12.5. tarfile
— Read and write tar archive files¶
Source code: Lib/tarfile.py
The tarfile
module makes it possible to read and write tar
archives, including those using gzip or bz2 compression.
(.zip
files can be read and written using the zipfile
module.)
Some facts and figures:
- reads and writes
gzip
andbz2
compressed archives. - read/write support for the POSIX.1-1988 (ustar) format.
- read/write support for the GNU tar format including longname and longlink extensions, read-only support for all variants of the sparse extension including restoration of sparse files.
- read/write support for the POSIX.1-2001 (pax) format.
- handles directories, regular files, hardlinks, symbolic links, fifos, character devices and block devices and is able to acquire and restore file information like timestamp, access permissions and owner.
-
tarfile.
open
(name=None, mode='r', fileobj=None, bufsize=10240, **kwargs)¶ Return a
TarFile
object for the pathname name. For detailed information onTarFile
objects and the keyword arguments that are allowed, see TarFile Objects.mode has to be a string of the form
'filemode[:compression]'
, it defaults to'r'
. Here is a full list of mode combinations:mode action 'r' or 'r:*'
Open for reading with transparent compression (recommended). 'r:'
Open for reading exclusively without compression. 'r:gz'
Open for reading with gzip compression. 'r:bz2'
Open for reading with bzip2 compression. 'a' or 'a:'
Open for appending with no compression. The file is created if it does not exist. 'w' or 'w:'
Open for uncompressed writing. 'w:gz'
Open for gzip compressed writing. 'w:bz2'
Open for bzip2 compressed writing. Note that
'a:gz'
or'a:bz2'
is not possible. If mode is not suitable to open a certain (compressed) file for reading,ReadError
is raised. Use mode'r'
to avoid this. If a compression method is not supported,CompressionError
is raised.If fileobj is specified, it is used as an alternative to a file object opened in binary mode for name. It is supposed to be at position 0.
For special purposes, there is a second format for mode:
'filemode|[compression]'
.tarfile.open()
will return aTarFile
object that processes its data as a stream of blocks. No random seeking will be done on the file. If given, fileobj may be any object that has aread()
orwrite()
method (depending on the mode). bufsize specifies the blocksize and defaults to20 * 512
bytes. Use this variant in combination with e.g.sys.stdin
, a socket file object or a tape device. However, such aTarFile
object is limited in that it does not allow to be accessed randomly, see Examples. The currently possible modes:Mode Action 'r|*'
Open a stream of tar blocks for reading with transparent compression. 'r|'
Open a stream of uncompressed tar blocks for reading. 'r|gz'
Open a gzip compressed stream for reading. 'r|bz2'
Open a bzip2 compressed stream for reading. 'w|'
Open an uncompressed stream for writing. 'w|gz'
Open an gzip compressed stream for writing. 'w|bz2'
Open an bzip2 compressed stream for writing.
-
class
tarfile.
TarFile
¶ Class for reading and writing tar archives. Do not use this class directly, better use
tarfile.open()
instead. See TarFile Objects.
-
tarfile.
is_tarfile
(name)¶ Return
True
if name is a tar archive file, that thetarfile
module can read.
The tarfile
module defines the following exceptions:
-
exception
tarfile.
ReadError
¶ Is raised when a tar archive is opened, that either cannot be handled by the
tarfile
module or is somehow invalid.
-
exception
tarfile.
CompressionError
¶ Is raised when a compression method is not supported or when the data cannot be decoded properly.
-
exception
tarfile.
StreamError
¶ Is raised for the limitations that are typical for stream-like
TarFile
objects.
-
exception
tarfile.
ExtractError
¶ Is raised for non-fatal errors when using
TarFile.extract()
, but only ifTarFile.errorlevel
== 2
.
-
exception
tarfile.
HeaderError
¶ Is raised by
TarInfo.frombuf()
if the buffer it gets is invalid.
Each of the following constants defines a tar archive format that the
tarfile
module is able to create. See section Supported tar formats for
details.
-
tarfile.
USTAR_FORMAT
¶ POSIX.1-1988 (ustar) format.
-
tarfile.
GNU_FORMAT
¶ GNU tar format.
-
tarfile.
PAX_FORMAT
¶ POSIX.1-2001 (pax) format.
-
tarfile.
