python第四周(模块化编程)

1:模块定义

模块:用来从逻辑上组织Python代码(变量,函数、类,逻辑:实现一个功能),本质就是.py结尾的Python文件(文件名:test.py,对应的模块名,test)。

包:本质就是一个文件夹或者是目录(必须带有一个_init_.py文件),包是用来从逻辑上组织模块的。

2.导入方法:

1):import module_test, module_test1 (调用方法的时候,需要module_test.   )

2):form moudule_test import * (* 表示所有的方法)(不建议使用,这个就相当于导入了程序。)  容易造成覆盖,出现问题。

3):form module_test import module_ajun  as module_ajun_test(作为一个别名来使用)

3:import本质 (路径 搜索和搜索路径)

1)      import module_test  相当于把module_test 的所有代码解释一遍,全部传递给module_test. 调用module_test的变量和方法。

2)      form moudule_test import name 相当于值调用了name变量,在当前模块,就不需要加前缀了。

总结:导入模块的本质就是把Python文件解释一遍。(import test  test=’test.py  all code’)

导入包的本质就是执行包下面的_init_.py文件

Import module_name--》mudule_name.py--》module_name.py的路径--》sys.path

os.path.abspath(_file_)=获取 当前目录

os.path.dirname(os.path.abspath(_file_))=获取当前目录的父目录

os.path.dirname(os.path.dirname (os.path.abspath(_file_)))=获取当前目录的父目录 的父目录

form .(点表示当前目录,就是_init_的目录)  import 包名

4.导入优化

怎么优化?每次都去找,很浪费时间?

使用from module_test  import test 这个方法,节约时间。

5.模块的分类

A:标准库

B:开源模块

C:自定义模块

A标准库

5.1time与datetime 两个库。

1)表示时间,格式化的时间格式:2017-07-28

2)时间戳:从1970.1.1日到现在总共经过了多少秒?

为什么从1970年1月1日开始呢?

3)元祖,共有九个元素表示。

UTC(Coordinated Universal Time,世界协调时)亦即格林威治天文时间,世界标准时间。在中国为UTC+8。DST(Daylight Saving Time)即夏令时。

时间戳(timestamp)的方式:通常来说,时间戳表示的是从1970年1月1日00:00:00开始按秒计算的偏移量。我们运行“type(time.time())”,返回的是float类型。返回时间戳方式的函数主要有time(),clock()等。

元组(struct_time)方式:struct_time元组共有9个元素,返回struct_time的函数主要有gmtime(),localtime(),strptime()。下面列出这种方式元组中的几个元素: 

 1 #Author:ajun
 2 import time
 3
 4 #print(time.process_time())#测量处理器运算时间,不包括sleep时间,不稳定
 5 #print(time.altzone)  #返回与utc时间的时间差,以秒计算\
 6 #print(time.asctime()) #返回时间格式Wed Jun 28 21:38:29 2017 格式,
 7 #print(time.localtime()) #返回本地时间 的struct time对象格式
 8 #print(time.gmtime(time.time()-800000)) #返回utc时间的struc时间对象格式
 9 #print(time.asctime(time.localtime())) #返回时间格式"Fri Aug 19 11:14:16 2016",
10 #print(time.ctime()) #返回Wed Jun 28 21:38:29 2017 格式, 同上
11 # 日期字符串 转成  时间戳
12 string_2_struct = time.strptime("2017/06/28","%Y/%m/%d") #将 日期字符串 转成 struct时间对象格式
13 print(string_2_struct)
14 # #
15 struct_2_stamp = time.mktime(string_2_struct) #将struct时间对象转成时间戳
16 print(struct_2_stamp)
17
18 #将时间戳转为字符串格式
19 print(time.gmtime(time.time()-86640)) #将utc时间戳转换成struct_time格式
20 print(time.strftime("%Y-%m-%d %H:%M:%S",time.gmtime()) ) #将utc struct_time格式转成指定的字符串格式
21
22 #时间加减
23 import datetime
24
25 print(datetime.datetime.now()) #返回 2017-06-28 21:11:01.433280
26 print(datetime.date.fromtimestamp(time.time()) )  # 时间戳直接转成日期格式 2017-06-28
27 # print(datetime.datetime.now() )
28 # print(datetime.datetime.now() + datetime.timedelta(3)) #当前时间+3天
29 # print(datetime.datetime.now() + datetime.timedelta(-3)) #当前时间-3天
30 # print(datetime.datetime.now() + datetime.timedelta(hours=3)) #当前时间+3小时
31 # print(datetime.datetime.now() + datetime.timedelta(minutes=30)) #当前时间+30分
32
33 #修改时间
34 c_time  = datetime.datetime.now()
35 print(c_time.replace(minute=3,hour=2)) #时间替换)) #时间替换

时间模块

时间转换图(一个来自alex,一个来自海峰老师)

%a    本地(locale)简化星期名称
%A    本地完整星期名称
%b    本地简化月份名称
%B    本地完整月份名称
%c    本地相应的日期和时间表示
%d    一个月中的第几天(01 - 31)
%H    一天中的第几个小时(24小时制,00 - 23)
%I    第几个小时(12小时制,01 - 12)
%j    一年中的第几天(001 - 366)
%m    月份(01 - 12)
%M    分钟数(00 - 59)
%p    本地am或者pm的相应符    一
%S    秒(01 - 61)    二
%U    一年中的星期数。(00 - 53星期天是一个星期的开始。)第一个星期天之前的所有天数都放在第0周。    三
%w    一个星期中的第几天(0 - 6,0是星期天)    三
%W    和%U基本相同,不同的是%W以星期一为一个星期的开始。
%x    本地相应日期
%X    本地相应时间
%y    去掉世纪的年份(00 - 99)
%Y    完整的年份
%Z    时区的名字(如果不存在为空字符)
%%    ‘%’字符

5.2random模块

随机数

import random
print (random.random())  #0.6445010863311293
#random.random()用于生成一个0到1的随机符点数: 0 <= n < 1.0
print (random.randint(1,7)) #4
#random.randint()的函数原型为:random.randint(a, b),用于生成一个指定范围内的整数。
# 其中参数a是下限,参数b是上限,生成的随机数n: a <= n <= b
print (random.randrange(1,10)) #5
#random.randrange的函数原型为:random.randrange([start], stop[, step]),
# 从指定范围内,按指定基数递增的集合中 获取一个随机数。如:random.randrange(10, 100, 2),
# 结果相当于从[10, 12, 14, 16, ... 96, 98]序列中获取一个随机数。
# random.randrange(10, 100, 2)在结果上与 random.choice(range(10, 100, 2) 等效。
print(random.choice(‘liukuni‘)) #i
#random.choice从序列中获取一个随机元素。
# 其函数原型为:random.choice(sequence)。参数sequence表示一个有序类型。
# 这里要说明一下:sequence在python不是一种特定的类型,而是泛指一系列的类型。
# list, tuple, 字符串都属于sequence。有关sequence可以查看python手册数据模型这一章。
# 下面是使用choice的一些例子:
print(random.choice("学习Python"))#学
print(random.choice(["JGood","is","a","handsome","boy"]))  #List
print(random.choice(("Tuple","List","Dict")))   #List
print(random.sample([1,2,3,4,5],3))    #[1, 2, 5]
#random.sample的函数原型为:random.sample(sequence, k),从指定序列中随机获取指定长度的片断。sample函数不会修改原有序列。

#!/usr/bin/env python
# encoding: utf-8
import random
import string
#随机整数:
print( random.randint(0,99))  #70

#随机选取0到100间的偶数:
print(random.randrange(0, 101, 2)) #4

#随机浮点数:
print( random.random()) #0.2746445568079129
print(random.uniform(1, 10)) #9.887001463194844

#随机字符:
print(random.choice(‘abcdefg&#%^*f‘)) #f

#多个字符中选取特定数量的字符:
print(random.sample(‘abcdefghij‘,3)) #[‘f‘, ‘h‘, ‘d‘]

#随机选取字符串:
print( random.choice ( [‘apple‘, ‘pear‘, ‘peach‘, ‘orange‘, ‘lemon‘] )) #apple
#洗牌#
items = [1,2,3,4,5,6,7]
print(items) #[1, 2, 3, 4, 5, 6, 7]
random.shuffle(items)
print(items) #[1, 4, 7, 2, 5, 3, 6]

应用实例

 1 import random
 2 checkcode=‘‘
 3 for i in range(5):
 4     current_a=random.randint(1,6)
 5     if current_a%2:
 6         temp = chr(random.randint(65,90))
 7     else:
 8         temp = random.randint(0,9)
 9     checkcode+=str(temp)
10 print(checkcode)

随机生成验证码的例子

5.3os模块

参考:https://docs.python.org/2/library/os.html?highlight=os#module-os (帮助)

http://www.cnblogs.com/alex3714/articles/5161349.html(alex)

http://egon09.blog.51cto.com/9161406/1840425(海峰老师)

#Author:ajun
os.getcwd() #获取当前工作目录,即当前python脚本工作的目录路径
os.chdir("dirname")  #改变当前脚本工作目录;相当于shell下cd
os.curdir # 返回当前目录: (‘.‘)
os.pardir # 获取当前目录的父目录字符串名:(‘..‘)
os.makedirs(‘dirname1/dirname2‘)    #可生成多层递归目录
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
os.mkdir(‘dirname‘)   # 生成单级目录;相当于shell中mkdir dirname
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
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
os.remove()  #删除一个文件
os.rename("oldname","newname")  #重命名文件/目录
os.stat(‘path/filename‘)  获取文件/目录信息
os.sep    #输出操作系统特定的路径分隔符,win下为"\\",Linux下为"/"
os.linesep    #输出当前平台使用的行终止符,win下为"\t\n",Linux下为"\n"
os.pathsep   # 输出用于分割文件路径的字符串
os.name   # 输出字符串指示当前使用平台。win->‘nt‘; Linux->‘posix‘
os.system("bash command")  #运行shell命令,直接显示
os.environ # 获取系统环境变量
os.path.abspath(path)  #返回path规范化的绝对路径
os.path.split(path)  #将path分割成目录和文件名二元组返回
os.path.dirname(path)  #返回path的目录。其实就是os.path.split(path)的第一个元素
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
os.path.exists(path)  #如果path存在,返回True;如果path不存在,返回False
os.path.isabs(path)  #如果path是绝对路径,返回True
os.path.isfile(path)  #如果path是一个存在的文件,返回True。否则返回False
os.path.isdir(path)  #如果path是一个存在的目录,则返回True。否则返回False
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
os.path.getatime(path)  #返回path所指向的文件或者目录的最后存取时间
os.path.getmtime(path)  #返回path所指向的文件或者目录的最后修改时间

5.4sys模块

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

5.5shutil模块

主要就是用于文件的拷贝和压缩包。

参考http://www.cnblogs.com/wupeiqi/articles/4963027.html

高级的 文件、文件夹、压缩包 处理模块

shutil.copyfileobj(fsrc, fdst[, length])
将文件内容拷贝到另一个文件中,可以部分内容

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

shutil.copyfile(src, dst)
拷贝文件

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.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.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.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.copy2(src, dst)
拷贝文件和状态信息

 1 def copy2(src, dst):
 2     """Copy data and all stat info ("cp -p src dst").
 3
 4     The destination may be a directory.
 5
 6     """
 7     if os.path.isdir(dst):
 8         dst = os.path.join(dst, os.path.basename(src))
 9     copyfile(src, dst)
10     copystat(src, dst)

shutil.ignore_patterns(*patterns)
shutil.copytree(src, dst, symlinks=False, ignore=None)
递归的去拷贝文件

例如:copytree(source, destination, ignore=ignore_patterns(‘*.pyc‘, ‘tmp*‘))

 1 def ignore_patterns(*patterns):
 2     """Function that can be used as copytree() ignore parameter.
 3
 4     Patterns is a sequence of glob-style patterns
 5     that are used to exclude files"""
 6     def _ignore_patterns(path, names):
 7         ignored_names = []
 8         for pattern in patterns:
 9             ignored_names.extend(fnmatch.filter(names, pattern))
10         return set(ignored_names)
11     return _ignore_patterns
12
13 def copytree(src, dst, symlinks=False, ignore=None):
14     """Recursively copy a directory tree using copy2().
15
16     The destination directory must not already exist.
17     If exception(s) occur, an Error is raised with a list of reasons.
18
19     If the optional symlinks flag is true, symbolic links in the
20     source tree result in symbolic links in the destination tree; if
21     it is false, the contents of the files pointed to by symbolic
22     links are copied.
23
24     The optional ignore argument is a callable. If given, it
25     is called with the `src` parameter, which is the directory
26     being visited by copytree(), and `names` which is the list of
27     `src` contents, as returned by os.listdir():
28
29         callable(src, names) -> ignored_names
30
31     Since copytree() is called recursively, the callable will be
32     called once for each directory that is copied. It returns a
33     list of names relative to the `src` directory that should
34     not be copied.
35
36     XXX Consider this example code rather than the ultimate tool.
37
38     """
39     names = os.listdir(src)
40     if ignore is not None:
41         ignored_names = ignore(src, names)
42     else:
43         ignored_names = set()
44
45     os.makedirs(dst)
46     errors = []
47     for name in names:
48         if name in ignored_names:
49             continue
50         srcname = os.path.join(src, name)
51         dstname = os.path.join(dst, name)
52         try:
53             if symlinks and os.path.islink(srcname):
54                 linkto = os.readlink(srcname)
55                 os.symlink(linkto, dstname)
56             elif os.path.isdir(srcname):
57                 copytree(srcname, dstname, symlinks, ignore)
58             else:
59                 # Will raise a SpecialFileError for unsupported file types
60                 copy2(srcname, dstname)
61         # catch the Error from the recursive copytree so that we can
62         # continue with other files
63         except Error, err:
64             errors.extend(err.args[0])
65         except EnvironmentError, why:
66             errors.append((srcname, dstname, str(why)))
67     try:
68         copystat(src, dst)
69     except OSError, why:
70         if WindowsError is not None and isinstance(why, WindowsError):
71             # Copying file access times may fail on Windows
72             pass
73         else:
74             errors.append((src, dst, str(why)))
75     if errors:
76         raise Error, errors

