Name	Size	Mode	Actions
2to3.rst.txt	15898	0644	editdlrm
abc.rst.txt	11805	0644	editdlrm
aifc.rst.txt	7503	0644	editdlrm
allos.rst.txt	678	0644	editdlrm
archiving.rst.txt	440	0644	editdlrm
argparse.rst.txt	77480	0644	editdlrm
array.rst.txt	10812	0644	editdlrm
ast.rst.txt	10159	0644	editdlrm
asynchat.rst.txt	8528	0644	editdlrm
asyncio-dev.rst.txt	13398	0644	editdlrm
asyncio-eventloop.rst.txt	33701	0644	editdlrm
asyncio-eventloops.rst.txt	7660	0644	editdlrm
asyncio-protocol.rst.txt	25170	0644	editdlrm
asyncio-queue.rst.txt	4328	0644	editdlrm
asyncio-stream.rst.txt	14363	0644	editdlrm
asyncio-subprocess.rst.txt	15544	0644	editdlrm
asyncio-sync.rst.txt	9078	0644	editdlrm
asyncio-task.rst.txt	25406	0644	editdlrm
asyncio.rst.txt	2272	0644	editdlrm
asyncore.rst.txt	13624	0644	editdlrm
atexit.rst.txt	3669	0644	editdlrm
audioop.rst.txt	10712	0644	editdlrm
base64.rst.txt	10371	0644	editdlrm
bdb.rst.txt	12985	0644	editdlrm
binary.rst.txt	654	0644	editdlrm
binascii.rst.txt	6539	0644	editdlrm
binhex.rst.txt	1709	0644	editdlrm
bisect.rst.txt	5398	0644	editdlrm
builtins.rst.txt	1465	0644	editdlrm
bz2.rst.txt	8825	0644	editdlrm
calendar.rst.txt	10988	0644	editdlrm
cgi.rst.txt	22650	0644	editdlrm
cgitb.rst.txt	2918	0644	editdlrm
chunk.rst.txt	5094	0644	editdlrm
cmath.rst.txt	9326	0644	editdlrm
cmd.rst.txt	13795	0644	editdlrm
code.rst.txt	7817	0644	editdlrm
codecs.rst.txt	75564	0644	editdlrm
codeop.rst.txt	3021	0644	editdlrm
collections.abc.rst.txt	12861	0644	editdlrm
collections.rst.txt	46063	0644	editdlrm
colorsys.rst.txt	1820	0644	editdlrm
compileall.rst.txt	8975	0644	editdlrm
concurrency.rst.txt	673	0644	editdlrm
concurrent.futures.rst.txt	16910	0644	editdlrm
concurrent.rst.txt	171	0644	editdlrm
configparser.rst.txt	48756	0644	editdlrm
constants.rst.txt	3331	0644	editdlrm
contextlib.rst.txt	28175	0644	editdlrm
copy.rst.txt	3378	0644	editdlrm
copyreg.rst.txt	2182	0644	editdlrm
crypt.rst.txt	5122	0644	editdlrm
crypto.rst.txt	411	0644	editdlrm
csv.rst.txt	19902	0644	editdlrm
ctypes.rst.txt	88613	0644	editdlrm
curses.ascii.rst.txt	8920	0644	editdlrm
curses.panel.rst.txt	2764	0644	editdlrm
curses.rst.txt	76397	0644	editdlrm
custominterp.rst.txt	569	0644	editdlrm
datatypes.rst.txt	751	0644	editdlrm
datetime.rst.txt	90524	0644	editdlrm
dbm.rst.txt	14293	0644	editdlrm
debug.rst.txt	471	0644	editdlrm
decimal.rst.txt	74869	0644	editdlrm
development.rst.txt	704	0644	editdlrm
difflib.rst.txt	29861	0644	editdlrm
dis.rst.txt	32567	0644	editdlrm
distribution.rst.txt	452	0644	editdlrm
distutils.rst.txt	1974	0644	editdlrm
doctest.rst.txt	71743	0644	editdlrm
dummy_threading.rst.txt	784	0644	editdlrm
email.charset.rst.txt	9293	0644	editdlrm
email.compat32-message.rst.txt	33493	0644	editdlrm
email.contentmanager.rst.txt	9112	0644	editdlrm
email.encoders.rst.txt	2715	0644	editdlrm
email.errors.rst.txt	4792	0644	editdlrm
email.examples.rst.txt	1915	0644	editdlrm
email.generator.rst.txt	13637	0644	editdlrm
email.header.rst.txt	9188	0644	editdlrm
email.headerregistry.rst.txt	17957	0644	editdlrm
email.iterators.rst.txt	2795	0644	editdlrm
email.message.rst.txt	33008	0644	editdlrm
email.mime.rst.txt	11721	0644	editdlrm
email.parser.rst.txt	14092	0644	editdlrm
email.policy.rst.txt	27022	0644	editdlrm
email.rst.txt	6785	0644	editdlrm
email.util.rst.txt	9214	0644	editdlrm
ensurepip.rst.txt	4987	0644	editdlrm
enum.rst.txt	32751	0644	editdlrm
errno.rst.txt	6811	0644	editdlrm
exceptions.rst.txt	25570	0644	editdlrm
faulthandler.rst.txt	6136	0644	editdlrm
fcntl.rst.txt	7152	0644	editdlrm
filecmp.rst.txt	5623	0644	editdlrm
fileformats.rst.txt	287	0644	editdlrm
