Python学习第六天

时间：2016-03-05 01:45:09 阅读：451 评论：0 收藏：0 [点我收藏+]

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模块：

shutil 模块：

高级的文件、文件夹、压缩包处理模块

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

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

View Code

shutil.copyfile(src, dst)
拷贝文件

 1 def copyfile(src, dst):
 2     """Copy data from src to dst"""
 3     if _samefile(src, dst):
 4         raise Error("`%s` and `%s` are the same file" % (src, dst))
 5 
 6     for fn in [src, dst]:
 7         try:
 8             st = os.stat(fn)
 9         except OSError:
10             # File most likely does not exist
11             pass
12         else:
13             # XXX What about other special files? (sockets, devices...)
14             if stat.S_ISFIFO(st.st_mode):
15                 raise SpecialFileError("`%s` is a named pipe" % fn)
16 
17     with open(src, ‘rb‘) as fsrc:
18         with open(dst, ‘wb‘) as fdst:
19             copyfileobj(fsrc, fdst)

View Code

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

1 def copymode(src, dst):
2     """Copy mode bits from src to dst"""
3     if hasattr(os, ‘chmod‘):
4         st = os.stat(src)
5         mode = stat.S_IMODE(st.st_mode)
6         os.chmod(dst, mode)

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

 1 def copystat(src, dst):
 2     """Copy all stat info (mode bits, atime, mtime, flags) from src to dst"""
 3     st = os.stat(src)
 4     mode = stat.S_IMODE(st.st_mode)
 5     if hasattr(os, ‘utime‘):
 6         os.utime(dst, (st.st_atime, st.st_mtime))
 7     if hasattr(os, ‘chmod‘):
 8         os.chmod(dst, mode)
 9     if hasattr(os, ‘chflags‘) and hasattr(st, ‘st_flags‘):
10         try:
11             os.chflags(dst, st.st_flags)
12         except OSError, why:
13             for err in ‘EOPNOTSUPP‘, ‘ENOTSUP‘:
14                 if hasattr(errno, err) and why.errno == getattr(errno, err):
15                     break
16             else:
17                 raise

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shutil.copy(src, dst)
拷贝文件和权限

 1 def copy(src, dst):
 2     """Copy data and mode bits ("cp src dst").
 3 
 4     The destination may be a directory.
 5 
 6     """
 7     if os.path.isdir(dst):
 8         dst = os.path.join(dst, os.path.basename(src))
 9     copyfile(src, dst)
10     copymode(src, dst)

View Code

shutil.copy2(src, dst)
拷贝文件和状态信息

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

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

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

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

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

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

View Code

shutil.move(src, dst)
递归的去移动文件

 1 def move(src, dst):
 2     """Recursively move a file or directory to another location. This is
 3     similar to the Unix "mv" command.
 4 
 5     If the destination is a directory or a symlink to a directory, the source
 6     is moved inside the directory. The destination path must not already
 7     exist.
 8 
 9     If the destination already exists but is not a directory, it may be
10     overwritten depending on os.rename() semantics.
11 
12     If the destination is on our current filesystem, then rename() is used.
13     Otherwise, src is copied to the destination and then removed.
14     A lot more could be done here...  A look at a mv.c shows a lot of
15     the issues this implementation glosses over.
16 
17     """
18     real_dst = dst
19     if os.path.isdir(dst):
20         if _samefile(src, dst):
21             # We might be on a case insensitive filesystem,
22             # perform the rename anyway.
23             os.rename(src, dst)
24             return
25 
26         real_dst = os.path.join(dst, _basename(src))
27         if os.path.exists(real_dst):
28             raise Error, "Destination path ‘%s‘ already exists" % real_dst
29     try:
30         os.rename(src, real_dst)
31     except OSError:
32         if os.path.isdir(src):
33             if _destinsrc(src, dst):
34                 raise Error, "Cannot move a directory ‘%s‘ into itself ‘%s‘." % (src, dst)
35             copytree(src, real_dst, symlinks=True)
36             rmtree(src)
37         else:
38             copy2(src, real_dst)
39             os.unlink(src)

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shutil.make_archive(base_name, format,...)

创建压缩包并返回文件路径，例如：zip、tar

base_name：压缩包的文件名，也可以是压缩包的路径。只是文件名时，则保存至当前目录，否则保存至指定路径，
如：www =>保存至当前路径
如：/Users/wupeiqi/www =>保存至/Users/wupeiqi/
format：压缩包种类，“zip”, “tar”, “bztar”，“gztar”
root_dir：要压缩的文件夹路径（默认当前目录）
owner：用户，默认当前用户
group：组，默认当前组

logger：用于记录日志，通常是logging.Logger对象

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

View Code

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

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

 1 import zipfile
 2 
 3 # 压缩
 4 z = zipfile.ZipFile(‘laxi.zip‘, ‘w‘)
 5 z.write(‘a.log‘)
 6 z.write(‘data.data‘)
 7 z.close()
 8 
 9 # 解压
10 z = zipfile.ZipFile(‘laxi.zip‘, ‘r‘)
11 z.extractall()
12 z.close()

zipfile文件压缩解压

 1 import tarfile
 2 
 3 # 压缩
 4 tar = tarfile.open(‘your.tar‘,‘w‘)
 5 tar.add(‘/Users/wupeiqi/PycharmProjects/bbs2.zip‘, arcname=‘bbs2.zip‘)
 6 tar.add(‘/Users/wupeiqi/PycharmProjects/cmdb.zip‘, arcname=‘cmdb.zip‘)
 7 tar.close()
 8 
 9 # 解压
10 tar = tarfile.open(‘your.tar‘,‘r‘)
11 tar.extractall()  # 可设置解压地址
12 tar.close()
13 
14 tarfile 压缩解压

tarfile文件压缩解压

  1 class ZipFile(object):
  2     """ Class with methods to open, read, write, close, list zip files.
  3 
  4     z = ZipFile(file, mode="r", compression=ZIP_STORED, allowZip64=False)
  5 
  6     file: Either the path to the file, or a file-like object.
  7           If it is a path, the file will be opened and closed by ZipFile.
  8     mode: The mode can be either read "r", write "w" or append "a".
  9     compression: ZIP_STORED (no compression) or ZIP_DEFLATED (requires zlib).
 10     allowZip64: if True ZipFile will create files with ZIP64 extensions when
 11                 needed, otherwise it will raise an exception when this would
 12                 be necessary.
 13 
 14     """
 15 
 16     fp = None                   # Set here since __del__ checks it
 17 
 18     def __init__(self, file, mode="r", compression=ZIP_STORED, allowZip64=False):
 19         """Open the ZIP file with mode read "r", write "w" or append "a"."""
 20         if mode not in ("r", "w", "a"):
 21             raise RuntimeError(‘ZipFile() requires mode "r", "w", or "a"‘)
 22 
 23         if compression == ZIP_STORED:
 24             pass
 25         elif compression == ZIP_DEFLATED:
 26             if not zlib:
 27                 raise RuntimeError, 28                       "Compression requires the (missing) zlib module"
 29         else:
 30             raise RuntimeError, "That compression method is not supported"
 31 
 32         self._allowZip64 = allowZip64
 33         self._didModify = False
 34         self.debug = 0  # Level of printing: 0 through 3
 35         self.NameToInfo = {}    # Find file info given name
 36         self.filelist = []      # List of ZipInfo instances for archive
 37         self.compression = compression  # Method of compression
 38         self.mode = key = mode.replace(‘b‘, ‘‘)[0]
 39         self.pwd = None
 40         self._comment = ‘‘
 41 
 42         # Check if we were passed a file-like object
 43         if isinstance(file, basestring):
 44             self._filePassed = 0
 45             self.filename = file
 46             modeDict = {‘r‘ : ‘rb‘, ‘w‘: ‘wb‘, ‘a‘ : ‘r+b‘}
 47             try:
 48                 self.fp = open(file, modeDict[mode])
 49             except IOError:
 50                 if mode == ‘a‘:
 51                     mode = key = ‘w‘
 52                     self.fp = open(file, modeDict[mode])
 53                 else:
 54                     raise
 55         else:
 56             self._filePassed = 1
 57             self.fp = file
 58             self.filename = getattr(file, ‘name‘, None)
 59 
 60         try:
 61             if key == ‘r‘:
 62                 self._RealGetContents()
 63             elif key == ‘w‘:
 64                 # set the modified flag so central directory gets written
 65                 # even if no files are added to the archive
 66                 self._didModify = True
 67             elif key == ‘a‘:
 68                 try:
 69                     # See if file is a zip file
 70                     self._RealGetContents()
 71                     # seek to start of directory and overwrite
 72                     self.fp.seek(self.start_dir, 0)
 73                 except BadZipfile:
 74                     # file is not a zip file, just append
 75                     self.fp.seek(0, 2)
 76 
 77                     # set the modified flag so central directory gets written
 78                     # even if no files are added to the archive
 79                     self._didModify = True
 80             else:
 81                 raise RuntimeError(‘Mode must be "r", "w" or "a"‘)
 82         except:
 83             fp = self.fp
 84             self.fp = None
 85             if not self._filePassed:
 86                 fp.close()
 87             raise
 88 
 89     def __enter__(self):
 90         return self
 91 
 92     def __exit__(self, type, value, traceback):
 93         self.close()
 94 
 95     def _RealGetContents(self):
 96         """Read in the table of contents for the ZIP file."""
 97         fp = self.fp
 98         try:
 99             endrec = _EndRecData(fp)
100         except IOError:
101             raise BadZipfile("File is not a zip file")
102         if not endrec:
103             raise BadZipfile, "File is not a zip file"
104         if self.debug > 1:
105             print endrec
106         size_cd = endrec[_ECD_SIZE]             # bytes in central directory
107         offset_cd = endrec[_ECD_OFFSET]         # offset of central directory
108         self._comment = endrec[_ECD_COMMENT]    # archive comment
109 
110         # "concat" is zero, unless zip was concatenated to another file
111         concat = endrec[_ECD_LOCATION] - size_cd - offset_cd
112         if endrec[_ECD_SIGNATURE] == stringEndArchive64:
113             # If Zip64 extension structures are present, account for them
114             concat -= (sizeEndCentDir64 + sizeEndCentDir64Locator)
115 
116         if self.debug > 2:
117             inferred = concat + offset_cd
118             print "given, inferred, offset", offset_cd, inferred, concat
119         # self.start_dir:  Position of start of central directory
120         self.start_dir = offset_cd + concat
121         fp.seek(self.start_dir, 0)
122         data = fp.read(size_cd)
123         fp = cStringIO.StringIO(data)
124         total = 0
125         while total < size_cd:
126             centdir = fp.read(sizeCentralDir)
127             if len(centdir) != sizeCentralDir:
128                 raise BadZipfile("Truncated central directory")
129             centdir = struct.unpack(structCentralDir, centdir)
130             if centdir[_CD_SIGNATURE] != stringCentralDir:
131                 raise BadZipfile("Bad magic number for central directory")
132             if self.debug > 2:
133                 print centdir
134             filename = fp.read(centdir[_CD_FILENAME_LENGTH])
135             # Create ZipInfo instance to store file information
136             x = ZipInfo(filename)
137             x.extra = fp.read(centdir[_CD_EXTRA_FIELD_LENGTH])
138             x.comment = fp.read(centdir[_CD_COMMENT_LENGTH])
139             x.header_offset = centdir[_CD_LOCAL_HEADER_OFFSET]
140             (x.create_version, x.create_system, x.extract_version, x.reserved,
141                 x.flag_bits, x.compress_type, t, d,
142                 x.CRC, x.compress_size, x.file_size) = centdir[1:12]
143             x.volume, x.internal_attr, x.external_attr = centdir[15:18]
144             # Convert date/time code to (year, month, day, hour, min, sec)
145             x._raw_time = t
146             x.date_time = ( (d>>9)+1980, (d>>5)&0xF, d&0x1F,
147                                      t>>11, (t>>5)&0x3F, (t&0x1F) * 2 )
148 
149             x._decodeExtra()
150             x.header_offset = x.header_offset + concat
151             x.filename = x._decodeFilename()
152             self.filelist.append(x)
153             self.NameToInfo[x.filename] = x
154 
155             # update total bytes read from central directory
156             total = (total + sizeCentralDir + centdir[_CD_FILENAME_LENGTH]
157                      + centdir[_CD_EXTRA_FIELD_LENGTH]
158                      + centdir[_CD_COMMENT_LENGTH])
159 
160             if self.debug > 2:
161                 print "total", total
162 
163 
164     def namelist(self):
165         """Return a list of file names in the archive."""
166         l = []
167         for data in self.filelist:
168             l.append(data.filename)
169         return l
170 
171     def infolist(self):
172         """Return a list of class ZipInfo instances for files in the
173         archive."""
174         return self.filelist
175 
176     def printdir(self):
177         """Print a table of contents for the zip file."""
178         print "%-46s %19s %12s" % ("File Name", "Modified    ", "Size")
179         for zinfo in self.filelist:
180             date = "%d-%02d-%02d %02d:%02d:%02d" % zinfo.date_time[:6]
181             print "%-46s %s %12d" % (zinfo.filename, date, zinfo.file_size)
182 
183     def testzip(self):
184         """Read all the files and check the CRC."""
185         chunk_size = 2 ** 20
186         for zinfo in self.filelist:
187             try:
188                 # Read by chunks, to avoid an OverflowError or a
189                 # MemoryError with very large embedded files.
190                 with self.open(zinfo.filename, "r") as f:
191                     while f.read(chunk_size):     # Check CRC-32
192                         pass
193             except BadZipfile:
194                 return zinfo.filename
195 
196     def getinfo(self, name):
197         """Return the instance of ZipInfo given ‘name‘."""
198         info = self.NameToInfo.get(name)
199         if info is None:
200             raise KeyError(
201                 ‘There is no item named %r in the archive‘ % name)
202 
203         return info
204 
205     def setpassword(self, pwd):
206         """Set default password for encrypted files."""
207         self.pwd = pwd
208 
209     @property
210     def comment(self):
211         """The comment text associated with the ZIP file."""
212         return self._comment
213 
214     @comment.setter
215     def comment(self, comment):
216         # check for valid comment length
217         if len(comment) > ZIP_MAX_COMMENT:
218             import warnings
219             warnings.warn(‘Archive comment is too long; truncating to %d bytes‘
220                           % ZIP_MAX_COMMENT, stacklevel=2)
221             comment = comment[:ZIP_MAX_COMMENT]
222         self._comment = comment
223         self._didModify = True
224 
225     def read(self, name, pwd=None):
226         """Return file bytes (as a string) for name."""
227         return self.open(name, "r", pwd).read()
228 
229     def open(self, name, mode="r", pwd=None):
230         """Return file-like object for ‘name‘."""
231         if mode not in ("r", "U", "rU"):
232             raise RuntimeError, ‘open() requires mode "r", "U", or "rU"‘
233         if not self.fp:
234             raise RuntimeError, 235                   "Attempt to read ZIP archive that was already closed"