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

 1 def rmtree(path, ignore_errors=False, onerror=None):
 2     """Recursively delete a directory tree.
 3
 4     If ignore_errors is set, errors are ignored; otherwise, if onerror
 5     is set, it is called to handle the error with arguments (func,
 6     path, exc_info) where func is os.listdir, os.remove, or os.rmdir;
 7     path is the argument to that function that caused it to fail; and
 8     exc_info is a tuple returned by sys.exc_info().  If ignore_errors
 9     is false and onerror is None, an exception is raised.
10
11     """
12     if ignore_errors:
13         def onerror(*args):
14             pass
15     elif onerror is None:
16         def onerror(*args):
17             raise
18     try:
19         if os.path.islink(path):
20             # symlinks to directories are forbidden, see bug #1669
21             raise OSError("Cannot call rmtree on a symbolic link")
22     except OSError:
23         onerror(os.path.islink, path, sys.exc_info())
24         # can‘t continue even if onerror hook returns
25         return
26     names = []
27     try:
28         names = os.listdir(path)
29     except os.error, err:
30         onerror(os.listdir, path, sys.exc_info())
31     for name in names:
32         fullname = os.path.join(path, name)
33         try:
34             mode = os.lstat(fullname).st_mode
35         except os.error:
36             mode = 0
37         if stat.S_ISDIR(mode):
38             rmtree(fullname, ignore_errors, onerror)
39         else:
40             try:
41                 os.remove(fullname)
42             except os.error, err:
43                 onerror(os.remove, fullname, sys.exc_info())
44     try:
45         os.rmdir(path)
46     except os.error:
47         onerror(os.rmdir, path, sys.exc_info())

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.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
  • 1 #将 /Users/wupeiqi/Downloads/test 下的文件打包放置当前程序目录
    2
    3 import shutil
    4 ret = shutil.make_archive("wwwwwwwwww", ‘gztar‘, root_dir=‘/Users/wupeiqi/Downloads/test‘)
    5
    6
    7 #将 /Users/wupeiqi/Downloads/test 下的文件打包放置 /Users/wupeiqi/目录
    8 import shutil
    9 ret = shutil.make_archive("/Users/wupeiqi/wwwwwwwwww", ‘gztar‘, root_dir=‘/Users/wupeiqi/Downloads/test‘)

     1 def make_archive(base_name, format, root_dir=None, base_dir=None, verbose=0,
     2                  dry_run=0, owner=None, group=None, logger=None):
     3     """Create an archive file (eg. zip or tar).
     4
     5     ‘base_name‘ is the name of the file to create, minus any format-specific
     6     extension; ‘format‘ is the archive format: one of "zip", "tar", "bztar"
     7     or "gztar".
     8
     9     ‘root_dir‘ is a directory that will be the root directory of the
    10     archive; ie. we typically chdir into ‘root_dir‘ before creating the
    11     archive.  ‘base_dir‘ is the directory where we start archiving from;
    12     ie. ‘base_dir‘ will be the common prefix of all files and
    13     directories in the archive.  ‘root_dir‘ and ‘base_dir‘ both default
    14     to the current directory.  Returns the name of the archive file.
    15
    16     ‘owner‘ and ‘group‘ are used when creating a tar archive. By default,
    17     uses the current owner and group.
    18     """
    19     save_cwd = os.getcwd()
    20     if root_dir is not None:
    21         if logger is not None:
    22             logger.debug("changing into ‘%s‘", root_dir)
    23         base_name = os.path.abspath(base_name)
    24         if not dry_run:
    25             os.chdir(root_dir)
    26
    27     if base_dir is None:
    28         base_dir = os.curdir
    29
    30     kwargs = {‘dry_run‘: dry_run, ‘logger‘: logger}
    31
    32     try:
    33         format_info = _ARCHIVE_FORMATS[format]
    34     except KeyError:
    35         raise ValueError, "unknown archive format ‘%s‘" % format
    36
    37     func = format_info[0]
    38     for arg, val in format_info[1]:
    39         kwargs[arg] = val
    40
    41     if format != ‘zip‘:
    42         kwargs[‘owner‘] = owner
    43         kwargs[‘group‘] = group
    44
    45     try:
    46         filename = func(base_name, base_dir, **kwargs)
    47     finally:
    48         if root_dir is not None:
    49             if logger is not None:
    50                 logger.debug("changing back to ‘%s‘", save_cwd)
    51             os.chdir(save_cwd)
    52
    53     return filename

  • shutil 对压缩包的处理是调用 ZipFile 和 TarFile 两个模块来进行的,详细:
  •  1 import zipfile
     2
     3 # 压缩
     4 z = zipfile.ZipFile(‘laxi.zip‘, ‘w‘)
     5 z.write(‘a.log‘)
     6 z.write(‘data.data‘)
     7 z.close()
     8
     9 # 解压
    10 z = zipfile.ZipFile(‘laxi.zip‘, ‘r‘)
    11 z.extractall()
    12 z.close()

    zipfile 压缩解压

     1 import tarfile
     2
     3 # 压缩
     4 tar = tarfile.open(‘your.tar‘,‘w‘)
     5 tar.add(‘/Users/wupeiqi/PycharmProjects/bbs2.zip‘, arcname=‘bbs2.zip‘)
     6 tar.add(‘/Users/wupeiqi/PycharmProjects/cmdb.zip‘, arcname=‘cmdb.zip‘)
     7 tar.close()
     8
     9 # 解压
    10 tar = tarfile.open(‘your.tar‘,‘r‘)
    11 tar.extractall()  # 可设置解压地址
    12 tar.close()