DEFAULT_FORMAT
¶ The default format for creating archives. This is currently
GNU_FORMAT
.
The following variables are available on module level:
-
tarfile.
ENCODING
¶ The default character encoding:
'utf-8'
on Windows,sys.getfilesystemencoding()
otherwise.
See also
- Module
zipfile
- Documentation of the
zipfile
standard module. - GNU tar manual, Basic Tar Format
- Documentation for tar archive files, including GNU tar extensions.
12.5.1. TarFile Objects¶
The TarFile
object provides an interface to a tar archive. A tar
archive is a sequence of blocks. An archive member (a stored file) is made up of
a header block followed by data blocks. It is possible to store a file in a tar
archive several times. Each archive member is represented by a TarInfo
object, see TarInfo Objects for details.
A TarFile
object can be used as a context manager in a with
statement. It will automatically be closed when the block is completed. Please
note that in the event of an exception an archive opened for writing will not
be finalized; only the internally used file object will be closed. See the
Examples section for a use case.
New in version 3.2:
New in version 3.2: Added support for the context manager protocol.
-
class
tarfile.
TarFile
(name=None, mode='r', fileobj=None, format=DEFAULT_FORMAT, tarinfo=TarInfo, dereference=False, ignore_zeros=False, encoding=ENCODING, errors='surrogateescape', pax_headers=None, debug=0, errorlevel=0) All following arguments are optional and can be accessed as instance attributes as well.
name is the pathname of the archive. It can be omitted if fileobj is given. In this case, the file object’s
name
attribute is used if it exists.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.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 will be used from position 0.
Note
fileobj is not closed, when
TarFile
is closed.format controls the archive format. It must be one of the constants
USTAR_FORMAT
,GNU_FORMAT
orPAX_FORMAT
that are defined at module level.The tarinfo argument can be used to replace the default
TarInfo
class with a different one.If dereference is
False
, add symbolic and hard links to the archive. If it isTrue
, add the content of the target files to the archive. This has no effect on systems that do not support symbolic links.If ignore_zeros is
False
, treat an empty block as the end of the archive. If it isTrue
, skip empty (and invalid) blocks and try to get as many members as possible. This is only useful for reading concatenated or damaged archives.debug can be set from
0
(no debug messages) up to3
(all debug messages). The messages are written tosys.stderr
.If errorlevel is
0
, all errors are ignored when usingTarFile.extract()
. Nevertheless, they appear as error messages in the debug output, when debugging is enabled. If1
, all fatal errors are raised asOSError
orIOError
exceptions. If2
, all non-fatal errors are raised asTarError
exceptions as well.The encoding and errors arguments define the character encoding to be used for reading or writing the archive and how conversion errors are going to be handled. The default settings will work for most users. See section Unicode issues for in-depth information.
Changed in version 3.2:
Changed in version 3.2: Use
'surrogateescape'
as the default for the errors argument.
The pax_headers argument is an optional dictionary of strings which
will be added as a pax global header if format is PAX_FORMAT
.
-
TarFile.
open
(...)¶ Alternative constructor. The
tarfile.open()
function is actually a shortcut to this classmethod.
-
TarFile.
getmember
(name)¶ Return a
TarInfo
object for member name. If name can not be found in the archive,KeyError
is raised.Note
If a member occurs more than once in the archive, its last occurrence is assumed to be the most up-to-date version.
-
TarFile.
getmembers
()¶ Return the members of the archive as a list of
TarInfo
objects. The list has the same order as the members in the archive.
-
TarFile.
getnames
()¶ Return the members as a list of their names. It has the same order as the list returned by
getmembers()
.
-
TarFile.
list
(verbose=True)¶ Print a table of contents to
sys.stdout
. If verbose isFalse
, only the names of the members are printed. If it isTrue
, output similar to that of ls -l is produced.
-
TarFile.
next
()¶ Return the next member of the archive as a
TarInfo
object, whenTarFile
is opened for reading. ReturnNone
if there is no more available.
-
TarFile.
extractall
(path=".", members=None)¶ Extract all members from the archive to the current working directory or directory path. If optional members is given, it must be a subset of the list returned by
getmembers()
. Directory information like owner, modification time and permissions are set after all members have been extracted. This is done to work around two problems: A directory’s modification time is reset each time a file is created in it. And, if a directory’s permissions do not allow writing, extracting files to it will fail.Warning
Never extract archives from untrusted sources without prior inspection. It is possible that files are created outside of path, e.g. members that have absolute filenames starting with
"/"
or filenames with two dots".."
