file, mode, zinfo, zd,
                        close_fileobj=should_close)
            except:
                if should_close:
                    zef_file.close()
                raise
    
        def extract(self, member, path=None, pwd=None):
            """Extract a member from the archive to the current working directory,
               using its full name. Its file information is extracted as accurately
               as possible. `member' may be a filename or a ZipInfo object. You can
               specify a different directory using `path'.
            """
            if not isinstance(member, ZipInfo):
                member = self.getinfo(member)
    
            if path is None:
                path = os.getcwd()
    
            return self._extract_member(member, path, pwd)
    
        def extractall(self, path=None, members=None, pwd=None):
            """Extract all members from the archive to the current working
               directory. `path' specifies a different directory to extract to.
               `members' is optional and must be a subset of the list returned
               by namelist().
            """
            if members is None:
                members = self.namelist()
    
            for zipinfo in members:
                self.extract(zipinfo, path, pwd)
    
        def _extract_member(self, member, targetpath, pwd):
            """Extract the ZipInfo object 'member' to a physical
               file on the path targetpath.
            """
            # build the destination pathname, replacing
            # forward slashes to platform specific separators.
            arcname = member.filename.replace('/', os.path.sep)
    
            if os.path.altsep:
                arcname = arcname.replace(os.path.altsep, os.path.sep)
            # interpret absolute pathname as relative, remove drive letter or
            # UNC path, redundant separators, "." and ".." components.
            arcname = os.path.splitdrive(arcname)[1]
            arcname = os.path.sep.join(x for x in arcname.split(os.path.sep)
                        if x not in ('', os.path.curdir, os.path.pardir))
            if os.path.sep == '\':
                # filter illegal characters on Windows
                illegal = ':<>|"?*'
                if isinstance(arcname, unicode):
                    table = {ord(c): ord('_') for c in illegal}
                else:
                    table = string.maketrans(illegal, '_' * len(illegal))
                arcname = arcname.translate(table)
                # remove trailing dots
                arcname = (x.rstrip('.') for x in arcname.split(os.path.sep))
                arcname = os.path.sep.join(x for x in arcname if x)
    
            targetpath = os.path.join(targetpath, arcname)
            targetpath = os.path.normpath(targetpath)
    
            # Create all upper directories if necessary.
            upperdirs = os.path.dirname(targetpath)
            if upperdirs and not os.path.exists(upperdirs):
                os.makedirs(upperdirs)
    
            if member.filename[-1] == '/':
                if not os.path.isdir(targetpath):
                    os.mkdir(targetpath)
                return targetpath
    
            with self.open(member, pwd=pwd) as source, 
                 file(targetpath, "wb") as target:
                shutil.copyfileobj(source, target)
    
            return targetpath
    
        def _writecheck(self, zinfo):
            """Check for errors before writing a file to the archive."""
            if zinfo.filename in self.NameToInfo:
                import warnings
                warnings.warn('Duplicate name: %r' % zinfo.filename, stacklevel=3)
            if self.mode not in ("w", "a"):
                raise RuntimeError, 'write() requires mode "w" or "a"'
            if not self.fp:
                raise RuntimeError, 
                      "Attempt to write ZIP archive that was already closed"
            if zinfo.compress_type == ZIP_DEFLATED and not zlib:
                raise RuntimeError, 
                      "Compression requires the (missing) zlib module"
            if zinfo.compress_type not in (ZIP_STORED, ZIP_DEFLATED):
                raise RuntimeError, 
                      "That compression method is not supported"
            if not self._allowZip64:
                requires_zip64 = None
                if len(self.filelist) >= ZIP_FILECOUNT_LIMIT:
                    requires_zip64 = "Files count"
                elif zinfo.file_size > ZIP64_LIMIT:
                    requires_zip64 = "Filesize"
                elif zinfo.header_offset > ZIP64_LIMIT:
                    requires_zip64 = "Zipfile size"
                if requires_zip64:
                    raise LargeZipFile(requires_zip64 +
                                       " would require ZIP64 extensions")
    
        def write(self, filename, arcname=None, compress_type=None):
            """Put the bytes from filename into the archive under the name
            arcname."""
            if not self.fp:
                raise RuntimeError(
                      "Attempt to write to ZIP archive that was already closed")
    
            st = os.stat(filename)
            isdir = stat.S_ISDIR(st.st_mode)
            mtime = time.localtime(st.st_mtime)
            date_time = mtime[0:6]
            # Create ZipInfo instance to store file information
            if arcname is None:
                arcname = filename
            arcname = os.path.normpath(os.path.splitdrive(arcname)[1])
            while arcname[0] in (os.sep, os.altsep):
                arcname = arcname[1:]
            if isdir:
                arcname += '/'
            zinfo = ZipInfo(arcname, date_time)
            zinfo.external_attr = (st[0] & 0xFFFF) << 16L      # Unix attributes
            if compress_type is None:
                zinfo.compress_type = self.compression
            else:
                zinfo.compress_type = compress_type
    
            zinfo.file_size = st.st_size
            zinfo.flag_bits = 0x00
            zinfo.header_offset = self.fp.tell()    # Start of header bytes
    
            self._writecheck(zinfo)
            self._didModify = True
    
            if isdir:
                zinfo.file_size = 0
                zinfo.compress_size = 0
                zinfo.CRC = 0
                zinfo.external_attr |= 0x10  # MS-DOS directory flag
                self.filelist.append(zinfo)
                self.NameToInfo[zinfo.filename] = zinfo
                self.fp.write(zinfo.FileHeader(False))
                return
    