    tarfile 压缩解压

      1 class ZipFile(object):
      2     """ Class with methods to open, read, write, close, list zip files.
      3
      4     z = ZipFile(file, mode="r", compression=ZIP_STORED, allowZip64=False)
      5
      6     file: Either the path to the file, or a file-like object.
      7           If it is a path, the file will be opened and closed by ZipFile.
      8     mode: The mode can be either read "r", write "w" or append "a".
      9     compression: ZIP_STORED (no compression) or ZIP_DEFLATED (requires zlib).
     10     allowZip64: if True ZipFile will create files with ZIP64 extensions when
     11                 needed, otherwise it will raise an exception when this would
     12                 be necessary.
     13
     14     """
     15
     16     fp = None                   # Set here since __del__ checks it
     17
     18     def __init__(self, file, mode="r", compression=ZIP_STORED, allowZip64=False):
     19         """Open the ZIP file with mode read "r", write "w" or append "a"."""
     20         if mode not in ("r", "w", "a"):
     21             raise RuntimeError(‘ZipFile() requires mode "r", "w", or "a"‘)
     22
     23         if compression == ZIP_STORED:
     24             pass
     25         elif compression == ZIP_DEFLATED:
     26             if not zlib:
     27                 raise RuntimeError, 28                       "Compression requires the (missing) zlib module"
     29         else:
     30             raise RuntimeError, "That compression method is not supported"
     31
     32         self._allowZip64 = allowZip64
     33         self._didModify = False
     34         self.debug = 0  # Level of printing: 0 through 3
     35         self.NameToInfo = {}    # Find file info given name
     36         self.filelist = []      # List of ZipInfo instances for archive
     37         self.compression = compression  # Method of compression
     38         self.mode = key = mode.replace(‘b‘, ‘‘)[0]
     39         self.pwd = None
     40         self._comment = ‘‘
     41
     42         # Check if we were passed a file-like object
     43         if isinstance(file, basestring):
     44             self._filePassed = 0
     45             self.filename = file
     46             modeDict = {‘r‘ : ‘rb‘, ‘w‘: ‘wb‘, ‘a‘ : ‘r+b‘}
     47             try:
     48                 self.fp = open(file, modeDict[mode])
     49             except IOError:
     50                 if mode == ‘a‘:
     51                     mode = key = ‘w‘
     52                     self.fp = open(file, modeDict[mode])
     53                 else:
     54                     raise
     55         else:
     56             self._filePassed = 1
     57             self.fp = file
     58             self.filename = getattr(file, ‘name‘, None)
     59
     60         try:
     61             if key == ‘r‘:
     62                 self._RealGetContents()
     63             elif key == ‘w‘:
     64                 # set the modified flag so central directory gets written
     65                 # even if no files are added to the archive
     66                 self._didModify = True
     67             elif key == ‘a‘:
     68                 try:
     69                     # See if file is a zip file
     70                     self._RealGetContents()
     71                     # seek to start of directory and overwrite
     72                     self.fp.seek(self.start_dir, 0)
     73                 except BadZipfile:
     74                     # file is not a zip file, just append
     75                     self.fp.seek(0, 2)
     76
     77                     # set the modified flag so central directory gets written
     78                     # even if no files are added to the archive
     79                     self._didModify = True
     80             else:
     81                 raise RuntimeError(‘Mode must be "r", "w" or "a"‘)
     82         except:
     83             fp = self.fp
     84             self.fp = None
     85             if not self._filePassed:
     86                 fp.close()
     87             raise
     88
     89     def __enter__(self):
     90         return self
     91
     92     def __exit__(self, type, value, traceback):
     93         self.close()
     94
     95     def _RealGetContents(self):
     96         """Read in the table of contents for the ZIP file."""
     97         fp = self.fp
     98         try:
     99             endrec = _EndRecData(fp)
    100         except IOError:
    101             raise BadZipfile("File is not a zip file")
    102         if not endrec:
    103             raise BadZipfile, "File is not a zip file"
    104         if self.debug > 1:
    105             print endrec
    106         size_cd = endrec[_ECD_SIZE]             # bytes in central directory
    107         offset_cd = endrec[_ECD_OFFSET]         # offset of central directory
    108         self._comment = endrec[_ECD_COMMENT]    # archive comment
    109
    110         # "concat" is zero, unless zip was concatenated to another file
    111         concat = endrec[_ECD_LOCATION] - size_cd - offset_cd
    112         if endrec[_ECD_SIGNATURE] == stringEndArchive64:
    113             # If Zip64 extension structures are present, account for them
    114             concat -= (sizeEndCentDir64 + sizeEndCentDir64Locator)
    115
    116         if self.debug > 2:
    117             inferred = concat + offset_cd
    118             print "given, inferred, offset", offset_cd, inferred, concat
    119         # self.start_dir:  Position of start of central directory
    120         self.start_dir = offset_cd + concat
    121         fp.seek(self.start_dir, 0)
    122         data = fp.read(size_cd)
    123         fp = cStringIO.StringIO(data)
    124         total = 0
    125         while total < size_cd:
    126             centdir = fp.read(sizeCentralDir)
    127             if len(centdir) != sizeCentralDir:
    128                 raise BadZipfile("Truncated central directory")
    129             centdir = struct.unpack(structCentralDir, centdir)
    130             if centdir[_CD_SIGNATURE] != stringCentralDir:
    131                 raise BadZipfile("Bad magic number for central directory")
    132             if self.debug > 2:
    133                 print centdir
    134             filename = fp.read(centdir[_CD_FILENAME_LENGTH])
    135             # Create ZipInfo instance to store file information
    136             x = ZipInfo(filename)
    137             x.extra = fp.read(centdir[_CD_EXTRA_FIELD_LENGTH])
    138             x.comment = fp.read(centdir[_CD_COMMENT_LENGTH])
    139             x.header_offset = centdir[_CD_LOCAL_HEADER_OFFSET]
    140             (x.create_version, x.create_system, x.extract_version, x.reserved,
    141                 x.flag_bits, x.compress_type, t, d,
    142                 x.CRC, x.compress_size, x.file_size) = centdir[1:12]
    143             x.volume, x.internal_attr, x.external_attr = centdir[15:18]
    144             # Convert date/time code to (year, month, day, hour, min, sec)
    145             x._raw_time = t
    146             x.date_time = ( (d>>9)+1980, (d>>5)&0xF, d&0x1F,
    147                                      t>>11, (t>>5)&0x3F, (t&0x1F) * 2 )
    148
    149             x._decodeExtra()
    150             x.header_offset = x.header_offset + concat
    151             x.filename = x._decodeFilename()
    152             self.filelist.append(x)
    153             self.NameToInfo[x.filename] = x
    154
    155             # update total bytes read from central directory
    156             total = (total + sizeCentralDir + centdir[_CD_FILENAME_LENGTH]
    157                      + centdir[_CD_EXTRA_FIELD_LENGTH]
    158                      + centdir[_CD_COMMENT_LENGTH])
    159
    160             if self.debug > 2:
    161                 print "total", total
    162
    163
    164     def namelist(self):
    165         """Return a list of file names in the archive."""
    166         l = []
    167         for data in self.filelist:
    168             l.append(data.filename)
    169         return l
    170
    171     def infolist(self):
    172         """Return a list of class ZipInfo instances for files in the
    173         archive."""
    174         return self.filelist
    175
    176     def printdir(self):
    177         """Print a table of contents for the zip file."""
    178         print "%-46s %19s %12s" % ("File Name", "Modified    ", "Size")
    179         for zinfo in self.filelist:
    180             date = "%d-%02d-%02d %02d:%02d:%02d" % zinfo.date_time[:6]
    181             print "%-46s %s %12d" % (zinfo.filename, date, zinfo.file_size)
    182
    183     def testzip(self):
    184         """Read all the files and check the CRC."""
    185         chunk_size = 2 ** 20
    186         for zinfo in self.filelist:
    187             try:
    188                 # Read by chunks, to avoid an OverflowError or a
    189                 # MemoryError with very large embedded files.
    190                 with self.open(zinfo.filename, "r") as f:
    191                     while f.read(chunk_size):     # Check CRC-32
    192                         pass
    193             except BadZipfile:
    194                 return zinfo.filename
    195
    196     def getinfo(self, name):
    197         """Return the instance of ZipInfo given ‘name‘."""
    198         info = self.NameToInfo.get(name)
    199         if info is None:
    200             raise KeyError(
    201                 ‘There is no item named %r in the archive‘ % name)
    202
    203         return info
    204
    205     def setpassword(self, pwd):
    206         """Set default password for encrypted files."""
    207         self.pwd = pwd
    208
    209     @property
    210     def comment(self):
    211         """The comment text associated with the ZIP file."""
    212         return self._comment
    213
    214     @comment.setter
    215     def comment(self, comment):
    216         # check for valid comment length
    217         if len(comment) > ZIP_MAX_COMMENT:
    218             import warnings
    219             warnings.warn(‘Archive comment is too long; truncating to %d bytes‘
    220                           % ZIP_MAX_COMMENT, stacklevel=2)
    221             comment = comment[:ZIP_MAX_COMMENT]
    222         self._comment = comment
    223         self._didModify = True
    224
    225     def read(self, name, pwd=None):
    226         """Return file bytes (as a string) for name."""
    227         return self.open(name, "r", pwd).read()
    228
    229     def open(self, name, mode="r", pwd=None):
    230         """Return file-like object for ‘name‘."""
    231         if mode not in ("r", "U", "rU"):
    232             raise RuntimeError, ‘open() requires mode "r", "U", or "rU"‘
    233         if not self.fp:
    234             raise RuntimeError, 235                   "Attempt to read ZIP archive that was already closed"
    236
    237         # Only open a new file for instances where we were not
    238         # given a file object in the constructor
    239         if self._filePassed:
    240             zef_file = self.fp
    241             should_close = False
    242         else:
    243             zef_file = open(self.filename, ‘rb‘)
    244             should_close = True
    245
    246         try:
    247             # Make sure we have an info object
    248             if isinstance(name, ZipInfo):
    249                 # ‘name‘ is already an info object
    250                 zinfo = name
    251             else:
    252                 # Get info object for name
    253                 zinfo = self.getinfo(name)
    254
    255             zef_file.seek(zinfo.header_offset, 0)
    256
    257             # Skip the file header:
    258             fheader = zef_file.read(sizeFileHeader)
    259             if len(fheader) != sizeFileHeader:
    260                 raise BadZipfile("Truncated file header")
    261             fheader = struct.unpack(structFileHeader, fheader)
    262             if fheader[_FH_SIGNATURE] != stringFileHeader:
    263                 raise BadZipfile("Bad magic number for file header")
    264
    265             fname = zef_file.read(fheader[_FH_FILENAME_LENGTH])
    266             if fheader[_FH_EXTRA_FIELD_LENGTH]:
    267                 zef_file.read(fheader[_FH_EXTRA_FIELD_LENGTH])
    268
    269             if fname != zinfo.orig_filename:
    270                 raise BadZipfile, 271                         ‘File name in directory "%s" and header "%s" differ.‘ % (
    272                             zinfo.orig_filename, fname)
    273
    274             # check for encrypted flag & handle password
    275             is_encrypted = zinfo.flag_bits & 0x1
    276             zd = None
    277             if is_encrypted:
    278                 if not pwd:
    279                     pwd = self.pwd
    280                 if not pwd:
    281                     raise RuntimeError, "File %s is encrypted, " 282                         "password required for extraction" % name
    283
    284                 zd = _ZipDecrypter(pwd)
    285                 # The first 12 bytes in the cypher stream is an encryption header
    286                 #  used to strengthen the algorithm. The first 11 bytes are
    287                 #  completely random, while the 12th contains the MSB of the CRC,
    288                 #  or the MSB of the file time depending on the header type
    289                 #  and is used to check the correctness of the password.
    290                 bytes = zef_file.read(12)
    291                 h = map(zd, bytes[0:12])
    292                 if zinfo.flag_bits & 0x8:
    293                     # compare against the file type from extended local headers
    294                     check_byte = (zinfo._raw_time >> 8) & 0xff
    295                 else:
    296                     # compare against the CRC otherwise
    297                     check_byte = (zinfo.CRC >> 24) & 0xff
    298                 if ord(h[11]) != check_byte:
    299                     raise RuntimeError("Bad password for file", name)
    300
    301             return ZipExtFile(zef_file, mode, zinfo, zd,
    302                     close_fileobj=should_close)
    303         except:
    304             if should_close:
    305                 zef_file.close()
    306             raise
    307
    308     def extract(self, member, path=None, pwd=None):
    309         """Extract a member from the archive to the current working directory,
    310            using its full name. Its file information is extracted as accurately
    311            as possible. `member‘ may be a filename or a ZipInfo object. You can
    312            specify a different directory using `path‘.
    313         """
    314         if not isinstance(member, ZipInfo):
    315             member = self.getinfo(member)
    316
    317         if path is None:
    318             path = os.getcwd()
    319
    320         return self._extract_member(member, path, pwd)
    321
    322     def extractall(self, path=None, members=None, pwd=None):
    323         """Extract all members from the archive to the current working
    324            directory. `path‘ specifies a different directory to extract to.
    325            `members‘ is optional and must be a subset of the list returned
    326            by namelist().
    327         """
    328         if members is None:
    329             members = self.namelist()
    330
    331         for zipinfo in members:
    332             self.extract(zipinfo, path, pwd)
    333
    334     def _extract_member(self, member, targetpath, pwd):
    335         """Extract the ZipInfo object ‘member‘ to a physical
    336            file on the path targetpath.
    337         """
    338         # build the destination pathname, replacing
    339         # forward slashes to platform specific separators.
    340         arcname = member.filename.replace(‘/‘, os.path.sep)
    341
    342         if os.path.altsep:
    343             arcname = arcname.replace(os.path.altsep, os.path.sep)
    344         # interpret absolute pathname as relative, remove drive letter or
    345         # UNC path, redundant separators, "." and ".." components.