.
-
TarFile.
extract
(member, path="", set_attrs=True)¶ 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. File attributes (owner, mtime, mode) are set unless set_attrs is False.Note
The
extract()
method does not take care of several extraction issues. In most cases you should consider using theextractall()
method.Warning
See the warning for
extractall()
.Changed in version 3.2:
Changed in version 3.2: Added the set_attrs parameter.
-
TarFile.
extractfile
(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.Note
The file-like object is read-only. It provides the methods
read()
,readline()
,readlines()
,seek()
,tell()
, andclose()
, and also supports iteration over its lines.
-
TarFile.
add
(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
. If exclude is given, it must be a function that takes one filename argument and returns a boolean value. Depending on this value the respective file is either excluded (True
) or added (False
). If filter is specified it must be a keyword argument. It should be a function that takes aTarInfo
object argument and returns the changedTarInfo
object. If it instead returnsNone
theTarInfo
object will be excluded from the archive. See Examples for an example.Changed in version 3.2:
Changed in version 3.2: Added the filter parameter.
Deprecated since version 3.2:
Deprecated since version 3.2: The exclude parameter is deprecated, please use the filter parameter instead.
-
TarFile.
addfile
(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 createTarInfo
objects usinggettarinfo()
.Note
On Windows platforms, fileobj should always be opened with mode
'rb'
to avoid irritation about the file size.
-
TarFile.
gettarinfo
(name=None, arcname=None, fileobj=None)¶ Create a
TarInfo
object for either the file name or the file object fileobj (usingos.fstat()
on its file descriptor). You can modify some of theTarInfo
‘s attributes before you add it usingaddfile()
. If given, arcname specifies an alternative name for the file in the archive.
-
TarFile.
close
()¶ Close the
TarFile
. In write mode, two finishing zero blocks are appended to the archive.
-
TarFile.
pax_headers
¶ A dictionary containing key-value pairs of pax global headers.
12.5.2. TarInfo Objects¶
A TarInfo
object represents one member in a TarFile
. Aside
from storing all required attributes of a file (like file type, size, time,
permissions, owner etc.), it provides some useful methods to determine its type.
It does not contain the file’s data itself.
TarInfo
objects are returned by TarFile
‘s methods
getmember()
, getmembers()
and gettarinfo()
.
-
TarInfo.
frombuf
(buf)¶ Create and return a
TarInfo
object from string buffer buf.Raises
HeaderError
if the buffer is invalid..
-
TarInfo.
fromtarfile
(tarfile)¶ Read the next member from the
TarFile
object tarfile and return it as aTarInfo
object.
-
TarInfo.
tobuf
(format=DEFAULT_FORMAT, encoding=ENCODING, errors='surrogateescape')¶ Create a string buffer from a
TarInfo
object. For information on the arguments see the constructor of theTarFile
class.Changed in version 3.2:
Changed in version 3.2: Use
'surrogateescape'
as the default for the errors argument.
A TarInfo
object has the following public data attributes:
-
TarInfo.
name
¶ Name of the archive member.
-
TarInfo.
size
¶ Size in bytes.
-
TarInfo.
mtime
¶ Time of last modification.
-
TarInfo.
mode
¶ Permission bits.
-
TarInfo.
type
¶ File type. type is usually one of these constants:
REGTYPE
,AREGTYPE
,LNKTYPE
,SYMTYPE
,DIRTYPE
,FIFOTYPE
,CONTTYPE
,CHRTYPE
,BLKTYPE
,GNUTYPE_SPARSE
. To determine the type of aTarInfo
object more conveniently, use theis_*()
methods below.
-
TarInfo.
linkname
¶ Name of the target file name, which is only present in
TarInfo
objects of typeLNKTYPE
andSYMTYPE
.
-
TarInfo.
uid
¶ User ID of the user who originally stored this member.
-
TarInfo.
gid
¶ Group ID of the user who originally stored this member.
-
TarInfo.
uname
¶ User name.
-
TarInfo.
gname
¶ Group name.
-
TarInfo.
pax_headers
¶ A dictionary containing key-value pairs of an associated pax extended header.
A TarInfo
object also provides some convenient query methods: