• python 常用模块


    一、os模块

    用于提供系统级别的操作

    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"	
    ",Linux下为"
    "
    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
    

    二、sys 模块

    sys.argv           命令行参数List,第一个元素是程序本身路径
    sys.exit(n)        退出程序,正常退出时exit(0)
    sys.version        获取Python解释程序的版本信息
    sys.maxint         最大的Int值
    sys.path           返回模块的搜索路径,初始化时使用PYTHONPATH环境变量的值
    sys.platform       返回操作系统平台名称
    sys.stdout.write('please:')
    val = sys.stdin.readline()[:-1]
    sys.path.append("") 添加路径为环境变量
    sys.exit()
    # xxx/Python35/lib 内置模块路径 # xxx/Python35/lib/site-packages 第三方

     常用sys:

    print sys.argv
    print len(sys.argv)
    print sys.argv[0]
    print sys.argv[1]
    answer = argv[1]
    if answer == "a":
    sys.exit("goodbye")
    ############### python2 test.py a b ###### 
    ['test.py', 'a', 'b'] 3 test.py a



     往屏幕输出:

    import sys
    var = "#"*50
    sys.stdout.write("#%s"%var)
    

    执行: python test.py

     

    动态输出进度条:

    for i in range(1,100):
        sys.stdout.write('
    ') # 清空原行
        sys.stdout.write("%s%% |%s"% (int(i),int(i)*'*'))
        sys.stdout.flush() # 每次刷新到屏幕
        time.sleep(0.1)

    os,sys常用方法:

    # -*- coding:utf8 -*-
    
    '''
    这里是文件的注释
    '''
    print vars()
    print (__doc__)   # 会输出以上内容的注释
    print (__file__)  # 文件本身路径。/Users/steven/PycharmProjects/Mydjango/test.py
    # print (__cached__) # 缓存,python2 没有
    
    
    from lib.com import commons
    print (commons.__package__)  # 会输出导入包的路径
    print (__name__)  # __main__ 入口文件
    print (commons.__name__) # lib.com.commons  ,在自己的文件下运行也是__main__
    print (__builtins__)  # 内置函数在__builtins__
    
    # 只有执行 python test.py时, __name__ == "__main__": 否则等于模块名
    # 调用主函数之前,必须加 if __name__ == "__main__":
    import os
    print os.path.dirname(__file__)   # /Users/steven/PycharmProjects/Mydjango
    print os.path.basename(__file__)  # test.py
    
    # 将/Users/steven/PycharmProjects/Mydjango/bin 添加到path里面,
    path_1 =  os.path.dirname(__file__)
    path_2 = "/bin"
    path_3 =  os.path.join(path_1+path_2)
    
    import sys
    sys.path.append(path_3)
    

    三、hashlib

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

    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()

    以上加密算法虽然依然非常厉害,但时候存在缺陷,即:通过撞库可以反解。所以,有必要对加密算法中添加自定义key再来做加密。

    import hashlib
     
    # ######## md5 ########
     
    hash = hashlib.md5('898oaFs09f')
    hash.update('admin')
    print hash.hexdigest()

    还不够吊?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

    import hmac
    h = hmac.new('wueiqi')
    h.update('hellowo')
    print h.hexdigest()

    四、json 和 pickle

    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

    import pickle
    data = {"name":"steven","age":19,"sex":"man"}
    p_str = pickle.dumps(data)
    print p_str
    
    with open("/Users/steven/aaa","w") as fp:
        pickle.dump(data,fp)
    
    
    
    import json
    j_str = json.dumps(data)
    print j_str
    
    with open("/Users/steven/bbb","w") as fp:
        json.dump(data,fp)

    常用方法:

    # -*- coding:utf8 -*-
    import json
    print ("今天学习json")
    
    # json本身是字符串,json.load 可将 字典、列表、元祖形式的字符串,转换为相应的 字典、列表、元祖
    # s = "{'desc':'invilad-citykey','status':'1002'}"  不可以这样写,其它语言不认识
    s = '{"desc":"invilad-citykey","status":"1002"}'
    l = "[1,2,3,4]"
    
    # 将json转换为字典
    result = json.loads(s)
    print result,type(result)
    
    # 将json转换为字典
    result = json.loads(l)
    print result,type(result)
    
    
    l = [1,2,3,4]
    s = {"desc":"invilad-citykey","status":"1002"}
    # 将列表转换为字符串。
    result = json.dumps(l)
    print result,type(result)
    result = json.dumps(s)
    print result,type(result)
    
    
    s = {"desc":"invilad-citykey","status":"1002"}
    # 先将字典转换为字符串,然后将字符串写到t.txt文件中
    json.dump(s,open('t.txt','w'))
    # 先打开文件,读取文件,又将文件转化为字典
    ret  = json.load(open('t.txt','r'))
    print ret,type(ret)
    
    t = (1,2,3,'a')
    ret = json.dumps(t)
    print ret,type(ret)  # [1, 2, 3, "a"] <type 'str'> 结果是列表形式的字符串
    

    五、执行系统命令

    可以执行shell命令的相关模块和函数有:

    • os.system
    • os.spawn*
    • os.popen*          --废弃
    • popen2.*           --废弃
    • commands.*      --废弃,3.x中被移除
    import commands
    
    result = commands.getoutput('cmd')
    result = commands.getstatus('cmd')
    result = commands.getstatusoutput('cmd')

    以上执行shell命令的相关的模块和函数的功能均在 subprocess 模块中实现,并提供了更丰富的功能。

    call 

    执行命令,返回状态码

    ret = subprocess.call(["ls", "-l"], shell=False)
    ret = subprocess.call("ls -l", shell=True)

    shell = True ,允许 shell 命令是字符串形式

    check_call

    执行命令,如果执行状态码是 0 ,则返回0,否则抛异常

    subprocess.check_call(["ls", "-l"])
    subprocess.check_call("exit 1", shell=True)

    check_output

    执行命令,如果状态码是 0 ,则返回执行结果,否则抛异常

    subprocess.check_output(["echo", "Hello World!"])
    subprocess.check_output("exit 1", shell=True)

    subprocess.Popen(...) 

    用于执行复杂的系统命令

    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
      • 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

     执行普通命令

    import subprocess
    ret1 = subprocess.Popen(["mkdir","t1"])
    ret2 = subprocess.Popen("mkdir t2", shell=True)

    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
    import subprocess
    
    obj = subprocess.Popen("mkdir t3", shell=True, cwd='/home/dev',)
    import subprocess
    
    obj = subprocess.Popen(["python"], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    obj.stdin.write('print 1 
     ')
    obj.stdin.write('print 2 
     ')
    obj.stdin.write('print 3 
     ')
    obj.stdin.write('print 4 
     ')
    obj.stdin.close()
    
    cmd_out = obj.stdout.read()
    obj.stdout.close()
    cmd_error = obj.stderr.read()
    obj.stderr.close()
    
    print cmd_out
    print cmd_error
    import subprocess
    
    obj = subprocess.Popen(["python"], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    obj.stdin.write('print 1 
     ')
    obj.stdin.write('print 2 
     ')
    obj.stdin.write('print 3 
     ')
    obj.stdin.write('print 4 
     ')
    
    out_error_list = obj.communicate()
    print out_error_list
    import subprocess
    
    obj = subprocess.Popen(["python"], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    out_error_list = obj.communicate('print "hello"')
    print out_error_list

    六、shutil

    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

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

    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)
    copyfile

    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)
    copymode

    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
    copystat

    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)
    copy

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

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

    shutil.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*'))

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

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

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

    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)
    move

    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
    #将 /Users/wupeiqi/Downloads/test 下的文件打包放置当前程序目录
     
    import shutil
    ret = shutil.make_archive("wwwwwwwwww", 'gztar', root_dir='/Users/wupeiqi/Downloads/test')
     
     
    #将 /Users/wupeiqi/Downloads/test 下的文件打包放置 /Users/wupeiqi/目录
    import shutil
    ret = shutil.make_archive("/Users/wupeiqi/wwwwwwwwww", 'gztar', root_dir='/Users/wupeiqi/Downloads/test')
    
    def make_archive(base_name, format, root_dir=None, base_dir=None, verbose=0,
                     dry_run=0, owner=None, group=None, logger=None):
        """Create an archive file (eg. zip or tar).
    
        'base_name' is the name of the file to create, minus any format-specific
        extension; 'format' is the archive format: one of "zip", "tar", "bztar"
        or "gztar".
    
        'root_dir' is a directory that will be the root directory of the
        archive; ie. we typically chdir into 'root_dir' before creating the
        archive.  'base_dir' is the directory where we start archiving from;
        ie. 'base_dir' will be the common prefix of all files and
        directories in the archive.  'root_dir' and 'base_dir' both default
        to the current directory.  Returns the name of the archive file.
    