    346         arcname = os.path.splitdrive(arcname)[1]
    347         arcname = os.path.sep.join(x for x in arcname.split(os.path.sep)
    348                     if x not in (‘‘, os.path.curdir, os.path.pardir))
    349         if os.path.sep == ‘\\‘:
    350             # filter illegal characters on Windows
    351             illegal = ‘:<>|"?*‘
    352             if isinstance(arcname, unicode):
    353                 table = {ord(c): ord(‘_‘) for c in illegal}
    354             else:
    355                 table = string.maketrans(illegal, ‘_‘ * len(illegal))
    356             arcname = arcname.translate(table)
    357             # remove trailing dots
    358             arcname = (x.rstrip(‘.‘) for x in arcname.split(os.path.sep))
    359             arcname = os.path.sep.join(x for x in arcname if x)
    360
    361         targetpath = os.path.join(targetpath, arcname)
    362         targetpath = os.path.normpath(targetpath)
    363
    364         # Create all upper directories if necessary.
    365         upperdirs = os.path.dirname(targetpath)
    366         if upperdirs and not os.path.exists(upperdirs):
    367             os.makedirs(upperdirs)
    368
    369         if member.filename[-1] == ‘/‘:
    370             if not os.path.isdir(targetpath):
    371                 os.mkdir(targetpath)
    372             return targetpath
    373
    374         with self.open(member, pwd=pwd) as source, 375              file(targetpath, "wb") as target:
    376             shutil.copyfileobj(source, target)
    377
    378         return targetpath
    379
    380     def _writecheck(self, zinfo):
    381         """Check for errors before writing a file to the archive."""
    382         if zinfo.filename in self.NameToInfo:
    383             import warnings
    384             warnings.warn(‘Duplicate name: %r‘ % zinfo.filename, stacklevel=3)
    385         if self.mode not in ("w", "a"):
    386             raise RuntimeError, ‘write() requires mode "w" or "a"‘
    387         if not self.fp:
    388             raise RuntimeError, 389                   "Attempt to write ZIP archive that was already closed"
    390         if zinfo.compress_type == ZIP_DEFLATED and not zlib:
    391             raise RuntimeError, 392                   "Compression requires the (missing) zlib module"
    393         if zinfo.compress_type not in (ZIP_STORED, ZIP_DEFLATED):
    394             raise RuntimeError, 395                   "That compression method is not supported"
    396         if not self._allowZip64:
    397             requires_zip64 = None
    398             if len(self.filelist) >= ZIP_FILECOUNT_LIMIT:
    399                 requires_zip64 = "Files count"
    400             elif zinfo.file_size > ZIP64_LIMIT:
    401                 requires_zip64 = "Filesize"
    402             elif zinfo.header_offset > ZIP64_LIMIT:
    403                 requires_zip64 = "Zipfile size"
    404             if requires_zip64:
    405                 raise LargeZipFile(requires_zip64 +
    406                                    " would require ZIP64 extensions")
    407
    408     def write(self, filename, arcname=None, compress_type=None):
    409         """Put the bytes from filename into the archive under the name
    410         arcname."""
    411         if not self.fp:
    412             raise RuntimeError(
    413                   "Attempt to write to ZIP archive that was already closed")
    414
    415         st = os.stat(filename)
    416         isdir = stat.S_ISDIR(st.st_mode)
    417         mtime = time.localtime(st.st_mtime)
    418         date_time = mtime[0:6]
    419         # Create ZipInfo instance to store file information
    420         if arcname is None:
    421             arcname = filename
    422         arcname = os.path.normpath(os.path.splitdrive(arcname)[1])
    423         while arcname[0] in (os.sep, os.altsep):
    424             arcname = arcname[1:]
    425         if isdir:
    426             arcname += ‘/‘
    427         zinfo = ZipInfo(arcname, date_time)
    428         zinfo.external_attr = (st[0] & 0xFFFF) << 16L      # Unix attributes
    429         if compress_type is None:
    430             zinfo.compress_type = self.compression
    431         else:
    432             zinfo.compress_type = compress_type
    433
    434         zinfo.file_size = st.st_size
    435         zinfo.flag_bits = 0x00
    436         zinfo.header_offset = self.fp.tell()    # Start of header bytes
    437
    438         self._writecheck(zinfo)
    439         self._didModify = True
    440
    441         if isdir:
    442             zinfo.file_size = 0
    443             zinfo.compress_size = 0
    444             zinfo.CRC = 0
    445             zinfo.external_attr |= 0x10  # MS-DOS directory flag
    446             self.filelist.append(zinfo)
    447             self.NameToInfo[zinfo.filename] = zinfo
    448             self.fp.write(zinfo.FileHeader(False))
    449             return
    450
    451         with open(filename, "rb") as fp:
    452             # Must overwrite CRC and sizes with correct data later
    453             zinfo.CRC = CRC = 0
    454             zinfo.compress_size = compress_size = 0
    455             # Compressed size can be larger than uncompressed size
    456             zip64 = self._allowZip64 and 457                     zinfo.file_size * 1.05 > ZIP64_LIMIT
    458             self.fp.write(zinfo.FileHeader(zip64))
    459             if zinfo.compress_type == ZIP_DEFLATED:
    460                 cmpr = zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION,
    461                      zlib.DEFLATED, -15)
    462             else:
    463                 cmpr = None
    464             file_size = 0
    465             while 1:
    466                 buf = fp.read(1024 * 8)
    467                 if not buf:
    468                     break
    469                 file_size = file_size + len(buf)
    470                 CRC = crc32(buf, CRC) & 0xffffffff
    471                 if cmpr:
    472                     buf = cmpr.compress(buf)
    473                     compress_size = compress_size + len(buf)
    474                 self.fp.write(buf)
    475         if cmpr:
    476             buf = cmpr.flush()
    477             compress_size = compress_size + len(buf)
    478             self.fp.write(buf)
    479             zinfo.compress_size = compress_size
    480         else:
    481             zinfo.compress_size = file_size
    482         zinfo.CRC = CRC
    483         zinfo.file_size = file_size
    484         if not zip64 and self._allowZip64:
    485             if file_size > ZIP64_LIMIT:
    486                 raise RuntimeError(‘File size has increased during compressing‘)
    487             if compress_size > ZIP64_LIMIT:
    488                 raise RuntimeError(‘Compressed size larger than uncompressed size‘)
    489         # Seek backwards and write file header (which will now include
    490         # correct CRC and file sizes)
    491         position = self.fp.tell()       # Preserve current position in file
    492         self.fp.seek(zinfo.header_offset, 0)
    493         self.fp.write(zinfo.FileHeader(zip64))
    494         self.fp.seek(position, 0)
    495         self.filelist.append(zinfo)
    496         self.NameToInfo[zinfo.filename] = zinfo
    497
    498     def writestr(self, zinfo_or_arcname, bytes, compress_type=None):
    499         """Write a file into the archive.  The contents is the string
    500         ‘bytes‘.  ‘zinfo_or_arcname‘ is either a ZipInfo instance or
    501         the name of the file in the archive."""
    502         if not isinstance(zinfo_or_arcname, ZipInfo):
    503             zinfo = ZipInfo(filename=zinfo_or_arcname,
    504                             date_time=time.localtime(time.time())[:6])
    505
    506             zinfo.compress_type = self.compression
    507             if zinfo.filename[-1] == ‘/‘:
    508                 zinfo.external_attr = 0o40775 << 16   # drwxrwxr-x
    509                 zinfo.external_attr |= 0x10           # MS-DOS directory flag
    510             else:
    511                 zinfo.external_attr = 0o600 << 16     # ?rw-------
    512         else:
    513             zinfo = zinfo_or_arcname
    514
    515         if not self.fp:
    516             raise RuntimeError(
    517                   "Attempt to write to ZIP archive that was already closed")
    518
    519         if compress_type is not None:
    520             zinfo.compress_type = compress_type
    521
    522         zinfo.file_size = len(bytes)            # Uncompressed size
    523         zinfo.header_offset = self.fp.tell()    # Start of header bytes
    524         self._writecheck(zinfo)
    525         self._didModify = True
    526         zinfo.CRC = crc32(bytes) & 0xffffffff       # CRC-32 checksum
    527         if zinfo.compress_type == ZIP_DEFLATED:
    528             co = zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION,
    529                  zlib.DEFLATED, -15)
    530             bytes = co.compress(bytes) + co.flush()
    531             zinfo.compress_size = len(bytes)    # Compressed size
    532         else:
    533             zinfo.compress_size = zinfo.file_size
    534         zip64 = zinfo.file_size > ZIP64_LIMIT or 535                 zinfo.compress_size > ZIP64_LIMIT
    536         if zip64 and not self._allowZip64:
    537             raise LargeZipFile("Filesize would require ZIP64 extensions")
    538         self.fp.write(zinfo.FileHeader(zip64))
    539         self.fp.write(bytes)
    540         if zinfo.flag_bits & 0x08:
    541             # Write CRC and file sizes after the file data
    542             fmt = ‘<LQQ‘ if zip64 else ‘<LLL‘
    543             self.fp.write(struct.pack(fmt, zinfo.CRC, zinfo.compress_size,
    544                   zinfo.file_size))
    545         self.fp.flush()
    546         self.filelist.append(zinfo)
    547         self.NameToInfo[zinfo.filename] = zinfo
    548
    549     def __del__(self):
    550         """Call the "close()" method in case the user forgot."""
    551         self.close()
    552
    553     def close(self):
    554         """Close the file, and for mode "w" and "a" write the ending
    555         records."""
    556         if self.fp is None:
    557             return
    558
    559         try:
    560             if self.mode in ("w", "a") and self._didModify: # write ending records
    561                 pos1 = self.fp.tell()
    562                 for zinfo in self.filelist:         # write central directory
    563                     dt = zinfo.date_time
    564                     dosdate = (dt[0] - 1980) << 9 | dt[1] << 5 | dt[2]
    565                     dostime = dt[3] << 11 | dt[4] << 5 | (dt[5] // 2)
    566                     extra = []
    567                     if zinfo.file_size > ZIP64_LIMIT 568                             or zinfo.compress_size > ZIP64_LIMIT:
    569                         extra.append(zinfo.file_size)
    570                         extra.append(zinfo.compress_size)
    571                         file_size = 0xffffffff
    572                         compress_size = 0xffffffff
    573                     else:
    574                         file_size = zinfo.file_size
    575                         compress_size = zinfo.compress_size
    576
    577                     if zinfo.header_offset > ZIP64_LIMIT:
    578                         extra.append(zinfo.header_offset)
    579                         header_offset = 0xffffffffL
    580                     else:
    581                         header_offset = zinfo.header_offset
    582
    583                     extra_data = zinfo.extra
    584                     if extra:
    585                         # Append a ZIP64 field to the extra‘s
    586                         extra_data = struct.pack(
    587                                 ‘<HH‘ + ‘Q‘*len(extra),
    588                                 1, 8*len(extra), *extra) + extra_data
    589
    590                         extract_version = max(45, zinfo.extract_version)
    591                         create_version = max(45, zinfo.create_version)
    592                     else:
    593                         extract_version = zinfo.extract_version
    594                         create_version = zinfo.create_version
    595
    596                     try:
    597                         filename, flag_bits = zinfo._encodeFilenameFlags()
    598                         centdir = struct.pack(structCentralDir,
    599                         stringCentralDir, create_version,
    600                         zinfo.create_system, extract_version, zinfo.reserved,
    601                         flag_bits, zinfo.compress_type, dostime, dosdate,
    602                         zinfo.CRC, compress_size, file_size,
    603                         len(filename), len(extra_data), len(zinfo.comment),
    604                         0, zinfo.internal_attr, zinfo.external_attr,
    605                         header_offset)
    606                     except DeprecationWarning:
    607                         print >>sys.stderr, (structCentralDir,
    608                         stringCentralDir, create_version,
    609                         zinfo.create_system, extract_version, zinfo.reserved,
    610                         zinfo.flag_bits, zinfo.compress_type, dostime, dosdate,
    611                         zinfo.CRC, compress_size, file_size,
    612                         len(zinfo.filename), len(extra_data), len(zinfo.comment),
    613                         0, zinfo.internal_attr, zinfo.external_attr,
    614                         header_offset)
    615                         raise
    616                     self.fp.write(centdir)
    617                     self.fp.write(filename)
    618                     self.fp.write(extra_data)
    619                     self.fp.write(zinfo.comment)
    620
    621                 pos2 = self.fp.tell()
    622                 # Write end-of-zip-archive record
    623                 centDirCount = len(self.filelist)
    624                 centDirSize = pos2 - pos1
    625                 centDirOffset = pos1
    626                 requires_zip64 = None
    627                 if centDirCount > ZIP_FILECOUNT_LIMIT:
    628                     requires_zip64 = "Files count"
    629                 elif centDirOffset > ZIP64_LIMIT:
    630                     requires_zip64 = "Central directory offset"
    631                 elif centDirSize > ZIP64_LIMIT:
    632                     requires_zip64 = "Central directory size"
    633                 if requires_zip64:
    634                     # Need to write the ZIP64 end-of-archive records
    635                     if not self._allowZip64:
    636                         raise LargeZipFile(requires_zip64 +
    637                                            " would require ZIP64 extensions")
    638                     zip64endrec = struct.pack(
    639                             structEndArchive64, stringEndArchive64,
    640                             44, 45, 45, 0, 0, centDirCount, centDirCount,
    641                             centDirSize, centDirOffset)
    642                     self.fp.write(zip64endrec)
    643
    644                     zip64locrec = struct.pack(
    645                             structEndArchive64Locator,
    646                             stringEndArchive64Locator, 0, pos2, 1)
    647                     self.fp.write(zip64locrec)
    648                     centDirCount = min(centDirCount, 0xFFFF)
    649                     centDirSize = min(centDirSize, 0xFFFFFFFF)
    650                     centDirOffset = min(centDirOffset, 0xFFFFFFFF)
    651
    652                 endrec = struct.pack(structEndArchive, stringEndArchive,
    653                                     0, 0, centDirCount, centDirCount,
    654                                     centDirSize, centDirOffset, len(self._comment))
    655                 self.fp.write(endrec)
    656                 self.fp.write(self._comment)
    657                 self.fp.flush()
    658         finally:
    659             fp = self.fp
    660             self.fp = None
    661             if not self._filePassed:
    662                 fp.close()

