cpython/Doc/library/gzip.rst

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:mod:`gzip` --- Support for :program:`gzip` files
=================================================
.. module:: gzip
:synopsis: Interfaces for gzip compression and decompression using file objects.
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**Source code:** :source:`Lib/gzip.py`
--------------
Merged revisions 61981,61984-61987,61992-61993,61997-62000 via svnmerge from svn+ssh://pythondev@svn.python.org/python/trunk ........ r61981 | amaury.forgeotdarc | 2008-03-28 01:21:34 +0100 (Fri, 28 Mar 2008) | 2 lines test_future3.py is a regular test file, and should be part of the test suite ........ r61984 | jeffrey.yasskin | 2008-03-28 05:11:18 +0100 (Fri, 28 Mar 2008) | 6 lines Kill a race in test_threading in which the exception info in a thread finishing up after it was joined had a traceback pointing to that thread's (deleted) target attribute, while the test was trying to check that the target was destroyed. Big thanks to Antoine Pitrou for diagnosing the race and pointing out sys.exc_clear() to kill the exception early. This fixes issue 2496. ........ r61985 | neal.norwitz | 2008-03-28 05:41:34 +0100 (Fri, 28 Mar 2008) | 1 line Allow use of other ports so the test can pass if 9091 is in use ........ r61986 | jeffrey.yasskin | 2008-03-28 05:53:10 +0100 (Fri, 28 Mar 2008) | 2 lines Print more information the next time test_socket throws the wrong exception. ........ r61987 | neal.norwitz | 2008-03-28 05:58:51 +0100 (Fri, 28 Mar 2008) | 5 lines Revert r61969 which added casts to Py_CHARMASK to avoid compiler warnings. Rather than sprinkle casts throughout the code, change Py_CHARMASK to always cast it's result to an unsigned char. This should ensure we do the right thing when accessing an array with the result. ........ r61992 | neal.norwitz | 2008-03-28 06:34:59 +0100 (Fri, 28 Mar 2008) | 2 lines Fix compiler warning about finite() missing on Solaris. ........ r61993 | neal.norwitz | 2008-03-28 07:34:03 +0100 (Fri, 28 Mar 2008) | 11 lines Bug 1503: Get the test to pass on OSX. This should make the test more reliable, but I'm not convinced it is the right solution. We need to determine if this causes the test to hang on any platforms or do other bad things. Even if it gets the test to pass reliably, it might be that we want to fix this in socket. The socket returned from accept() is different on different platforms (inheriting attributes or not) and we might want to ensure that the attributes (at least blocking) is the same across all platforms. ........ r61997 | neal.norwitz | 2008-03-28 08:36:31 +0100 (Fri, 28 Mar 2008) | 1 line Name the main method correctly so the test is run ........ r61998 | gregory.p.smith | 2008-03-28 09:00:44 +0100 (Fri, 28 Mar 2008) | 7 lines This patch moves some tests from test_urllib2_net to test_urllib2_localnet. The moved tests use a local server rather than going out to external servers. Accepts patch from issue2429. Contributed by Jerry Seutter & Michael Foord (fuzzyman) at PyCon 2008. ........ r61999 | georg.brandl | 2008-03-28 09:06:56 +0100 (Fri, 28 Mar 2008) | 2 lines #2406: add examples to gzip docs. ........ r62000 | gregory.p.smith | 2008-03-28 09:32:09 +0100 (Fri, 28 Mar 2008) | 4 lines Accept patch issue2426 by Paul Kippes (kippesp). Adds sqlite3.Connection.iterdump to allow dumping of databases. ........
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This module provides a simple interface to compress and decompress files just
like the GNU programs :program:`gzip` and :program:`gunzip` would.
The data compression is provided by the :mod:`zlib` module.
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The :mod:`gzip` module provides the :class:`GzipFile` class. The :class:`GzipFile`
class reads and writes :program:`gzip`\ -format files, automatically compressing
or decompressing the data so that it looks like an ordinary :term:`file object`.
Merged revisions 61981,61984-61987,61992-61993,61997-62000 via svnmerge from svn+ssh://pythondev@svn.python.org/python/trunk ........ r61981 | amaury.forgeotdarc | 2008-03-28 01:21:34 +0100 (Fri, 28 Mar 2008) | 2 lines test_future3.py is a regular test file, and should be part of the test suite ........ r61984 | jeffrey.yasskin | 2008-03-28 05:11:18 +0100 (Fri, 28 Mar 2008) | 6 lines Kill a race in test_threading in which the exception info in a thread finishing up after it was joined had a traceback pointing to that thread's (deleted) target attribute, while the test was trying to check that the target was destroyed. Big thanks to Antoine Pitrou for diagnosing the race and pointing out sys.exc_clear() to kill the exception early. This fixes issue 2496. ........ r61985 | neal.norwitz | 2008-03-28 05:41:34 +0100 (Fri, 28 Mar 2008) | 1 line Allow use of other ports so the test can pass if 9091 is in use ........ r61986 | jeffrey.yasskin | 2008-03-28 05:53:10 +0100 (Fri, 28 Mar 2008) | 2 lines Print more information the next time test_socket throws the wrong exception. ........ r61987 | neal.norwitz | 2008-03-28 05:58:51 +0100 (Fri, 28 Mar 2008) | 5 lines Revert r61969 which added casts to Py_CHARMASK to avoid compiler warnings. Rather than sprinkle casts throughout the code, change Py_CHARMASK to always cast it's result to an unsigned char. This should ensure we do the right thing when accessing an array with the result. ........ r61992 | neal.norwitz | 2008-03-28 06:34:59 +0100 (Fri, 28 Mar 2008) | 2 lines Fix compiler warning about finite() missing on Solaris. ........ r61993 | neal.norwitz | 2008-03-28 07:34:03 +0100 (Fri, 28 Mar 2008) | 11 lines Bug 1503: Get the test to pass on OSX. This should make the test more reliable, but I'm not convinced it is the right solution. We need to determine if this causes the test to hang on any platforms or do other bad things. Even if it gets the test to pass reliably, it might be that we want to fix this in socket. The socket returned from accept() is different on different platforms (inheriting attributes or not) and we might want to ensure that the attributes (at least blocking) is the same across all platforms. ........ r61997 | neal.norwitz | 2008-03-28 08:36:31 +0100 (Fri, 28 Mar 2008) | 1 line Name the main method correctly so the test is run ........ r61998 | gregory.p.smith | 2008-03-28 09:00:44 +0100 (Fri, 28 Mar 2008) | 7 lines This patch moves some tests from test_urllib2_net to test_urllib2_localnet. The moved tests use a local server rather than going out to external servers. Accepts patch from issue2429. Contributed by Jerry Seutter & Michael Foord (fuzzyman) at PyCon 2008. ........ r61999 | georg.brandl | 2008-03-28 09:06:56 +0100 (Fri, 28 Mar 2008) | 2 lines #2406: add examples to gzip docs. ........ r62000 | gregory.p.smith | 2008-03-28 09:32:09 +0100 (Fri, 28 Mar 2008) | 4 lines Accept patch issue2426 by Paul Kippes (kippesp). Adds sqlite3.Connection.iterdump to allow dumping of databases. ........
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Note that additional file formats which can be decompressed by the
:program:`gzip` and :program:`gunzip` programs, such as those produced by
:program:`compress` and :program:`pack`, are not supported by this module.
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Merged revisions 58817-58861 via svnmerge from svn+ssh://pythondev@svn.python.org/python/trunk ........ r58822 | brett.cannon | 2007-11-02 23:47:02 -0700 (Fri, 02 Nov 2007) | 2 lines Add a missing quotation mark. ........ r58840 | skip.montanaro | 2007-11-04 07:56:52 -0800 (Sun, 04 Nov 2007) | 2 lines Note change to get_dialect semantics in 2.5. Will backport to 2.5. ........ r58844 | georg.brandl | 2007-11-04 09:43:49 -0800 (Sun, 04 Nov 2007) | 2 lines Fix syntax for versionchanged markup. ........ r58850 | gregory.p.smith | 2007-11-04 18:32:26 -0800 (Sun, 04 Nov 2007) | 9 lines Fixes bug 477182 on pybsddb.sf.net. DB objects now load the flags and pay attention to them when opening an existing database. This means that d[] behaves properly even on databases previously created with DB_DUP or DB_DUPSORT flags to allow duplicate keys. http://sourceforge.net/tracker/index.php?func=detail&aid=477182&group_id=13900&atid=113900 Do not backport, this bugfix could be considered an API change. ........ r58851 | gregory.p.smith | 2007-11-04 18:56:31 -0800 (Sun, 04 Nov 2007) | 3 lines Add the bsddb.db.DBEnv.lock_id_free method. Improve test_lock's tempdir creation and cleanup. ........ r58852 | gregory.p.smith | 2007-11-05 01:06:28 -0800 (Mon, 05 Nov 2007) | 3 lines * db->get_types is only available in BerkeleyDB >= 4.2 * get compiling with older versions of python again for a stand alone release. ........ r58853 | gregory.p.smith | 2007-11-05 01:07:40 -0800 (Mon, 05 Nov 2007) | 2 lines * db->get_flags is only available in BerkeleyDB >= 4.2 ........ r58854 | mark.summerfield | 2007-11-05 01:22:48 -0800 (Mon, 05 Nov 2007) | 3 lines Added cross-references between the various archive file formats. ........ r58857 | mark.summerfield | 2007-11-05 06:38:50 -0800 (Mon, 05 Nov 2007) | 5 lines Clarified the fact that you can have comments for individual archive members even though comments to the archive itself aren't currently supported. ........
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For other archive formats, see the :mod:`bz2`, :mod:`zipfile`, and
:mod:`tarfile` modules.