fileinput.rst.txt	8051	0644	editdlrm
filesys.rst.txt	961	0644	editdlrm
fnmatch.rst.txt	3103	0644	editdlrm
formatter.rst.txt	13242	0644	editdlrm
fpectl.rst.txt	4180	0644	editdlrm
fractions.rst.txt	6364	0644	editdlrm
frameworks.rst.txt	391	0644	editdlrm
ftplib.rst.txt	17552	0644	editdlrm
functional.rst.txt	365	0644	editdlrm
functions.rst.txt	71621	0644	editdlrm
functools.rst.txt	18503	0644	editdlrm
gc.rst.txt	9694	0644	editdlrm
getopt.rst.txt	6557	0644	editdlrm
getpass.rst.txt	1882	0644	editdlrm
gettext.rst.txt	25588	0644	editdlrm
glob.rst.txt	3508	0644	editdlrm
grp.rst.txt	2417	0644	editdlrm
gzip.rst.txt	8301	0644	editdlrm
hashlib.rst.txt	26523	0644	editdlrm
heapq.rst.txt	13402	0644	editdlrm
hmac.rst.txt	4020	0644	editdlrm
html.entities.rst.txt	1319	0644	editdlrm
html.parser.rst.txt	11275	0644	editdlrm
html.rst.txt	1304	0644	editdlrm
http.client.rst.txt	18870	0644	editdlrm
http.cookiejar.rst.txt	27832	0644	editdlrm
http.cookies.rst.txt	8645	0644	editdlrm
http.rst.txt	7096	0644	editdlrm
http.server.rst.txt	17639	0644	editdlrm
i18n.rst.txt	408	0644	editdlrm
idle.rst.txt	25834	0644	editdlrm
imaplib.rst.txt	20367	0644	editdlrm
imghdr.rst.txt	2938	0644	editdlrm
imp.rst.txt	15548	0644	editdlrm
importlib.rst.txt	53563	0644	editdlrm
index.rst.txt	2258	0644	editdlrm
inspect.rst.txt	53928	0644	editdlrm
internet.rst.txt	992	0644	editdlrm
intro.rst.txt	2645	0644	editdlrm
io.rst.txt	40328	0644	editdlrm
ipaddress.rst.txt	32340	0644	editdlrm
ipc.rst.txt	649	0644	editdlrm
itertools.rst.txt	38459	0644	editdlrm
json.rst.txt	27876	0644	editdlrm
keyword.rst.txt	617	0644	editdlrm
language.rst.txt	522	0644	editdlrm
linecache.rst.txt	2408	0644	editdlrm
locale.rst.txt	25470	0644	editdlrm
logging.config.rst.txt	33886	0644	editdlrm
logging.handlers.rst.txt	42497	0644	editdlrm
logging.rst.txt	60479	0644	editdlrm
lzma.rst.txt	17361	0644	editdlrm
macpath.rst.txt	707	0644	editdlrm
mailbox.rst.txt	63055	0644	editdlrm
mailcap.rst.txt	3691	0644	editdlrm
markup.rst.txt	679	0644	editdlrm
marshal.rst.txt	4855	0644	editdlrm
math.rst.txt	14375	0644	editdlrm
mimetypes.rst.txt	9839	0644	editdlrm
misc.rst.txt	247	0644	editdlrm
mm.rst.txt	431	0644	editdlrm
mmap.rst.txt	11232	0644	editdlrm
modulefinder.rst.txt	3240	0644	editdlrm
modules.rst.txt	355	0644	editdlrm
msilib.rst.txt	18612	0644	editdlrm
msvcrt.rst.txt	4392	0644	editdlrm
multiprocessing.rst.txt	104494	0644	editdlrm
netdata.rst.txt	339	0644	editdlrm
netrc.rst.txt	3007	0644	editdlrm
nis.rst.txt	1993	0644	editdlrm
nntplib.rst.txt	21821	0644	editdlrm
numbers.rst.txt	8089	0644	editdlrm
numeric.rst.txt	696	0644	editdlrm
operator.rst.txt	18989	0644	editdlrm
optparse.rst.txt	76996	0644	editdlrm
os.path.rst.txt	16419	0644	editdlrm
os.rst.txt	137534	0644	editdlrm
ossaudiodev.rst.txt	17845	0644	editdlrm
othergui.rst.txt	2822	0644	editdlrm
parser.rst.txt	15148	0644	editdlrm
pathlib.rst.txt	30045	0644	editdlrm
pdb.rst.txt	19454	0644	editdlrm
persistence.rst.txt	591	0644	editdlrm
pickle.rst.txt	37440	0644	editdlrm
pickletools.rst.txt	3729	0644	editdlrm
pipes.rst.txt	2557	0644	editdlrm
pkgutil.rst.txt	8730	0644	editdlrm
platform.rst.txt	9624	0644	editdlrm
plistlib.rst.txt	7398	0644	editdlrm
poplib.rst.txt	8197	0644	editdlrm
posix.rst.txt	3694	0644	editdlrm
pprint.rst.txt	14274	0644	editdlrm
profile.rst.txt	27969	0644	editdlrm
pty.rst.txt	3123	0644	editdlrm
pwd.rst.txt	2739	0644	editdlrm
pyclbr.rst.txt	3297	0644	editdlrm
pydoc.rst.txt	4688	0644	editdlrm
pyexpat.rst.txt	28620	0644	editdlrm
python.rst.txt	475	0644	editdlrm
py_compile.rst.txt	3851	0644	editdlrm