    ZipFile源代码

      1 class TarFile(object):
      2     """The TarFile Class provides an interface to tar archives.
      3     """
      4
      5     debug = 0                   # May be set from 0 (no msgs) to 3 (all msgs)
      6
      7     dereference = False         # If true, add content of linked file to the
      8                                 # tar file, else the link.
      9
     10     ignore_zeros = False        # If true, skips empty or invalid blocks and
     11                                 # continues processing.
     12
     13     errorlevel = 1              # If 0, fatal errors only appear in debug
     14                                 # messages (if debug >= 0). If > 0, errors
     15                                 # are passed to the caller as exceptions.
     16
     17     format = DEFAULT_FORMAT     # The format to use when creating an archive.
     18
     19     encoding = ENCODING         # Encoding for 8-bit character strings.
     20
     21     errors = None               # Error handler for unicode conversion.
     22
     23     tarinfo = TarInfo           # The default TarInfo class to use.
     24
     25     fileobject = ExFileObject   # The default ExFileObject class to use.
     26
     27     def __init__(self, name=None, mode="r", fileobj=None, format=None,
     28             tarinfo=None, dereference=None, ignore_zeros=None, encoding=None,
     29             errors=None, pax_headers=None, debug=None, errorlevel=None):
     30         """Open an (uncompressed) tar archive `name‘. `mode‘ is either ‘r‘ to
     31            read from an existing archive, ‘a‘ to append data to an existing
     32            file or ‘w‘ to create a new file overwriting an existing one. `mode‘
     33            defaults to ‘r‘.
     34            If `fileobj‘ is given, it is used for reading or writing data. If it
     35            can be determined, `mode‘ is overridden by `fileobj‘s mode.
     36            `fileobj‘ is not closed, when TarFile is closed.
     37         """
     38         modes = {"r": "rb", "a": "r+b", "w": "wb"}
     39         if mode not in modes:
     40             raise ValueError("mode must be ‘r‘, ‘a‘ or ‘w‘")
     41         self.mode = mode
     42         self._mode = modes[mode]
     43
     44         if not fileobj:
     45             if self.mode == "a" and not os.path.exists(name):
     46                 # Create nonexistent files in append mode.
     47                 self.mode = "w"
     48                 self._mode = "wb"
     49             fileobj = bltn_open(name, self._mode)
     50             self._extfileobj = False
     51         else:
     52             if name is None and hasattr(fileobj, "name"):
     53                 name = fileobj.name
     54             if hasattr(fileobj, "mode"):
     55                 self._mode = fileobj.mode
     56             self._extfileobj = True
     57         self.name = os.path.abspath(name) if name else None
     58         self.fileobj = fileobj
     59
     60         # Init attributes.
     61         if format is not None:
     62             self.format = format
     63         if tarinfo is not None:
     64             self.tarinfo = tarinfo
     65         if dereference is not None:
     66             self.dereference = dereference
     67         if ignore_zeros is not None:
     68             self.ignore_zeros = ignore_zeros
     69         if encoding is not None:
     70             self.encoding = encoding
     71
     72         if errors is not None:
     73             self.errors = errors
     74         elif mode == "r":
     75             self.errors = "utf-8"
     76         else:
     77             self.errors = "strict"
     78
     79         if pax_headers is not None and self.format == PAX_FORMAT:
     80             self.pax_headers = pax_headers
     81         else:
     82             self.pax_headers = {}
     83
     84         if debug is not None:
     85             self.debug = debug
     86         if errorlevel is not None:
     87             self.errorlevel = errorlevel
     88
     89         # Init datastructures.
     90         self.closed = False
     91         self.members = []       # list of members as TarInfo objects
     92         self._loaded = False    # flag if all members have been read
     93         self.offset = self.fileobj.tell()
     94                                 # current position in the archive file
     95         self.inodes = {}        # dictionary caching the inodes of
     96                                 # archive members already added
     97
     98         try:
     99             if self.mode == "r":
    100                 self.firstmember = None
    101                 self.firstmember = self.next()
    102
    103             if self.mode == "a":
    104                 # Move to the end of the archive,
    105                 # before the first empty block.
    106                 while True:
    107                     self.fileobj.seek(self.offset)
    108                     try:
    109                         tarinfo = self.tarinfo.fromtarfile(self)
    110                         self.members.append(tarinfo)
    111                     except EOFHeaderError:
    112                         self.fileobj.seek(self.offset)
    113                         break
    114                     except HeaderError, e:
    115                         raise ReadError(str(e))
    116
    117             if self.mode in "aw":
    118                 self._loaded = True
    119
    120                 if self.pax_headers:
    121                     buf = self.tarinfo.create_pax_global_header(self.pax_headers.copy())
    122                     self.fileobj.write(buf)
    123                     self.offset += len(buf)
    124         except:
    125             if not self._extfileobj:
    126                 self.fileobj.close()
    127             self.closed = True
    128             raise
    129
    130     def _getposix(self):
    131         return self.format == USTAR_FORMAT
    132     def _setposix(self, value):
    133         import warnings
    134         warnings.warn("use the format attribute instead", DeprecationWarning,
    135                       2)
    136         if value:
    137             self.format = USTAR_FORMAT
    138         else:
    139             self.format = GNU_FORMAT
    140     posix = property(_getposix, _setposix)
    141
    142     #--------------------------------------------------------------------------
    143     # Below are the classmethods which act as alternate constructors to the
    144     # TarFile class. The open() method is the only one that is needed for
    145     # public use; it is the "super"-constructor and is able to select an
    146     # adequate "sub"-constructor for a particular compression using the mapping
    147     # from OPEN_METH.
    148     #
    149     # This concept allows one to subclass TarFile without losing the comfort of
    150     # the super-constructor. A sub-constructor is registered and made available
    151     # by adding it to the mapping in OPEN_METH.
    152
    153     @classmethod
    154     def open(cls, name=None, mode="r", fileobj=None, bufsize=RECORDSIZE, **kwargs):
    155         """Open a tar archive for reading, writing or appending. Return
    156            an appropriate TarFile class.
    157
    158            mode:
    159            ‘r‘ or ‘r:*‘ open for reading with transparent compression
    160            ‘r:‘         open for reading exclusively uncompressed
    161            ‘r:gz‘       open for reading with gzip compression
    162            ‘r:bz2‘      open for reading with bzip2 compression
    163            ‘a‘ or ‘a:‘  open for appending, creating the file if necessary
    164            ‘w‘ or ‘w:‘  open for writing without compression
    165            ‘w:gz‘       open for writing with gzip compression
    166            ‘w:bz2‘      open for writing with bzip2 compression
    167
    168            ‘r|*‘        open a stream of tar blocks with transparent compression
    169            ‘r|‘         open an uncompressed stream of tar blocks for reading
    170            ‘r|gz‘       open a gzip compressed stream of tar blocks
    171            ‘r|bz2‘      open a bzip2 compressed stream of tar blocks
    172            ‘w|‘         open an uncompressed stream for writing
    173            ‘w|gz‘       open a gzip compressed stream for writing
    174            ‘w|bz2‘      open a bzip2 compressed stream for writing
    175         """
    176
    177         if not name and not fileobj:
    178             raise ValueError("nothing to open")
    179
    180         if mode in ("r", "r:*"):
    181             # Find out which *open() is appropriate for opening the file.
    182             for comptype in cls.OPEN_METH:
    183                 func = getattr(cls, cls.OPEN_METH[comptype])
    184                 if fileobj is not None:
    185                     saved_pos = fileobj.tell()
    186                 try:
    187                     return func(name, "r", fileobj, **kwargs)
    188                 except (ReadError, CompressionError), e:
    189                     if fileobj is not None:
    190                         fileobj.seek(saved_pos)
    191                     continue
    192             raise ReadError("file could not be opened successfully")
    193
    194         elif ":" in mode:
    195             filemode, comptype = mode.split(":", 1)
    196             filemode = filemode or "r"
    197             comptype = comptype or "tar"
    198
    199             # Select the *open() function according to
    200             # given compression.
    201             if comptype in cls.OPEN_METH:
    202                 func = getattr(cls, cls.OPEN_METH[comptype])
    203             else:
    204                 raise CompressionError("unknown compression type %r" % comptype)
    205             return func(name, filemode, fileobj, **kwargs)
    206
    207         elif "|" in mode:
    208             filemode, comptype = mode.split("|", 1)
    209             filemode = filemode or "r"
    210             comptype = comptype or "tar"
    211
    212             if filemode not in ("r", "w"):
    213                 raise ValueError("mode must be ‘r‘ or ‘w‘")
    214
    215             stream = _Stream(name, filemode, comptype, fileobj, bufsize)
    216             try:
    217                 t = cls(name, filemode, stream, **kwargs)
    218             except:
    219                 stream.close()
    220                 raise
    221             t._extfileobj = False
    222             return t
    223
    224         elif mode in ("a", "w"):
    225             return cls.taropen(name, mode, fileobj, **kwargs)
    226
    227         raise ValueError("undiscernible mode")
    228
    229     @classmethod
    230     def taropen(cls, name, mode="r", fileobj=None, **kwargs):
    231         """Open uncompressed tar archive name for reading or writing.
    232         """
    233         if mode not in ("r", "a", "w"):
    234             raise ValueError("mode must be ‘r‘, ‘a‘ or ‘w‘")
    235         return cls(name, mode, fileobj, **kwargs)
    236
    237     @classmethod
    238     def gzopen(cls, name, mode="r", fileobj=None, compresslevel=9, **kwargs):
    239         """Open gzip compressed tar archive name for reading or writing.
    240            Appending is not allowed.
    241         """
    242         if mode not in ("r", "w"):
    243             raise ValueError("mode must be ‘r‘ or ‘w‘")
    244
    245         try:
    246             import gzip
    247             gzip.GzipFile
    248         except (ImportError, AttributeError):
    249             raise CompressionError("gzip module is not available")
    250
    251         try:
    252             fileobj = gzip.GzipFile(name, mode, compresslevel, fileobj)
    253         except OSError:
    254             if fileobj is not None and mode == ‘r‘:
    255                 raise ReadError("not a gzip file")
    256             raise
    257
    258         try:
    259             t = cls.taropen(name, mode, fileobj, **kwargs)
    260         except IOError:
    261             fileobj.close()
    262             if mode == ‘r‘:
    263                 raise ReadError("not a gzip file")
    264             raise
    265         except:
    266             fileobj.close()
    267             raise
    268         t._extfileobj = False
    269         return t
    270
    271     @classmethod
    272     def bz2open(cls, name, mode="r", fileobj=None, compresslevel=9, **kwargs):
    273         """Open bzip2 compressed tar archive name for reading or writing.
    274            Appending is not allowed.
    275         """
    276         if mode not in ("r", "w"):
    277             raise ValueError("mode must be ‘r‘ or ‘w‘.")
    278
    279         try:
    280             import bz2
    281         except ImportError:
    282             raise CompressionError("bz2 module is not available")
    283
    284         if fileobj is not None:
    285             fileobj = _BZ2Proxy(fileobj, mode)
    286         else:
    287             fileobj = bz2.BZ2File(name, mode, compresslevel=compresslevel)
    288
    289         try:
    290             t = cls.taropen(name, mode, fileobj, **kwargs)
    291         except (IOError, EOFError):
    292             fileobj.close()
    293             if mode == ‘r‘:
    294                 raise ReadError("not a bzip2 file")
    295             raise
    296         except:
    297             fileobj.close()
    298             raise
    299         t._extfileobj = False
    300         return t
    301
    302     # All *open() methods are registered here.
    303     OPEN_METH = {
    304         "tar": "taropen",   # uncompressed tar
    305         "gz":  "gzopen",    # gzip compressed tar
    306         "bz2": "bz2open"    # bzip2 compressed tar
    307     }
    308
    309     #--------------------------------------------------------------------------
    310     # The public methods which TarFile provides:
    311
    312     def close(self):
    313         """Close the TarFile. In write-mode, two finishing zero blocks are
    314            appended to the archive.
    315         """
    316         if self.closed:
    317             return
    318
    319         if self.mode in "aw":
    320             self.fileobj.write(NUL * (BLOCKSIZE * 2))
    321             self.offset += (BLOCKSIZE * 2)
    322             # fill up the end with zero-blocks
    323             # (like option -b20 for tar does)
    324             blocks, remainder = divmod(self.offset, RECORDSIZE)
    325             if remainder > 0:
    326                 self.fileobj.write(NUL * (RECORDSIZE - remainder))
    327
    328         if not self._extfileobj:
    329             self.fileobj.close()
    330         self.closed = True
    331
    332     def getmember(self, name):
    333         """Return a TarInfo object for member `name‘. If `name‘ can not be
    334            found in the archive, KeyError is raised. If a member occurs more
    335            than once in the archive, its last occurrence is assumed to be the
    336            most up-to-date version.
    337         """
    338         tarinfo = self._getmember(name)
    339         if tarinfo is None:
    340             raise KeyError("filename %r not found" % name)
    341         return tarinfo
    342
    343     def getmembers(self):
    344         """Return the members of the archive as a list of TarInfo objects. The
    345            list has the same order as the members in the archive.
    346         """
    347         self._check()
    348         if not self._loaded:    # if we want to obtain a list of
    349             self._load()        # all members, we first have to
    350                                 # scan the whole archive.
    351         return self.members
    352
    353     def getnames(self):
    354         """Return the members of the archive as a list of their names. It has
    355            the same order as the list returned by getmembers().
    356         """
    357         return [tarinfo.name for tarinfo in self.getmembers()]
    358
    359     def gettarinfo(self, name=None, arcname=None, fileobj=None):
    360         """Create a TarInfo object for either the file `name‘ or the file
    361            object `fileobj‘ (using os.fstat on its file descriptor). You can
    362            modify some of the TarInfo‘s attributes before you add it using
    363            addfile(). If given, `arcname‘ specifies an alternative name for the
    364            file in the archive.
    365         """
    366         self._check("aw")
    367
    368         # When fileobj is given, replace name by
    369         # fileobj‘s real name.
    370         if fileobj is not None:
    371             name = fileobj.name
    372
    373         # Building the name of the member in the archive.
    374         # Backward slashes are converted to forward slashes,
    375         # Absolute paths are turned to relative paths.
    376         if arcname is None:
    377             arcname = name
    378         drv, arcname = os.path.splitdrive(arcname)
    379         arcname = arcname.replace(os.sep, "/")
    380         arcname = arcname.lstrip("/")
    381
    382         # Now, fill the TarInfo object with
    383         # information specific for the file.
    384         tarinfo = self.tarinfo()
    385         tarinfo.tarfile = self
    386
    387         # Use os.stat or os.lstat, depending on platform
    388         # and if symlinks shall be resolved.
    389         if fileobj is None:
    390             if hasattr(os, "lstat") and not self.dereference:
    391                 statres = os.lstat(name)
    392             else:
    393                 statres = os.stat(name)
    394         else:
    395             statres = os.fstat(fileobj.fileno())
    396         linkname = ""
    397
    398         stmd = statres.st_mode
    399         if stat.S_ISREG(stmd):
    400             inode = (statres.st_ino, statres.st_dev)
    401             if not self.dereference and statres.st_nlink > 1 and 402                     inode in self.inodes and arcname != self.inodes[inode]:
    403                 # Is it a hardlink to an already
    404                 # archived file?
    405                 type = LNKTYPE
    406                 linkname = self.inodes[inode]
    407             else:
    408                 # The inode is added only if its valid.
    409                 # For win32 it is always 0.
    410                 type = REGTYPE
    411                 if inode[0]:
    412                     self.inodes[inode] = arcname
    413         elif stat.S_ISDIR(stmd):
    414             type = DIRTYPE
    415         elif stat.S_ISFIFO(stmd):
    416             type = FIFOTYPE
    417         elif stat.S_ISLNK(stmd):
    418             type = SYMTYPE
    419             linkname = os.readlink(name)
    420         elif stat.S_ISCHR(stmd):
    421             type = CHRTYPE
    422         elif stat.S_ISBLK(stmd):
    423             type = BLKTYPE
    424         else:
    425             return None
    426
    427         # Fill the TarInfo object with all
    428         # information we can get.
    429         tarinfo.name = arcname
    430         tarinfo.mode = stmd
    431         tarinfo.uid = statres.st_uid
    432         tarinfo.gid = statres.st_gid
    433         if type == REGTYPE:
    434             tarinfo.size = statres.st_size
    435         else:
    436             tarinfo.size = 0L
    437         tarinfo.mtime = statres.st_mtime
    438         tarinfo.type = type
    439         tarinfo.linkname = linkname
    440         if pwd:
    441             try:
    442                 tarinfo.uname = pwd.getpwuid(tarinfo.uid)[0]
    443             except KeyError:
    444                 pass
    445         if grp:
    446             try:
    447                 tarinfo.gname = grp.getgrgid(tarinfo.gid)[0]
    448             except KeyError:
    449                 pass
    450
    451         if type in (CHRTYPE, BLKTYPE):
    452             if hasattr(os, "major") and hasattr(os, "minor"):
    453                 tarinfo.devmajor = os.major(statres.st_rdev)
    454                 tarinfo.devminor = os.minor(statres.st_rdev)
    455         return tarinfo
    456
    457     def list(self, verbose=True):
    458         """Print a table of contents to sys.stdout. If `verbose‘ is False, only
    459            the names of the members are printed. If it is True, an `ls -l‘-like
    460            output is produced.
    461         """
    462         self._check()
    463
    464         for tarinfo in self:
    465             if verbose:
    466                 print filemode(tarinfo.mode),
    467                 print "%s/%s" % (tarinfo.uname or tarinfo.uid,
    468                                  tarinfo.gname or tarinfo.gid),
    469                 if tarinfo.ischr() or tarinfo.isblk():
    470                     print "%10s" % ("%d,%d" 471                                     % (tarinfo.devmajor, tarinfo.devminor)),
    472                 else:
    473                     print "%10d" % tarinfo.size,
    474                 print "%d-%02d-%02d %02d:%02d:%02d" 475                       % time.localtime(tarinfo.mtime)[:6],
    476
    477             print tarinfo.name + ("/" if tarinfo.isdir() else ""),
    478
    479             if verbose:
    480                 if tarinfo.issym():
    481                     print "->", tarinfo.linkname,
    482                 if tarinfo.islnk():
    483                     print "link to", tarinfo.linkname,
    484             print
    485
    486     def add(self, name, arcname=None, recursive=True, exclude=None, filter=None):
    487         """Add the file `name‘ to the archive. `name‘ may be any type of file
    488            (directory, fifo, symbolic link, etc.). If given, `arcname‘
    489            specifies an alternative name for the file in the archive.
    490            Directories are added recursively by default. This can be avoided by
    491            setting `recursive‘ to False. `exclude‘ is a function that should
    492            return True for each filename to be excluded. `filter‘ is a function
    493            that expects a TarInfo object argument and returns the changed
    494            TarInfo object, if it returns None the TarInfo object will be
    495            excluded from the archive.
    496         """
    497         self._check("aw")
    498
    499         if arcname is None:
    500             arcname = name
    501
    502         # Exclude pathnames.
    503         if exclude is not None:
    504             import warnings
    505             warnings.warn("use the filter argument instead",
    506                     DeprecationWarning, 2)
    507             if exclude(name):
    508                 self._dbg(2, "tarfile: Excluded %r" % name)
    509                 return
    510
    511         # Skip if somebody tries to archive the archive...
    512         if self.name is not None and os.path.abspath(name) == self.name:
    513             self._dbg(2, "tarfile: Skipped %r" % name)
    514             return
    515
    516         self._dbg(1, name)
    517
    518         # Create a TarInfo object from the file.
    519         tarinfo = self.gettarinfo(name, arcname)
    520
    521         if tarinfo is None:
    522             self._dbg(1, "tarfile: Unsupported type %r" % name)
    523             return
    524
    525         # Change or exclude the TarInfo object.
    526         if filter is not None:
    527             tarinfo = filter(tarinfo)
    528             if tarinfo is None:
    529                 self._dbg(2, "tarfile: Excluded %r" % name)
    530                 return
    531
    532         # Append the tar header and data to the archive.
    533         if tarinfo.isreg():
    534             with bltn_open(name, "rb") as f:
    535                 self.addfile(tarinfo, f)
    536
    537         elif tarinfo.isdir():
    538             self.addfile(tarinfo)
    539             if recursive:
    540                 for f in os.listdir(name):
    541                     self.add(os.path.join(name, f), os.path.join(arcname, f),
    542                             recursive, exclude, filter)
    543
    544         else:
    545             self.addfile(tarinfo)
    546
    547     def addfile(self, tarinfo, fileobj=None):
    548         """Add the TarInfo object `tarinfo‘ to the archive. If `fileobj‘ is
    549            given, tarinfo.size bytes are read from it and added to the archive.
    550            You can create TarInfo objects using gettarinfo().
    551            On Windows platforms, `fileobj‘ should always be opened with mode
    552            ‘rb‘ to avoid irritation about the file size.
    553         """
    554         self._check("aw")
    555
    556         tarinfo = copy.copy(tarinfo)
    557
    558         buf = tarinfo.tobuf(self.format, self.encoding, self.errors)
    559         self.fileobj.write(buf)
    560         self.offset += len(buf)
    561
    562         # If there‘s data to follow, append it.
    563         if fileobj is not None:
    564             copyfileobj(fileobj, self.fileobj, tarinfo.size)
    565             blocks, remainder = divmod(tarinfo.size, BLOCKSIZE)
    566             if remainder > 0:
    567                 self.fileobj.write(NUL * (BLOCKSIZE - remainder))
    568                 blocks += 1
    569             self.offset += blocks * BLOCKSIZE
    570
    571         self.members.append(tarinfo)
    572
    573     def extractall(self, path=".", members=None):
    574         """Extract all members from the archive to the current working
    575            directory and set owner, modification time and permissions on
    576            directories afterwards. `path‘ specifies a different directory
    577            to extract to. `members‘ is optional and must be a subset of the
    578            list returned by getmembers().
    579         """
    580         directories = []
    581
    582         if members is None:
    583             members = self
    584
    585         for tarinfo in members:
    586             if tarinfo.isdir():
    587                 # Extract directories with a safe mode.
    588                 directories.append(tarinfo)
    589                 tarinfo = copy.copy(tarinfo)
    590                 tarinfo.mode = 0700
    591             self.extract(tarinfo, path)
    592
    593         # Reverse sort directories.
    594         directories.sort(key=operator.attrgetter(‘name‘))
    595         directories.reverse()
    596
    597         # Set correct owner, mtime and filemode on directories.
    598         for tarinfo in directories:
    599             dirpath = os.path.join(path, tarinfo.name)
    600             try:
    601                 self.chown(tarinfo, dirpath)
    602                 self.utime(tarinfo, dirpath)
    603                 self.chmod(tarinfo, dirpath)
    604             except ExtractError, e:
    605                 if self.errorlevel > 1:
    606                     raise
    607                 else:
    608                     self._dbg(1, "tarfile: %s" % e)
    609
    610     def extract(self, member, path=""):
    611         """Extract a member from the archive to the current working directory,
    612            using its full name. Its file information is extracted as accurately
    613            as possible. `member‘ may be a filename or a TarInfo object. You can
    614            specify a different directory using `path‘.
    615         """
    616         self._check("r")
    617
    618         if isinstance(member, basestring):
    619             tarinfo = self.getmember(member)
    620         else:
    621             tarinfo = member
    622
    623         # Prepare the link target for makelink().
    624         if tarinfo.islnk():
    625             tarinfo._link_target = os.path.join(path, tarinfo.linkname)
    626
    627         try:
    628             self._extract_member(tarinfo, os.path.join(path, tarinfo.name))
    629         except EnvironmentError, e:
    630             if self.errorlevel > 0:
    631                 raise
    632             else:
    633                 if e.filename is None:
    634                     self._dbg(1, "tarfile: %s" % e.strerror)
    635                 else:
    636                     self._dbg(1, "tarfile: %s %r" % (e.strerror, e.filename))
    637         except ExtractError, e:
    638             if self.errorlevel > 1:
    639                 raise
    640             else:
    641                 self._dbg(1, "tarfile: %s" % e)
    642
    643     def extractfile(self, member):
    644         """Extract a member from the archive as a file object. `member‘ may be
    645            a filename or a TarInfo object. If `member‘ is a regular file, a
    646            file-like object is returned. If `member‘ is a link, a file-like
    647            object is constructed from the link‘s target. If `member‘ is none of
    648            the above, None is returned.
    649            The file-like object is read-only and provides the following
    650            methods: read(), readline(), readlines(), seek() and tell()
    651         """
    652         self._check("r")
    653
    654         if isinstance(member, basestring):
    655             tarinfo = self.getmember(member)
    656         else:
    657             tarinfo = member
    658
    659         if tarinfo.isreg():
    660             return self.fileobject(self, tarinfo)
    661
    662         elif tarinfo.type not in SUPPORTED_TYPES:
    663             # If a member‘s type is unknown, it is treated as a
    664             # regular file.
    665             return self.fileobject(self, tarinfo)
    666
    667         elif tarinfo.islnk() or tarinfo.issym():
    668             if isinstance(self.fileobj, _Stream):
    669                 # A small but ugly workaround for the case that someone tries
    670                 # to extract a (sym)link as a file-object from a non-seekable
    671                 # stream of tar blocks.
    672                 raise StreamError("cannot extract (sym)link as file object")
    673             else:
    674                 # A (sym)link‘s file object is its target‘s file object.
    675                 return self.extractfile(self._find_link_target(tarinfo))
    676         else:
    677             # If there‘s no data associated with the member (directory, chrdev,
    678             # blkdev, etc.), return None instead of a file object.
    679             return None
    680
    681     def _extract_member(self, tarinfo, targetpath):
    682         """Extract the TarInfo object tarinfo to a physical
    683            file called targetpath.
    684         """
    685         # Fetch the TarInfo object for the given name
    686         # and build the destination pathname, replacing
    687         # forward slashes to platform specific separators.
    688         targetpath = targetpath.rstrip("/")
    689         targetpath = targetpath.replace("/", os.sep)
    690
    691         # Create all upper directories.
    692         upperdirs = os.path.dirname(targetpath)
    693         if upperdirs and not os.path.exists(upperdirs):
    694             # Create directories that are not part of the archive with
    695             # default permissions.
    696             os.makedirs(upperdirs)
    697
    698         if tarinfo.islnk() or tarinfo.issym():
    699             self._dbg(1, "%s -> %s" % (tarinfo.name, tarinfo.linkname))
    700         else:
    701             self._dbg(1, tarinfo.name)
    702
    703         if tarinfo.isreg():
    704             self.makefile(tarinfo, targetpath)
    705         elif tarinfo.isdir():
    706             self.makedir(tarinfo, targetpath)
    707         elif tarinfo.isfifo():
    708             self.makefifo(tarinfo, targetpath)
    709         elif tarinfo.ischr() or tarinfo.isblk():
    710             self.makedev(tarinfo, targetpath)
    711         elif tarinfo.islnk() or tarinfo.issym():
    712             self.makelink(tarinfo, targetpath)
    713         elif tarinfo.type not in SUPPORTED_TYPES:
    714             self.makeunknown(tarinfo, targetpath)
    715         else:
    716             self.makefile(tarinfo, targetpath)
    717
    718         self.chown(tarinfo, targetpath)
    719         if not tarinfo.issym():
    720             self.chmod(tarinfo, targetpath)
    721             self.utime(tarinfo, targetpath)
    722
    723     #--------------------------------------------------------------------------
    724     # Below are the different file methods. They are called via
    725     # _extract_member() when extract() is called. They can be replaced in a
    726     # subclass to implement other functionality.
    727
    728     def makedir(self, tarinfo, targetpath):
    729         """Make a directory called targetpath.
    730         """
    731         try:
    732             # Use a safe mode for the directory, the real mode is set
    733             # later in _extract_member().
    734             os.mkdir(targetpath, 0700)
    735         except EnvironmentError, e:
    736             if e.errno != errno.EEXIST:
    737                 raise
    738
    739     def makefile(self, tarinfo, targetpath):
    740         """Make a file called targetpath.
    741         """
    742         source = self.extractfile(tarinfo)
    743         try:
    744             with bltn_open(targetpath, "wb") as target:
    745                 copyfileobj(source, target)
    746         finally:
    747             source.close()
    748
    749     def makeunknown(self, tarinfo, targetpath):
    750         """Make a file from a TarInfo object with an unknown type
    751            at targetpath.
    752         """
    753         self.makefile(tarinfo, targetpath)
    754         self._dbg(1, "tarfile: Unknown file type %r, " 755                      "extracted as regular file." % tarinfo.type)
    756
    757     def makefifo(self, tarinfo, targetpath):
    758         """Make a fifo called targetpath.
    759         """
    760         if hasattr(os, "mkfifo"):
    761             os.mkfifo(targetpath)
    762         else:
    763             raise ExtractError("fifo not supported by system")
    764
    765     def makedev(self, tarinfo, targetpath):
    766         """Make a character or block device called targetpath.
    767         """
    768         if not hasattr(os, "mknod") or not hasattr(os, "makedev"):
    769             raise ExtractError("special devices not supported by system")
    770
    771         mode = tarinfo.mode
    772         if tarinfo.isblk():
    773             mode |= stat.S_IFBLK
    774         else:
    775             mode |= stat.S_IFCHR
    776
    777         os.mknod(targetpath, mode,
    778                  os.makedev(tarinfo.devmajor, tarinfo.devminor))
    779
    780     def makelink(self, tarinfo, targetpath):
    781         """Make a (symbolic) link called targetpath. If it cannot be created
    782           (platform limitation), we try to make a copy of the referenced file
    783           instead of a link.
    784         """
    785         if hasattr(os, "symlink") and hasattr(os, "link"):
    786             # For systems that support symbolic and hard links.
    787             if tarinfo.issym():
    788                 if os.path.lexists(targetpath):
    789                     os.unlink(targetpath)
    790                 os.symlink(tarinfo.linkname, targetpath)
    791             else:
    792                 # See extract().
    793                 if os.path.exists(tarinfo._link_target):
    794                     if os.path.lexists(targetpath):
    795                         os.unlink(targetpath)
    796                     os.link(tarinfo._link_target, targetpath)
    797                 else:
    798                     self._extract_member(self._find_link_target(tarinfo), targetpath)
    799         else:
    800             try:
    801                 self._extract_member(self._find_link_target(tarinfo), targetpath)
    802             except KeyError:
    803                 raise ExtractError("unable to resolve link inside archive")
    804
    805     def chown(self, tarinfo, targetpath):
    806         """Set owner of targetpath according to tarinfo.
    807         """
    808         if pwd and hasattr(os, "geteuid") and os.geteuid() == 0:
    809             # We have to be root to do so.
    810             try:
    811                 g = grp.getgrnam(tarinfo.gname)[2]
    812             except KeyError:
    813                 g = tarinfo.gid
    814             try:
    815                 u = pwd.getpwnam(tarinfo.uname)[2]
    816             except KeyError:
    817                 u = tarinfo.uid
    818             try:
    819                 if tarinfo.issym() and hasattr(os, "lchown"):
    820                     os.lchown(targetpath, u, g)
    821                 else:
    822                     if sys.platform != "os2emx":
    823                         os.chown(targetpath, u, g)
    824             except EnvironmentError, e:
    825                 raise ExtractError("could not change owner")
    826
    827     def chmod(self, tarinfo, targetpath):
    828         """Set file permissions of targetpath according to tarinfo.
    829         """
    830         if hasattr(os, ‘chmod‘):
    831             try:
    832                 os.chmod(targetpath, tarinfo.mode)
    833             except EnvironmentError, e:
    834                 raise ExtractError("could not change mode")
    835
    836     def utime(self, tarinfo, targetpath):
    837         """Set modification time of targetpath according to tarinfo.
    838         """
    839         if not hasattr(os, ‘utime‘):
    840             return
    841         try:
    842             os.utime(targetpath, (tarinfo.mtime, tarinfo.mtime))
    843         except EnvironmentError, e:
    844             raise ExtractError("could not change modification time")
    845
    846     #--------------------------------------------------------------------------
    847     def next(self):
    848         """Return the next member of the archive as a TarInfo object, when
    849            TarFile is opened for reading. Return None if there is no more
    850            available.
    851         """
    852         self._check("ra")
    853         if self.firstmember is not None:
    854             m = self.firstmember
    855             self.firstmember = None
    856             return m
    857
    858         # Read the next block.
    859         self.fileobj.seek(self.offset)
    860         tarinfo = None
    861         while True:
    862             try:
    863                 tarinfo = self.tarinfo.fromtarfile(self)
    864             except EOFHeaderError, e:
    865                 if self.ignore_zeros:
    866                     self._dbg(2, "0x%X: %s" % (self.offset, e))
    867                     self.offset += BLOCKSIZE
    868                     continue
    869             except InvalidHeaderError, e:
    870                 if self.ignore_zeros:
    871                     self._dbg(2, "0x%X: %s" % (self.offset, e))
    872                     self.offset += BLOCKSIZE
    873                     continue
    874                 elif self.offset == 0:
    875                     raise ReadError(str(e))
    876             except EmptyHeaderError:
    877                 if self.offset == 0:
    878                     raise ReadError("empty file")
    879             except TruncatedHeaderError, e:
    880                 if self.offset == 0:
    881                     raise ReadError(str(e))
    882             except SubsequentHeaderError, e:
    883                 raise ReadError(str(e))
    884             break
    885
    886         if tarinfo is not None:
    887             self.members.append(tarinfo)
    888         else:
    889             self._loaded = True
    890
    891         return tarinfo
    892
    893     #--------------------------------------------------------------------------
    894     # Little helper methods:
    895
    896     def _getmember(self, name, tarinfo=None, normalize=False):
    897         """Find an archive member by name from bottom to top.
    898            If tarinfo is given, it is used as the starting point.
    899         """
    900         # Ensure that all members have been loaded.
    901         members = self.getmembers()
    902
    903         # Limit the member search list up to tarinfo.
    904         if tarinfo is not None:
    905             members = members[:members.index(tarinfo)]
    906
    907         if normalize:
    908             name = os.path.normpath(name)
    909
    910         for member in reversed(members):
    911             if normalize:
    912                 member_name = os.path.normpath(member.name)
    913             else:
    914                 member_name = member.name
    915
    916             if name == member_name:
    917                 return member
    918
    919     def _load(self):
    920         """Read through the entire archive file and look for readable
    921            members.
    922         """
    923         while True:
    924             tarinfo = self.next()
    925             if tarinfo is None:
    926                 break
    927         self._loaded = True
    928
    929     def _check(self, mode=None):
    930         """Check if TarFile is still open, and if the operation‘s mode
    931            corresponds to TarFile‘s mode.
    932         """
    933         if self.closed:
    934             raise IOError("%s is closed" % self.__class__.__name__)
    935         if mode is not None and self.mode not in mode:
    936             raise IOError("bad operation for mode %r" % self.mode)
    937
    938     def _find_link_target(self, tarinfo):
    939         """Find the target member of a symlink or hardlink member in the
    940            archive.
    941         """
    942         if tarinfo.issym():
    943             # Always search the entire archive.
    944             linkname = "/".join(filter(None, (os.path.dirname(tarinfo.name), tarinfo.linkname)))
    945             limit = None
    946         else:
    947             # Search the archive before the link, because a hard link is
    948             # just a reference to an already archived file.
    949             linkname = tarinfo.linkname
    950             limit = tarinfo
    951
    952         member = self._getmember(linkname, tarinfo=limit, normalize=True)
    953         if member is None:
    954             raise KeyError("linkname %r not found" % linkname)
    955         return member
    956
    957     def __iter__(self):
    958         """Provide an iterator object.
    959         """
    960         if self._loaded:
    961             return iter(self.members)
    962         else:
    963             return TarIter(self)
    964
    965     def _dbg(self, level, msg):
    966         """Write debugging output to sys.stderr.
    967         """
    968         if level <= self.debug:
    969             print >> sys.stderr, msg
    970
    971     def __enter__(self):
    972         self._check()
    973         return self
    974
    975     def __exit__(self, type, value, traceback):
    976         if type is None:
    977             self.close()
    978         else:
    979             # An exception occurred. We must not call close() because
    980             # it would try to write end-of-archive blocks and padding.
    981             if not self._extfileobj:
    982                 self.fileobj.close()
    983             self.closed = True
    984 # class TarFile

    TarFile 源代码

5.6json和pickle模块

json主要应用于Python中的数据交换,pickle应用于不用的编程语言之间的数据交换。

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
  • pickle,用于python特有的类型 和 python的数据类型间进行转换

Json模块提供了四个功能:dumps、dump、loads、load

pickle模块提供了四个功能:dumps、dump、loads、load

下面例子为Python2.7中的例子。

5.7shelve模块

shelve模块是一个简单的k,v将内存数据通过文件持久化的模块,可以持久化任何pickle可支持的python数据格式。是对pickle的更上一次的封装。

 1 import shelve
 2
 3 d = shelve.open(‘shelve_test‘) #打开一个文件
 4
 5 class Test(object):
 6     def __init__(self,n):
 7         self.n = n
 8
 9
10 t = Test(123)
11 t2 = Test(123334)
12
13 name = ["alex","rain","test"]
14 d["test"] = name #持久化列表
15 d["t1"] = t      #持久化类
16 d["t2"] = t2
17
18 d.close()

5.8xml模块

xml是实现不同语言或程序之间进行数据交换的协议,跟json差不多,但json使用起来更简单,不过,古时候,在json还没诞生的黑暗年代,大家只能选择用xml呀,至今很多传统公司如金融行业的很多系统的接口还主要是xml。

xml的格式如下,就是通过<>节点来区别数据结构的:

 1 <?xml version="1.0"?>
 2 <data>
 3     <country name="Liechtenstein">
 4         <rank updated="yes">2</rank>
 5         <year>2008</year>
 6         <gdppc>141100</gdppc>
 7         <neighbor name="Austria" direction="E"/>
 8         <neighbor name="Switzerland" direction="W"/>
 9     </country>
10     <country name="Singapore">
11         <rank updated="yes">5</rank>
12         <year>2011</year>
13         <gdppc>59900</gdppc>
14         <neighbor name="Malaysia" direction="N"/>
15     </country>
16     <country name="Panama">
17         <rank updated="yes">69</rank>
18         <year>2011</year>
19         <gdppc>13600</gdppc>
20         <neighbor name="Costa Rica" direction="W"/>
21         <neighbor name="Colombia" direction="E"/>
22     </country>
23 </data>

xml模块

xml协议在各个语言里的都 是支持的,在python中可以用以下模块操作xml

 1 import xml.etree.ElementTree as ET
 2
 3 tree = ET.parse("xmltest.xml")
 4 root = tree.getroot()
 5 print(root.tag)
 6
 7 #遍历xml文档
 8 for child in root:
 9     print(child.tag, child.attrib)
10     for i in child:
11         print(i.tag,i.text)
12
13 #只遍历year 节点
14 for node in root.iter(‘year‘):
15     print(node.tag,node.text)

修改和删除xml文档内容

 1 import xml.etree.ElementTree as ET
 2
 3 tree = ET.parse("xmltest.xml")
 4 root = tree.getroot()
 5
 6 #修改
 7 for node in root.iter(‘year‘):
 8     new_year = int(node.text) + 1
 9     node.text = str(new_year)
10     node.set("updated","yes")
11
12 tree.write("xmltest.xml")
13
14
15 #删除node
16 for country in root.findall(‘country‘):
17    rank = int(country.find(‘rank‘).text)
18    if rank > 50:
19      root.remove(country)
20
21 tree.write(‘output.xml‘)

自己 创建Xml

 1 import xml.etree.ElementTree as ET
 2
 3
 4 new_xml = ET.Element("namelist")
 5 name = ET.SubElement(new_xml,"name",attrib={"enrolled":"yes"})
 6 age = ET.SubElement(name,"age",attrib={"checked":"no"})
 7 sex = ET.SubElement(name,"sex")
 8 sex.text = ‘33‘
 9 name2 = ET.SubElement(new_xml,"name",attrib={"enrolled":"no"})
10 age = ET.SubElement(name2,"age")
11 age.text = ‘19‘
12
13 et = ET.ElementTree(new_xml) #生成文档对象
14 et.write("test.xml", encoding="utf-8",xml_declaration=True)
15
16 ET.dump(new_xml) #打印生成的格式

5.9PyYAML模块

pyyaml主要实现配置文档的书写。

load一下,编程字典的格式。

Python也可以很容易的处理ymal文档格式,只不过需要安装一个模块,参考文档:http://pyyaml.org/wiki/PyYAMLDocumentation

5.10ConfigParser模块

用于生成和修改常见配置文档,当前模块的名称在 python 3.x 版本中变更为 configparser。

一般都是读配置文件,解析配置文件。修改用的不是很多。

来看一个好多软件的常见文档格式如下:

 1 [DEFAULT]
 2 ServerAliveInterval = 45
 3 Compression = yes
 4 CompressionLevel = 9
 5 ForwardX11 = yes
 6
 7 [bitbucket.org]
 8 User = hg
 9
10 [topsecret.server.com]
11 Port = 50022
12 ForwardX11 = no

如果想用python生成一个这样的文档怎么做呢?

import configparser

config = configparser.ConfigParser()
config["DEFAULT"] = {‘ServerAliveInterval‘: ‘45‘,
                      ‘Compression‘: ‘yes‘,
                     ‘CompressionLevel‘: ‘9‘}

config[‘bitbucket.org‘] = {}
config[‘bitbucket.org‘][‘User‘] = ‘hg‘
config[‘topsecret.server.com‘] = {}
topsecret = config[‘topsecret.server.com‘]
topsecret[‘Host Port‘] = ‘50022‘     # mutates the parser
topsecret[‘ForwardX11‘] = ‘no‘  # same here
config[‘DEFAULT‘][‘ForwardX11‘] = ‘yes‘
with open(‘example.ini‘, ‘w‘) as configfile:
   config.write(configfile)

写完了还可以再读出来哈。

 1 >>> import configparser
 2 >>> config = configparser.ConfigParser()
 3 >>> config.sections()
 4 []
 5 >>> config.read(‘example.ini‘)
 6 [‘example.ini‘]
 7 >>> config.sections()
 8 [‘bitbucket.org‘, ‘topsecret.server.com‘]
 9 >>> ‘bitbucket.org‘ in config
10 True
11 >>> ‘bytebong.com‘ in config
12 False
13 >>> config[‘bitbucket.org‘][‘User‘]
14 ‘hg‘
15 >>> config[‘DEFAULT‘][‘Compression‘]
16 ‘yes‘
17 >>> topsecret = config[‘topsecret.server.com‘]
18 >>> topsecret[‘ForwardX11‘]
19 ‘no‘
20 >>> topsecret[‘Port‘]
21 ‘50022‘
22 >>> for key in config[‘bitbucket.org‘]: print(key)
23 ...
24 user
25 compressionlevel
26 serveraliveinterval
27 compression
28 forwardx11
29 >>> config[‘bitbucket.org‘][‘ForwardX11‘]
30 ‘yes‘

configparser增删改查语法

 1 [section1]
 2 k1 = v1
 3 k2:v2
 4
 5 [section2]
 6 k1 = v1
 7
 8 import ConfigParser
 9
10 config = ConfigParser.ConfigParser()
11 config.read(‘i.cfg‘)
12
13 # ########## 读 ##########
14 #secs = config.sections()
15 #print secs
16 #options = config.options(‘group2‘)
17 #print options
18
19 #item_list = config.items(‘group2‘)
20 #print item_list
21
22 #val = config.get(‘group1‘,‘key‘)
23 #val = config.getint(‘group1‘,‘key‘)
24
25 # ########## 改写 ##########
26 #sec = config.remove_section(‘group1‘)
27 #config.write(open(‘i.cfg‘, "w"))
28
29 #sec = config.has_section(‘wupeiqi‘)
30 #sec = config.add_section(‘wupeiqi‘)
31 #config.write(open(‘i.cfg‘, "w"))
32
33
34 #config.set(‘group2‘,‘k1‘,11111)
35 #config.write(open(‘i.cfg‘, "w"))
36
37 #config.remove_option(‘group2‘,‘age‘)
38 #config.write(open(‘i.cfg‘, "w"))

5.11hashlib模块  

用于加密相关的操作,3.x里代替了md5模块和sha模块,主要提供 SHA1, SHA224, SHA256, SHA384, SHA512 ,MD5 算法

MD5不能反解的

import hashlib

m = hashlib.md5()
m.update(b"Hello")
m.update(b"It‘s me")
print(m.digest())
m.update(b"It‘s been a long time since last time we ...")

print(m.digest()) #2进制格式hash
print(len(m.hexdigest())) #16进制格式hash
‘‘‘
def digest(self, *args, **kwargs): # real signature unknown
    """ Return the digest value as a string of binary data. """
    pass

def hexdigest(self, *args, **kwargs): # real signature unknown
    """ Return the digest value as a string of hexadecimal digits. """
    pass

‘‘‘
import hashlib

# ######## md5 ########

hash = hashlib.md5()
hash.update(‘admin‘)
print(hash.hexdigest())

# ######## sha1 ########

hash = hashlib.sha1()
hash.update(‘admin‘)
print(hash.hexdigest())

# ######## sha256 ########

hash = hashlib.sha256()
hash.update(‘admin‘)
print(hash.hexdigest())

# ######## sha384 ########

hash = hashlib.sha384()
hash.update(‘admin‘)
print(hash.hexdigest())

# ######## sha512 ########

hash = hashlib.sha512()
hash.update(‘admin‘)
print(hash.hexdigest())

python 还有一个 hmac 模块,它内部对我们创建 key 和 内容 再进行处理然后再加密

散列消息鉴别码,简称HMAC,是一种基于消息鉴别码MAC(Message Authentication Code)的鉴别机制。使用HMAC时,消息通讯的双方,通过验证消息中加入的鉴别密钥K来鉴别消息的真伪;

一般用于网络通信中消息加密,前提是双方先要约定好key,就像接头暗号一样,然后消息发送把用key把消息加密,接收方用key + 消息明文再加密,拿加密后的值 跟 发送者的相对比是否相等,这样就能验证消息的真实性,及发送者的合法性了。

1 import hmac
2 h = hmac.new(b‘天王盖地虎‘, b‘宝塔镇河妖‘)
3 print h.hexdigest()

更多关于md5,sha1,sha256等介绍的文章看这里https://www.tbs-certificates.co.uk/FAQ/en/sha256.html

5.12Subprocess模块 

常用subprocess方法示例

#执行命令,返回命令执行状态 , 0 or 非0
>>> retcode = subprocess.call(["ls", "-l"])

#执行命令,如果命令结果为0,就正常返回,否则抛异常
>>> subprocess.check_call(["ls", "-l"])
0

#接收字符串格式命令,返回元组形式,第1个元素是执行状态,第2个是命令结果 
>>> subprocess.getstatusoutput(‘ls /bin/ls‘)
(0, ‘/bin/ls‘)

#接收字符串格式命令,并返回结果
>>> subprocess.getoutput(‘ls /bin/ls‘)
‘/bin/ls‘

#执行命令,并返回结果,注意是返回结果,不是打印,下例结果返回给res
>>> res=subprocess.check_output([‘ls‘,‘-l‘])
>>> res
b‘total 0\ndrwxr-xr-x 12 alex staff 408 Nov 2 11:05 OldBoyCRM\n‘

#上面那些方法,底层都是封装的subprocess.Popen
poll()
Check if child process has terminated. Returns returncode

wait()
Wait for child process to terminate. Returns returncode attribute.

terminate() 杀掉所启动进程
communicate() 等待任务结束

stdin 标准输入

stdout 标准输出

stderr 标准错误

pid
The process ID of the child process.

#例子
>>> p = subprocess.Popen("df -h|grep disk",stdin=subprocess.PIPE,stdout=subprocess.PIPE,shell=True)
>>> p.stdout.read()
b‘/dev/disk1 465Gi 64Gi 400Gi 14% 16901472 104938142 14% /\n‘

调用subprocess.run(...)是推荐的常用方法,在大多数情况下能满足需求,但如果你可能需要进行一些复杂的与系统的交互的话,你还可以用subprocess.Popen(),语法如下:

1 p = subprocess.Popen("find / -size +1000000 -exec ls -shl {} \;",shell=True,stdout=subprocess.PIPE)
2 print(p.stdout.read())

可用参数:

    • args:shell命令,可以是字符串或者序列类型(如:list,元组)
    • bufsize:指定缓冲。0 无缓冲,1 行缓冲,其他 缓冲区大小,负值 系统缓冲
    • stdin, stdout, stderr:分别表示程序的标准输入、输出、错误句柄
    • preexec_fn:只在Unix平台下有效,用于指定一个可执行对象(callable object),它将在子进程运行之前被调用
    • close_sfs:在windows平台下,如果close_fds被设置为True,则新创建的子进程将不会继承父进程的输入、输出、错误管道。
      所以不能将close_fds设置为True同时重定向子进程的标准输入、输出与错误(stdin, stdout, stderr)。
    • shell:同上
    • cwd:用于设置子进程的当前目录
    • env:用于指定子进程的环境变量。如果env = None,子进程的环境变量将从父进程中继承。
    • universal_newlines:不同系统的换行符不同,True -> 同意使用 \n
    • startupinfo与createionflags只在windows下有效
      将被传递给底层的CreateProcess()函数,用于设置子进程的一些属性,如:主窗口的外观,进程的优先级等等

终端输入的命令分为两种:

  • 输入即可得到输出,如:ifconfig
  • 输入进行某环境,依赖再输入,如:python

需要交互的命令示例

import subprocess

obj = subprocess.Popen(["python"], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
obj.stdin.write(‘print 1 \n ‘)
obj.stdin.write(‘print 2 \n ‘)
obj.stdin.write(‘print 3 \n ‘)
obj.stdin.write(‘print 4 \n ‘)

out_error_list = obj.communicate(timeout=10)
print out_error_list

subprocess实现sudo 自动输入密码

 1 import subprocess
 2
 3 def mypass():
 4     mypass = ‘123‘ #or get the password from anywhere
 5     return mypass
 6
 7 echo = subprocess.Popen([‘echo‘,mypass()],
 8                         stdout=subprocess.PIPE,
 9                         )
10
11 sudo = subprocess.Popen([‘sudo‘,‘-S‘,‘iptables‘,‘-L‘],
12                         stdin=echo.stdout,
13                         stdout=subprocess.PIPE,
14                         )
15
16 end_of_pipe = sudo.stdout
17
18 print "Password ok \n Iptables Chains %s" % end_of_pipe.read()

5.13logging模块

很多程序都有记录日志的需求,并且日志中包含的信息即有正常的程序访问日志,还可能有错误、警告等信息输出,python的logging模块提供了标准的日志接口,你可以通过它存储各种格式的日志,logging的日志可以分为 debug()info()warning()error() and critical() 5个级别,下面我们看一下怎么用。

1 import logging
2
3 logging.warning("user [alex] attempted wrong password more than 3 times")
4 logging.critical("server is down")
5
6 #输出
7 WARNING:root:user [alex] attempted wrong password more than 3 times
8 CRITICAL:root:server is down

如果想把日志写到文件里,也很简单

1 import logging
2
3 logging.basicConfig(filename=‘example.log‘,level=logging.INFO)
4 logging.debug(‘This message should go to the log file‘)
5 logging.info(‘So should this‘)
6 logging.warning(‘And this, too‘)

其中下面这句中的level=loggin.INFO意思是,把日志纪录级别设置为INFO,也就是说,只有比日志是INFO或比INFO级别更高的日志才会被纪录到文件里,在这个例子, 第一条日志是不会被纪录的,如果希望纪录debug的日志,那把日志级别改成DEBUG就行了。

logging.basicConfig(filename=‘example.log‘,level=logging.INFO)

感觉上面的日志格式忘记加上时间啦,日志不知道时间怎么行呢,下面就来加上!

1 import logging
2 logging.basicConfig(format=‘%(asctime)s %(message)s‘, datefmt=‘%m/%d/%Y %I:%M:%S %p‘)
3 logging.warning(‘is when this event was logged.‘)
4
5 #输出
6 12/12/2010 11:46:36 AM is when this event was logged.

如果想同时把log打印在屏幕和文件日志里,就需要了解一点复杂的知识 了

Python 使用logging模块记录日志涉及四个主要类,使用官方文档中的概括最为合适:

logger提供了应用程序可以直接使用的接口;

handler将(logger创建的)日志记录发送到合适的目的输出;

filter提供了细度设备来决定输出哪条日志记录;

formatter决定日志记录的最终输出格式。

日志的格式


%(name)s


Logger的名字


%(levelno)s


数字形式的日志级别


%(levelname)s


文本形式的日志级别


%(pathname)s


调用日志输出函数的模块的完整路径名,可能没有


%(filename)s


调用日志输出函数的模块的文件名


%(module)s


调用日志输出函数的模块名


%(funcName)s


调用日志输出函数的函数名


%(lineno)d


调用日志输出函数的语句所在的代码行


%(created)f


当前时间,用UNIX标准的表示时间的浮 点数表示


%(relativeCreated)d


输出日志信息时的,自Logger创建以 来的毫秒数


%(asctime)s


字符串形式的当前时间。默认格式是 “2003-07-08 16:49:45,896”。逗号后面的是毫秒


%(thread)d


线程ID。可能没有


%(threadName)s


线程名。可能没有


%(process)d


进程ID。可能没有


%(message)s


用户输出的消息

logger
每个程序在输出信息之前都要获得一个Logger。Logger通常对应了程序的模块名,比如聊天工具的图形界面模块可以这样获得它的Logger:
LOG=logging.getLogger(”chat.gui”)
而核心模块可以这样:
LOG=logging.getLogger(”chat.kernel”)

Logger.setLevel(lel):指定最低的日志级别,低于lel的级别将被忽略。debug是最低的内置级别,critical为最高
Logger.addFilter(filt)、Logger.removeFilter(filt):添加或删除指定的filter
Logger.addHandler(hdlr)、Logger.removeHandler(hdlr):增加或删除指定的handler
Logger.debug()、Logger.info()、Logger.warning()、Logger.error()、Logger.critical():可以设置的日志级别

handler

handler对象负责发送相关的信息到指定目的地。Python的日志系统有多种Handler可以使用。有些Handler可以把信息输出到控制台,有些Logger可以把信息输出到文件,还有些 Handler可以把信息发送到网络上。如果觉得不够用,还可以编写自己的Handler。可以通过addHandler()方法添加多个多handler
Handler.setLevel(lel):指定被处理的信息级别,低于lel级别的信息将被忽略
Handler.setFormatter():给这个handler选择一个格式
Handler.addFilter(filt)、Handler.removeFilter(filt):新增或删除一个filter对象

每个Logger可以附加多个Handler。接下来我们就来介绍一些常用的Handler:
1) logging.StreamHandler
使用这个Handler可以向类似与sys.stdout或者sys.stderr的任何文件对象(file object)输出信息。它的构造函数是:
StreamHandler([strm])
其中strm参数是一个文件对象。默认是sys.stderr

2) logging.FileHandler
和StreamHandler类似,用于向一个文件输出日志信息。不过FileHandler会帮你打开这个文件。它的构造函数是:
FileHandler(filename[,mode])
filename是文件名,必须指定一个文件名。
mode是文件的打开方式。参见Python内置函数open()的用法。默认是’a‘,即添加到文件末尾。

3) logging.handlers.RotatingFileHandler
这个Handler类似于上面的FileHandler,但是它可以管理文件大小。当文件达到一定大小之后,它会自动将当前日志文件改名,然后创建 一个新的同名日志文件继续输出。比如日志文件是chat.log。当chat.log达到指定的大小之后,RotatingFileHandler自动把 文件改名为chat.log.1。不过,如果chat.log.1已经存在,会先把chat.log.1重命名为chat.log.2。。。最后重新创建 chat.log,继续输出日志信息。它的构造函数是:
RotatingFileHandler( filename[, mode[, maxBytes[, backupCount]]])
其中filename和mode两个参数和FileHandler一样。
maxBytes用于指定日志文件的最大文件大小。如果maxBytes为0,意味着日志文件可以无限大,这时上面描述的重命名过程就不会发生。
backupCount用于指定保留的备份文件的个数。比如,如果指定为2,当上面描述的重命名过程发生时,原有的chat.log.2并不会被更名,而是被删除。

4) logging.handlers.TimedRotatingFileHandler
这个Handler和RotatingFileHandler类似,不过,它没有通过判断文件大小来决定何时重新创建日志文件,而是间隔一定时间就 自动创建新的日志文件。重命名的过程与RotatingFileHandler类似,不过新的文件不是附加数字,而是当前时间。它的构造函数是:
TimedRotatingFileHandler( filename [,when [,interval [,backupCount]]])
其中filename参数和backupCount参数和RotatingFileHandler具有相同的意义。
interval是时间间隔。
when参数是一个字符串。表示时间间隔的单位,不区分大小写。它有以下取值:
S 秒
M 分
H 小时
D 天
W 每星期(interval==0时代表星期一)
midnight 每天凌晨

 1 import logging
 2
 3 #create logger
 4 logger = logging.getLogger(‘TEST-LOG‘)
 5 logger.setLevel(logging.DEBUG)
 6
 7
 8 # create console handler and set level to debug
 9 ch = logging.StreamHandler()
10 ch.setLevel(logging.DEBUG)
11
12 # create file handler and set level to warning
13 fh = logging.FileHandler("access.log")
14 fh.setLevel(logging.WARNING)
15 # create formatter
16 formatter = logging.Formatter(‘%(asctime)s - %(name)s - %(levelname)s - %(message)s‘)
17
18 # add formatter to ch and fh
19 ch.setFormatter(formatter)
20 fh.setFormatter(formatter)
21
22 # add ch and fh to logger
23 logger.addHandler(ch)
24 logger.addHandler(fh)
25
26 # ‘application‘ code
27 logger.debug(‘debug message‘)
28 logger.info(‘info message‘)
29 logger.warn(‘warn message‘)
30 logger.error(‘error message‘)
31 logger.critical(‘critical message‘)

文件自动截断例子

 1 import logging
 2
 3 from logging import handlers
 4
 5 logger = logging.getLogger(__name__)
 6
 7 log_file = "timelog.log"
 8 #fh = handlers.RotatingFileHandler(filename=log_file,maxBytes=10,backupCount=3)
 9 fh = handlers.TimedRotatingFileHandler(filename=log_file,when="S",interval=5,backupCount=3)
10
11
12 formatter = logging.Formatter(‘%(asctime)s %(module)s:%(lineno)d %(message)s‘)
13
14 fh.setFormatter(formatter)
15
16 logger.addHandler(fh)
17
18
19 logger.warning("test1")
20 logger.warning("test12")
21 logger.warning("test13")
22 logger.warning("test14")

5.14 RE模块

常用正则表达式符号

 1 ‘.‘     默认匹配除\n之外的任意一个字符,若指定flag DOTALL,则匹配任意字符,包括换行
 2 ‘^‘     匹配字符开头,若指定flags MULTILINE,这种也可以匹配上(r"^a","\nabc\neee",flags=re.MULTILINE)
 3 ‘$‘     匹配字符结尾,或e.search("foo$","bfoo\nsdfsf",flags=re.MULTILINE).group()也可以
 4 ‘*‘     匹配*号前的字符0次或多次,re.findall("ab*","cabb3abcbbac")  结果为[‘abb‘, ‘ab‘, ‘a‘]
 5 ‘+‘     匹配前一个字符1次或多次,re.findall("ab+","ab+cd+abb+bba") 结果[‘ab‘, ‘abb‘]
 6 ‘?‘     匹配前一个字符1次或0次
 7 ‘{m}‘   匹配前一个字符m次
 8 ‘{n,m}‘ 匹配前一个字符n到m次,re.findall("ab{1,3}","abb abc abbcbbb") 结果‘abb‘, ‘ab‘, ‘abb‘]
 9 ‘|‘     匹配|左或|右的字符,re.search("abc|ABC","ABCBabcCD").group() 结果‘ABC‘
10 ‘(...)‘ 分组匹配,re.search("(abc){2}a(123|456)c", "abcabca456c").group() 结果 abcabca456c
11
12
13 ‘\A‘    只从字符开头匹配,re.search("\Aabc","alexabc") 是匹配不到的
14 ‘\Z‘    匹配字符结尾,同$
15 ‘\d‘    匹配数字0-9
16 ‘\D‘    匹配非数字
17 ‘\w‘    匹配[A-Za-z0-9]
18 ‘\W‘    匹配非[A-Za-z0-9]
19 ‘s‘     匹配空白字符、\t、\n、\r , re.search("\s+","ab\tc1\n3").group() 结果 ‘\t‘
20
21 ‘(?P<name>...)‘ 分组匹配 re.search("(?P<province>[0-9]{4})(?P<city>[0-9]{2})(?P<birthday>[0-9]{4})","371481199306143242").groupdict("city") 结果{‘province‘: ‘3714‘, ‘city‘: ‘81‘, ‘birthday‘: ‘1993‘}

最常用的匹配语法

1 re.match 从头开始匹配
2 re.search 匹配包含
3 re.findall 把所有匹配到的字符放到以列表中的元素返回
4 re.splitall 以匹配到的字符当做列表分隔符
5 re.sub      匹配字符并替换

反斜杠的困扰
与大多数编程语言相同,正则表达式里使用"\"作为转义字符,这就可能造成反斜杠困扰。假如你需要匹配文本中的字符"\",那么使用编程语言表示的正则表达式里将需要4个反斜杠"\\\\":前两个和后两个分别用于在编程语言里转义成反斜杠,转换成两个反斜杠后再在正则表达式里转义成一个反斜杠。Python里的原生字符串很好地解决了这个问题,这个例子中的正则表达式可以使用r"\\"表示。同样,匹配一个数字的"\\d"可以写成r"\d"。有了原生字符串,你再也不用担心是不是漏写了反斜杠,写出来的表达式也更直观。

仅需轻轻知道的几个匹配模式

1 re.I(re.IGNORECASE): 忽略大小写(括号内是完整写法,下同)
2 M(MULTILINE): 多行模式,改变‘^‘和‘$‘的行为
3 S(DOTALL): 点任意匹配模式,改变‘.‘的行为
时间: 2024-11-03 14:24:27

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