        'owner' and 'group' are used when creating a tar archive. By default,
        uses the current owner and group.
        """
        save_cwd = os.getcwd()
        if root_dir is not None:
            if logger is not None:
                logger.debug("changing into '%s'", root_dir)
            base_name = os.path.abspath(base_name)
            if not dry_run:
                os.chdir(root_dir)
    
        if base_dir is None:
            base_dir = os.curdir
    
        kwargs = {'dry_run': dry_run, 'logger': logger}
    
        try:
            format_info = _ARCHIVE_FORMATS[format]
        except KeyError:
            raise ValueError, "unknown archive format '%s'" % format
    
        func = format_info[0]
        for arg, val in format_info[1]:
            kwargs[arg] = val
    
        if format != 'zip':
            kwargs['owner'] = owner
            kwargs['group'] = group
    
        try:
            filename = func(base_name, base_dir, **kwargs)
        finally:
            if root_dir is not None:
                if logger is not None:
                    logger.debug("changing back to '%s'", save_cwd)
                os.chdir(save_cwd)
    
        return filename
    View Code

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

    import zipfile
    
    # 压缩
    z = zipfile.ZipFile('laxi.zip', 'w')
    z.write('a.log')
    z.write('data.data')
    z.close()
    
    # 解压
    z = zipfile.ZipFile('laxi.zip', 'r')
    z.extractall()
    z.close()
    shutil
    import tarfile
    
    # 压缩
    tar = tarfile.open('your.tar','w')
    tar.add('/Users/wupeiqi/PycharmProjects/bbs2.zip', arcname='bbs2.zip')
    tar.add('/Users/wupeiqi/PycharmProjects/cmdb.zip', arcname='cmdb.zip')
    tar.close()
    
    # 解压
    tar = tarfile.open('your.tar','r')
    tar.extractall()  # 可设置解压地址
    tar.close()
    tarfile
    class ZipFile(object):
        """ Class with methods to open, read, write, close, list zip files.
    
        z = ZipFile(file, mode="r", compression=ZIP_STORED, allowZip64=False)
    
        file: Either the path to the file, or a file-like object.
              If it is a path, the file will be opened and closed by ZipFile.
        mode: The mode can be either read "r", write "w" or append "a".
        compression: ZIP_STORED (no compression) or ZIP_DEFLATED (requires zlib).
        allowZip64: if True ZipFile will create files with ZIP64 extensions when
                    needed, otherwise it will raise an exception when this would
                    be necessary.
    
        """
    
        fp = None                   # Set here since __del__ checks it
    
        def __init__(self, file, mode="r", compression=ZIP_STORED, allowZip64=False):
            """Open the ZIP file with mode read "r", write "w" or append "a"."""
            if mode not in ("r", "w", "a"):
                raise RuntimeError('ZipFile() requires mode "r", "w", or "a"')
    
            if compression == ZIP_STORED:
                pass
            elif compression == ZIP_DEFLATED:
                if not zlib:
                    raise RuntimeError,
                          "Compression requires the (missing) zlib module"
            else:
                raise RuntimeError, "That compression method is not supported"
    
            self._allowZip64 = allowZip64
            self._didModify = False
            self.debug = 0  # Level of printing: 0 through 3
            self.NameToInfo = {}    # Find file info given name
            self.filelist = []      # List of ZipInfo instances for archive
            self.compression = compression  # Method of compression
            self.mode = key = mode.replace('b', '')[0]
            self.pwd = None
            self._comment = ''
    
            # Check if we were passed a file-like object
            if isinstance(file, basestring):
                self._filePassed = 0
                self.filename = file
                modeDict = {'r' : 'rb', 'w': 'wb', 'a' : 'r+b'}
                try:
                    self.fp = open(file, modeDict[mode])
                except IOError:
                    if mode == 'a':
                        mode = key = 'w'
                        self.fp = open(file, modeDict[mode])
                    else:
                        raise
            else:
                self._filePassed = 1
                self.fp = file
                self.filename = getattr(file, 'name', None)
    
            try:
                if key == 'r':
                    self._RealGetContents()
                elif key == 'w':
                    # set the modified flag so central directory gets written
                    # even if no files are added to the archive
                    self._didModify = True
                elif key == 'a':
                    try:
                        # See if file is a zip file
                        self._RealGetContents()
                        # seek to start of directory and overwrite
                        self.fp.seek(self.start_dir, 0)
                    except BadZipfile:
                        # file is not a zip file, just append
                        self.fp.seek(0, 2)
    
                        # set the modified flag so central directory gets written
                        # even if no files are added to the archive
                        self._didModify = True
                else:
                    raise RuntimeError('Mode must be "r", "w" or "a"')
            except:
                fp = self.fp
                self.fp = None
                if not self._filePassed:
                    fp.close()
                raise
    
        def __enter__(self):
            return self
    
        def __exit__(self, type, value, traceback):
            self.close()
    
        def _RealGetContents(self):
            """Read in the table of contents for the ZIP file."""
            fp = self.fp
            try:
                endrec = _EndRecData(fp)
            except IOError:
                raise BadZipfile("File is not a zip file")
            if not endrec:
                raise BadZipfile, "File is not a zip file"
            if self.debug > 1:
                print endrec
            size_cd = endrec[_ECD_SIZE]             # bytes in central directory
            offset_cd = endrec[_ECD_OFFSET]         # offset of central directory
            self._comment = endrec[_ECD_COMMENT]    # archive comment
    
            # "concat" is zero, unless zip was concatenated to another file
            concat = endrec[_ECD_LOCATION] - size_cd - offset_cd
            if endrec[_ECD_SIGNATURE] == stringEndArchive64:
                # If Zip64 extension structures are present, account for them
                concat -= (sizeEndCentDir64 + sizeEndCentDir64Locator)
    
            if self.debug > 2:
                inferred = concat + offset_cd
                print "given, inferred, offset", offset_cd, inferred, concat
            # self.start_dir:  Position of start of central directory
            self.start_dir = offset_cd + concat
            fp.seek(self.start_dir, 0)
            data = fp.read(size_cd)
            fp = cStringIO.StringIO(data)
            total = 0
            while total < size_cd:
                centdir = fp.read(sizeCentralDir)
                if len(centdir) != sizeCentralDir:
                    raise BadZipfile("Truncated central directory")
                centdir = struct.unpack(structCentralDir, centdir)
                if centdir[_CD_SIGNATURE] != stringCentralDir:
                    raise BadZipfile("Bad magic number for central directory")
                if self.debug > 2:
                    print centdir
                filename = fp.read(centdir[_CD_FILENAME_LENGTH])
                # Create ZipInfo instance to store file information
                x = ZipInfo(filename)
                x.extra = fp.read(centdir[_CD_EXTRA_FIELD_LENGTH])
                x.comment = fp.read(centdir[_CD_COMMENT_LENGTH])
                x.header_offset = centdir[_CD_LOCAL_HEADER_OFFSET]
                (x.create_version, x.create_system, x.extract_version, x.reserved,
                    x.flag_bits, x.compress_type, t, d,
                    x.CRC, x.compress_size, x.file_size) = centdir[1:12]
                x.volume, x.internal_attr, x.external_attr = centdir[15:18]
                # Convert date/time code to (year, month, day, hour, min, sec)
                x._raw_time = t
                x.date_time = ( (d>>9)+1980, (d>>5)&0xF, d&0x1F,
                                         t>>11, (t>>5)&0x3F, (t&0x1F) * 2 )
    
                x._decodeExtra()
                x.header_offset = x.header_offset + concat
                x.filename = x._decodeFilename()
                self.filelist.append(x)
                self.NameToInfo[x.filename] = x
    
                # update total bytes read from central directory
                total = (total + sizeCentralDir + centdir[_CD_FILENAME_LENGTH]
                         + centdir[_CD_EXTRA_FIELD_LENGTH]
                         + centdir[_CD_COMMENT_LENGTH])
    
                if self.debug > 2:
                    print "total", total
    
    
        def namelist(self):
            """Return a list of file names in the archive."""
            l = []
            for data in self.filelist:
                l.append(data.filename)
            return l
    
        def infolist(self):
            """Return a list of class ZipInfo instances for files in the
            archive."""
            return self.filelist
    
        def printdir(self):
            """Print a table of contents for the zip file."""
            print "%-46s %19s %12s" % ("File Name", "Modified    ", "Size")
            for zinfo in self.filelist:
                date = "%d-%02d-%02d %02d:%02d:%02d" % zinfo.date_time[:6]
                print "%-46s %s %12d" % (zinfo.filename, date, zinfo.file_size)
    
        def testzip(self):
            """Read all the files and check the CRC."""
            chunk_size = 2 ** 20
            for zinfo in self.filelist:
                try:
                    # Read by chunks, to avoid an OverflowError or a
                    # MemoryError with very large embedded files.
                    with self.open(zinfo.filename, "r") as f:
                        while f.read(chunk_size):     # Check CRC-32
                            pass
                except BadZipfile:
                    return zinfo.filename
    
        def getinfo(self, name):
            """Return the instance of ZipInfo given 'name'."""
            info = self.NameToInfo.get(name)
            if info is None:
                raise KeyError(
                    'There is no item named %r in the archive' % name)
    
            return info
    
        def setpassword(self, pwd):
            """Set default password for encrypted files."""
            self.pwd = pwd
    