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The module defines the following items:
.. class:: GzipFile(filename=None, mode=None, compresslevel=9, fileobj=None, mtime=None)
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Constructor for the :class:`GzipFile` class, which simulates most of the
methods of a :term:`file object`, with the exception of the :meth:`truncate`
method. At least one of *fileobj* and *filename* must be given a non-trivial
value.
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The new class instance is based on *fileobj*, which can be a regular file, a
:class:`StringIO` object, or any other object which simulates a file. It
defaults to ``None``, in which case *filename* is opened to provide a file
object.
When *fileobj* is not ``None``, the *filename* argument is only used to be
included in the :program:`gzip` file header, which may includes the original
filename of the uncompressed file. It defaults to the filename of *fileobj*, if
discernible; otherwise, it defaults to the empty string, and in this case the
original filename is not included in the header.
The *mode* argument can be any of ``'r'``, ``'rb'``, ``'a'``, ``'ab'``, ``'w'``,
or ``'wb'``, depending on whether the file will be read or written. The default
is the mode of *fileobj* if discernible; otherwise, the default is ``'rb'``. If
not given, the 'b' flag will be added to the mode to ensure the file is opened
in binary mode for cross-platform portability.
The *compresslevel* argument is an integer from ``1`` to ``9`` controlling the
level of compression; ``1`` is fastest and produces the least compression, and
``9`` is slowest and produces the most compression. The default is ``9``.
The *mtime* argument is an optional numeric timestamp to be written to
Merged revisions 69998-69999,70002,70022-70023,70025-70026,70061,70086,70145,70171,70183,70188,70235,70244,70275,70281 via svnmerge from svn+ssh://pythondev@svn.python.org/python/trunk ........ r69998 | benjamin.peterson | 2009-02-26 13:04:40 -0600 (Thu, 26 Feb 2009) | 1 line the startship is rather outdated now ........ r69999 | benjamin.peterson | 2009-02-26 13:05:59 -0600 (Thu, 26 Feb 2009) | 1 line comma ........ r70002 | andrew.kuchling | 2009-02-26 16:34:30 -0600 (Thu, 26 Feb 2009) | 1 line The curses panel library is now supported ........ r70022 | georg.brandl | 2009-02-27 10:23:18 -0600 (Fri, 27 Feb 2009) | 1 line #5361: fix typo. ........ r70023 | georg.brandl | 2009-02-27 10:39:26 -0600 (Fri, 27 Feb 2009) | 1 line #5363: fix cmpfiles() docs. Another instance where a prose description is twice as long as the code. ........ r70025 | georg.brandl | 2009-02-27 10:52:55 -0600 (Fri, 27 Feb 2009) | 1 line #5344: fix punctuation. ........ r70026 | georg.brandl | 2009-02-27 10:59:03 -0600 (Fri, 27 Feb 2009) | 1 line #5365: add quick look conversion table for different time representations. ........ r70061 | hirokazu.yamamoto | 2009-02-28 09:24:00 -0600 (Sat, 28 Feb 2009) | 1 line Binary flag is needed on windows. ........ r70086 | benjamin.peterson | 2009-03-01 21:35:12 -0600 (Sun, 01 Mar 2009) | 1 line fix a silly problem of caching gone wrong #5401 ........ r70145 | benjamin.peterson | 2009-03-03 16:51:57 -0600 (Tue, 03 Mar 2009) | 1 line making the writing more formal ........ r70171 | facundo.batista | 2009-03-04 15:18:17 -0600 (Wed, 04 Mar 2009) | 3 lines Fixed a typo. ........ r70183 | benjamin.peterson | 2009-03-04 18:17:57 -0600 (Wed, 04 Mar 2009) | 1 line add example ........ r70188 | hirokazu.yamamoto | 2009-03-05 03:34:14 -0600 (Thu, 05 Mar 2009) | 1 line Fixed memory leak on failure. ........ r70235 | benjamin.peterson | 2009-03-07 18:21:17 -0600 (Sat, 07 Mar 2009) | 1 line fix funky indentation ........ r70244 | martin.v.loewis | 2009-03-08 09:06:19 -0500 (Sun, 08 Mar 2009) | 2 lines Add Chris Withers. ........ r70275 | georg.brandl | 2009-03-09 11:35:48 -0500 (Mon, 09 Mar 2009) | 2 lines Add missing space. ........ r70281 | benjamin.peterson | 2009-03-09 15:38:56 -0500 (Mon, 09 Mar 2009) | 1 line gzip and bz2 are context managers ........
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the stream when compressing. All :program:`gzip` compressed streams are
required to contain a timestamp. If omitted or ``None``, the current
time is used. This module ignores the timestamp when decompressing;
however, some programs, such as :program:`gunzip`\ , make use of it.
The format of the timestamp is the same as that of the return value of
``time.time()`` and of the ``st_mtime`` member of the object returned
by ``os.stat()``.
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Calling a :class:`GzipFile` object's :meth:`close` method does not close
*fileobj*, since you might wish to append more material after the compressed
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data. This also allows you to pass a :class:`io.BytesIO` object opened for
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writing as *fileobj*, and retrieve the resulting memory buffer using the
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:class:`io.BytesIO` object's :meth:`~io.BytesIO.getvalue` method.