            with open(filename, "rb") as fp:
                # Must overwrite CRC and sizes with correct data later
                zinfo.CRC = CRC = 0
                zinfo.compress_size = compress_size = 0
                # Compressed size can be larger than uncompressed size
                zip64 = self._allowZip64 and 
                        zinfo.file_size * 1.05 > ZIP64_LIMIT
                self.fp.write(zinfo.FileHeader(zip64))
                if zinfo.compress_type == ZIP_DEFLATED:
                    cmpr = zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION,
                         zlib.DEFLATED, -15)
                else:
                    cmpr = None
                file_size = 0
                while 1:
                    buf = fp.read(1024 * 8)
                    if not buf:
                        break
                    file_size = file_size + len(buf)
                    CRC = crc32(buf, CRC) & 0xffffffff
                    if cmpr:
                        buf = cmpr.compress(buf)
                        compress_size = compress_size + len(buf)
                    self.fp.write(buf)
            if cmpr:
                buf = cmpr.flush()
                compress_size = compress_size + len(buf)
                self.fp.write(buf)
                zinfo.compress_size = compress_size
            else:
                zinfo.compress_size = file_size
            zinfo.CRC = CRC
            zinfo.file_size = file_size
            if not zip64 and self._allowZip64:
                if file_size > ZIP64_LIMIT:
                    raise RuntimeError('File size has increased during compressing')
                if compress_size > ZIP64_LIMIT:
                    raise RuntimeError('Compressed size larger than uncompressed size')
            # Seek backwards and write file header (which will now include
            # correct CRC and file sizes)
            position = self.fp.tell()       # Preserve current position in file
            self.fp.seek(zinfo.header_offset, 0)
            self.fp.write(zinfo.FileHeader(zip64))
            self.fp.seek(position, 0)
            self.filelist.append(zinfo)
            self.NameToInfo[zinfo.filename] = zinfo
    
        def writestr(self, zinfo_or_arcname, bytes, compress_type=None):
            """Write a file into the archive.  The contents is the string
            'bytes'.  'zinfo_or_arcname' is either a ZipInfo instance or
            the name of the file in the archive."""
            if not isinstance(zinfo_or_arcname, ZipInfo):
                zinfo = ZipInfo(filename=zinfo_or_arcname,
                                date_time=time.localtime(time.time())[:6])
    
                zinfo.compress_type = self.compression
                if zinfo.filename[-1] == '/':
                    zinfo.external_attr = 0o40775 << 16   # drwxrwxr-x
                    zinfo.external_attr |= 0x10           # MS-DOS directory flag
                else:
                    zinfo.external_attr = 0o600 << 16     # ?rw-------
            else:
                zinfo = zinfo_or_arcname
    
            if not self.fp:
                raise RuntimeError(
                      "Attempt to write to ZIP archive that was already closed")
    
            if compress_type is not None:
                zinfo.compress_type = compress_type
    
            zinfo.file_size = len(bytes)            # Uncompressed size
            zinfo.header_offset = self.fp.tell()    # Start of header bytes
            self._writecheck(zinfo)
            self._didModify = True
            zinfo.CRC = crc32(bytes) & 0xffffffff       # CRC-32 checksum
            if zinfo.compress_type == ZIP_DEFLATED:
                co = zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION,
                     zlib.DEFLATED, -15)
                bytes = co.compress(bytes) + co.flush()
                zinfo.compress_size = len(bytes)    # Compressed size
            else:
                zinfo.compress_size = zinfo.file_size
            zip64 = zinfo.file_size > ZIP64_LIMIT or 
                    zinfo.compress_size > ZIP64_LIMIT
            if zip64 and not self._allowZip64:
                raise LargeZipFile("Filesize would require ZIP64 extensions")
            self.fp.write(zinfo.FileHeader(zip64))
            self.fp.write(bytes)
            if zinfo.flag_bits & 0x08:
                # Write CRC and file sizes after the file data
                fmt = '<LQQ' if zip64 else '<LLL'
                self.fp.write(struct.pack(fmt, zinfo.CRC, zinfo.compress_size,
                      zinfo.file_size))
            self.fp.flush()
            self.filelist.append(zinfo)
            self.NameToInfo[zinfo.filename] = zinfo
    
        def __del__(self):
            """Call the "close()" method in case the user forgot."""
            self.close()
    
        def close(self):
            """Close the file, and for mode "w" and "a" write the ending
            records."""
            if self.fp is None:
                return
    
            try:
                if self.mode in ("w", "a") and self._didModify: # write ending records
                    pos1 = self.fp.tell()
                    for zinfo in self.filelist:         # write central directory
                        dt = zinfo.date_time
                        dosdate = (dt[0] - 1980) << 9 | dt[1] << 5 | dt[2]
                        dostime = dt[3] << 11 | dt[4] << 5 | (dt[5] // 2)
                        extra = []
                        if zinfo.file_size > ZIP64_LIMIT 
                                or zinfo.compress_size > ZIP64_LIMIT:
                            extra.append(zinfo.file_size)
                            extra.append(zinfo.compress_size)
                            file_size = 0xffffffff
                            compress_size = 0xffffffff
                        else:
                            file_size = zinfo.file_size
                            compress_size = zinfo.compress_size
    
                        if zinfo.header_offset > ZIP64_LIMIT:
                            extra.append(zinfo.header_offset)
                            header_offset = 0xffffffffL
                        else:
                            header_offset = zinfo.header_offset
    
                        extra_data = zinfo.extra
                        if extra:
                            # Append a ZIP64 field to the extra's
                            extra_data = struct.pack(
                                    '<HH' + 'Q'*len(extra),
                                    1, 8*len(extra), *extra) + extra_data
    
                            extract_version = max(45, zinfo.extract_version)
                            create_version = max(45, zinfo.create_version)
                        else:
                            extract_version = zinfo.extract_version
                            create_version = zinfo.create_version
    