        @property
        def comment(self):
            """The comment text associated with the ZIP file."""
            return self._comment
    
        @comment.setter
        def comment(self, comment):
            # check for valid comment length
            if len(comment) > ZIP_MAX_COMMENT:
                import warnings
                warnings.warn('Archive comment is too long; truncating to %d bytes'
                              % ZIP_MAX_COMMENT, stacklevel=2)
                comment = comment[:ZIP_MAX_COMMENT]
            self._comment = comment
            self._didModify = True
    
        def read(self, name, pwd=None):
            """Return file bytes (as a string) for name."""
            return self.open(name, "r", pwd).read()
    
        def open(self, name, mode="r", pwd=None):
            """Return file-like object for 'name'."""
            if mode not in ("r", "U", "rU"):
                raise RuntimeError, 'open() requires mode "r", "U", or "rU"'
            if not self.fp:
                raise RuntimeError, 
                      "Attempt to read ZIP archive that was already closed"
    
            # Only open a new file for instances where we were not
            # given a file object in the constructor
            if self._filePassed:
                zef_file = self.fp
                should_close = False
            else:
                zef_file = open(self.filename, 'rb')
                should_close = True
    
            try:
                # Make sure we have an info object
                if isinstance(name, ZipInfo):
                    # 'name' is already an info object
                    zinfo = name
                else:
                    # Get info object for name
                    zinfo = self.getinfo(name)
    
                zef_file.seek(zinfo.header_offset, 0)
    
                # Skip the file header:
                fheader = zef_file.read(sizeFileHeader)
                if len(fheader) != sizeFileHeader:
                    raise BadZipfile("Truncated file header")
                fheader = struct.unpack(structFileHeader, fheader)
                if fheader[_FH_SIGNATURE] != stringFileHeader:
                    raise BadZipfile("Bad magic number for file header")
    
                fname = zef_file.read(fheader[_FH_FILENAME_LENGTH])
                if fheader[_FH_EXTRA_FIELD_LENGTH]:
                    zef_file.read(fheader[_FH_EXTRA_FIELD_LENGTH])
    
                if fname != zinfo.orig_filename:
                    raise BadZipfile, 
                            'File name in directory "%s" and header "%s" differ.' % (
                                zinfo.orig_filename, fname)
    
                # check for encrypted flag & handle password
                is_encrypted = zinfo.flag_bits & 0x1
                zd = None
                if is_encrypted:
                    if not pwd:
                        pwd = self.pwd
                    if not pwd:
                        raise RuntimeError, "File %s is encrypted, " 
                            "password required for extraction" % name
    
                    zd = _ZipDecrypter(pwd)
                    # The first 12 bytes in the cypher stream is an encryption header
                    #  used to strengthen the algorithm. The first 11 bytes are
                    #  completely random, while the 12th contains the MSB of the CRC,
                    #  or the MSB of the file time depending on the header type
                    #  and is used to check the correctness of the password.
                    bytes = zef_file.read(12)
                    h = map(zd, bytes[0:12])
                    if zinfo.flag_bits & 0x8:
                        # compare against the file type from extended local headers
                        check_byte = (zinfo._raw_time >> 8) & 0xff
                    else:
                        # compare against the CRC otherwise
                        check_byte = (zinfo.CRC >> 24) & 0xff
                    if ord(h[11]) != check_byte:
                        raise RuntimeError("Bad password for file", name)
    
                return ZipExtFile(zef_file, mode, zinfo, zd,
                        close_fileobj=should_close)
            except:
                if should_close:
                    zef_file.close()
                raise
    
        def extract(self, member, path=None, pwd=None):
            """Extract a member from the archive to the current working directory,
               using its full name. Its file information is extracted as accurately
               as possible. `member' may be a filename or a ZipInfo object. You can
               specify a different directory using `path'.
            """
            if not isinstance(member, ZipInfo):
                member = self.getinfo(member)
    
            if path is None:
                path = os.getcwd()
    
            return self._extract_member(member, path, pwd)
    
        def extractall(self, path=None, members=None, pwd=None):
            """Extract all members from the archive to the current working
               directory. `path' specifies a different directory to extract to.
               `members' is optional and must be a subset of the list returned
               by namelist().
            """
            if members is None:
                members = self.namelist()
    
            for zipinfo in members:
                self.extract(zipinfo, path, pwd)
    
        def _extract_member(self, member, targetpath, pwd):
            """Extract the ZipInfo object 'member' to a physical
               file on the path targetpath.
            """
            # build the destination pathname, replacing
            # forward slashes to platform specific separators.
            arcname = member.filename.replace('/', os.path.sep)
    
            if os.path.altsep:
                arcname = arcname.replace(os.path.altsep, os.path.sep)
            # interpret absolute pathname as relative, remove drive letter or
            # UNC path, redundant separators, "." and ".." components.
            arcname = os.path.splitdrive(arcname)[1]
            arcname = os.path.sep.join(x for x in arcname.split(os.path.sep)
                        if x not in ('', os.path.curdir, os.path.pardir))
            if os.path.sep == '\':
                # filter illegal characters on Windows
                illegal = ':<>|"?*'
                if isinstance(arcname, unicode):
                    table = {ord(c): ord('_') for c in illegal}
                else:
                    table = string.maketrans(illegal, '_' * len(illegal))
                arcname = arcname.translate(table)
                # remove trailing dots
                arcname = (x.rstrip('.') for x in arcname.split(os.path.sep))
                arcname = os.path.sep.join(x for x in arcname if x)
    
            targetpath = os.path.join(targetpath, arcname)
            targetpath = os.path.normpath(targetpath)
    
            # Create all upper directories if necessary.
            upperdirs = os.path.dirname(targetpath)
            if upperdirs and not os.path.exists(upperdirs):
                os.makedirs(upperdirs)
    
            if member.filename[-1] == '/':
                if not os.path.isdir(targetpath):
                    os.mkdir(targetpath)
                return targetpath
    
            with self.open(member, pwd=pwd) as source, 
                 file(targetpath, "wb") as target:
                shutil.copyfileobj(source, target)
    
            return targetpath
    
        def _writecheck(self, zinfo):
            """Check for errors before writing a file to the archive."""
            if zinfo.filename in self.NameToInfo:
                import warnings
                warnings.warn('Duplicate name: %r' % zinfo.filename, stacklevel=3)
            if self.mode not in ("w", "a"):
                raise RuntimeError, 'write() requires mode "w" or "a"'
            if not self.fp:
                raise RuntimeError, 
                      "Attempt to write ZIP archive that was already closed"
            if zinfo.compress_type == ZIP_DEFLATED and not zlib:
                raise RuntimeError, 
                      "Compression requires the (missing) zlib module"
            if zinfo.compress_type not in (ZIP_STORED, ZIP_DEFLATED):
                raise RuntimeError, 
                      "That compression method is not supported"
            if not self._allowZip64:
                requires_zip64 = None
                if len(self.filelist) >= ZIP_FILECOUNT_LIMIT:
                    requires_zip64 = "Files count"
                elif zinfo.file_size > ZIP64_LIMIT:
                    requires_zip64 = "Filesize"
                elif zinfo.header_offset > ZIP64_LIMIT:
                    requires_zip64 = "Zipfile size"
                if requires_zip64:
                    raise LargeZipFile(requires_zip64 +
                                       " would require ZIP64 extensions")
    
        def write(self, filename, arcname=None, compress_type=None):
            """Put the bytes from filename into the archive under the name
            arcname."""
            if not self.fp:
                raise RuntimeError(
                      "Attempt to write to ZIP archive that was already closed")
    
            st = os.stat(filename)
            isdir = stat.S_ISDIR(st.st_mode)
            mtime = time.localtime(st.st_mtime)
            date_time = mtime[0:6]
            # Create ZipInfo instance to store file information
            if arcname is None:
                arcname = filename
            arcname = os.path.normpath(os.path.splitdrive(arcname)[1])
            while arcname[0] in (os.sep, os.altsep):
                arcname = arcname[1:]
            if isdir:
                arcname += '/'
            zinfo = ZipInfo(arcname, date_time)
            zinfo.external_attr = (st[0] & 0xFFFF) << 16L      # Unix attributes
            if compress_type is None:
                zinfo.compress_type = self.compression
            else:
                zinfo.compress_type = compress_type
    
            zinfo.file_size = st.st_size
            zinfo.flag_bits = 0x00
            zinfo.header_offset = self.fp.tell()    # Start of header bytes
    