236 
237         # Only open a new file for instances where we were not
238         # given a file object in the constructor
239         if self._filePassed:
240             zef_file = self.fp
241             should_close = False
242         else:
243             zef_file = open(self.filename, ‘rb‘)
244             should_close = True
245 
246         try:
247             # Make sure we have an info object
248             if isinstance(name, ZipInfo):
249                 # ‘name‘ is already an info object
250                 zinfo = name
251             else:
252                 # Get info object for name
253                 zinfo = self.getinfo(name)
254 
255             zef_file.seek(zinfo.header_offset, 0)
256 
257             # Skip the file header:
258             fheader = zef_file.read(sizeFileHeader)
259             if len(fheader) != sizeFileHeader:
260                 raise BadZipfile("Truncated file header")
261             fheader = struct.unpack(structFileHeader, fheader)
262             if fheader[_FH_SIGNATURE] != stringFileHeader:
263                 raise BadZipfile("Bad magic number for file header")
264 
265             fname = zef_file.read(fheader[_FH_FILENAME_LENGTH])
266             if fheader[_FH_EXTRA_FIELD_LENGTH]:
267                 zef_file.read(fheader[_FH_EXTRA_FIELD_LENGTH])
268 
269             if fname != zinfo.orig_filename:
270                 raise BadZipfile, 271                         ‘File name in directory "%s" and header "%s" differ.‘ % (
272                             zinfo.orig_filename, fname)
273 
274             # check for encrypted flag & handle password
275             is_encrypted = zinfo.flag_bits & 0x1
276             zd = None
277             if is_encrypted:
278                 if not pwd:
279                     pwd = self.pwd
280                 if not pwd:
281                     raise RuntimeError, "File %s is encrypted, " 282                         "password required for extraction" % name
283 
284                 zd = _ZipDecrypter(pwd)
285                 # The first 12 bytes in the cypher stream is an encryption header
286                 #  used to strengthen the algorithm. The first 11 bytes are
287                 #  completely random, while the 12th contains the MSB of the CRC,
288                 #  or the MSB of the file time depending on the header type
289                 #  and is used to check the correctness of the password.
290                 bytes = zef_file.read(12)
291                 h = map(zd, bytes[0:12])
292                 if zinfo.flag_bits & 0x8:
293                     # compare against the file type from extended local headers
294                     check_byte = (zinfo._raw_time >> 8) & 0xff
295                 else:
296                     # compare against the CRC otherwise
297                     check_byte = (zinfo.CRC >> 24) & 0xff
298                 if ord(h[11]) != check_byte:
299                     raise RuntimeError("Bad password for file", name)
300 
301             return ZipExtFile(zef_file, mode, zinfo, zd,
302                     close_fileobj=should_close)
303         except:
304             if should_close:
305                 zef_file.close()
306             raise
307 
308     def extract(self, member, path=None, pwd=None):
309         """Extract a member from the archive to the current working directory,
310            using its full name. Its file information is extracted as accurately
311            as possible. `member‘ may be a filename or a ZipInfo object. You can
312            specify a different directory using `path‘.
313         """
314         if not isinstance(member, ZipInfo):
315             member = self.getinfo(member)
316 
317         if path is None:
318             path = os.getcwd()
319 
320         return self._extract_member(member, path, pwd)
321 
322     def extractall(self, path=None, members=None, pwd=None):
323         """Extract all members from the archive to the current working
324            directory. `path‘ specifies a different directory to extract to.
325            `members‘ is optional and must be a subset of the list returned
326            by namelist().
327         """
328         if members is None:
329             members = self.namelist()
330 
331         for zipinfo in members:
332             self.extract(zipinfo, path, pwd)
333 
334     def _extract_member(self, member, targetpath, pwd):
335         """Extract the ZipInfo object ‘member‘ to a physical
336            file on the path targetpath.
337         """
338         # build the destination pathname, replacing
339         # forward slashes to platform specific separators.
340         arcname = member.filename.replace(‘/‘, os.path.sep)
341 
342         if os.path.altsep:
343             arcname = arcname.replace(os.path.altsep, os.path.sep)
344         # interpret absolute pathname as relative, remove drive letter or
345         # UNC path, redundant separators, "." and ".." components.
346         arcname = os.path.splitdrive(arcname)[1]
347         arcname = os.path.sep.join(x for x in arcname.split(os.path.sep)
348                     if x not in (‘‘, os.path.curdir, os.path.pardir))
349         if os.path.sep == ‘\\‘:
350             # filter illegal characters on Windows
351             illegal = ‘:<>|"?*‘
352             if isinstance(arcname, unicode):
353                 table = {ord(c): ord(‘_‘) for c in illegal}
354             else:
355                 table = string.maketrans(illegal, ‘_‘ * len(illegal))
356             arcname = arcname.translate(table)
357             # remove trailing dots
358             arcname = (x.rstrip(‘.‘) for x in arcname.split(os.path.sep))
359             arcname = os.path.sep.join(x for x in arcname if x)
360 
361         targetpath = os.path.join(targetpath, arcname)
362         targetpath = os.path.normpath(targetpath)
363 
364         # Create all upper directories if necessary.
365         upperdirs = os.path.dirname(targetpath)
366         if upperdirs and not os.path.exists(upperdirs):
367             os.makedirs(upperdirs)
368 
369         if member.filename[-1] == ‘/‘:
370             if not os.path.isdir(targetpath):
371                 os.mkdir(targetpath)
372             return targetpath
373 
374         with self.open(member, pwd=pwd) as source, 375              file(targetpath, "wb") as target:
376             shutil.copyfileobj(source, target)
377 
378         return targetpath
379 
380     def _writecheck(self, zinfo):
381         """Check for errors before writing a file to the archive."""
382         if zinfo.filename in self.NameToInfo:
383             import warnings
384             warnings.warn(‘Duplicate name: %r‘ % zinfo.filename, stacklevel=3)
385         if self.mode not in ("w", "a"):
386             raise RuntimeError, ‘write() requires mode "w" or "a"‘
387         if not self.fp:
388             raise RuntimeError, 389                   "Attempt to write ZIP archive that was already closed"
390         if zinfo.compress_type == ZIP_DEFLATED and not zlib:
391             raise RuntimeError, 392                   "Compression requires the (missing) zlib module"
393         if zinfo.compress_type not in (ZIP_STORED, ZIP_DEFLATED):
394             raise RuntimeError, 395                   "That compression method is not supported"
396         if not self._allowZip64:
397             requires_zip64 = None
398             if len(self.filelist) >= ZIP_FILECOUNT_LIMIT:
399                 requires_zip64 = "Files count"
400             elif zinfo.file_size > ZIP64_LIMIT:
401                 requires_zip64 = "Filesize"
402             elif zinfo.header_offset > ZIP64_LIMIT:
403                 requires_zip64 = "Zipfile size"
404             if requires_zip64:
405                 raise LargeZipFile(requires_zip64 +
406                                    " would require ZIP64 extensions")
407 
408     def write(self, filename, arcname=None, compress_type=None):
409         """Put the bytes from filename into the archive under the name
410         arcname."""
411         if not self.fp:
412             raise RuntimeError(
413                   "Attempt to write to ZIP archive that was already closed")
414 
415         st = os.stat(filename)
416         isdir = stat.S_ISDIR(st.st_mode)
417         mtime = time.localtime(st.st_mtime)
418         date_time = mtime[0:6]
419         # Create ZipInfo instance to store file information
420         if arcname is None:
421             arcname = filename
422         arcname = os.path.normpath(os.path.splitdrive(arcname)[1])
423         while arcname[0] in (os.sep, os.altsep):
424             arcname = arcname[1:]
425         if isdir:
426             arcname += ‘/‘
427         zinfo = ZipInfo(arcname, date_time)
428         zinfo.external_attr = (st[0] & 0xFFFF) << 16L      # Unix attributes
429         if compress_type is None:
430             zinfo.compress_type = self.compression
431         else:
432             zinfo.compress_type = compress_type
433 
434         zinfo.file_size = st.st_size
435         zinfo.flag_bits = 0x00
436         zinfo.header_offset = self.fp.tell()    # Start of header bytes
437 
438         self._writecheck(zinfo)
439         self._didModify = True
440 
441         if isdir:
442             zinfo.file_size = 0
443             zinfo.compress_size = 0
444             zinfo.CRC = 0
445             zinfo.external_attr |= 0x10  # MS-DOS directory flag
446             self.filelist.append(zinfo)
447             self.NameToInfo[zinfo.filename] = zinfo
448             self.fp.write(zinfo.FileHeader(False))
449             return
450 
451         with open(filename, "rb") as fp:
452             # Must overwrite CRC and sizes with correct data later
453             zinfo.CRC = CRC = 0
454             zinfo.compress_size = compress_size = 0
455             # Compressed size can be larger than uncompressed size
456             zip64 = self._allowZip64 and 457                     zinfo.file_size * 1.05 > ZIP64_LIMIT
458             self.fp.write(zinfo.FileHeader(zip64))
459             if zinfo.compress_type == ZIP_DEFLATED:
460                 cmpr = zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION,
461                      zlib.DEFLATED, -15)
462             else:
463                 cmpr = None
464             file_size = 0
465             while 1:
466                 buf = fp.read(1024 * 8)
467                 if not buf:
468                     break
469                 file_size = file_size + len(buf)
470                 CRC = crc32(buf, CRC) & 0xffffffff
471                 if cmpr:
472                     buf = cmpr.compress(buf)
473                     compress_size = compress_size + len(buf)
474                 self.fp.write(buf)
475         if cmpr:
476             buf = cmpr.flush()
477             compress_size = compress_size + len(buf)
478             self.fp.write(buf)
479             zinfo.compress_size = compress_size
480         else:
481             zinfo.compress_size = file_size
482         zinfo.CRC = CRC
483         zinfo.file_size = file_size
484         if not zip64 and self._allowZip64:
485             if file_size > ZIP64_LIMIT:
486                 raise RuntimeError(‘File size has increased during compressing‘)
487             if compress_size > ZIP64_LIMIT:
488                 raise RuntimeError(‘Compressed size larger than uncompressed size‘)
489         # Seek backwards and write file header (which will now include
490         # correct CRC and file sizes)
491         position = self.fp.tell()       # Preserve current position in file
492         self.fp.seek(zinfo.header_offset, 0)
493         self.fp.write(zinfo.FileHeader(zip64))
494         self.fp.seek(position, 0)
495         self.filelist.append(zinfo)
496         self.NameToInfo[zinfo.filename] = zinfo
497 
498     def writestr(self, zinfo_or_arcname, bytes, compress_type=None):
499         """Write a file into the archive.  The contents is the string
500         ‘bytes‘.  ‘zinfo_or_arcname‘ is either a ZipInfo instance or
501         the name of the file in the archive."""
502         if not isinstance(zinfo_or_arcname, ZipInfo):
503             zinfo = ZipInfo(filename=zinfo_or_arcname,
504                             date_time=time.localtime(time.time())[:6])
505 
506             zinfo.compress_type = self.compression
507             if zinfo.filename[-1] == ‘/‘:
508                 zinfo.external_attr = 0o40775 << 16   # drwxrwxr-x
509                 zinfo.external_attr |= 0x10           # MS-DOS directory flag
510             else:
511                 zinfo.external_attr = 0o600 << 16     # ?rw-------
512         else:
513             zinfo = zinfo_or_arcname
514 
515         if not self.fp:
516             raise RuntimeError(
517                   "Attempt to write to ZIP archive that was already closed")
518 
519         if compress_type is not None:
520             zinfo.compress_type = compress_type
521 
522         zinfo.file_size = len(bytes)            # Uncompressed size
523         zinfo.header_offset = self.fp.tell()    # Start of header bytes
524         self._writecheck(zinfo)
525         self._didModify = True
526         zinfo.CRC = crc32(bytes) & 0xffffffff       # CRC-32 checksum
527         if zinfo.compress_type == ZIP_DEFLATED:
528             co = zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION,
529                  zlib.DEFLATED, -15)
530             bytes = co.compress(bytes) + co.flush()
531             zinfo.compress_size = len(bytes)    # Compressed size
532         else:
533             zinfo.compress_size = zinfo.file_size
534         zip64 = zinfo.file_size > ZIP64_LIMIT or 535                 zinfo.compress_size > ZIP64_LIMIT
536         if zip64 and not self._allowZip64:
537             raise LargeZipFile("Filesize would require ZIP64 extensions")
538         self.fp.write(zinfo.FileHeader(zip64))
539         self.fp.write(bytes)
540         if zinfo.flag_bits & 0x08:
541             # Write CRC and file sizes after the file data
542             fmt = ‘<LQQ‘ if zip64 else ‘<LLL‘
543             self.fp.write(struct.pack(fmt, zinfo.CRC, zinfo.compress_size,
544                   zinfo.file_size))
545         self.fp.flush()
546         self.filelist.append(zinfo)
547         self.NameToInfo[zinfo.filename] = zinfo
548 
549     def __del__(self):
550         """Call the "close()" method in case the user forgot."""
551         self.close()
552 
553     def close(self):
554         """Close the file, and for mode "w" and "a" write the ending
555         records."""
556         if self.fp is None:
557             return
558 
559         try:
560             if self.mode in ("w", "a") and self._didModify: # write ending records
561                 pos1 = self.fp.tell()
562                 for zinfo in self.filelist:         # write central directory
563                     dt = zinfo.date_time
564                     dosdate = (dt[0] - 1980) << 9 | dt[1] << 5 | dt[2]
565                     dostime = dt[3] << 11 | dt[4] << 5 | (dt[5] // 2)
566                     extra = []
567                     if zinfo.file_size > ZIP64_LIMIT 568                             or zinfo.compress_size > ZIP64_LIMIT:
569                         extra.append(zinfo.file_size)
570                         extra.append(zinfo.compress_size)
571                         file_size = 0xffffffff
572                         compress_size = 0xffffffff
573                     else:
574                         file_size = zinfo.file_size
575                         compress_size = zinfo.compress_size
576 
577                     if zinfo.header_offset > ZIP64_LIMIT:
578                         extra.append(zinfo.header_offset)
579                         header_offset = 0xffffffffL
580                     else:
581                         header_offset = zinfo.header_offset
582 
583                     extra_data = zinfo.extra
584                     if extra:
585                         # Append a ZIP64 field to the extra‘s
586                         extra_data = struct.pack(
587                                 ‘<HH‘ + ‘Q‘*len(extra),
588                                 1, 8*len(extra), *extra) + extra_data
589 
590                         extract_version = max(45, zinfo.extract_version)
591                         create_version = max(45, zinfo.create_version)
592                     else:
593                         extract_version = zinfo.extract_version
594                         create_version = zinfo.create_version
595 
596                     try:
597                         filename, flag_bits = zinfo._encodeFilenameFlags()
598                         centdir = struct.pack(structCentralDir,
599                         stringCentralDir, create_version,
600                         zinfo.create_system, extract_version, zinfo.reserved,
601                         flag_bits, zinfo.compress_type, dostime, dosdate,
602                         zinfo.CRC, compress_size, file_size,
603                         len(filename), len(extra_data), len(zinfo.comment),
604                         0, zinfo.internal_attr, zinfo.external_attr,
605                         header_offset)
606                     except DeprecationWarning:
607                         print >>sys.stderr, (structCentralDir,
608                         stringCentralDir, create_version,
609                         zinfo.create_system, extract_version, zinfo.reserved,
610                         zinfo.flag_bits, zinfo.compress_type, dostime, dosdate,
611                         zinfo.CRC, compress_size, file_size,
612                         len(zinfo.filename), len(extra_data), len(zinfo.comment),
613                         0, zinfo.internal_attr, zinfo.external_attr,
614                         header_offset)
615                         raise
616                     self.fp.write(centdir)
617                     self.fp.write(filename)
618                     self.fp.write(extra_data)
619                     self.fp.write(zinfo.comment)
620 
621                 pos2 = self.fp.tell()
622                 # Write end-of-zip-archive record
623                 centDirCount = len(self.filelist)
624                 centDirSize = pos2 - pos1
625                 centDirOffset = pos1
626                 requires_zip64 = None
627                 if centDirCount > ZIP_FILECOUNT_LIMIT:
628                     requires_zip64 = "Files count"
629                 elif centDirOffset > ZIP64_LIMIT:
630                     requires_zip64 = "Central directory offset"
631                 elif centDirSize > ZIP64_LIMIT:
632                     requires_zip64 = "Central directory size"
633                 if requires_zip64:
634                     # Need to write the ZIP64 end-of-archive records
635                     if not self._allowZip64:
636                         raise LargeZipFile(requires_zip64 +
637                                            " would require ZIP64 extensions")
638                     zip64endrec = struct.pack(
639                             structEndArchive64, stringEndArchive64,
640                             44, 45, 45, 0, 0, centDirCount, centDirCount,
641                             centDirSize, centDirOffset)
642                     self.fp.write(zip64endrec)
643 
644                     zip64locrec = struct.pack(
645                             structEndArchive64Locator,
646                             stringEndArchive64Locator, 0, pos2, 1)
647                     self.fp.write(zip64locrec)
648                     centDirCount = min(centDirCount, 0xFFFF)
649                     centDirSize = min(centDirSize, 0xFFFFFFFF)
650                     centDirOffset = min(centDirOffset, 0xFFFFFFFF)
651 
652                 endrec = struct.pack(structEndArchive, stringEndArchive,
653                                     0, 0, centDirCount, centDirCount,
654                                     centDirSize, centDirOffset, len(self._comment))
655                 self.fp.write(endrec)
656                 self.fp.write(self._comment)
657                 self.fp.flush()
658         finally:
659             fp = self.fp
660             self.fp = None
661             if not self._filePassed:
662                 fp.close()
663 
664 ZipFile

zipfile

  1 class TarFile(object):
  2     """The TarFile Class provides an interface to tar archives.
  3     """
  4 
  5     debug = 0                   # May be set from 0 (no msgs) to 3 (all msgs)
  6 
  7     dereference = False         # If true, add content of linked file to the
  8                                 # tar file, else the link.
  9 
 10     ignore_zeros = False        # If true, skips empty or invalid blocks and
 11                                 # continues processing.
 12 
 13     errorlevel = 1              # If 0, fatal errors only appear in debug
 14                                 # messages (if debug >= 0). If > 0, errors
 15                                 # are passed to the caller as exceptions.
 16 
 17     format = DEFAULT_FORMAT     # The format to use when creating an archive.
 18 
 19     encoding = ENCODING         # Encoding for 8-bit character strings.
 20 
 21     errors = None               # Error handler for unicode conversion.
 22 
 23     tarinfo = TarInfo           # The default TarInfo class to use.
 24 
 25     fileobject = ExFileObject   # The default ExFileObject class to use.
 26 
 27     def __init__(self, name=None, mode="r", fileobj=None, format=None,
 28             tarinfo=None, dereference=None, ignore_zeros=None, encoding=None,
 29             errors=None, pax_headers=None, debug=None, errorlevel=None):
 30         """Open an (uncompressed) tar archive `name‘. `mode‘ is either ‘r‘ to
 31            read from an existing archive, ‘a‘ to append data to an existing
 32            file or ‘w‘ to create a new file overwriting an existing one. `mode‘
 33            defaults to ‘r‘.
 34            If `fileobj‘ is given, it is used for reading or writing data. If it
 35            can be determined, `mode‘ is overridden by `fileobj‘s mode.
 36            `fileobj‘ is not closed, when TarFile is closed.
 37         """
 38         modes = {"r": "rb", "a": "r+b", "w": "wb"}
 39         if mode not in modes:
 40             raise ValueError("mode must be ‘r‘, ‘a‘ or ‘w‘")
 41         self.mode = mode
 42         self._mode = modes[mode]
 43 
 44         if not fileobj:
 45             if self.mode == "a" and not os.path.exists(name):
 46                 # Create nonexistent files in append mode.
 47                 self.mode = "w"
 48                 self._mode = "wb"
 49             fileobj = bltn_open(name, self._mode)
 50             self._extfileobj = False
 51         else:
 52             if name is None and hasattr(fileobj, "name"):
 53                 name = fileobj.name
 54             if hasattr(fileobj, "mode"):
 55                 self._mode = fileobj.mode
 56             self._extfileobj = True
 57         self.name = os.path.abspath(name) if name else None
 58         self.fileobj = fileobj
 59 
 60         # Init attributes.
 61         if format is not None:
 62             self.format = format
 63         if tarinfo is not None:
 64             self.tarinfo = tarinfo
 65         if dereference is not None:
 66             self.dereference = dereference
 67         if ignore_zeros is not None:
 68             self.ignore_zeros = ignore_zeros
 69         if encoding is not None:
 70             self.encoding = encoding
 71 
 72         if errors is not None:
 73             self.errors = errors
 74         elif mode == "r":
 75             self.errors = "utf-8"
 76         else:
 77             self.errors = "strict"
 78 
 79         if pax_headers is not None and self.format == PAX_FORMAT:
 80             self.pax_headers = pax_headers
 81         else:
 82             self.pax_headers = {}
 83 
 84         if debug is not None:
 85             self.debug = debug
 86         if errorlevel is not None:
 87             self.errorlevel = errorlevel
 88 
 89         # Init datastructures.
 90         self.closed = False
 91         self.members = []       # list of members as TarInfo objects
 92         self._loaded = False    # flag if all members have been read
 93         self.offset = self.fileobj.tell()
 94                                 # current position in the archive file
 95         self.inodes = {}        # dictionary caching the inodes of
 96                                 # archive members already added
 97 
 98         try:
 99             if self.mode == "r":
100                 self.firstmember = None
101                 self.firstmember = self.next()
102 
103             if self.mode == "a":
104                 # Move to the end of the archive,
105                 # before the first empty block.
106                 while True:
107                     self.fileobj.seek(self.offset)
108                     try:
109                         tarinfo = self.tarinfo.fromtarfile(self)
110                         self.members.append(tarinfo)
111                     except EOFHeaderError:
112                         self.fileobj.seek(self.offset)
113                         break
114                     except HeaderError, e:
115                         raise ReadError(str(e))
116 
117             if self.mode in "aw":
118                 self._loaded = True
119 
120                 if self.pax_headers:
121                     buf = self.tarinfo.create_pax_global_header(self.pax_headers.copy())
122                     self.fileobj.write(buf)
123                     self.offset += len(buf)
124         except:
125             if not self._extfileobj:
126                 self.fileobj.close()
127             self.closed = True
128             raise
129 
130     def _getposix(self):
131         return self.format == USTAR_FORMAT
132     def _setposix(self, value):
133         import warnings
134         warnings.warn("use the format attribute instead", DeprecationWarning,
135                       2)
136         if value:
137             self.format = USTAR_FORMAT
138         else:
139             self.format = GNU_FORMAT
140     posix = property(_getposix, _setposix)
141 
142     #--------------------------------------------------------------------------
143     # Below are the classmethods which act as alternate constructors to the
144     # TarFile class. The open() method is the only one that is needed for
145     # public use; it is the "super"-constructor and is able to select an
146     # adequate "sub"-constructor for a particular compression using the mapping
147     # from OPEN_METH.
148     #
149     # This concept allows one to subclass TarFile without losing the comfort of
150     # the super-constructor. A sub-constructor is registered and made available
151     # by adding it to the mapping in OPEN_METH.
152 
153     @classmethod
154     def open(cls, name=None, mode="r", fileobj=None, bufsize=RECORDSIZE, **kwargs):
155         """Open a tar archive for reading, writing or appending. Return
156            an appropriate TarFile class.
157 
158            mode:
159            ‘r‘ or ‘r:*‘ open for reading with transparent compression
160            ‘r:‘         open for reading exclusively uncompressed
161            ‘r:gz‘       open for reading with gzip compression
162            ‘r:bz2‘      open for reading with bzip2 compression
163            ‘a‘ or ‘a:‘  open for appending, creating the file if necessary
164            ‘w‘ or ‘w:‘  open for writing without compression
165            ‘w:gz‘       open for writing with gzip compression
166            ‘w:bz2‘      open for writing with bzip2 compression
167 
168            ‘r|*‘        open a stream of tar blocks with transparent compression
169            ‘r|‘         open an uncompressed stream of tar blocks for reading
170            ‘r|gz‘       open a gzip compressed stream of tar blocks
171            ‘r|bz2‘      open a bzip2 compressed stream of tar blocks
172            ‘w|‘         open an uncompressed stream for writing
173            ‘w|gz‘       open a gzip compressed stream for writing
174            ‘w|bz2‘      open a bzip2 compressed stream for writing
175         """
176 
177         if not name and not fileobj:
178             raise ValueError("nothing to open")
179 
180         if mode in ("r", "r:*"):
181             # Find out which *open() is appropriate for opening the file.
182             for comptype in cls.OPEN_METH:
183                 func = getattr(cls, cls.OPEN_METH[comptype])
184                 if fileobj is not None:
185                     saved_pos = fileobj.tell()
186                 try:
187                     return func(name, "r", fileobj, **kwargs)
188                 except (ReadError, CompressionError), e:
189                     if fileobj is not None:
190                         fileobj.seek(saved_pos)
191                     continue
192             raise ReadError("file could not be opened successfully")
193 
194         elif ":" in mode:
195             filemode, comptype = mode.split(":", 1)
196             filemode = filemode or "r"
197             comptype = comptype or "tar"
198 
199             # Select the *open() function according to
200             # given compression.
201             if comptype in cls.OPEN_METH:
202                 func = getattr(cls, cls.OPEN_METH[comptype])
203             else:
204                 raise CompressionError("unknown compression type %r" % comptype)
205             return func(name, filemode, fileobj, **kwargs)
206 
207         elif "|" in mode:
208             filemode, comptype = mode.split("|", 1)
209             filemode = filemode or "r"
210             comptype = comptype or "tar"
211 
212             if filemode not in ("r", "w"):
213                 raise ValueError("mode must be ‘r‘ or ‘w‘")
214 
215             stream = _Stream(name, filemode, comptype, fileobj, bufsize)
216             try:
217                 t = cls(name, filemode, stream, **kwargs)
218             except:
219                 stream.close()
220                 raise
221             t._extfileobj = False
222             return t
223 
224         elif mode in ("a", "w"):
225             return cls.taropen(name, mode, fileobj, **kwargs)
226 
227         raise ValueError("undiscernible mode")
228 
229     @classmethod
230     def taropen(cls, name, mode="r", fileobj=None, **kwargs):
231         """Open uncompressed tar archive name for reading or writing.
232         """
233         if mode not in ("r", "a", "w"):
234             raise ValueError("mode must be ‘r‘, ‘a‘ or ‘w‘")
235         return cls(name, mode, fileobj, **kwargs)
236 
237     @classmethod
238     def gzopen(cls, name, mode="r", fileobj=None, compresslevel=9, **kwargs):
239         """Open gzip compressed tar archive name for reading or writing.
240            Appending is not allowed.
241         """
242         if mode not in ("r", "w"):
243             raise ValueError("mode must be ‘r‘ or ‘w‘")
244 
245         try:
246             import gzip
247             gzip.GzipFile
248         except (ImportError, AttributeError):
249             raise CompressionError("gzip module is not available")
250 
251         try:
252             fileobj = gzip.GzipFile(name, mode, compresslevel, fileobj)
253         except OSError:
254             if fileobj is not None and mode == ‘r‘:
255                 raise ReadError("not a gzip file")
256             raise
257 
258         try:
259             t = cls.taropen(name, mode, fileobj, **kwargs)
260         except IOError:
261             fileobj.close()
262             if mode == ‘r‘:
263                 raise ReadError("not a gzip file")
264             raise
265         except:
266             fileobj.close()
267             raise
268         t._extfileobj = False
269         return t
270 
271     @classmethod
272     def bz2open(cls, name, mode="r", fileobj=None, compresslevel=9, **kwargs):
273         """Open bzip2 compressed tar archive name for reading or writing.
274            Appending is not allowed.
275         """
276         if mode not in ("r", "w"):
277             raise ValueError("mode must be ‘r‘ or ‘w‘.")
278 
279         try:
280             import bz2
281         except ImportError:
282             raise CompressionError("bz2 module is not available")
283 
284         if fileobj is not None:
285             fileobj = _BZ2Proxy(fileobj, mode)
286         else:
287             fileobj = bz2.BZ2File(name, mode, compresslevel=compresslevel)
288 
289         try:
290             t = cls.taropen(name, mode, fileobj, **kwargs)
291         except (IOError, EOFError):
292             fileobj.close()
293             if mode == ‘r‘:
294                 raise ReadError("not a bzip2 file")
295             raise
296         except:
297             fileobj.close()
298             raise
299         t._extfileobj = False
300         return t
301 
302     # All *open() methods are registered here.
303     OPEN_METH = {
304         "tar": "taropen",   # uncompressed tar
305         "gz":  "gzopen",    # gzip compressed tar
306         "bz2": "bz2open"    # bzip2 compressed tar
307     }
308 
309     #--------------------------------------------------------------------------
310     # The public methods which TarFile provides:
311 
312     def close(self):
313         """Close the TarFile. In write-mode, two finishing zero blocks are
314            appended to the archive.
315         """
316         if self.closed:
317             return
318 
319         if self.mode in "aw":
320             self.fileobj.write(NUL * (BLOCKSIZE * 2))
321             self.offset += (BLOCKSIZE * 2)
322             # fill up the end with zero-blocks
323             # (like option -b20 for tar does)
324             blocks, remainder = divmod(self.offset, RECORDSIZE)
325             if remainder > 0:
326                 self.fileobj.write(NUL * (RECORDSIZE - remainder))
327 
328         if not self._extfileobj:
329             self.fileobj.close()
330         self.closed = True
331 
332     def getmember(self, name):
333         """Return a TarInfo object for member `name‘. If `name‘ can not be
334            found in the archive, KeyError is raised. If a member occurs more
335            than once in the archive, its last occurrence is assumed to be the
336            most up-to-date version.
337         """
338         tarinfo = self._getmember(name)
339         if tarinfo is None:
340             raise KeyError("filename %r not found" % name)
341         return tarinfo
342 
343     def getmembers(self):
344         """Return the members of the archive as a list of TarInfo objects. The
345            list has the same order as the members in the archive.
346         """
347         self._check()
348         if not self._loaded:    # if we want to obtain a list of
349             self._load()        # all members, we first have to
350                                 # scan the whole archive.
351         return self.members
352 
353     def getnames(self):
354         """Return the members of the archive as a list of their names. It has
355            the same order as the list returned by getmembers().
356         """
357         return [tarinfo.name for tarinfo in self.getmembers()]
358 
359     def gettarinfo(self, name=None, arcname=None, fileobj=None):
360         """Create a TarInfo object for either the file `name‘ or the file
361            object `fileobj‘ (using os.fstat on its file descriptor). You can
362            modify some of the TarInfo‘s attributes before you add it using
363            addfile(). If given, `arcname‘ specifies an alternative name for the
364            file in the archive.
365         """
366         self._check("aw")
367 
368         # When fileobj is given, replace name by
369         # fileobj‘s real name.
370         if fileobj is not None:
371             name = fileobj.name
372 
373         # Building the name of the member in the archive.
374         # Backward slashes are converted to forward slashes,
375         # Absolute paths are turned to relative paths.
376         if arcname is None:
377             arcname = name
378         drv, arcname = os.path.splitdrive(arcname)
379         arcname = arcname.replace(os.sep, "/")
380         arcname = arcname.lstrip("/")
381 
382         # Now, fill the TarInfo object with
383         # information specific for the file.
384         tarinfo = self.tarinfo()
385         tarinfo.tarfile = self
386 
387         # Use os.stat or os.lstat, depending on platform
388         # and if symlinks shall be resolved.
389         if fileobj is None:
390             if hasattr(os, "lstat") and not self.dereference:
391                 statres = os.lstat(name)
392             else:
393                 statres = os.stat(name)
394         else:
395             statres = os.fstat(fileobj.fileno())
396         linkname = ""
397 
398         stmd = statres.st_mode
399         if stat.S_ISREG(stmd):
400             inode = (statres.st_ino, statres.st_dev)
401             if not self.dereference and statres.st_nlink > 1 and 402                     inode in self.inodes and arcname != self.inodes[inode]:
403                 # Is it a hardlink to an already
404                 # archived file?
405                 type = LNKTYPE
406                 linkname = self.inodes[inode]
407             else:
408                 # The inode is added only if its valid.
409                 # For win32 it is always 0.
410                 type = REGTYPE
411                 if inode[0]:
412                     self.inodes[inode] = arcname
413         elif stat.S_ISDIR(stmd):
414             type = DIRTYPE
415         elif stat.S_ISFIFO(stmd):
416             type = FIFOTYPE
417         elif stat.S_ISLNK(stmd):
418             type = SYMTYPE
419             linkname = os.readlink(name)
420         elif stat.S_ISCHR(stmd):
421             type = CHRTYPE
422         elif stat.S_ISBLK(stmd):
423             type = BLKTYPE
424         else:
425             return None
426 
427         # Fill the TarInfo object with all
428         # information we can get.
429         tarinfo.name = arcname
430         tarinfo.mode = stmd
431         tarinfo.uid = statres.st_uid
432         tarinfo.gid = statres.st_gid
433         if type == REGTYPE:
434             tarinfo.size = statres.st_size
435         else:
436             tarinfo.size = 0L
437         tarinfo.mtime = statres.st_mtime
438         tarinfo.type = type
439         tarinfo.linkname = linkname
440         if pwd:
441             try:
442                 tarinfo.uname = pwd.getpwuid(tarinfo.uid)[0]
443             except KeyError:
444                 pass
445         if grp:
446             try:
447                 tarinfo.gname = grp.getgrgid(tarinfo.gid)[0]
448             except KeyError:
449                 pass
450 
451         if type in (CHRTYPE, BLKTYPE):
452             if hasattr(os, "major") and hasattr(os, "minor"):
453                 tarinfo.devmajor = os.major(statres.st_rdev)
454                 tarinfo.devminor = os.minor(statres.st_rdev)
455         return tarinfo
456 
457     def list(self, verbose=True):
458         """Print a table of contents to sys.stdout. If `verbose‘ is False, only
459            the names of the members are printed. If it is True, an `ls -l‘-like
460            output is produced.
461         """
462         self._check()
463 
464         for tarinfo in self:
465             if verbose:
466                 print filemode(tarinfo.mode),
467                 print "%s/%s" % (tarinfo.uname or tarinfo.uid,
468                                  tarinfo.gname or tarinfo.gid),
469                 if tarinfo.ischr() or tarinfo.isblk():
470                     print "%10s" % ("%d,%d" 471                                     % (tarinfo.devmajor, tarinfo.devminor)),
472                 else:
473                     print "%10d" % tarinfo.size,
474                 print "%d-%02d-%02d %02d:%02d:%02d" 475                       % time.localtime(tarinfo.mtime)[:6],
476 
477             print tarinfo.name + ("/" if tarinfo.isdir() else ""),
478 
479             if verbose:
480                 if tarinfo.issym():
481                     print "->", tarinfo.linkname,
482                 if tarinfo.islnk():
483                     print "link to", tarinfo.linkname,
484             print
485 
486     def add(self, name, arcname=None, recursive=True, exclude=None, filter=None):
487         """Add the file `name‘ to the archive. `name‘ may be any type of file
488            (directory, fifo, symbolic link, etc.). If given, `arcname‘
489            specifies an alternative name for the file in the archive.
490            Directories are added recursively by default. This can be avoided by
491            setting `recursive‘ to False. `exclude‘ is a function that should
492            return True for each filename to be excluded. `filter‘ is a function
493            that expects a TarInfo object argument and returns the changed
494            TarInfo object, if it returns None the TarInfo object will be
495            excluded from the archive.
496         """
497         self._check("aw")
498 
499         if arcname is None:
500             arcname = name
501 
502         # Exclude pathnames.
503         if exclude is not None:
504             import warnings
505             warnings.warn("use the filter argument instead",
506                     DeprecationWarning, 2)
507             if exclude(name):
508                 self._dbg(2, "tarfile: Excluded %r" % name)
509                 return
510 
511         # Skip if somebody tries to archive the archive...
512         if self.name is not None and os.path.abspath(name) == self.name:
513             self._dbg(2, "tarfile: Skipped %r" % name)
514             return
515 
516         self._dbg(1, name)
517 
518         # Create a TarInfo object from the file.
519         tarinfo = self.gettarinfo(name, arcname)
520 
521         if tarinfo is None:
522             self._dbg(1, "tarfile: Unsupported type %r" % name)
523             return
524 
525         # Change or exclude the TarInfo object.
526         if filter is not None:
527             tarinfo = filter(tarinfo)
528             if tarinfo is None:
529                 self._dbg(2, "tarfile: Excluded %r" % name)
530                 return
531 
532         # Append the tar header and data to the archive.
533         if tarinfo.isreg():
534             with bltn_open(name, "rb") as f:
535                 self.addfile(tarinfo, f)
536 
537         elif tarinfo.isdir():
538             self.addfile(tarinfo)
539             if recursive:
540                 for f in os.listdir(name):
541                     self.add(os.path.join(name, f), os.path.join(arcname, f),
542                             recursive, exclude, filter)
543 
544         else:
545             self.addfile(tarinfo)
546 
547     def addfile(self, tarinfo, fileobj=None):
548         """Add the TarInfo object `tarinfo‘ to the archive. If `fileobj‘ is
549            given, tarinfo.size bytes are read from it and added to the archive.
550            You can create TarInfo objects using gettarinfo().
551            On Windows platforms, `fileobj‘ should always be opened with mode
552            ‘rb‘ to avoid irritation about the file size.
553         """
554         self._check("aw")
555 
556         tarinfo = copy.copy(tarinfo)
557 
558         buf = tarinfo.tobuf(self.format, self.encoding, self.errors)
559         self.fileobj.write(buf)
560         self.offset += len(buf)
561 
562         # If there‘s data to follow, append it.
563         if fileobj is not None:
564             copyfileobj(fileobj, self.fileobj, tarinfo.size)
565             blocks, remainder = divmod(tarinfo.size, BLOCKSIZE)
566             if remainder > 0:
567                 self.fileobj.write(NUL * (BLOCKSIZE - remainder))
568                 blocks += 1
569             self.offset += blocks * BLOCKSIZE
570 
571         self.members.append(tarinfo)
572 
573     def extractall(self, path=".", members=None):
574         """Extract all members from the archive to the current working
575            directory and set owner, modification time and permissions on
576            directories afterwards. `path‘ specifies a different directory
577            to extract to. `members‘ is optional and must be a subset of the
578            list returned by getmembers().
579         """
580         directories = []
581 
582         if members is None:
583             members = self
584 
585         for tarinfo in members:
586             if tarinfo.isdir():
587                 # Extract directories with a safe mode.
588                 directories.append(tarinfo)
589                 tarinfo = copy.copy(tarinfo)
590                 tarinfo.mode = 0700
591             self.extract(tarinfo, path)
592 
593         # Reverse sort directories.
594         directories.sort(key=operator.attrgetter(‘name‘))
595         directories.reverse()
596 
597         # Set correct owner, mtime and filemode on directories.
598         for tarinfo in directories:
599             dirpath = os.path.join(path, tarinfo.name)
600             try:
601                 self.chown(tarinfo, dirpath)
602                 self.utime(tarinfo, dirpath)
603                 self.chmod(tarinfo, dirpath)
604             except ExtractError, e:
605                 if self.errorlevel > 1:
606                     raise
607                 else:
608                     self._dbg(1, "tarfile: %s" % e)
609 
610     def extract(self, member, path=""):
611         """Extract a member from the archive to the current working directory,
612            using its full name. Its file information is extracted as accurately
613            as possible. `member‘ may be a filename or a TarInfo object. You can
614            specify a different directory using `path‘.
615         """
616         self._check("r")
617 
618         if isinstance(member, basestring):
619             tarinfo = self.getmember(member)
620         else:
621             tarinfo = member
622 
623         # Prepare the link target for makelink().
624         if tarinfo.islnk():
625             tarinfo._link_target = os.path.join(path, tarinfo.linkname)
626 
627         try:
628             self._extract_member(tarinfo, os.path.join(path, tarinfo.name))
629         except EnvironmentError, e:
630             if self.errorlevel > 0:
631                 raise
632             else:
633                 if e.filename is None:
634                     self._dbg(1, "tarfile: %s" % e.strerror)
635                 else:
636                     self._dbg(1, "tarfile: %s %r" % (e.strerror, e.filename))
637         except ExtractError, e:
638             if self.errorlevel > 1:
639                 raise
640             else:
641                 self._dbg(1, "tarfile: %s" % e)
642 
643     def extractfile(self, member):
644         """Extract a member from the archive as a file object. `member‘ may be
645            a filename or a TarInfo object. If `member‘ is a regular file, a
646            file-like object is returned. If `member‘ is a link, a file-like
647            object is constructed from the link‘s target. If `member‘ is none of
648            the above, None is returned.
649            The file-like object is read-only and provides the following