queue.rst.txt	7268	0644	editdlrm
quopri.rst.txt	2571	0644	editdlrm
random.rst.txt	18503	0644	editdlrm
re.rst.txt	64936	0644	editdlrm
readline.rst.txt	11943	0644	editdlrm
reprlib.rst.txt	5162	0644	editdlrm
resource.rst.txt	12291	0644	editdlrm
rlcompleter.rst.txt	2294	0644	editdlrm
runpy.rst.txt	8285	0644	editdlrm
sched.rst.txt	4842	0644	editdlrm
secrets.rst.txt	5930	0644	editdlrm
select.rst.txt	28175	0644	editdlrm
selectors.rst.txt	8925	0644	editdlrm
shelve.rst.txt	8390	0644	editdlrm
shlex.rst.txt	16441	0644	editdlrm
shutil.rst.txt	26014	0644	editdlrm
signal.rst.txt	17218	0644	editdlrm
site.rst.txt	9628	0644	editdlrm
smtpd.rst.txt	10806	0644	editdlrm
smtplib.rst.txt	23439	0644	editdlrm
sndhdr.rst.txt	1994	0644	editdlrm
socket.rst.txt	68202	0644	editdlrm
socketserver.rst.txt	23712	0644	editdlrm
spwd.rst.txt	2958	0644	editdlrm
sqlite3.rst.txt	39215	0644	editdlrm
ssl.rst.txt	96021	0644	editdlrm
stat.rst.txt	9805	0644	editdlrm
statistics.rst.txt	15301	0644	editdlrm
stdtypes.rst.txt	179240	0644	editdlrm
string.rst.txt	35374	0644	editdlrm
stringprep.rst.txt	4279	0644	editdlrm
struct.rst.txt	19581	0644	editdlrm
subprocess.rst.txt	45793	0644	editdlrm
sunau.rst.txt	7390	0644	editdlrm
superseded.rst.txt	258	0644	editdlrm
symbol.rst.txt	975	0644	editdlrm
symtable.rst.txt	4964	0644	editdlrm
sys.rst.txt	58273	0644	editdlrm
sysconfig.rst.txt	8749	0644	editdlrm
syslog.rst.txt	4302	0644	editdlrm
tabnanny.rst.txt	2007	0644	editdlrm
tarfile.rst.txt	31749	0644	editdlrm
telnetlib.rst.txt	7899	0644	editdlrm
tempfile.rst.txt	13857	0644	editdlrm
termios.rst.txt	3751	0644	editdlrm
test.rst.txt	25764	0644	editdlrm
text.rst.txt	584	0644	editdlrm
textwrap.rst.txt	10519	0644	editdlrm
threading.rst.txt	39257	0644	editdlrm
time.rst.txt	32967	0644	editdlrm
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tk.rst.txt	1639	0644	editdlrm
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unittest.rst.txt	93304	0644	editdlrm
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xml.sax.handler.rst.txt	15399	0644	editdlrm
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xml.sax.utils.rst.txt	3901	0644	editdlrm
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zipapp.rst.txt	17392	0644	editdlrm
zipfile.rst.txt	24005	0644	editdlrm
zipimport.rst.txt	5805	0644	editdlrm
zlib.rst.txt	13912	0644	editdlrm
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__future__.rst.txt	5245	0644	editdlrm
__main__.rst.txt	904	0644	editdlrm

:mod:`zlib` --- Compression compatible with :program:`gzip` =========================================================== .. module:: zlib :synopsis: Low-level interface to compression and decompression routines compatible with gzip. -------------- For applications that require data compression, the functions in this module allow compression and decompression, using the zlib library. The zlib library has its own home page at http://www.zlib.net. There are known incompatibilities between the Python module and versions of the zlib library earlier than 1.1.3; 1.1.3 has a security vulnerability, so we recommend using 1.1.4 or later. zlib's functions have many options and often need to be used in a particular order. This documentation doesn't attempt to cover all of the permutations; consult the zlib manual at http://www.zlib.net/manual.html for authoritative information. For reading and writing ``.gz`` files see the :mod:`gzip` module. The available exception and functions in this module are: .. exception:: error Exception raised on compression and decompression errors. .. function:: adler32(data[, value]) Computes an