            self._writecheck(zinfo)
            self._didModify = True
    
            if isdir:
                zinfo.file_size = 0
                zinfo.compress_size = 0
                zinfo.CRC = 0
                zinfo.external_attr |= 0x10  # MS-DOS directory flag
                self.filelist.append(zinfo)
                self.NameToInfo[zinfo.filename] = zinfo
                self.fp.write(zinfo.FileHeader(False))
                return
    
            with open(filename, "rb") as fp:
                # Must overwrite CRC and sizes with correct data later
                zinfo.CRC = CRC = 0
                zinfo.compress_size = compress_size = 0
                # Compressed size can be larger than uncompressed size
                zip64 = self._allowZip64 and 
                        zinfo.file_size * 1.05 > ZIP64_LIMIT
                self.fp.write(zinfo.FileHeader(zip64))
                if zinfo.compress_type == ZIP_DEFLATED:
                    cmpr = zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION,
                         zlib.DEFLATED, -15)
                else:
                    cmpr = None
                file_size = 0
                while 1:
                    buf = fp.read(1024 * 8)
                    if not buf:
                        break
                    file_size = file_size + len(buf)
                    CRC = crc32(buf, CRC) & 0xffffffff
                    if cmpr:
                        buf = cmpr.compress(buf)
                        compress_size = compress_size + len(buf)
                    self.fp.write(buf)
            if cmpr:
                buf = cmpr.flush()
                compress_size = compress_size + len(buf)
                self.fp.write(buf)
                zinfo.compress_size = compress_size
            else:
                zinfo.compress_size = file_size
            zinfo.CRC = CRC
            zinfo.file_size = file_size
            if not zip64 and self._allowZip64:
                if file_size > ZIP64_LIMIT:
                    raise RuntimeError('File size has increased during compressing')
                if compress_size > ZIP64_LIMIT:
                    raise RuntimeError('Compressed size larger than uncompressed size')
            # Seek backwards and write file header (which will now include
            # correct CRC and file sizes)
            position = self.fp.tell()       # Preserve current position in file
            self.fp.seek(zinfo.header_offset, 0)
            self.fp.write(zinfo.FileHeader(zip64))
            self.fp.seek(position, 0)
            self.filelist.append(zinfo)
            self.NameToInfo[zinfo.filename] = zinfo
    
        def writestr(self, zinfo_or_arcname, bytes, compress_type=None):
            """Write a file into the archive.  The contents is the string
            'bytes'.  'zinfo_or_arcname' is either a ZipInfo instance or
            the name of the file in the archive."""
            if not isinstance(zinfo_or_arcname, ZipInfo):
                zinfo = ZipInfo(filename=zinfo_or_arcname,
                                date_time=time.localtime(time.time())[:6])
    
                zinfo.compress_type = self.compression
                if zinfo.filename[-1] == '/':
                    zinfo.external_attr = 0o40775 << 16   # drwxrwxr-x
                    zinfo.external_attr |= 0x10           # MS-DOS directory flag
                else:
                    zinfo.external_attr = 0o600 << 16     # ?rw-------
            else:
                zinfo = zinfo_or_arcname
    
            if not self.fp:
                raise RuntimeError(
                      "Attempt to write to ZIP archive that was already closed")
    
            if compress_type is not None:
                zinfo.compress_type = compress_type
    
            zinfo.file_size = len(bytes)            # Uncompressed size
            zinfo.header_offset = self.fp.tell()    # Start of header bytes
            self._writecheck(zinfo)
            self._didModify = True
            zinfo.CRC = crc32(bytes) & 0xffffffff       # CRC-32 checksum
            if zinfo.compress_type == ZIP_DEFLATED:
                co = zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION,
                     zlib.DEFLATED, -15)
                bytes = co.compress(bytes) + co.flush()
                zinfo.compress_size = len(bytes)    # Compressed size
            else:
                zinfo.compress_size = zinfo.file_size
            zip64 = zinfo.file_size > ZIP64_LIMIT or 
                    zinfo.compress_size > ZIP64_LIMIT
            if zip64 and not self._allowZip64:
                raise LargeZipFile("Filesize would require ZIP64 extensions")
            self.fp.write(zinfo.FileHeader(zip64))
            self.fp.write(bytes)
            if zinfo.flag_bits & 0x08:
                # Write CRC and file sizes after the file data
                fmt = '<LQQ' if zip64 else '<LLL'
                self.fp.write(struct.pack(fmt, zinfo.CRC, zinfo.compress_size,
                      zinfo.file_size))
            self.fp.flush()
            self.filelist.append(zinfo)
            self.NameToInfo[zinfo.filename] = zinfo
    
        def __del__(self):
            """Call the "close()" method in case the user forgot."""
            self.close()
    
        def close(self):
            """Close the file, and for mode "w" and "a" write the ending
            records."""
            if self.fp is None:
                return
    
            try:
                if self.mode in ("w", "a") and self._didModify: # write ending records
                    pos1 = self.fp.tell()
                    for zinfo in self.filelist:         # write central directory
                        dt = zinfo.date_time
                        dosdate = (dt[0] - 1980) << 9 | dt[1] << 5 | dt[2]
                        dostime = dt[3] << 11 | dt[4] << 5 | (dt[5] // 2)
                        extra = []
                        if zinfo.file_size > ZIP64_LIMIT 
                                or zinfo.compress_size > ZIP64_LIMIT:
                            extra.append(zinfo.file_size)
                            extra.append(zinfo.compress_size)
                            file_size = 0xffffffff
                            compress_size = 0xffffffff
                        else:
                            file_size = zinfo.file_size
                            compress_size = zinfo.compress_size
    
                        if zinfo.header_offset > ZIP64_LIMIT:
                            extra.append(zinfo.header_offset)
                            header_offset = 0xffffffffL
                        else:
                            header_offset = zinfo.header_offset
    
                        extra_data = zinfo.extra
                        if extra:
                            # Append a ZIP64 field to the extra's
                            extra_data = struct.pack(
                                    '<HH' + 'Q'*len(extra),
                                    1, 8*len(extra), *extra) + extra_data
    
                            extract_version = max(45, zinfo.extract_version)
                            create_version = max(45, zinfo.create_version)
                        else:
                            extract_version = zinfo.extract_version
                            create_version = zinfo.create_version
    
                        try:
                            filename, flag_bits = zinfo._encodeFilenameFlags()
                            centdir = struct.pack(structCentralDir,
                            stringCentralDir, create_version,
                            zinfo.create_system, extract_version, zinfo.reserved,
                            flag_bits, zinfo.compress_type, dostime, dosdate,
                            zinfo.CRC, compress_size, file_size,
                            len(filename), len(extra_data), len(zinfo.comment),
                            0, zinfo.internal_attr, zinfo.external_attr,
                            header_offset)
                        except DeprecationWarning:
                            print >>sys.stderr, (structCentralDir,
                            stringCentralDir, create_version,
                            zinfo.create_system, extract_version, zinfo.reserved,
                            zinfo.flag_bits, zinfo.compress_type, dostime, dosdate,
                            zinfo.CRC, compress_size, file_size,
                            len(zinfo.filename), len(extra_data), len(zinfo.comment),
                            0, zinfo.internal_attr, zinfo.external_attr,
                            header_offset)
                            raise
                        self.fp.write(centdir)
                        self.fp.write(filename)
                        self.fp.write(extra_data)
                        self.fp.write(zinfo.comment)
    
                    pos2 = self.fp.tell()
                    # Write end-of-zip-archive record
                    centDirCount = len(self.filelist)
                    centDirSize = pos2 - pos1
                    centDirOffset = pos1
                    requires_zip64 = None
                    if centDirCount > ZIP_FILECOUNT_LIMIT:
                        requires_zip64 = "Files count"
                    elif centDirOffset > ZIP64_LIMIT:
                        requires_zip64 = "Central directory offset"
                    elif centDirSize > ZIP64_LIMIT:
                        requires_zip64 = "Central directory size"
                    if requires_zip64:
                        # Need to write the ZIP64 end-of-archive records
                        if not self._allowZip64:
                            raise LargeZipFile(requires_zip64 +
                                               " would require ZIP64 extensions")
                        zip64endrec = struct.pack(
                                structEndArchive64, stringEndArchive64,
                                44, 45, 45, 0, 0, centDirCount, centDirCount,
                                centDirSize, centDirOffset)
                        self.fp.write(zip64endrec)
    
                        zip64locrec = struct.pack(
                                structEndArchive64Locator,
                                stringEndArchive64Locator, 0, pos2, 1)
                        self.fp.write(zip64locrec)
                        centDirCount = min(centDirCount, 0xFFFF)
                        centDirSize = min(centDirSize, 0xFFFFFFFF)
                        centDirOffset = min(centDirOffset, 0xFFFFFFFF)
    
                    endrec = struct.pack(structEndArchive, stringEndArchive,
                                        0, 0, centDirCount, centDirCount,
                                        centDirSize, centDirOffset, len(self._comment))
                    self.fp.write(endrec)
                    self.fp.write(self._comment)
                    self.fp.flush()
            finally:
                fp = self.fp
                self.fp = None
                if not self._filePassed:
                    fp.close()
    View Code
    class TarFile(object):
        """The TarFile Class provides an interface to tar archives.
        """
    
        debug = 0                   # May be set from 0 (no msgs) to 3 (all msgs)
    
        dereference = False         # If true, add content of linked file to the
                                    # tar file, else the link.
    