650            methods: read(), readline(), readlines(), seek() and tell()
651         """
652         self._check("r")
653 
654         if isinstance(member, basestring):
655             tarinfo = self.getmember(member)
656         else:
657             tarinfo = member
658 
659         if tarinfo.isreg():
660             return self.fileobject(self, tarinfo)
661 
662         elif tarinfo.type not in SUPPORTED_TYPES:
663             # If a member‘s type is unknown, it is treated as a
664             # regular file.
665             return self.fileobject(self, tarinfo)
666 
667         elif tarinfo.islnk() or tarinfo.issym():
668             if isinstance(self.fileobj, _Stream):
669                 # A small but ugly workaround for the case that someone tries
670                 # to extract a (sym)link as a file-object from a non-seekable
671                 # stream of tar blocks.
672                 raise StreamError("cannot extract (sym)link as file object")
673             else:
674                 # A (sym)link‘s file object is its target‘s file object.
675                 return self.extractfile(self._find_link_target(tarinfo))
676         else:
677             # If there‘s no data associated with the member (directory, chrdev,
678             # blkdev, etc.), return None instead of a file object.
679             return None
680 
681     def _extract_member(self, tarinfo, targetpath):
682         """Extract the TarInfo object tarinfo to a physical
683            file called targetpath.
684         """
685         # Fetch the TarInfo object for the given name
686         # and build the destination pathname, replacing
687         # forward slashes to platform specific separators.
688         targetpath = targetpath.rstrip("/")
689         targetpath = targetpath.replace("/", os.sep)
690 
691         # Create all upper directories.
692         upperdirs = os.path.dirname(targetpath)
693         if upperdirs and not os.path.exists(upperdirs):
694             # Create directories that are not part of the archive with
695             # default permissions.
696             os.makedirs(upperdirs)
697 
698         if tarinfo.islnk() or tarinfo.issym():
699             self._dbg(1, "%s -> %s" % (tarinfo.name, tarinfo.linkname))
700         else:
701             self._dbg(1, tarinfo.name)
702 
703         if tarinfo.isreg():
704             self.makefile(tarinfo, targetpath)
705         elif tarinfo.isdir():
706             self.makedir(tarinfo, targetpath)
707         elif tarinfo.isfifo():
708             self.makefifo(tarinfo, targetpath)
709         elif tarinfo.ischr() or tarinfo.isblk():
710             self.makedev(tarinfo, targetpath)
711         elif tarinfo.islnk() or tarinfo.issym():
712             self.makelink(tarinfo, targetpath)
713         elif tarinfo.type not in SUPPORTED_TYPES:
714             self.makeunknown(tarinfo, targetpath)
715         else:
716             self.makefile(tarinfo, targetpath)
717 
718         self.chown(tarinfo, targetpath)
719         if not tarinfo.issym():
720             self.chmod(tarinfo, targetpath)
721             self.utime(tarinfo, targetpath)
722 
723     #--------------------------------------------------------------------------
724     # Below are the different file methods. They are called via
725     # _extract_member() when extract() is called. They can be replaced in a
726     # subclass to implement other functionality.
727 
728     def makedir(self, tarinfo, targetpath):
729         """Make a directory called targetpath.
730         """
731         try:
732             # Use a safe mode for the directory, the real mode is set
733             # later in _extract_member().
734             os.mkdir(targetpath, 0700)
735         except EnvironmentError, e:
736             if e.errno != errno.EEXIST:
737                 raise
738 
739     def makefile(self, tarinfo, targetpath):
740         """Make a file called targetpath.
741         """
742         source = self.extractfile(tarinfo)
743         try:
744             with bltn_open(targetpath, "wb") as target:
745                 copyfileobj(source, target)
746         finally:
747             source.close()
748 
749     def makeunknown(self, tarinfo, targetpath):
750         """Make a file from a TarInfo object with an unknown type
751            at targetpath.
752         """
753         self.makefile(tarinfo, targetpath)
754         self._dbg(1, "tarfile: Unknown file type %r, " 755                      "extracted as regular file." % tarinfo.type)
756 
757     def makefifo(self, tarinfo, targetpath):
758         """Make a fifo called targetpath.
759         """
760         if hasattr(os, "mkfifo"):
761             os.mkfifo(targetpath)
762         else:
763             raise ExtractError("fifo not supported by system")
764 
765     def makedev(self, tarinfo, targetpath):
766         """Make a character or block device called targetpath.
767         """
768         if not hasattr(os, "mknod") or not hasattr(os, "makedev"):
769             raise ExtractError("special devices not supported by system")
770 
771         mode = tarinfo.mode
772         if tarinfo.isblk():
773             mode |= stat.S_IFBLK
774         else:
775             mode |= stat.S_IFCHR
776 
777         os.mknod(targetpath, mode,
778                  os.makedev(tarinfo.devmajor, tarinfo.devminor))
779 
780     def makelink(self, tarinfo, targetpath):
781         """Make a (symbolic) link called targetpath. If it cannot be created
782           (platform limitation), we try to make a copy of the referenced file
783           instead of a link.
784         """
785         if hasattr(os, "symlink") and hasattr(os, "link"):
786             # For systems that support symbolic and hard links.
787             if tarinfo.issym():
788                 if os.path.lexists(targetpath):
789                     os.unlink(targetpath)
790                 os.symlink(tarinfo.linkname, targetpath)
791             else:
792                 # See extract().
793                 if os.path.exists(tarinfo._link_target):
794                     if os.path.lexists(targetpath):
795                         os.unlink(targetpath)
796                     os.link(tarinfo._link_target, targetpath)
797                 else:
798                     self._extract_member(self._find_link_target(tarinfo), targetpath)
799         else:
800             try:
801                 self._extract_member(self._find_link_target(tarinfo), targetpath)
802             except KeyError:
803                 raise ExtractError("unable to resolve link inside archive")
804 
805     def chown(self, tarinfo, targetpath):
806         """Set owner of targetpath according to tarinfo.
807         """
808         if pwd and hasattr(os, "geteuid") and os.geteuid() == 0:
809             # We have to be root to do so.
810             try:
811                 g = grp.getgrnam(tarinfo.gname)[2]
812             except KeyError:
813                 g = tarinfo.gid
814             try:
815                 u = pwd.getpwnam(tarinfo.uname)[2]
816             except KeyError:
817                 u = tarinfo.uid
818             try:
819                 if tarinfo.issym() and hasattr(os, "lchown"):
820                     os.lchown(targetpath, u, g)
821                 else:
822                     if sys.platform != "os2emx":
823                         os.chown(targetpath, u, g)
824             except EnvironmentError, e:
825                 raise ExtractError("could not change owner")
826 
827     def chmod(self, tarinfo, targetpath):
828         """Set file permissions of targetpath according to tarinfo.
829         """
830         if hasattr(os, ‘chmod‘):
831             try:
832                 os.chmod(targetpath, tarinfo.mode)
833             except EnvironmentError, e:
834                 raise ExtractError("could not change mode")
835 
836     def utime(self, tarinfo, targetpath):
837         """Set modification time of targetpath according to tarinfo.
838         """
839         if not hasattr(os, ‘utime‘):
840             return
841         try:
842             os.utime(targetpath, (tarinfo.mtime, tarinfo.mtime))
843         except EnvironmentError, e:
844             raise ExtractError("could not change modification time")
845 
846     #--------------------------------------------------------------------------
847     def next(self):
848         """Return the next member of the archive as a TarInfo object, when
849            TarFile is opened for reading. Return None if there is no more
850            available.
851         """
852         self._check("ra")
853         if self.firstmember is not None:
854             m = self.firstmember
855             self.firstmember = None
856             return m
857 
858         # Read the next block.
859         self.fileobj.seek(self.offset)
860         tarinfo = None
861         while True:
862             try:
863                 tarinfo = self.tarinfo.fromtarfile(self)
864             except EOFHeaderError, e:
865                 if self.ignore_zeros:
866                     self._dbg(2, "0x%X: %s" % (self.offset, e))
867                     self.offset += BLOCKSIZE
868                     continue
869             except InvalidHeaderError, e:
870                 if self.ignore_zeros:
871                     self._dbg(2, "0x%X: %s" % (self.offset, e))
872                     self.offset += BLOCKSIZE
873                     continue
874                 elif self.offset == 0:
875                     raise ReadError(str(e))
876             except EmptyHeaderError:
877                 if self.offset == 0:
878                     raise ReadError("empty file")
879             except TruncatedHeaderError, e:
880                 if self.offset == 0:
881                     raise ReadError(str(e))
882             except SubsequentHeaderError, e:
883                 raise ReadError(str(e))
884             break
885 
886         if tarinfo is not None:
887             self.members.append(tarinfo)
888         else:
889             self._loaded = True
890 
891         return tarinfo
892 
893     #--------------------------------------------------------------------------
894     # Little helper methods:
895 
896     def _getmember(self, name, tarinfo=None, normalize=False):
897         """Find an archive member by name from bottom to top.
898            If tarinfo is given, it is used as the starting point.
899         """
900         # Ensure that all members have been loaded.
901         members = self.getmembers()
902 
903         # Limit the member search list up to tarinfo.
904         if tarinfo is not None:
905             members = members[:members.index(tarinfo)]
906 
907         if normalize:
908             name = os.path.normpath(name)
909 
910         for member in reversed(members):
911             if normalize:
912                 member_name = os.path.normpath(member.name)
913             else:
914                 member_name = member.name
915 
916             if name == member_name:
917                 return member
918 
919     def _load(self):
920         """Read through the entire archive file and look for readable
921            members.
922         """
923         while True:
924             tarinfo = self.next()
925             if tarinfo is None:
926                 break
927         self._loaded = True
928 
929     def _check(self, mode=None):
930         """Check if TarFile is still open, and if the operation‘s mode
931            corresponds to TarFile‘s mode.
932         """
933         if self.closed:
934             raise IOError("%s is closed" % self.__class__.__name__)
935         if mode is not None and self.mode not in mode:
936             raise IOError("bad operation for mode %r" % self.mode)
937 
938     def _find_link_target(self, tarinfo):
939         """Find the target member of a symlink or hardlink member in the
940            archive.
941         """
942         if tarinfo.issym():
943             # Always search the entire archive.
944             linkname = "/".join(filter(None, (os.path.dirname(tarinfo.name), tarinfo.linkname)))
945             limit = None
946         else:
947             # Search the archive before the link, because a hard link is
948             # just a reference to an already archived file.
949             linkname = tarinfo.linkname
950             limit = tarinfo
951 
952         member = self._getmember(linkname, tarinfo=limit, normalize=True)
953         if member is None:
954             raise KeyError("linkname %r not found" % linkname)
955         return member
956 
957     def __iter__(self):
958         """Provide an iterator object.
959         """
960         if self._loaded:
961             return iter(self.members)
962         else:
963             return TarIter(self)
964 
965     def _dbg(self, level, msg):
966         """Write debugging output to sys.stderr.
967         """
968         if level <= self.debug:
969             print >> sys.stderr, msg
970 
971     def __enter__(self):
972         self._check()
973         return self
974 
975     def __exit__(self, type, value, traceback):
976         if type is None:
977             self.close()
978         else:
979             # An exception occurred. We must not call close() because
980             # it would try to write end-of-archive blocks and padding.
981             if not self._extfileobj:
982                 self.fileobj.close()
983             self.closed = True
984 # class TarFile
985 
986 TarFile

TarFile

shelve 模块

shelve模块是一个简单的k,v将内存数据通过文件持久化的模块，可以持久化任何pickle可支持的python数据格式

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

View Code

xml处理模块

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

xml的格式如下，就是通过<>节点来区别数据结构的:

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

View Code

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

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

View Code

修改和删除xml文档内容

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

View Code

自己创建xml文档

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

View Code

PyYAML模块

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

ConfigParser模块
用于生成和修改常见配置文件，来看一个好多软件的常见文档格式如下

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

如果想用python生成一个这样的文档怎么做呢？

 1 import configparser
 2  
 3 config = configparser.ConfigParser()
 4 config["DEFAULT"] = {‘ServerAliveInterval‘: ‘45‘,
 5                       ‘Compression‘: ‘yes‘,
 6                      ‘CompressionLevel‘: ‘9‘}
 7  
 8 config[‘bitbucket.org‘] = {}
 9 config[‘bitbucket.org‘][‘User‘] = ‘hg‘
10 config[‘topsecret.server.com‘] = {}
11 topsecret = config[‘topsecret.server.com‘]
12 topsecret[‘Host Port‘] = ‘50022‘     # mutates the parser
13 topsecret[‘ForwardX11‘] = ‘no‘  # same here
14 config[‘DEFAULT‘][‘ForwardX11‘] = ‘yes‘
15 with open(‘example.ini‘, ‘w‘) as configfile:
16    config.write(configfile)

技术分享

 1 >>> topsecret[‘Port‘]
 2 ‘50022‘
 3 >>> for key in config[‘bitbucket.org‘]: print(key)
 4 ...
 5 user
 6 compressionlevel
 7 serveraliveinterval
 8 compression
 9 forwardx11
10 >>> config[‘bitbucket.org‘][‘ForwardX11‘]
11 ‘yes‘

configparser增删改查语法

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

View Code

hashlib模块　　

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

 1 import hashlib
 2  
 3 m = hashlib.md5()
 4 m.update(b"Hello")
 5 m.update(b"It‘s me")
 6 print(m.digest())
 7 m.update(b"It‘s been a long time since last time we ...")
 8  
 9 print(m.digest()) #2进制格式hash
10 print(len(m.hexdigest())) #16进制格式hash
11 ‘‘‘
12 def digest(self, *args, **kwargs): # real signature unknown
13     """ Return the digest value as a string of binary data. """
14     pass
15  
16 def hexdigest(self, *args, **kwargs): # real signature unknown
17     """ Return the digest value as a string of hexadecimal digits. """
18     pass
19  
20 ‘‘‘
21 import hashlib
22  
23 # ######## md5 ########
24  
25 hash = hashlib.md5()
26 hash.update(‘admin‘)
27 print(hash.hexdigest())
28  
29 # ######## sha1 ########
30  
31 hash = hashlib.sha1()
32 hash.update(‘admin‘)
33 print(hash.hexdigest())
34  
35 # ######## sha256 ########
36  
37 hash = hashlib.sha256()
38 hash.update(‘admin‘)
39 print(hash.hexdigest())
40  
41  
42 # ######## sha384 ########
43  
44 hash = hashlib.sha384()
45 hash.update(‘admin‘)
46 print(hash.hexdigest())
47  
48 # ######## sha512 ########
49  
50 hash = hashlib.sha512()
51 hash.update(‘admin‘)
52 print(hash.hexdigest())

View Code

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

```
1 import hmac
2 h = hmac.new(‘wueiqi‘)
3 h.update(‘hellowo‘)
4 print h.hexdigest()
```
更多关于md5,sha1,sha256等介绍的文章看这里https://www.tbs-certificates.co.uk/FAQ/en/sha256.html
Subprocess模块

Python学习第六天

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原文地址：http://www.cnblogs.com/Peony-Y/p/5243989.html

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