                        try:
                            filename, flag_bits = zinfo._encodeFilenameFlags()
                            centdir = struct.pack(structCentralDir,
                            stringCentralDir, create_version,
                            zinfo.create_system, extract_version, zinfo.reserved,
                            flag_bits, zinfo.compress_type, dostime, dosdate,
                            zinfo.CRC, compress_size, file_size,
                            len(filename), len(extra_data), len(zinfo.comment),
                            0, zinfo.internal_attr, zinfo.external_attr,
                            header_offset)
                        except DeprecationWarning:
                            print >>sys.stderr, (structCentralDir,
                            stringCentralDir, create_version,
                            zinfo.create_system, extract_version, zinfo.reserved,
                            zinfo.flag_bits, zinfo.compress_type, dostime, dosdate,
                            zinfo.CRC, compress_size, file_size,
                            len(zinfo.filename), len(extra_data), len(zinfo.comment),
                            0, zinfo.internal_attr, zinfo.external_attr,
                            header_offset)
                            raise
                        self.fp.write(centdir)
                        self.fp.write(filename)
                        self.fp.write(extra_data)
                        self.fp.write(zinfo.comment)
    
                    pos2 = self.fp.tell()
                    # Write end-of-zip-archive record
                    centDirCount = len(self.filelist)
                    centDirSize = pos2 - pos1
                    centDirOffset = pos1
                    requires_zip64 = None
                    if centDirCount > ZIP_FILECOUNT_LIMIT:
                        requires_zip64 = "Files count"
                    elif centDirOffset > ZIP64_LIMIT:
                        requires_zip64 = "Central directory offset"
                    elif centDirSize > ZIP64_LIMIT:
                        requires_zip64 = "Central directory size"
                    if requires_zip64:
                        # Need to write the ZIP64 end-of-archive records
                        if not self._allowZip64:
                            raise LargeZipFile(requires_zip64 +
                                               " would require ZIP64 extensions")
                        zip64endrec = struct.pack(
                                structEndArchive64, stringEndArchive64,
                                44, 45, 45, 0, 0, centDirCount, centDirCount,
                                centDirSize, centDirOffset)
                        self.fp.write(zip64endrec)
    
                        zip64locrec = struct.pack(
                                structEndArchive64Locator,
                                stringEndArchive64Locator, 0, pos2, 1)
                        self.fp.write(zip64locrec)
                        centDirCount = min(centDirCount, 0xFFFF)
                        centDirSize = min(centDirSize, 0xFFFFFFFF)
                        centDirOffset = min(centDirOffset, 0xFFFFFFFF)
    
                    endrec = struct.pack(structEndArchive, stringEndArchive,
                                        0, 0, centDirCount, centDirCount,
                                        centDirSize, centDirOffset, len(self._comment))
                    self.fp.write(endrec)
                    self.fp.write(self._comment)
                    self.fp.flush()
            finally:
                fp = self.fp
                self.fp = None
                if not self._filePassed:
                    fp.close()
    
    ZipFile
    
    ZipFile 源码
    ZipFile 源码
    class TarFile(object):
        """The TarFile Class provides an interface to tar archives.
        """
    
        debug = 0                   # May be set from 0 (no msgs) to 3 (all msgs)
    
        dereference = False         # If true, add content of linked file to the
                                    # tar file, else the link.
    
        ignore_zeros = False        # If true, skips empty or invalid blocks and
                                    # continues processing.
    
        errorlevel = 1              # If 0, fatal errors only appear in debug
                                    # messages (if debug >= 0). If > 0, errors
                                    # are passed to the caller as exceptions.
    
        format = DEFAULT_FORMAT     # The format to use when creating an archive.
    
        encoding = ENCODING         # Encoding for 8-bit character strings.
    
        errors = None               # Error handler for unicode conversion.
    
        tarinfo = TarInfo           # The default TarInfo class to use.
    
        fileobject = ExFileObject   # The default ExFileObject class to use.
    
        def __init__(self, name=None, mode="r", fileobj=None, format=None,
                tarinfo=None, dereference=None, ignore_zeros=None, encoding=None,
                errors=None, pax_headers=None, debug=None, errorlevel=None):
            """Open an (uncompressed) tar archive `name'. `mode' is either 'r' to
               read from an existing archive, 'a' to append data to an existing
               file or 'w' to create a new file overwriting an existing one. `mode'
               defaults to 'r'.
               If `fileobj' is given, it is used for reading or writing data. If it
               can be determined, `mode' is overridden by `fileobj's mode.
               `fileobj' is not closed, when TarFile is closed.
            """
            modes = {"r": "rb", "a": "r+b", "w": "wb"}
            if mode not in modes:
                raise ValueError("mode must be 'r', 'a' or 'w'")
            self.mode = mode
            self._mode = modes[mode]
    
            if not fileobj:
                if self.mode == "a" and not os.path.exists(name):
                    # Create nonexistent files in append mode.
                    self.mode = "w"
                    self._mode = "wb"
                fileobj = bltn_open(name, self._mode)
                self._extfileobj = False
            else:
                if name is None and hasattr(fileobj, "name"):
                    name = fileobj.name
                if hasattr(fileobj, "mode"):
                    self._mode = fileobj.mode
                self._extfileobj = True
            self.name = os.path.abspath(name) if name else None
            self.fileobj = fileobj
    
            # Init attributes.
            if format is not None:
                self.format = format
            if tarinfo is not None:
                self.tarinfo = tarinfo
            if dereference is not None:
                self.dereference = dereference
            if ignore_zeros is not None:
                self.ignore_zeros = ignore_zeros
            if encoding is not None:
                self.encoding = encoding
    
            if errors is not None:
                self.errors = errors
            elif mode == "r":
                self.errors = "utf-8"
            else:
                self.errors = "strict"
    
            if pax_headers is not None and self.format == PAX_FORMAT:
                self.pax_headers = pax_headers
            else:
                self.pax_headers = {}
    
            if debug is not None:
                self.debug = debug
            if errorlevel is not None:
                self.errorlevel = errorlevel
    
            # Init datastructures.
            self.closed = False
            self.members = []       # list of members as TarInfo objects
            self._loaded = False    # flag if all members have been read
            self.offset = self.fileobj.tell()
                                    # current position in the archive file
            self.inodes = {}        # dictionary caching the inodes of
                                    # archive members already added
    
            try:
                if self.mode == "r":
                    self.firstmember = None
                    self.firstmember = self.next()
    
                if self.mode == "a":
                    # Move to the end of the archive,
                    # before the first empty block.
                    while True:
                        self.fileobj.seek(self.offset)
                        try:
                            tarinfo = self.tarinfo.fromtarfile(self)
                            self.members.append(tarinfo)
                        except EOFHeaderError:
                            self.fileobj.seek(self.offset)
                            break
                        except HeaderError, e:
                            raise ReadError(str(e))
    
                if self.mode in "aw":
                    self._loaded = True
    
                    if self.pax_headers:
                        buf = self.tarinfo.create_pax_global_header(self.pax_headers.copy())
                        self.fileobj.write(buf)
                        self.offset += len(buf)
            except:
                if not self._extfileobj:
                    self.fileobj.close()
                self.closed = True
                raise
    
        def _getposix(self):
            return self.format == USTAR_FORMAT
        def _setposix(self, value):
            import warnings
            warnings.warn("use the format attribute instead", DeprecationWarning,
                          2)
            if value:
                self.format = USTAR_FORMAT
            else:
                self.format = GNU_FORMAT
        posix = property(_getposix, _setposix)
    
        #--------------------------------------------------------------------------
        # Below are the classmethods which act as alternate constructors to the
        # TarFile class. The open() method is the only one that is needed for
        # public use; it is the "super"-constructor and is able to select an
        # adequate "sub"-constructor for a particular compression using the mapping
        # from OPEN_METH.
        #
        # This concept allows one to subclass TarFile without losing the comfort of
        # the super-constructor. A sub-constructor is registered and made available
        # by adding it to the mapping in OPEN_METH.
    
        @classmethod
        def open(cls, name=None, mode="r", fileobj=None, bufsize=RECORDSIZE, **kwargs):
            """Open a tar archive for reading, writing or appending. Return
               an appropriate TarFile class.
    
               mode:
               'r' or 'r:*' open for reading with transparent compression
               'r:'         open for reading exclusively uncompressed
               'r:gz'       open for reading with gzip compression
               'r:bz2'      open for reading with bzip2 compression
               'a' or 'a:'  open for appending, creating the file if necessary
               'w' or 'w:'  open for writing without compression
               'w:gz'       open for writing with gzip compression
               'w:bz2'      open for writing with bzip2 compression
    
               'r|*'        open a stream of tar blocks with transparent compression
               'r|'         open an uncompressed stream of tar blocks for reading
               'r|gz'       open a gzip compressed stream of tar blocks
               'r|bz2'      open a bzip2 compressed stream of tar blocks
               'w|'         open an uncompressed stream for writing
               'w|gz'       open a gzip compressed stream for writing
               'w|bz2'      open a bzip2 compressed stream for writing
            """
    
            if not name and not fileobj:
                raise ValueError("nothing to open")
    
            if mode in ("r", "r:*"):
                # Find out which *open() is appropriate for opening the file.
                for comptype in cls.OPEN_METH:
                    func = getattr(cls, cls.OPEN_METH[comptype])
                    if fileobj is not None:
                        saved_pos = fileobj.tell()
                    try:
                        return func(name, "r", fileobj, **kwargs)
                    except (ReadError, CompressionError), e:
                        if fileobj is not None:
                            fileobj.seek(saved_pos)
                        continue
                raise ReadError("file could not be opened successfully")
    
            elif ":" in mode:
                filemode, comptype = mode.split(":", 1)
                filemode = filemode or "r"
                comptype = comptype or "tar"
    
                # Select the *open() function according to
                # given compression.
                if comptype in cls.OPEN_METH:
                    func = getattr(cls, cls.OPEN_METH[comptype])
                else:
                    raise CompressionError("unknown compression type %r" % comptype)
                return func(name, filemode, fileobj, **kwargs)
    
            elif "|" in mode:
                filemode, comptype = mode.split("|", 1)
                filemode = filemode or "r"
                comptype = comptype or "tar"
    
                if filemode not in ("r", "w"):
                    raise ValueError("mode must be 'r' or 'w'")
    
                stream = _Stream(name, filemode, comptype, fileobj, bufsize)
                try:
                    t = cls(name, filemode, stream, **kwargs)
                except:
                    stream.close()
                    raise
                t._extfileobj = False
                return t
    
            elif mode in ("a", "w"):
                return cls.taropen(name, mode, fileobj, **kwargs)
    
            raise ValueError("undiscernible mode")
    
        @classmethod
        def taropen(cls, name, mode="r", fileobj=None, **kwargs):
            """Open uncompressed tar archive name for reading or writing.
            """
            if mode not in ("r", "a", "w"):
                raise ValueError("mode must be 'r', 'a' or 'w'")
            return cls(name, mode, fileobj, **kwargs)
    
        @classmethod
        def gzopen(cls, name, mode="r", fileobj=None, compresslevel=9, **kwargs):
            """Open gzip compressed tar archive name for reading or writing.
               Appending is not allowed.
            """
            if mode not in ("r", "w"):
                raise ValueError("mode must be 'r' or 'w'")
    
            try:
                import gzip
                gzip.GzipFile
            except (ImportError, AttributeError):
                raise CompressionError("gzip module is not available")
    
            try:
                fileobj = gzip.GzipFile(name, mode, compresslevel, fileobj)
            except OSError:
                if fileobj is not None and mode == 'r':
                    raise ReadError("not a gzip file")
                raise
    
            try:
                t = cls.taropen(name, mode, fileobj, **kwargs)
            except IOError:
                fileobj.close()
                if mode == 'r':
                    raise ReadError("not a gzip file")
                raise
            except:
                fileobj.close()
                raise
            t._extfileobj = False
            return t
    
        @classmethod
        def bz2open(cls, name, mode="r", fileobj=None, compresslevel=9, **kwargs):
            """Open bzip2 compressed tar archive name for reading or writing.
               Appending is not allowed.
            """
            if mode not in ("r", "w"):
                raise ValueError("mode must be 'r' or 'w'.")
    
            try:
                import bz2
            except ImportError:
                raise CompressionError("bz2 module is not available")
    
            if fileobj is not None:
                fileobj = _BZ2Proxy(fileobj, mode)
            else:
                fileobj = bz2.BZ2File(name, mode, compresslevel=compresslevel)
    
            try:
                t = cls.taropen(name, mode, fileobj, **kwargs)
            except (IOError, EOFError):
                fileobj.close()
                if mode == 'r':
                    raise ReadError("not a bzip2 file")
                raise
            except:
                fileobj.close()
                raise
            t._extfileobj = False
            return t
    
        # All *open() methods are registered here.
        OPEN_METH = {
            "tar": "taropen",   # uncompressed tar
            "gz":  "gzopen",    # gzip compressed tar
            "bz2": "bz2open"    # bzip2 compressed tar
        }
    
        #--------------------------------------------------------------------------
        # The public methods which TarFile provides:
    
        def close(self):
            """Close the TarFile. In write-mode, two finishing zero blocks are
               appended to the archive.
            """
            if self.closed:
                return
    
            if self.mode in "aw":
                self.fileobj.write(NUL * (BLOCKSIZE * 2))
                self.offset += (BLOCKSIZE * 2)
                # fill up the end with zero-blocks
                # (like option -b20 for tar does)
                blocks, remainder = divmod(self.offset, RECORDSIZE)
                if remainder > 0:
                    self.fileobj.write(NUL * (RECORDSIZE - remainder))
    
            if not self._extfileobj:
                self.fileobj.close()
            self.closed = True
    
        def getmember(self, name):
            """Return a TarInfo object for member `name'. If `name' can not be
               found in the archive, KeyError is raised. If a member occurs more
               than once in the archive, its last occurrence is assumed to be the
               most up-to-date version.
            """
            tarinfo = self._getmember(name)
            if tarinfo is None:
                raise KeyError("filename %r not found" % name)
            return tarinfo
    
        def getmembers(self):
            """Return the members of the archive as a list of TarInfo objects. The
               list has the same order as the members in the archive.
            """
            self._check()
            if not self._loaded:    # if we want to obtain a list of
                self._load()        # all members, we first have to
                                    # scan the whole archive.
            return self.members
    
        def getnames(self):
            """Return the members of the archive as a list of their names. It has
               the same order as the list returned by getmembers().
            """
            return [tarinfo.name for tarinfo in self.getmembers()]
    
        def gettarinfo(self, name=None, arcname=None, fileobj=None):
            """Create a TarInfo object for either the file `name' or the file
               object `fileobj' (using os.fstat on its file descriptor). You can
               modify some of the TarInfo's attributes before you add it using
               addfile(). If given, `arcname' specifies an alternative name for the
               file in the archive.
            """
            self._check("aw")
    
            # When fileobj is given, replace name by
            # fileobj's real name.
            if fileobj is not None:
                name = fileobj.name
    
            # Building the name of the member in the archive.
            # Backward slashes are converted to forward slashes,
            # Absolute paths are turned to relative paths.
            if arcname is None:
                arcname = name
            drv, arcname = os.path.splitdrive(arcname)
            arcname = arcname.replace(os.sep, "/")
            arcname = arcname.lstrip("/")
    
            # Now, fill the TarInfo object with
            # information specific for the file.
            tarinfo = self.tarinfo()
            tarinfo.tarfile = self
    
            # Use os.stat or os.lstat, depending on platform
            # and if symlinks shall be resolved.
            if fileobj is None:
                if hasattr(os, "lstat") and not self.dereference:
                    statres = os.lstat(name)
                else:
                    statres = os.stat(name)
            else:
                statres = os.fstat(fileobj.fileno())
            linkname = ""
    
            stmd = statres.st_mode
            if stat.S_ISREG(stmd):
                inode = (statres.st_ino, statres.st_dev)
                if not self.dereference and statres.st_nlink > 1 and 
                        inode in self.inodes and arcname != self.inodes[inode]:
                    # Is it a hardlink to an already
                    # archived file?
                    type = LNKTYPE
                    linkname = self.inodes[inode]
                else:
                    # The inode is added only if its valid.
                    # For win32 it is always 0.
                    type = REGTYPE
                    if inode[0]:
                        self.inodes[inode] = arcname
            elif stat.S_ISDIR(stmd):
                type = DIRTYPE
            elif stat.S_ISFIFO(stmd):
                type = FIFOTYPE
            elif stat.S_ISLNK(stmd):
                type = SYMTYPE
                linkname = os.readlink(name)
            elif stat.S_ISCHR(stmd):
                type = CHRTYPE
            elif stat.S_ISBLK(stmd):
                type = BLKTYPE
            else:
                return None
    
            # Fill the TarInfo object with all
            # information we can get.
            tarinfo.name = arcname
            tarinfo.mode = stmd
            tarinfo.uid = statres.st_uid
            tarinfo.gid = statres.st_gid
            if type == REGTYPE:
                tarinfo.size = statres.st_size
            else:
                tarinfo.size = 0L
            tarinfo.mtime = statres.st_mtime
            tarinfo.type = type
            tarinfo.linkname = linkname
            if pwd:
                try:
                    tarinfo.uname = pwd.getpwuid(tarinfo.uid)[0]
                except KeyError:
                    pass
            if grp:
                try:
                    tarinfo.gname = grp.getgrgid(tarinfo.gid)[0]
                except KeyError:
                    pass
    
            if type in (CHRTYPE, BLKTYPE):
                if hasattr(os, "major") and hasattr(os, "minor"):
                    tarinfo.devmajor = os.major(statres.st_rdev)
                    tarinfo.devminor = os.minor(statres.st_rdev)
            return tarinfo
    
        def list(self, verbose=True):
            """Print a table of contents to sys.stdout. If `verbose' is False, only
               the names of the members are printed. If it is True, an `ls -l'-like
               output is produced.
            """
            self._check()
    
            for tarinfo in self:
                if verbose:
                    print filemode(tarinfo.mode),
                    print "%s/%s" % (tarinfo.uname or tarinfo.uid,
                                     tarinfo.gname or tarinfo.gid),
                    if tarinfo.ischr() or tarinfo.isblk():
                        print "%10s" % ("%d,%d" 
                                        % (tarinfo.devmajor, tarinfo.devminor)),
                    else:
                        print "%10d" % tarinfo.size,
                    print "%d-%02d-%02d %02d:%02d:%02d" 
                          % time.localtime(tarinfo.mtime)[:6],
    
                print tarinfo.name + ("/" if tarinfo.isdir() else ""),
    
                if verbose:
                    if tarinfo.issym():
                        print "->", tarinfo.linkname,
                    if tarinfo.islnk():
                        print "link to", tarinfo.linkname,
                print
    
        def add(self, name, arcname=None, recursive=True, exclude=None, filter=None):
            """Add the file `name' to the archive. `name' may be any type of file
               (directory, fifo, symbolic link, etc.). If given, `arcname'
               specifies an alternative name for the file in the archive.
               Directories are added recursively by default. This can be avoided by
               setting `recursive' to False. `exclude' is a function that should
               return True for each filename to be excluded. `filter' is a function
               that expects a TarInfo object argument and returns the changed
               TarInfo object, if it returns None the TarInfo object will be
               excluded from the archive.
            """
            self._check("aw")
    
            if arcname is None:
                arcname = name
    
            # Exclude pathnames.
            if exclude is not None:
                import warnings
                warnings.warn("use the filter argument instead",
                        DeprecationWarning, 2)
                if exclude(name):
                    self._dbg(2, "tarfile: Excluded %r" % name)
                    return
    
            # Skip if somebody tries to archive the archive...
            if self.name is not None and os.path.abspath(name) == self.name:
                self._dbg(2, "tarfile: Skipped %r" % name)
                return
    
            self._dbg(1, name)
    
            # Create a TarInfo object from the file.
            tarinfo = self.gettarinfo(name, arcname)
    
            if tarinfo is None:
                self._dbg(1, "tarfile: Unsupported type %r" % name)
                return
    
            # Change or exclude the TarInfo object.
            if filter is not None:
                tarinfo = filter(tarinfo)
                if tarinfo is None:
                    self._dbg(2, "tarfile: Excluded %r" % name)
                    return
    
            # Append the tar header and data to the archive.
            if tarinfo.isreg():
                with bltn_open(name, "rb") as f:
                    self.addfile(tarinfo, f)
    
            elif tarinfo.isdir():
                self.addfile(tarinfo)
                if recursive:
                    for f in os.listdir(name):
                        self.add(os.path.join(name, f), os.path.join(arcname, f),
                                recursive, exclude, filter)
    
            else:
                self.addfile(tarinfo)
    
        def addfile(self, tarinfo, fileobj=None):
            """Add the TarInfo object `tarinfo' to the archive. If `fileobj' is
               given, tarinfo.size bytes are read from it and added to the archive.
               You can create TarInfo objects using gettarinfo().
               On Windows platforms, `fileobj' should always be opened with mode
               'rb' to avoid irritation about the file size.
            """
            self._check("aw")
    
            tarinfo = copy.copy(tarinfo)
    
            buf = tarinfo.tobuf(self.format, self.encoding, self.errors)
            self.fileobj.write(buf)
            self.offset += len(buf)
    
            # If there's data to follow, append it.
            if fileobj is not None:
                copyfileobj(fileobj, self.fileobj, tarinfo.size)
                blocks, remainder = divmod(tarinfo.size, BLOCKSIZE)
                if remainder > 0:
                    self.fileobj.write(NUL * (BLOCKSIZE - remainder))
                    blocks += 1
                self.offset += blocks * BLOCKSIZE
    
            self.members.append(tarinfo)
    
        def extractall(self, path=".", members=None):
            """Extract all members from the archive to the current working
               directory and set owner, modification time and permissions on
               directories afterwards. `path' specifies a different directory
               to extract to. `members' is optional and must be a subset of the
               list returned by getmembers().
            """
            directories = []
    
            if members is None:
                members = self
    
            for tarinfo in members:
                if tarinfo.isdir():
                    # Extract directories with a safe mode.
                    directories.append(tarinfo)
                    tarinfo = copy.copy(tarinfo)
                    tarinfo.mode = 0700
                self.extract(tarinfo, path)
    
            # Reverse sort directories.
            directories.sort(key=operator.attrgetter('name'))
            directories.reverse()
    
            # Set correct owner, mtime and filemode on directories.
            for tarinfo in directories:
                dirpath = os.path.join(path, tarinfo.name)
                try:
                    self.chown(tarinfo, dirpath)
                    self.utime(tarinfo, dirpath)
                    self.chmod(tarinfo, dirpath)
                except ExtractError, e:
                    if self.errorlevel > 1:
                        raise
                    else:
                        self._dbg(1, "tarfile: %s" % e)
    
        def extract(self, member, path=""):
            """Extract a member from the archive to the current working directory,
               using its full name. Its file information is extracted as accurately
               as possible. `member' may be a filename or a TarInfo object. You can
               specify a different directory using `path'.
            """
            self._check("r")
    
            if isinstance(member, basestring):
                tarinfo = self.getmember(member)
            else:
                tarinfo = member
    
            # Prepare the link target for makelink().
            if tarinfo.islnk():
                tarinfo._link_target = os.path.join(path, tarinfo.linkname)
    
            try:
                self._extract_member(tarinfo, os.path.join(path, tarinfo.name))
            except EnvironmentError, e:
                if self.errorlevel > 0:
                    raise
                else:
                    if e.filename is None:
                        self._dbg(1, "tarfile: %s" % e.strerror)
                    else:
                        self._dbg(1, "tarfile: %s %r" % (e.strerror, e.filename))
            except ExtractError, e:
                if self.errorlevel > 1:
                    raise
                else:
                    self._dbg(1, "tarfile: %s" % e)
    
        def extractfile(self, member):
            """Extract a member from the archive as a file object. `member' may be
               a filename or a TarInfo object. If `member' is a regular file, a
               file-like object is returned. If `member' is a link, a file-like
               object is constructed from the link's target. If `member' is none of
               the above, None is returned.
               The file-like object is read-only and provides the following
               methods: read(), readline(), readlines(), seek() and tell()
            """
            self._check("r")
    
            if isinstance(member, basestring):
                tarinfo = self.getmember(member)
            else:
                tarinfo = member
    
            if tarinfo.isreg():
                return self.fileobject(self, tarinfo)
    
            elif tarinfo.type not in SUPPORTED_TYPES:
                # If a member's type is unknown, it is treated as a
                # regular file.
                return self.fileobject(self, tarinfo)
    
            elif tarinfo.islnk() or tarinfo.issym():
                if isinstance(self.fileobj, _Stream):
                    # A small but ugly workaround for the case that someone tries
                    # to extract a (sym)link as a file-object from a non-seekable
                    # stream of tar blocks.
                    raise StreamError("cannot extract (sym)link as file object")
                else:
                    # A (sym)link's file object is its target's file object.
                    return self.extractfile(self._find_link_target(tarinfo))
            else:
                # If there's no data associated with the member (directory, chrdev,
                # blkdev, etc.), return None instead of a file object.
                return None
    
        def _extract_member(self, tarinfo, targetpath):
            """Extract the TarInfo object tarinfo to a physical
               file called targetpath.
            """
            # Fetch the TarInfo object for the given name
            # and build the destination pathname, replacing
            # forward slashes to platform specific separators.
            targetpath = targetpath.rstrip("/")
            targetpath = targetpath.replace("/", os.sep)
    
            # Create all upper directories.
            upperdirs = os.path.dirname(targetpath)
            if upperdirs and not os.path.exists(upperdirs):
                # Create directories that are not part of the archive with
                # default permissions.
                os.makedirs(upperdirs)
    
            if tarinfo.islnk() or tarinfo.issym():
                self._dbg(1, "%s -> %s" % (tarinfo.name, tarinfo.linkname))
            else:
                self._dbg(1, tarinfo.name)
    
            if tarinfo.isreg():
                self.makefile(tarinfo, targetpath)
            elif tarinfo.isdir():
                self.makedir(tarinfo, targetpath)
            elif tarinfo.isfifo():
                self.makefifo(tarinfo, targetpath)
            elif tarinfo.ischr() or tarinfo.isblk():
                self.makedev(tarinfo, targetpath)
            elif tarinfo.islnk() or tarinfo.issym():
                self.makelink(tarinfo, targetpath)
            elif tarinfo.type not in SUPPORTED_TYPES:
                self.makeunknown(tarinfo, targetpath)
            else:
                self.makefile(tarinfo, targetpath)
    
            self.chown(tarinfo, targetpath)
            if not tarinfo.issym():
                self.chmod(tarinfo, targetpath)
                self.utime(tarinfo, targetpath)
    
        #--------------------------------------------------------------------------
        # Below are the different file methods. They are called via
        # _extract_member() when extract() is called. They can be replaced in a
        # subclass to implement other functionality.
    
        def makedir(self, tarinfo, targetpath):
            """Make a directory called targetpath.
            """
            try:
                # Use a safe mode for the directory, the real mode is set
                # later in _extract_member().
                os.mkdir(targetpath, 0700)
            except EnvironmentError, e:
                if e.errno != errno.EEXIST:
                    raise
    
        def makefile(self, tarinfo, targetpath):
            """Make a file called targetpath.
            """
            source = self.extractfile(tarinfo)
            try:
                with bltn_open(targetpath, "wb") as target:
                    copyfileobj(source, target)
            finally:
                source.close()
    
        def makeunknown(self, tarinfo, targetpath):
            """Make a file from a TarInfo object with an unknown type
               at targetpath.
            """
            self.makefile(tarinfo, targetpath)
            self._dbg(1, "tarfile: Unknown file type %r, " 
                         "extracted as regular file." % tarinfo.type)
    
        def makefifo(self, tarinfo, targetpath):
            """Make a fifo called targetpath.
            """
            if hasattr(os, "mkfifo"):
                os.mkfifo(targetpath)
            else:
                raise ExtractError("fifo not supported by system")
    
        def makedev(self, tarinfo, targetpath):
            """Make a character or block device called targetpath.
            """
            if not hasattr(os, "mknod") or not hasattr(os, "makedev"):
                raise ExtractError("special devices not supported by system")
    
            mode = tarinfo.mode
            if tarinfo.isblk():
                mode |= stat.S_IFBLK
            else:
                mode |= stat.S_IFCHR
    
            os.mknod(targetpath, mode,
                     os.makedev(tarinfo.devmajor, tarinfo.devminor))
    
        def makelink(self, tarinfo, targetpath):
            """Make a (symbolic) link called targetpath. If it cannot be created
              (platform limitation), we try to make a copy of the referenced file
              instead of a link.
            """
            if hasattr(os, "symlink") and hasattr(os, "link"):
                # For systems that support symbolic and hard links.
                if tarinfo.issym():
                    if os.path.lexists(targetpath):
                        os.unlink(targetpath)
                    os.symlink(tarinfo.linkname, targetpath)
                else:
                    # See extract().
                    if os.path.exists(tarinfo._link_target):
                        if os.path.lexists(targetpath):
                            os.unlink(targetpath)
                        os.link(tarinfo._link_target, targetpath)
                    else:
                        self._extract_member(self._find_link_target(tarinfo), targetpath)
            else:
                try:
                    self._extract_member(self._find_link_target(tarinfo), targetpath)
                except KeyError:
                    raise ExtractError("unable to resolve link inside archive")
    
        def chown(self, tarinfo, targetpath):
            """Set owner of targetpath according to tarinfo.
            """
            if pwd and hasattr(os, "geteuid") and os.geteuid() == 0:
                # We have to be root to do so.
                try:
                    g = grp.getgrnam(tarinfo.gname)[2]
                except KeyError:
                    g = tarinfo.gid
                try:
                    u = pwd.getpwnam(tarinfo.uname)[2]
                except KeyError:
                    u = tarinfo.uid
                try:
                    if tarinfo.issym() and hasattr(os, "lchown"):
                        os.lchown(targetpath, u, g)
                    else:
                        if sys.platform != "os2emx":
                            os.chown(targetpath, u, g)
                except EnvironmentError, e:
                    raise ExtractError("could not change owner")
    
        def chmod(self, tarinfo, targetpath):
            """Set file permissions of targetpath according to tarinfo.
            """
            if hasattr(os, 'chmod'):
                try:
                    os.chmod(targetpath, tarinfo.mode)
                except EnvironmentError, e:
                    raise ExtractError("could not change mode")
    
        def utime(self, tarinfo, targetpath):
            """Set modification time of targetpath according to tarinfo.
            """
            if not hasattr(os, 'utime'):
                return
            try:
                os.utime(targetpath, (tarinfo.mtime, tarinfo.mtime))
            except EnvironmentError, e:
                raise ExtractError("could not change modification time")
    
        #--------------------------------------------------------------------------
        def next(self):
            """Return the next member of the archive as a TarInfo object, when
               TarFile is opened for reading. Return None if there is no more
               available.
            """
            self._check("ra")
            if self.firstmember is not None:
                m = self.firstmember
                self.firstmember = None
                return m
    
            # Read the next block.
            self.fileobj.seek(self.offset)
            tarinfo = None
            while True:
                try:
                    tarinfo = self.tarinfo.fromtarfile(self)
                except EOFHeaderError, e:
                    if self.ignore_zeros:
                        self._dbg(2, "0x%X: %s" % (self.offset, e))
                        self.offset += BLOCKSIZE
                        continue
                except InvalidHeaderError, e:
                    if self.ignore_zeros:
                        self._dbg(2, "0x%X: %s" % (self.offset, e))
                        self.offset += BLOCKSIZE
                        continue
                    elif self.offset == 0:
                        raise ReadError(str(e))
                except EmptyHeaderError:
                    if self.offset == 0:
                        raise ReadError("empty file")
                except TruncatedHeaderError, e:
                    if self.offset == 0:
                        raise ReadError(str(e))
                except SubsequentHeaderError, e:
                    raise ReadError(str(e))
                break
    
            if tarinfo is not None:
                self.members.append(tarinfo)
            else:
                self._loaded = True
    
            return tarinfo
    
        #--------------------------------------------------------------------------
        # Little helper methods:
    
        def _getmember(self, name, tarinfo=None, normalize=False):
            """Find an archive member by name from bottom to top.
               If tarinfo is given, it is used as the starting point.
            """
            # Ensure that all members have been loaded.
            members = self.getmembers()
    
            # Limit the member search list up to tarinfo.
            if tarinfo is not None:
                members = members[:members.index(tarinfo)]
    
            if normalize:
                name = os.path.normpath(name)
    
            for member in reversed(members):
                if normalize:
                    member_name = os.path.normpath(member.name)
                else:
                    member_name = member.name
    
                if name == member_name:
                    return member
    
        def _load(self):
            """Read through the entire archive file and look for readable
               members.
            """
            while True:
                tarinfo = self.next()
                if tarinfo is None:
                    break
            self._loaded = True
    
        def _check(self, mode=None):
            """Check if TarFile is still open, and if the operation's mode
               corresponds to TarFile's mode.
            """
            if self.closed:
                raise IOError("%s is closed" % self.__class__.__name__)
            if mode is not None and self.mode not in mode:
                raise IOError("bad operation for mode %r" % self.mode)
    
        def _find_link_target(self, tarinfo):
            """Find the target member of a symlink or hardlink member in the
               archive.
            """
            if tarinfo.issym():
                # Always search the entire archive.
                linkname = "/".join(filter(None, (os.path.dirname(tarinfo.name), tarinfo.linkname)))
                limit = None
            else:
                # Search the archive before the link, because a hard link is
                # just a reference to an already archived file.
                linkname = tarinfo.linkname
                limit = tarinfo
    
            member = self._getmember(linkname, tarinfo=limit, normalize=True)
            if member is None:
                raise KeyError("linkname %r not found" % linkname)
            return member
    
        def __iter__(self):
            """Provide an iterator object.
            """
            if self._loaded:
                return iter(self.members)
            else:
                return TarIter(self)
    
        def _dbg(self, level, msg):
            """Write debugging output to sys.stderr.
            """
            if level <= self.debug:
                print >> sys.stderr, msg
    
        def __enter__(self):
            self._check()
            return self
    
        def __exit__(self, type, value, traceback):
            if type is None:
                self.close()
            else:
                # An exception occurred. We must not call close() because
                # it would try to write end-of-archive blocks and padding.
                if not self._extfileobj:
                    self.fileobj.close()
                self.closed = True
    # class TarFile
    
    TarFile
    
    TarFile 源码
    TarFile 源码

        6、json 和 pickle模块

    文件只能存二进制或字符串,不能存其他类型,所以用到了用于序列化的两个模块:

    json,用于字符串和python数据类型间进行转换,将数据通过特殊的形式转换为所有语言都认识的字符串(字典,变量,列表)。

    pickle,用于python特有的类型和python的数据类型间进行转换,将数据通过特殊的形式转换为只有python认识的字符串(函数,类)。

        ① json模块:

     1 #json 序列化和反序列化
     2 import json
     3  
     4 info ={               #字典
     5     "name":"lzl",
     6     "age":"18"
     7 }
     8  
     9 with open("test","w") as f:
    10     f.write(json.dumps(info))   #用json把info写入到文件test中
    11  
    12 with open("test","r") as f:
    13     info = json.loads(f.read())
    14     print(info["name"])
    15  
    16 #lzl

        ② pickle模块:

     1 #pickle 序列化和反序列化
     2 import pickle        #pickle支持python特有的所有类型
     3  
     4 def func():                 #函数
     5     info ={
     6         "name":"lzl",
     7         "age":"18"
     8     }
     9     print(info,type(info))
    10  
    11 func()
    12 #{'age': '18', 'name': 'lzl'} <class 'dict'>
    13  
    14 with open("test","wb") as f:
    15     f.write(pickle.dumps(func))   #用pickle把func写入到文件test中 如果用json此时会报错
    16  
    17 with open("test","rb") as f:
    18     func_new = pickle.loads(f.read())
    19     func_new()
    20 #{'age': '18', 'name': 'lzl'} <class 'dict'>
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  • 原文地址:https://www.cnblogs.com/visonwong/p/9012139.html
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