        ignore_zeros = False        # If true, skips empty or invalid blocks and
                                    # continues processing.
    
        errorlevel = 1              # If 0, fatal errors only appear in debug
                                    # messages (if debug >= 0). If > 0, errors
                                    # are passed to the caller as exceptions.
    
        format = DEFAULT_FORMAT     # The format to use when creating an archive.
    
        encoding = ENCODING         # Encoding for 8-bit character strings.
    
        errors = None               # Error handler for unicode conversion.
    
        tarinfo = TarInfo           # The default TarInfo class to use.
    
        fileobject = ExFileObject   # The default ExFileObject class to use.
    
        def __init__(self, name=None, mode="r", fileobj=None, format=None,
                tarinfo=None, dereference=None, ignore_zeros=None, encoding=None,
                errors=None, pax_headers=None, debug=None, errorlevel=None):
            """Open an (uncompressed) tar archive `name'. `mode' is either 'r' to
               read from an existing archive, 'a' to append data to an existing
               file or 'w' to create a new file overwriting an existing one. `mode'
               defaults to 'r'.
               If `fileobj' is given, it is used for reading or writing data. If it
               can be determined, `mode' is overridden by `fileobj's mode.
               `fileobj' is not closed, when TarFile is closed.
            """
            modes = {"r": "rb", "a": "r+b", "w": "wb"}
            if mode not in modes:
                raise ValueError("mode must be 'r', 'a' or 'w'")
            self.mode = mode
            self._mode = modes[mode]
    
            if not fileobj:
                if self.mode == "a" and not os.path.exists(name):
                    # Create nonexistent files in append mode.
                    self.mode = "w"
                    self._mode = "wb"
                fileobj = bltn_open(name, self._mode)
                self._extfileobj = False
            else:
                if name is None and hasattr(fileobj, "name"):
                    name = fileobj.name
                if hasattr(fileobj, "mode"):
                    self._mode = fileobj.mode
                self._extfileobj = True
            self.name = os.path.abspath(name) if name else None
            self.fileobj = fileobj
    
            # Init attributes.
            if format is not None:
                self.format = format
            if tarinfo is not None:
                self.tarinfo = tarinfo
            if dereference is not None:
                self.dereference = dereference
            if ignore_zeros is not None:
                self.ignore_zeros = ignore_zeros
            if encoding is not None:
                self.encoding = encoding
    
            if errors is not None:
                self.errors = errors
            elif mode == "r":
                self.errors = "utf-8"
            else:
                self.errors = "strict"
    
            if pax_headers is not None and self.format == PAX_FORMAT:
                self.pax_headers = pax_headers
            else:
                self.pax_headers = {}
    
            if debug is not None:
                self.debug = debug
            if errorlevel is not None:
                self.errorlevel = errorlevel
    
            # Init datastructures.
            self.closed = False
            self.members = []       # list of members as TarInfo objects
            self._loaded = False    # flag if all members have been read
            self.offset = self.fileobj.tell()
                                    # current position in the archive file
            self.inodes = {}        # dictionary caching the inodes of
                                    # archive members already added
    
            try:
                if self.mode == "r":
                    self.firstmember = None
                    self.firstmember = self.next()
    
                if self.mode == "a":
                    # Move to the end of the archive,
                    # before the first empty block.
                    while True:
                        self.fileobj.seek(self.offset)
                        try:
                            tarinfo = self.tarinfo.fromtarfile(self)
                            self.members.append(tarinfo)
                        except EOFHeaderError:
                            self.fileobj.seek(self.offset)
                            break
                        except HeaderError, e:
                            raise ReadError(str(e))
    
                if self.mode in "aw":
                    self._loaded = True
    
                    if self.pax_headers:
                        buf = self.tarinfo.create_pax_global_header(self.pax_headers.copy())
                        self.fileobj.write(buf)
                        self.offset += len(buf)
            except:
                if not self._extfileobj:
                    self.fileobj.close()
                self.closed = True
                raise
    
        def _getposix(self):
            return self.format == USTAR_FORMAT
        def _setposix(self, value):
            import warnings
            warnings.warn("use the format attribute instead", DeprecationWarning,
                          2)
            if value:
                self.format = USTAR_FORMAT
            else:
                self.format = GNU_FORMAT
        posix = property(_getposix, _setposix)
    
        #--------------------------------------------------------------------------
        # Below are the classmethods which act as alternate constructors to the
        # TarFile class. The open() method is the only one that is needed for
        # public use; it is the "super"-constructor and is able to select an
        # adequate "sub"-constructor for a particular compression using the mapping
        # from OPEN_METH.
        #
        # This concept allows one to subclass TarFile without losing the comfort of
        # the super-constructor. A sub-constructor is registered and made available
        # by adding it to the mapping in OPEN_METH.
    
        @classmethod
        def open(cls, name=None, mode="r", fileobj=None, bufsize=RECORDSIZE, **kwargs):
            """Open a tar archive for reading, writing or appending. Return
               an appropriate TarFile class.
    
               mode:
               'r' or 'r:*' open for reading with transparent compression
               'r:'         open for reading exclusively uncompressed
               'r:gz'       open for reading with gzip compression
               'r:bz2'      open for reading with bzip2 compression
               'a' or 'a:'  open for appending, creating the file if necessary
               'w' or 'w:'  open for writing without compression
               'w:gz'       open for writing with gzip compression
               'w:bz2'      open for writing with bzip2 compression
    
               'r|*'        open a stream of tar blocks with transparent compression
               'r|'         open an uncompressed stream of tar blocks for reading
               'r|gz'       open a gzip compressed stream of tar blocks
               'r|bz2'      open a bzip2 compressed stream of tar blocks
               'w|'         open an uncompressed stream for writing
               'w|gz'       open a gzip compressed stream for writing
               'w|bz2'      open a bzip2 compressed stream for writing
            """
    
            if not name and not fileobj:
                raise ValueError("nothing to open")
    
            if mode in ("r", "r:*"):
                # Find out which *open() is appropriate for opening the file.
                for comptype in cls.OPEN_METH:
                    func = getattr(cls, cls.OPEN_METH[comptype])
                    if fileobj is not None:
                        saved_pos = fileobj.tell()
                    try:
                        return func(name, "r", fileobj, **kwargs)
                    except (ReadError, CompressionError), e:
                        if fileobj is not None:
                            fileobj.seek(saved_pos)
                        continue
                raise ReadError("file could not be opened successfully")
    
            elif ":" in mode:
                filemode, comptype = mode.split(":", 1)
                filemode = filemode or "r"
                comptype = comptype or "tar"
    
                # Select the *open() function according to
                # given compression.
                if comptype in cls.OPEN_METH:
                    func = getattr(cls, cls.OPEN_METH[comptype])
                else:
                    raise CompressionError("unknown compression type %r" % comptype)
                return func(name, filemode, fileobj, **kwargs)
    
            elif "|" in mode:
                filemode, comptype = mode.split("|", 1)
                filemode = filemode or "r"
                comptype = comptype or "tar"
    
                if filemode not in ("r", "w"):
                    raise ValueError("mode must be 'r' or 'w'")
    
                stream = _Stream(name, filemode, comptype, fileobj, bufsize)
                try:
                    t = cls(name, filemode, stream, **kwargs)
                except:
                    stream.close()
                    raise
                t._extfileobj = False
                return t
    
            elif mode in ("a", "w"):
                return cls.taropen(name, mode, fileobj, **kwargs)
    
            raise ValueError("undiscernible mode")
    
        @classmethod
        def taropen(cls, name, mode="r", fileobj=None, **kwargs):
            """Open uncompressed tar archive name for reading or writing.
            """
            if mode not in ("r", "a", "w"):
                raise ValueError("mode must be 'r', 'a' or 'w'")
            return cls(name, mode, fileobj, **kwargs)
    
        @classmethod
        def gzopen(cls, name, mode="r", fileobj=None, compresslevel=9, **kwargs):
            """Open gzip compressed tar archive name for reading or writing.
               Appending is not allowed.
            """
            if mode not in ("r", "w"):
                raise ValueError("mode must be 'r' or 'w'")
    
            try:
                import gzip
                gzip.GzipFile
            except (ImportError, AttributeError):
                raise CompressionError("gzip module is not available")
    
            try:
                fileobj = gzip.GzipFile(name, mode, compresslevel, fileobj)
            except OSError:
                if fileobj is not None and mode == 'r':
                    raise ReadError("not a gzip file")
                raise
    
            try:
                t = cls.taropen(name, mode, fileobj, **kwargs)
            except IOError:
                fileobj.close()
                if mode == 'r':
                    raise ReadError("not a gzip file")
                raise
            except:
                fileobj.close()
                raise
            t._extfileobj = False
            return t
    
        @classmethod
        def bz2open(cls, name, mode="r", fileobj=None, compresslevel=9, **kwargs):
            """Open bzip2 compressed tar archive name for reading or writing.
               Appending is not allowed.
            """
            if mode not in ("r", "w"):
                raise ValueError("mode must be 'r' or 'w'.")
    
            try:
                import bz2
            except ImportError:
                raise CompressionError("bz2 module is not available")
    
            if fileobj is not None:
                fileobj = _BZ2Proxy(fileobj, mode)
            else:
                fileobj = bz2.BZ2File(name, mode, compresslevel=compresslevel)
    
            try:
                t = cls.taropen(name, mode, fileobj, **kwargs)
            except (IOError, EOFError):
                fileobj.close()
                if mode == 'r':
                    raise ReadError("not a bzip2 file")
                raise
            except:
                fileobj.close()
                raise
            t._extfileobj = False
            return t
    
        # All *open() methods are registered here.
        OPEN_METH = {
            "tar": "taropen",   # uncompressed tar
            "gz":  "gzopen",    # gzip compressed tar
            "bz2": "bz2open"    # bzip2 compressed tar
        }
    
        #--------------------------------------------------------------------------
        # The public methods which TarFile provides:
    
        def close(self):
            """Close the TarFile. In write-mode, two finishing zero blocks are
               appended to the archive.
            """
            if self.closed:
                return
    
            if self.mode in "aw":
                self.fileobj.write(NUL * (BLOCKSIZE * 2))
                self.offset += (BLOCKSIZE * 2)
                # fill up the end with zero-blocks
                # (like option -b20 for tar does)
                blocks, remainder = divmod(self.offset, RECORDSIZE)
                if remainder > 0:
                    self.fileobj.write(NUL * (RECORDSIZE - remainder))
    
            if not self._extfileobj:
                self.fileobj.close()
            self.closed = True
    
        def getmember(self, name):
            """Return a TarInfo object for member `name'. If `name' can not be
               found in the archive, KeyError is raised. If a member occurs more
               than once in the archive, its last occurrence is assumed to be the
               most up-to-date version.
            """
            tarinfo = self._getmember(name)
            if tarinfo is None:
                raise KeyError("filename %r not found" % name)
            return tarinfo
    
        def getmembers(self):
            """Return the members of the archive as a list of TarInfo objects. The
               list has the same order as the members in the archive.
            """
            self._check()
            if not self._loaded:    # if we want to obtain a list of
                self._load()        # all members, we first have to
                                    # scan the whole archive.
            return self.members
    
        def getnames(self):
            """Return the members of the archive as a list of their names. It has
               the same order as the list returned by getmembers().
            """
            return [tarinfo.name for tarinfo in self.getmembers()]
    
        def gettarinfo(self, name=None, arcname=None, fileobj=None):
            """Create a TarInfo object for either the file `name' or the file
               object `fileobj' (using os.fstat on its file descriptor). You can
               modify some of the TarInfo's attributes before you add it using
               addfile(). If given, `arcname' specifies an alternative name for the
               file in the archive.
            """
            self._check("aw")
    
            # When fileobj is given, replace name by
            # fileobj's real name.
            if fileobj is not None:
                name = fileobj.name
    
            # Building the name of the member in the archive.
            # Backward slashes are converted to forward slashes,
            # Absolute paths are turned to relative paths.
            if arcname is None:
                arcname = name
            drv, arcname = os.path.splitdrive(arcname)
            arcname = arcname.replace(os.sep, "/")
            arcname = arcname.lstrip("/")
    
            # Now, fill the TarInfo object with
            # information specific for the file.
            tarinfo = self.tarinfo()
            tarinfo.tarfile = self
    
            # Use os.stat or os.lstat, depending on platform
            # and if symlinks shall be resolved.
            if fileobj is None:
                if hasattr(os, "lstat") and not self.dereference:
                    statres = os.lstat(name)
                else:
                    statres = os.stat(name)
            else:
                statres = os.fstat(fileobj.fileno())
            linkname = ""
    
            stmd = statres.st_mode
            if stat.S_ISREG(stmd):
                inode = (statres.st_ino, statres.st_dev)
                if not self.dereference and statres.st_nlink > 1 and 
                        inode in self.inodes and arcname != self.inodes[inode]:
                    # Is it a hardlink to an already
                    # archived file?
                    type = LNKTYPE
                    linkname = self.inodes[inode]
                else:
                    # The inode is added only if its valid.
                    # For win32 it is always 0.
                    type = REGTYPE
                    if inode[0]:
                        self.inodes[inode] = arcname
            elif stat.S_ISDIR(stmd):
                type = DIRTYPE
            elif stat.S_ISFIFO(stmd):
                type = FIFOTYPE
            elif stat.S_ISLNK(stmd):
                type = SYMTYPE
                linkname = os.readlink(name)
            elif stat.S_ISCHR(stmd):
                type = CHRTYPE
            elif stat.S_ISBLK(stmd):
                type = BLKTYPE
            else:
                return None
    
            # Fill the TarInfo object with all
            # information we can get.
            tarinfo.name = arcname
            tarinfo.mode = stmd
            tarinfo.uid = statres.st_uid
            tarinfo.gid = statres.st_gid
            if type == REGTYPE:
                tarinfo.size = statres.st_size
            else:
                tarinfo.size = 0L
            tarinfo.mtime = statres.st_mtime
            tarinfo.type = type
            tarinfo.linkname = linkname
            if pwd:
                try:
                    tarinfo.uname = pwd.getpwuid(tarinfo.uid)[0]
                except KeyError:
                    pass
            if grp:
                try:
                    tarinfo.gname = grp.getgrgid(tarinfo.gid)[0]
                except KeyError:
                    pass
    
            if type in (CHRTYPE, BLKTYPE):
                if hasattr(os, "major") and hasattr(os, "minor"):
                    tarinfo.devmajor = os.major(statres.st_rdev)
                    tarinfo.devminor = os.minor(statres.st_rdev)
            return tarinfo
    
        def list(self, verbose=True):
            """Print a table of contents to sys.stdout. If `verbose' is False, only
               the names of the members are printed. If it is True, an `ls -l'-like
               output is produced.
            """
            self._check()
    
            for tarinfo in self:
                if verbose:
                    print filemode(tarinfo.mode),
                    print "%s/%s" % (tarinfo.uname or tarinfo.uid,
                                     tarinfo.gname or tarinfo.gid),
                    if tarinfo.ischr() or tarinfo.isblk():
                        print "%10s" % ("%d,%d" 
                                        % (tarinfo.devmajor, tarinfo.devminor)),
                    else:
                        print "%10d" % tarinfo.size,
                    print "%d-%02d-%02d %02d:%02d:%02d" 
                          % time.localtime(tarinfo.mtime)[:6],
    
                print tarinfo.name + ("/" if tarinfo.isdir() else ""),
    
                if verbose:
                    if tarinfo.issym():
                        print "->", tarinfo.linkname,
                    if tarinfo.islnk():
                        print "link to", tarinfo.linkname,
                print
    
        def add(self, name, arcname=None, recursive=True, exclude=None, filter=None):
            """Add the file `name' to the archive. `name' may be any type of file
               (directory, fifo, symbolic link, etc.). If given, `arcname'
               specifies an alternative name for the file in the archive.
               Directories are added recursively by default. This can be avoided by
               setting `recursive' to False. `exclude' is a function that should
               return True for each filename to be excluded. `filter' is a function
               that expects a TarInfo object argument and returns the changed
               TarInfo object, if it returns None the TarInfo object will be
               excluded from the archive.
            """
            self._check("aw")
    
            if arcname is None:
                arcname = name
    
            # Exclude pathnames.
            if exclude is not None:
                import warnings
                warnings.warn("use the filter argument instead",
                        DeprecationWarning, 2)
                if exclude(name):
                    self._dbg(2, "tarfile: Excluded %r" % name)
                    return
    
            # Skip if somebody tries to archive the archive...
            if self.name is not None and os.path.abspath(name) == self.name:
                self._dbg(2, "tarfile: Skipped %r" % name)
                return
    
            self._dbg(1, name)
    
            # Create a TarInfo object from the file.
            tarinfo = self.gettarinfo(name, arcname)
    
            if tarinfo is None:
                self._dbg(1, "tarfile: Unsupported type %r" % name)
                return
    
            # Change or exclude the TarInfo object.
            if filter is not None:
                tarinfo = filter(tarinfo)
                if tarinfo is None:
                    self._dbg(2, "tarfile: Excluded %r" % name)
                    return
    
            # Append the tar header and data to the archive.
            if tarinfo.isreg():
                with bltn_open(name, "rb") as f:
                    self.addfile(tarinfo, f)
    
            elif tarinfo.isdir():
                self.addfile(tarinfo)
                if recursive:
                    for f in os.listdir(name):
                        self.add(os.path.join(name, f), os.path.join(arcname, f),
                                recursive, exclude, filter)
    
            else:
                self.addfile(tarinfo)
    
        def addfile(self, tarinfo, fileobj=None):
            """Add the TarInfo object `tarinfo' to the archive. If `fileobj' is
               given, tarinfo.size bytes are read from it and added to the archive.
               You can create TarInfo objects using gettarinfo().
               On Windows platforms, `fileobj' should always be opened with mode
               'rb' to avoid irritation about the file size.
            """
            self._check("aw")
    
            tarinfo = copy.copy(tarinfo)
    
            buf = tarinfo.tobuf(self.format, self.encoding, self.errors)
            self.fileobj.write(buf)
            self.offset += len(buf)
    
            # If there's data to follow, append it.
            if fileobj is not None:
                copyfileobj(fileobj, self.fileobj, tarinfo.size)
                blocks, remainder = divmod(tarinfo.size, BLOCKSIZE)
                if remainder > 0:
                    self.fileobj.write(NUL * (BLOCKSIZE - remainder))
                    blocks += 1
                self.offset += blocks * BLOCKSIZE
    
            self.members.append(tarinfo)
    
        def extractall(self, path=".", members=None):
            """Extract all members from the archive to the current working
               directory and set owner, modification time and permissions on
               directories afterwards. `path' specifies a different directory
               to extract to. `members' is optional and must be a subset of the
               list returned by getmembers().
            """
            directories = []
    
            if members is None:
                members = self
    
            for tarinfo in members:
                if tarinfo.isdir():
                    # Extract directories with a safe mode.
                    directories.append(tarinfo)
                    tarinfo = copy.copy(tarinfo)
                    tarinfo.mode = 0700
                self.extract(tarinfo, path)
    
            # Reverse sort directories.
            directories.sort(key=operator.attrgetter('name'))
            directories.reverse()
    
            # Set correct owner, mtime and filemode on directories.
            for tarinfo in directories:
                dirpath = os.path.join(path, tarinfo.name)
                try:
                    self.chown(tarinfo, dirpath)
                    self.utime(tarinfo, dirpath)
                    self.chmod(tarinfo, dirpath)
                except ExtractError, e:
                    if self.errorlevel > 1:
                        raise
                    else:
                        self._dbg(1, "tarfile: %s" % e)
    
        def extract(self, member, path=""):
            """Extract a member from the archive to the current working directory,
               using its full name. Its file information is extracted as accurately
               as possible. `member' may be a filename or a TarInfo object. You can
               specify a different directory using `path'.
            """
            self._check("r")
    
            if isinstance(member, basestring):
                tarinfo = self.getmember(member)
            else:
                tarinfo = member
    
            # Prepare the link target for makelink().
            if tarinfo.islnk():
                tarinfo._link_target = os.path.join(path, tarinfo.linkname)
    
            try:
                self._extract_member(tarinfo, os.path.join(path, tarinfo.name))
            except EnvironmentError, e:
                if self.errorlevel > 0:
                    raise
                else:
                    if e.filename is None:
                        self._dbg(1, "tarfile: %s" % e.strerror)
                    else:
                        self._dbg(1, "tarfile: %s %r" % (e.strerror, e.filename))
            except ExtractError, e:
                if self.errorlevel > 1:
                    raise
                else:
                    self._dbg(1, "tarfile: %s" % e)
    
        def extractfile(self, member):
            """Extract a member from the archive as a file object. `member' may be
               a filename or a TarInfo object. If `member' is a regular file, a
               file-like object is returned. If `member' is a link, a file-like
               object is constructed from the link's target. If `member' is none of
               the above, None is returned.
               The file-like object is read-only and provides the following
               methods: read(), readline(), readlines(), seek() and tell()
            """
            self._check("r")
    
            if isinstance(member, basestring):
                tarinfo = self.getmember(member)
            else:
                tarinfo = member
    
            if tarinfo.isreg():
                return self.fileobject(self, tarinfo)
    
            elif tarinfo.type not in SUPPORTED_TYPES:
                # If a member's type is unknown, it is treated as a
                # regular file.
                return self.fileobject(self, tarinfo)
    
            elif tarinfo.islnk() or tarinfo.issym():
                if isinstance(self.fileobj, _Stream):
                    # A small but ugly workaround for the case that someone tries
                    # to extract a (sym)link as a file-object from a non-seekable
                    # stream of tar blocks.
                    raise StreamError("cannot extract (sym)link as file object")
                else:
                    # A (sym)link's file object is its target's file object.
                    return self.extractfile(self._find_link_target(tarinfo))
            else:
                # If there's no data associated with the member (directory, chrdev,
                # blkdev, etc.), return None instead of a file object.
                return None
    
        def _extract_member(self, tarinfo, targetpath):
            """Extract the TarInfo object tarinfo to a physical
               file called targetpath.
            """
            # Fetch the TarInfo object for the given name
            # and build the destination pathname, replacing
            # forward slashes to platform specific separators.
            targetpath = targetpath.rstrip("/")
            targetpath = targetpath.replace("/", os.sep)
    
            # Create all upper directories.
            upperdirs = os.path.dirname(targetpath)
            if upperdirs and not os.path.exists(upperdirs):
                # Create directories that are not part of the archive with
                # default permissions.
                os.makedirs(upperdirs)
    
            if tarinfo.islnk() or tarinfo.issym():
                self._dbg(1, "%s -> %s" % (tarinfo.name, tarinfo.linkname))
            else:
                self._dbg(1, tarinfo.name)
    
            if tarinfo.isreg():
                self.makefile(tarinfo, targetpath)
            elif tarinfo.isdir():
                self.makedir(tarinfo, targetpath)
            elif tarinfo.isfifo():
                self.makefifo(tarinfo, targetpath)
            elif tarinfo.ischr() or tarinfo.isblk():
                self.makedev(tarinfo, targetpath)
            elif tarinfo.islnk() or tarinfo.issym():
                self.makelink(tarinfo, targetpath)
            elif tarinfo.type not in SUPPORTED_TYPES:
                self.makeunknown(tarinfo, targetpath)
            else:
                self.makefile(tarinfo, targetpath)
    
            self.chown(tarinfo, targetpath)
            if not tarinfo.issym():
                self.chmod(tarinfo, targetpath)
                self.utime(tarinfo, targetpath)
    
        #--------------------------------------------------------------------------
        # Below are the different file methods. They are called via
        # _extract_member() when extract() is called. They can be replaced in a
        # subclass to implement other functionality.
    
        def makedir(self, tarinfo, targetpath):
            """Make a directory called targetpath.
            """
            try:
                # Use a safe mode for the directory, the real mode is set
                # later in _extract_member().
                os.mkdir(targetpath, 0700)
            except EnvironmentError, e:
                if e.errno != errno.EEXIST:
                    raise
    
        def makefile(self, tarinfo, targetpath):
            """Make a file called targetpath.
            """
            source = self.extractfile(tarinfo)
            try:
                with bltn_open(targetpath, "wb") as target:
                    copyfileobj(source, target)
            finally:
                source.close()
    
        def makeunknown(self, tarinfo, targetpath):
            """Make a file from a TarInfo object with an unknown type
               at targetpath.
            """
            self.makefile(tarinfo, targetpath)
            self._dbg(1, "tarfile: Unknown file type %r, " 
                         "extracted as regular file." % tarinfo.type)
    
        def makefifo(self, tarinfo, targetpath):
            """Make a fifo called targetpath.
            """
            if hasattr(os, "mkfifo"):
                os.mkfifo(targetpath)
            else:
                raise ExtractError("fifo not supported by system")
    
        def makedev(self, tarinfo, targetpath):
            """Make a character or block device called targetpath.
            """
            if not hasattr(os, "mknod") or not hasattr(os, "makedev"):
                raise ExtractError("special devices not supported by system")
    
            mode = tarinfo.mode
            if tarinfo.isblk():
                mode |= stat.S_IFBLK
            else:
                mode |= stat.S_IFCHR
    
            os.mknod(targetpath, mode,
                     os.makedev(tarinfo.devmajor, tarinfo.devminor))
    
        def makelink(self, tarinfo, targetpath):
            """Make a (symbolic) link called targetpath. If it cannot be created
              (platform limitation), we try to make a copy of the referenced file
              instead of a link.
            """
            if hasattr(os, "symlink") and hasattr(os, "link"):
                # For systems that support symbolic and hard links.
                if tarinfo.issym():
                    if os.path.lexists(targetpath):
                        os.unlink(targetpath)
                    os.symlink(tarinfo.linkname, targetpath)
                else:
                    # See extract().
                    if os.path.exists(tarinfo._link_target):
                        if os.path.lexists(targetpath):
                            os.unlink(targetpath)
                        os.link(tarinfo._link_target, targetpath)
                    else:
                        self._extract_member(self._find_link_target(tarinfo), targetpath)
            else:
                try:
                    self._extract_member(self._find_link_target(tarinfo), targetpath)
                except KeyError:
                    raise ExtractError("unable to resolve link inside archive")
    
        def chown(self, tarinfo, targetpath):
            """Set owner of targetpath according to tarinfo.
            """
            if pwd and hasattr(os, "geteuid") and os.geteuid() == 0:
                # We have to be root to do so.
                try:
                    g = grp.getgrnam(tarinfo.gname)[2]
                except KeyError:
                    g = tarinfo.gid
                try:
                    u = pwd.getpwnam(tarinfo.uname)[2]
                except KeyError:
                    u = tarinfo.uid
                try:
                    if tarinfo.issym() and hasattr(os, "lchown"):
                        os.lchown(targetpath, u, g)
                    else:
                        if sys.platform != "os2emx":
                            os.chown(targetpath, u, g)
                except EnvironmentError, e:
                    raise ExtractError("could not change owner")
    
        def chmod(self, tarinfo, targetpath):
            """Set file permissions of targetpath according to tarinfo.
            """
            if hasattr(os, 'chmod'):
                try:
                    os.chmod(targetpath, tarinfo.mode)
                except EnvironmentError, e:
                    raise ExtractError("could not change mode")
    
        def utime(self, tarinfo, targetpath):
            """Set modification time of targetpath according to tarinfo.
            """
            if not hasattr(os, 'utime'):
                return
            try:
                os.utime(targetpath, (tarinfo.mtime, tarinfo.mtime))
            except EnvironmentError, e:
                raise ExtractError("could not change modification time")
    
        #--------------------------------------------------------------------------
        def next(self):
            """Return the next member of the archive as a TarInfo object, when
               TarFile is opened for reading. Return None if there is no more
               available.
            """
            self._check("ra")
            if self.firstmember is not None:
                m = self.firstmember
                self.firstmember = None
                return m
    
            # Read the next block.
            self.fileobj.seek(self.offset)
            tarinfo = None
            while True:
                try:
                    tarinfo = self.tarinfo.fromtarfile(self)
                except EOFHeaderError, e:
                    if self.ignore_zeros:
                        self._dbg(2, "0x%X: %s" % (self.offset, e))
                        self.offset += BLOCKSIZE
                        continue
                except InvalidHeaderError, e:
                    if self.ignore_zeros:
                        self._dbg(2, "0x%X: %s" % (self.offset, e))
                        self.offset += BLOCKSIZE
                        continue
                    elif self.offset == 0:
                        raise ReadError(str(e))
                except EmptyHeaderError:
                    if self.offset == 0:
                        raise ReadError("empty file")
                except TruncatedHeaderError, e:
                    if self.offset == 0:
                        raise ReadError(str(e))
                except SubsequentHeaderError, e:
                    raise ReadError(str(e))
                break
    
            if tarinfo is not None:
                self.members.append(tarinfo)
            else:
                self._loaded = True
    
            return tarinfo
    
        #--------------------------------------------------------------------------
        # Little helper methods:
    
        def _getmember(self, name, tarinfo=None, normalize=False):
            """Find an archive member by name from bottom to top.
               If tarinfo is given, it is used as the starting point.
            """
            # Ensure that all members have been loaded.
            members = self.getmembers()
    
            # Limit the member search list up to tarinfo.
            if tarinfo is not None:
                members = members[:members.index(tarinfo)]
    
            if normalize:
                name = os.path.normpath(name)
    
            for member in reversed(members):
                if normalize:
                    member_name = os.path.normpath(member.name)
                else:
                    member_name = member.name
    
                if name == member_name:
                    return member
    
        def _load(self):
            """Read through the entire archive file and look for readable
               members.
            """
            while True:
                tarinfo = self.next()
                if tarinfo is None:
                    break
            self._loaded = True
    
        def _check(self, mode=None):
            """Check if TarFile is still open, and if the operation's mode
               corresponds to TarFile's mode.
            """
            if self.closed:
                raise IOError("%s is closed" % self.__class__.__name__)
            if mode is not None and self.mode not in mode:
                raise IOError("bad operation for mode %r" % self.mode)
    
        def _find_link_target(self, tarinfo):
            """Find the target member of a symlink or hardlink member in the
               archive.
            """
            if tarinfo.issym():
                # Always search the entire archive.
                linkname = "/".join(filter(None, (os.path.dirname(tarinfo.name), tarinfo.linkname)))
                limit = None
            else:
                # Search the archive before the link, because a hard link is
                # just a reference to an already archived file.
                linkname = tarinfo.linkname
                limit = tarinfo
    
            member = self._getmember(linkname, tarinfo=limit, normalize=True)
            if member is None:
                raise KeyError("linkname %r not found" % linkname)
            return member
    
        def __iter__(self):
            """Provide an iterator object.
            """
            if self._loaded:
                return iter(self.members)
            else:
                return TarIter(self)
    
        def _dbg(self, level, msg):
            """Write debugging output to sys.stderr.
            """
            if level <= self.debug:
                print >> sys.stderr, msg
    
        def __enter__(self):
            self._check()
            return self
    
        def __exit__(self, type, value, traceback):
            if type is None:
                self.close()
            else:
                # An exception occurred. We must not call close() because
                # it would try to write end-of-archive blocks and padding.
                if not self._extfileobj:
                    self.fileobj.close()
                self.closed = True
    # class TarFile
    复制代码
     
    七、ConfigParser
    
    用于对特定的配置进行操作,当前模块的名称在 python 3.x 版本中变更为 configparser。
    
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    # 注释1
    ; 注释2
     
    [section1]
    k1 = v1
    k2:v2
     
    [section2]
    k1 = v1
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    import ConfigParser
     
    config = ConfigParser.ConfigParser()
    config.read('i.cfg')
     
    # ########## 读 ##########
    #secs = config.sections()
    #print secs
    #options = config.options('group2')
    #print options
     
    #item_list = config.items('group2')
    #print item_list
     
    #val = config.get('group1','key')
    #val = config.getint('group1','key')
     
    # ########## 改写 ##########
    #sec = config.remove_section('group1')
    #config.write(open('i.cfg', "w"))
     
    #sec = config.has_section('wupeiqi')
    #sec = config.add_section('wupeiqi')
    #config.write(open('i.cfg', "w"))
     
     
    #config.set('group2','k1',11111)
    #config.write(open('i.cfg', "w"))
     
    #config.remove_option('group2','age')
    #config.write(open('i.cfg', "w"))
    View Code

    七、ConfigParser 模块

    定义配置文件config.ini:

    [section1]
    k1 = v1
    k2 = v2
    
    [section2]
    name = steven
    
    [section3]
    test_server = "10.1.1.5"
    dev_server = "10.1.2.5"
    pro_server = "10.1.1.5"
    
    [section4]
    name = steven
    

    操作

    ## 读取配置文件 ##
    config=ConfigParser.ConfigParser()
    conf_path = os.path.dirname(os.path.realpath(__file__))+ '/config.ini'
    # 打开文件,放入到内存
    config.read(conf_path)
    # 读sections
    print config.sections()
    # 读options
    print config.options('server')
    # 读options的key和values
    print config.items('server')
    # 读特定的值
    print config.get('server','test_server')

    # 获取整数,浮点数
    print con.getint('long','age')
    print con.getfloat('long','age')

    ######## 改写操作 ######## # 修改section2 sec = config.remove_section('section2') config.write(open(conf_path, "w")) # 添加section4 sec = config.has_section('section4') sec = config.add_section('section4') config.write(open(conf_path, "w")) # 在section4下面添加键值 config.set('section4','name','steven') config.write(open(conf_path, "w")) config.remove_option('section4','age') config.write(open(conf_path, "w"))

     八、logging模块

    # -*- coding: utf-8 -*-
    import logging
    
    logging.basicConfig(
        filename='log.log',
        format='%(asctime)s - %(name)s - %(levelname)s -%(module)s:  %(message)s',
        datefmt='%Y-%m-%d %H:%M:%S %p',
        level=10
    )
    debug = "*"*20
    warning = "#"*40
    
    logging.debug('debug:%s'%debug)
    logging.info('info')
    logging.warning('warning :%s'%warning)
    logging.error('error')
    logging.critical('critical')
    logging.log(10,'log')
    

     关于等级

    CRITICAL = 50
    FATAL = CRITICAL
    ERROR = 40
    WARNING = 30
    WARN = WARNING
    INFO = 20
    DEBUG = 10
    NOTSET = 0
    

     只有大于当前日志等级的操作才会被记录。

    有以下格式可以配置。

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  • 原文地址:https://www.cnblogs.com/sunshine-long/p/12466697.html
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