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:class:`GzipFile` supports the :class:`io.BufferedIOBase` interface,
including iteration and the :keyword:`with` statement. Only the
:meth:`truncate` method isn't implemented.
Merged revisions 69998-69999,70002,70022-70023,70025-70026,70061,70086,70145,70171,70183,70188,70235,70244,70275,70281 via svnmerge from svn+ssh://pythondev@svn.python.org/python/trunk ........ r69998 | benjamin.peterson | 2009-02-26 13:04:40 -0600 (Thu, 26 Feb 2009) | 1 line the startship is rather outdated now ........ r69999 | benjamin.peterson | 2009-02-26 13:05:59 -0600 (Thu, 26 Feb 2009) | 1 line comma ........ r70002 | andrew.kuchling | 2009-02-26 16:34:30 -0600 (Thu, 26 Feb 2009) | 1 line The curses panel library is now supported ........ r70022 | georg.brandl | 2009-02-27 10:23:18 -0600 (Fri, 27 Feb 2009) | 1 line #5361: fix typo. ........ r70023 | georg.brandl | 2009-02-27 10:39:26 -0600 (Fri, 27 Feb 2009) | 1 line #5363: fix cmpfiles() docs. Another instance where a prose description is twice as long as the code. ........ r70025 | georg.brandl | 2009-02-27 10:52:55 -0600 (Fri, 27 Feb 2009) | 1 line #5344: fix punctuation. ........ r70026 | georg.brandl | 2009-02-27 10:59:03 -0600 (Fri, 27 Feb 2009) | 1 line #5365: add quick look conversion table for different time representations. ........ r70061 | hirokazu.yamamoto | 2009-02-28 09:24:00 -0600 (Sat, 28 Feb 2009) | 1 line Binary flag is needed on windows. ........ r70086 | benjamin.peterson | 2009-03-01 21:35:12 -0600 (Sun, 01 Mar 2009) | 1 line fix a silly problem of caching gone wrong #5401 ........ r70145 | benjamin.peterson | 2009-03-03 16:51:57 -0600 (Tue, 03 Mar 2009) | 1 line making the writing more formal ........ r70171 | facundo.batista | 2009-03-04 15:18:17 -0600 (Wed, 04 Mar 2009) | 3 lines Fixed a typo. ........ r70183 | benjamin.peterson | 2009-03-04 18:17:57 -0600 (Wed, 04 Mar 2009) | 1 line add example ........ r70188 | hirokazu.yamamoto | 2009-03-05 03:34:14 -0600 (Thu, 05 Mar 2009) | 1 line Fixed memory leak on failure. ........ r70235 | benjamin.peterson | 2009-03-07 18:21:17 -0600 (Sat, 07 Mar 2009) | 1 line fix funky indentation ........ r70244 | martin.v.loewis | 2009-03-08 09:06:19 -0500 (Sun, 08 Mar 2009) | 2 lines Add Chris Withers. ........ r70275 | georg.brandl | 2009-03-09 11:35:48 -0500 (Mon, 09 Mar 2009) | 2 lines Add missing space. ........ r70281 | benjamin.peterson | 2009-03-09 15:38:56 -0500 (Mon, 09 Mar 2009) | 1 line gzip and bz2 are context managers ........
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:class:`GzipFile` also provides the following method:
.. method:: peek([n])
Read *n* uncompressed bytes without advancing the file position.
At most one single read on the compressed stream is done to satisfy
the call. The number of bytes returned may be more or less than
requested.
.. versionadded:: 3.2
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.. versionchanged:: 3.1
Merged revisions 69998-69999,70002,70022-70023,70025-70026,70061,70086,70145,70171,70183,70188,70235,70244,70275,70281 via svnmerge from svn+ssh://pythondev@svn.python.org/python/trunk ........ r69998 | benjamin.peterson | 2009-02-26 13:04:40 -0600 (Thu, 26 Feb 2009) | 1 line the startship is rather outdated now ........ r69999 | benjamin.peterson | 2009-02-26 13:05:59 -0600 (Thu, 26 Feb 2009) | 1 line comma ........ r70002 | andrew.kuchling | 2009-02-26 16:34:30 -0600 (Thu, 26 Feb 2009) | 1 line The curses panel library is now supported ........ r70022 | georg.brandl | 2009-02-27 10:23:18 -0600 (Fri, 27 Feb 2009) | 1 line #5361: fix typo. ........ r70023 | georg.brandl | 2009-02-27 10:39:26 -0600 (Fri, 27 Feb 2009) | 1 line #5363: fix cmpfiles() docs. Another instance where a prose description is twice as long as the code. ........ r70025 | georg.brandl | 2009-02-27 10:52:55 -0600 (Fri, 27 Feb 2009) | 1 line #5344: fix punctuation. ........ r70026 | georg.brandl | 2009-02-27 10:59:03 -0600 (Fri, 27 Feb 2009) | 1 line #5365: add quick look conversion table for different time representations. ........ r70061 | hirokazu.yamamoto | 2009-02-28 09:24:00 -0600 (Sat, 28 Feb 2009) | 1 line Binary flag is needed on windows. ........ r70086 | benjamin.peterson | 2009-03-01 21:35:12 -0600 (Sun, 01 Mar 2009) | 1 line fix a silly problem of caching gone wrong #5401 ........ r70145 | benjamin.peterson | 2009-03-03 16:51:57 -0600 (Tue, 03 Mar 2009) | 1 line making the writing more formal ........ r70171 | facundo.batista | 2009-03-04 15:18:17 -0600 (Wed, 04 Mar 2009) | 3 lines Fixed a typo. ........ r70183 | benjamin.peterson | 2009-03-04 18:17:57 -0600 (Wed, 04 Mar 2009) | 1 line add example ........ r70188 | hirokazu.yamamoto | 2009-03-05 03:34:14 -0600 (Thu, 05 Mar 2009) | 1 line Fixed memory leak on failure. ........ r70235 | benjamin.peterson | 2009-03-07 18:21:17 -0600 (Sat, 07 Mar 2009) | 1 line fix funky indentation ........ r70244 | martin.v.loewis | 2009-03-08 09:06:19 -0500 (Sun, 08 Mar 2009) | 2 lines Add Chris Withers. ........ r70275 | georg.brandl | 2009-03-09 11:35:48 -0500 (Mon, 09 Mar 2009) | 2 lines Add missing space. ........ r70281 | benjamin.peterson | 2009-03-09 15:38:56 -0500 (Mon, 09 Mar 2009) | 1 line gzip and bz2 are context managers ........
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Support for the :keyword:`with` statement was added.
.. versionchanged:: 3.2
Support for zero-padded files was added.
.. versionchanged:: 3.2
Support for unseekable files was added.
.. versionchanged:: 3.3
The :meth:`io.BufferedIOBase.read1` method is now implemented.
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.. function:: open(filename, mode='rb', compresslevel=9)
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This is a shorthand for ``GzipFile(filename,`` ``mode,`` ``compresslevel)``.
The *filename* argument is required; *mode* defaults to ``'rb'`` and
*compresslevel* defaults to ``9``.
.. function:: compress(data, compresslevel=9)
Compress the *data*, returning a :class:`bytes` object containing
the compressed data. *compresslevel* has the same meaning as in
the :class:`GzipFile` constructor above.
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.. versionadded:: 3.2
.. function:: decompress(data)
Decompress the *data*, returning a :class:`bytes` object containing the
uncompressed data.
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.. versionadded:: 3.2
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Merged revisions 61981,61984-61987,61992-61993,61997-62000 via svnmerge from svn+ssh://pythondev@svn.python.org/python/trunk ........ r61981 | amaury.forgeotdarc | 2008-03-28 01:21:34 +0100 (Fri, 28 Mar 2008) | 2 lines test_future3.py is a regular test file, and should be part of the test suite ........ r61984 | jeffrey.yasskin | 2008-03-28 05:11:18 +0100 (Fri, 28 Mar 2008) | 6 lines Kill a race in test_threading in which the exception info in a thread finishing up after it was joined had a traceback pointing to that thread's (deleted) target attribute, while the test was trying to check that the target was destroyed. Big thanks to Antoine Pitrou for diagnosing the race and pointing out sys.exc_clear() to kill the exception early. This fixes issue 2496. ........ r61985 | neal.norwitz | 2008-03-28 05:41:34 +0100 (Fri, 28 Mar 2008) | 1 line Allow use of other ports so the test can pass if 9091 is in use ........ r61986 | jeffrey.yasskin | 2008-03-28 05:53:10 +0100 (Fri, 28 Mar 2008) | 2 lines Print more information the next time test_socket throws the wrong exception. ........ r61987 | neal.norwitz | 2008-03-28 05:58:51 +0100 (Fri, 28 Mar 2008) | 5 lines Revert r61969 which added casts to Py_CHARMASK to avoid compiler warnings. Rather than sprinkle casts throughout the code, change Py_CHARMASK to always cast it's result to an unsigned char. This should ensure we do the right thing when accessing an array with the result. ........ r61992 | neal.norwitz | 2008-03-28 06:34:59 +0100 (Fri, 28 Mar 2008) | 2 lines Fix compiler warning about finite() missing on Solaris. ........ r61993 | neal.norwitz | 2008-03-28 07:34:03 +0100 (Fri, 28 Mar 2008) | 11 lines Bug 1503: Get the test to pass on OSX. This should make the test more reliable, but I'm not convinced it is the right solution. We need to determine if this causes the test to hang on any platforms or do other bad things. Even if it gets the test to pass reliably, it might be that we want to fix this in socket. The socket returned from accept() is different on different platforms (inheriting attributes or not) and we might want to ensure that the attributes (at least blocking) is the same across all platforms. ........ r61997 | neal.norwitz | 2008-03-28 08:36:31 +0100 (Fri, 28 Mar 2008) | 1 line Name the main method correctly so the test is run ........ r61998 | gregory.p.smith | 2008-03-28 09:00:44 +0100 (Fri, 28 Mar 2008) | 7 lines This patch moves some tests from test_urllib2_net to test_urllib2_localnet. The moved tests use a local server rather than going out to external servers. Accepts patch from issue2429. Contributed by Jerry Seutter & Michael Foord (fuzzyman) at PyCon 2008. ........ r61999 | georg.brandl | 2008-03-28 09:06:56 +0100 (Fri, 28 Mar 2008) | 2 lines #2406: add examples to gzip docs. ........ r62000 | gregory.p.smith | 2008-03-28 09:32:09 +0100 (Fri, 28 Mar 2008) | 4 lines Accept patch issue2426 by Paul Kippes (kippesp). Adds sqlite3.Connection.iterdump to allow dumping of databases. ........
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.. _gzip-usage-examples:
Examples of usage
-----------------
Example of how to read a compressed file::
import gzip
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with gzip.open('/home/joe/file.txt.gz', 'rb') as f:
file_content = f.read()
Merged revisions 61981,61984-61987,61992-61993,61997-62000 via svnmerge from svn+ssh://pythondev@svn.python.org/python/trunk ........ r61981 | amaury.forgeotdarc | 2008-03-28 01:21:34 +0100 (Fri, 28 Mar 2008) | 2 lines test_future3.py is a regular test file, and should be part of the test suite ........ r61984 | jeffrey.yasskin | 2008-03-28 05:11:18 +0100 (Fri, 28 Mar 2008) | 6 lines Kill a race in test_threading in which the exception info in a thread finishing up after it was joined had a traceback pointing to that thread's (deleted) target attribute, while the test was trying to check that the target was destroyed. Big thanks to Antoine Pitrou for diagnosing the race and pointing out sys.exc_clear() to kill the exception early. This fixes issue 2496. ........ r61985 | neal.norwitz | 2008-03-28 05:41:34 +0100 (Fri, 28 Mar 2008) | 1 line Allow use of other ports so the test can pass if 9091 is in use ........ r61986 | jeffrey.yasskin | 2008-03-28 05:53:10 +0100 (Fri, 28 Mar 2008) | 2 lines Print more information the next time test_socket throws the wrong exception. ........ r61987 | neal.norwitz | 2008-03-28 05:58:51 +0100 (Fri, 28 Mar 2008) | 5 lines Revert r61969 which added casts to Py_CHARMASK to avoid compiler warnings. Rather than sprinkle casts throughout the code, change Py_CHARMASK to always cast it's result to an unsigned char. This should ensure we do the right thing when accessing an array with the result. ........ r61992 | neal.norwitz | 2008-03-28 06:34:59 +0100 (Fri, 28 Mar 2008) | 2 lines Fix compiler warning about finite() missing on Solaris. ........ r61993 | neal.norwitz | 2008-03-28 07:34:03 +0100 (Fri, 28 Mar 2008) | 11 lines Bug 1503: Get the test to pass on OSX. This should make the test more reliable, but I'm not convinced it is the right solution. We need to determine if this causes the test to hang on any platforms or do other bad things. Even if it gets the test to pass reliably, it might be that we want to fix this in socket. The socket returned from accept() is different on different platforms (inheriting attributes or not) and we might want to ensure that the attributes (at least blocking) is the same across all platforms. ........ r61997 | neal.norwitz | 2008-03-28 08:36:31 +0100 (Fri, 28 Mar 2008) | 1 line Name the main method correctly so the test is run ........ r61998 | gregory.p.smith | 2008-03-28 09:00:44 +0100 (Fri, 28 Mar 2008) | 7 lines This patch moves some tests from test_urllib2_net to test_urllib2_localnet. The moved tests use a local server rather than going out to external servers. Accepts patch from issue2429. Contributed by Jerry Seutter & Michael Foord (fuzzyman) at PyCon 2008. ........ r61999 | georg.brandl | 2008-03-28 09:06:56 +0100 (Fri, 28 Mar 2008) | 2 lines #2406: add examples to gzip docs. ........ r62000 | gregory.p.smith | 2008-03-28 09:32:09 +0100 (Fri, 28 Mar 2008) | 4 lines Accept patch issue2426 by Paul Kippes (kippesp). Adds sqlite3.Connection.iterdump to allow dumping of databases. ........
2008-03-28 07:53:29 -03:00
Example of how to create a compressed GZIP file::
import gzip
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content = b"Lots of content here"
with gzip.open('/home/joe/file.txt.gz', 'wb') as f:
f.write(content)
Merged revisions 61981,61984-61987,61992-61993,61997-62000 via svnmerge from svn+ssh://pythondev@svn.python.org/python/trunk ........ r61981 | amaury.forgeotdarc | 2008-03-28 01:21:34 +0100 (Fri, 28 Mar 2008) | 2 lines test_future3.py is a regular test file, and should be part of the test suite ........ r61984 | jeffrey.yasskin | 2008-03-28 05:11:18 +0100 (Fri, 28 Mar 2008) | 6 lines Kill a race in test_threading in which the exception info in a thread finishing up after it was joined had a traceback pointing to that thread's (deleted) target attribute, while the test was trying to check that the target was destroyed. Big thanks to Antoine Pitrou for diagnosing the race and pointing out sys.exc_clear() to kill the exception early. This fixes issue 2496. ........ r61985 | neal.norwitz | 2008-03-28 05:41:34 +0100 (Fri, 28 Mar 2008) | 1 line Allow use of other ports so the test can pass if 9091 is in use ........ r61986 | jeffrey.yasskin | 2008-03-28 05:53:10 +0100 (Fri, 28 Mar 2008) | 2 lines Print more information the next time test_socket throws the wrong exception. ........ r61987 | neal.norwitz | 2008-03-28 05:58:51 +0100 (Fri, 28 Mar 2008) | 5 lines Revert r61969 which added casts to Py_CHARMASK to avoid compiler warnings. Rather than sprinkle casts throughout the code, change Py_CHARMASK to always cast it's result to an unsigned char. This should ensure we do the right thing when accessing an array with the result. ........ r61992 | neal.norwitz | 2008-03-28 06:34:59 +0100 (Fri, 28 Mar 2008) | 2 lines Fix compiler warning about finite() missing on Solaris. ........ r61993 | neal.norwitz | 2008-03-28 07:34:03 +0100 (Fri, 28 Mar 2008) | 11 lines Bug 1503: Get the test to pass on OSX. This should make the test more reliable, but I'm not convinced it is the right solution. We need to determine if this causes the test to hang on any platforms or do other bad things. Even if it gets the test to pass reliably, it might be that we want to fix this in socket. The socket returned from accept() is different on different platforms (inheriting attributes or not) and we might want to ensure that the attributes (at least blocking) is the same across all platforms. ........ r61997 | neal.norwitz | 2008-03-28 08:36:31 +0100 (Fri, 28 Mar 2008) | 1 line Name the main method correctly so the test is run ........ r61998 | gregory.p.smith | 2008-03-28 09:00:44 +0100 (Fri, 28 Mar 2008) | 7 lines This patch moves some tests from test_urllib2_net to test_urllib2_localnet. The moved tests use a local server rather than going out to external servers. Accepts patch from issue2429. Contributed by Jerry Seutter & Michael Foord (fuzzyman) at PyCon 2008. ........ r61999 | georg.brandl | 2008-03-28 09:06:56 +0100 (Fri, 28 Mar 2008) | 2 lines #2406: add examples to gzip docs. ........ r62000 | gregory.p.smith | 2008-03-28 09:32:09 +0100 (Fri, 28 Mar 2008) | 4 lines Accept patch issue2426 by Paul Kippes (kippesp). Adds sqlite3.Connection.iterdump to allow dumping of databases. ........
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Example of how to GZIP compress an existing file::
import gzip
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with open('/home/joe/file.txt', 'rb') as f_in:
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with gzip.open('/home/joe/file.txt.gz', 'wb') as f_out:
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f_out.writelines(f_in)
Merged revisions 61981,61984-61987,61992-61993,61997-62000 via svnmerge from svn+ssh://pythondev@svn.python.org/python/trunk ........ r61981 | amaury.forgeotdarc | 2008-03-28 01:21:34 +0100 (Fri, 28 Mar 2008) | 2 lines test_future3.py is a regular test file, and should be part of the test suite ........ r61984 | jeffrey.yasskin | 2008-03-28 05:11:18 +0100 (Fri, 28 Mar 2008) | 6 lines Kill a race in test_threading in which the exception info in a thread finishing up after it was joined had a traceback pointing to that thread's (deleted) target attribute, while the test was trying to check that the target was destroyed. Big thanks to Antoine Pitrou for diagnosing the race and pointing out sys.exc_clear() to kill the exception early. This fixes issue 2496. ........ r61985 | neal.norwitz | 2008-03-28 05:41:34 +0100 (Fri, 28 Mar 2008) | 1 line Allow use of other ports so the test can pass if 9091 is in use ........ r61986 | jeffrey.yasskin | 2008-03-28 05:53:10 +0100 (Fri, 28 Mar 2008) | 2 lines Print more information the next time test_socket throws the wrong exception. ........ r61987 | neal.norwitz | 2008-03-28 05:58:51 +0100 (Fri, 28 Mar 2008) | 5 lines Revert r61969 which added casts to Py_CHARMASK to avoid compiler warnings. Rather than sprinkle casts throughout the code, change Py_CHARMASK to always cast it's result to an unsigned char. This should ensure we do the right thing when accessing an array with the result. ........ r61992 | neal.norwitz | 2008-03-28 06:34:59 +0100 (Fri, 28 Mar 2008) | 2 lines Fix compiler warning about finite() missing on Solaris. ........ r61993 | neal.norwitz | 2008-03-28 07:34:03 +0100 (Fri, 28 Mar 2008) | 11 lines Bug 1503: Get the test to pass on OSX. This should make the test more reliable, but I'm not convinced it is the right solution. We need to determine if this causes the test to hang on any platforms or do other bad things. Even if it gets the test to pass reliably, it might be that we want to fix this in socket. The socket returned from accept() is different on different platforms (inheriting attributes or not) and we might want to ensure that the attributes (at least blocking) is the same across all platforms. ........ r61997 | neal.norwitz | 2008-03-28 08:36:31 +0100 (Fri, 28 Mar 2008) | 1 line Name the main method correctly so the test is run ........ r61998 | gregory.p.smith | 2008-03-28 09:00:44 +0100 (Fri, 28 Mar 2008) | 7 lines This patch moves some tests from test_urllib2_net to test_urllib2_localnet. The moved tests use a local server rather than going out to external servers. Accepts patch from issue2429. Contributed by Jerry Seutter & Michael Foord (fuzzyman) at PyCon 2008. ........ r61999 | georg.brandl | 2008-03-28 09:06:56 +0100 (Fri, 28 Mar 2008) | 2 lines #2406: add examples to gzip docs. ........ r62000 | gregory.p.smith | 2008-03-28 09:32:09 +0100 (Fri, 28 Mar 2008) | 4 lines Accept patch issue2426 by Paul Kippes (kippesp). Adds sqlite3.Connection.iterdump to allow dumping of databases. ........
2008-03-28 07:53:29 -03:00
Example of how to GZIP compress a binary string::
import gzip
s_in = b"Lots of content here"
s_out = gzip.compress(s_in)
Merged revisions 61981,61984-61987,61992-61993,61997-62000 via svnmerge from svn+ssh://pythondev@svn.python.org/python/trunk ........ r61981 | amaury.forgeotdarc | 2008-03-28 01:21:34 +0100 (Fri, 28 Mar 2008) | 2 lines test_future3.py is a regular test file, and should be part of the test suite ........ r61984 | jeffrey.yasskin | 2008-03-28 05:11:18 +0100 (Fri, 28 Mar 2008) | 6 lines Kill a race in test_threading in which the exception info in a thread finishing up after it was joined had a traceback pointing to that thread's (deleted) target attribute, while the test was trying to check that the target was destroyed. Big thanks to Antoine Pitrou for diagnosing the race and pointing out sys.exc_clear() to kill the exception early. This fixes issue 2496. ........ r61985 | neal.norwitz | 2008-03-28 05:41:34 +0100 (Fri, 28 Mar 2008) | 1 line Allow use of other ports so the test can pass if 9091 is in use ........ r61986 | jeffrey.yasskin | 2008-03-28 05:53:10 +0100 (Fri, 28 Mar 2008) | 2 lines Print more information the next time test_socket throws the wrong exception. ........ r61987 | neal.norwitz | 2008-03-28 05:58:51 +0100 (Fri, 28 Mar 2008) | 5 lines Revert r61969 which added casts to Py_CHARMASK to avoid compiler warnings. Rather than sprinkle casts throughout the code, change Py_CHARMASK to always cast it's result to an unsigned char. This should ensure we do the right thing when accessing an array with the result. ........ r61992 | neal.norwitz | 2008-03-28 06:34:59 +0100 (Fri, 28 Mar 2008) | 2 lines Fix compiler warning about finite() missing on Solaris. ........ r61993 | neal.norwitz | 2008-03-28 07:34:03 +0100 (Fri, 28 Mar 2008) | 11 lines Bug 1503: Get the test to pass on OSX. This should make the test more reliable, but I'm not convinced it is the right solution. We need to determine if this causes the test to hang on any platforms or do other bad things. Even if it gets the test to pass reliably, it might be that we want to fix this in socket. The socket returned from accept() is different on different platforms (inheriting attributes or not) and we might want to ensure that the attributes (at least blocking) is the same across all platforms. ........ r61997 | neal.norwitz | 2008-03-28 08:36:31 +0100 (Fri, 28 Mar 2008) | 1 line Name the main method correctly so the test is run ........ r61998 | gregory.p.smith | 2008-03-28 09:00:44 +0100 (Fri, 28 Mar 2008) | 7 lines This patch moves some tests from test_urllib2_net to test_urllib2_localnet. The moved tests use a local server rather than going out to external servers. Accepts patch from issue2429. Contributed by Jerry Seutter & Michael Foord (fuzzyman) at PyCon 2008. ........ r61999 | georg.brandl | 2008-03-28 09:06:56 +0100 (Fri, 28 Mar 2008) | 2 lines #2406: add examples to gzip docs. ........ r62000 | gregory.p.smith | 2008-03-28 09:32:09 +0100 (Fri, 28 Mar 2008) | 4 lines Accept patch issue2426 by Paul Kippes (kippesp). Adds sqlite3.Connection.iterdump to allow dumping of databases. ........
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.. seealso::
Module :mod:`zlib`
The basic data compression module needed to support the :program:`gzip` file
format.