Adler-32 checksum of *data*. (An Adler-32 checksum is almost as reliable as a CRC32 but can be computed much more quickly.) The result is an unsigned 32-bit integer. If *value* is present, it is used as the starting value of the checksum; otherwise, a default value of 1 is used. Passing in *value* allows computing a running checksum over the concatenation of several inputs. The algorithm is not cryptographically strong, and should not be used for authentication or digital signatures. Since the algorithm is designed for use as a checksum algorithm, it is not suitable for use as a general hash algorithm. .. versionchanged:: 3.0 Always returns an unsigned value. To generate the same numeric value across all Python versions and platforms, use ``adler32(data) & 0xffffffff``. .. function:: compress(data, level=-1) Compresses the bytes in *data*, returning a bytes object containing compressed data. *level* is an integer from ``0`` to ``9`` or ``-1`` controlling the level of compression; ``1`` (Z_BEST_SPEED) is fastest and produces the least compression, ``9`` (Z_BEST_COMPRESSION) is slowest and produces the most. ``0`` (Z_NO_COMPRESSION) is no compression. The default value is ``-1`` (Z_DEFAULT_COMPRESSION). Z_DEFAULT_COMPRESSION represents a default compromise between speed and compression (currently equivalent to level 6). Raises the :exc:`error` exception if any error occurs. .. versionchanged:: 3.6 *level* can now be used as a keyword parameter. .. function:: compressobj(level=-1, method=DEFLATED, wbits=MAX_WBITS, memLevel=DEF_MEM_LEVEL, strategy=Z_DEFAULT_STRATEGY[, zdict]) Returns a compression object, to be used for compressing data streams that won't fit into memory at once. *level* is the compression level -- an integer from ``0`` to ``9`` or ``-1``. A value of ``1`` (Z_BEST_SPEED) is fastest and produces the least compression, while a value of ``9`` (Z_BEST_COMPRESSION) is slowest and produces the most. ``0`` (Z_NO_COMPRESSION) is no compression. The default value is ``-1`` (Z_DEFAULT_COMPRESSION). Z_DEFAULT_COMPRESSION represents a default compromise between speed and compression (currently equivalent to level 6). *method* is the compression algorithm. Currently, the only supported value is :const:`DEFLATED`. The *wbits* argument controls the size of the history buffer (or the "window size") used when compressing data, and whether a header and trailer is included in the output. It can take several ranges of values, defaulting to ``15`` (MAX_WBITS): * +9 to +15: The base-two logarithm of the window size, which therefore ranges between 512 and 32768. Larger values produce better compression at the expense of greater memory usage. The resulting output will include a zlib-specific header and trailer. * −9 to −15: Uses the absolute value of *wbits* as the window size logarithm, while producing a raw output stream with no header or trailing checksum. * +25 to +31 = 16 + (9 to 15): Uses the low 4 bits of the value as the window size logarithm, while including a basic :program:`gzip` header and trailing checksum in the output. The *memLevel* argument controls the amount of memory used for the internal compression state. Valid values range from ``1`` to ``9``. Higher values use more memory, but are faster and produce smaller output. *strategy* is used to tune the compression algorithm. Possible values are :const:`Z_DEFAULT_STRATEGY`, :const:`Z_FILTERED`, :const:`Z_HUFFMAN_ONLY`, :const:`Z_RLE` (zlib 1.2.0.1) and :const:`Z_FIXED` (zlib 1.2.2.2). *zdict* is a predefined compression dictionary. This is a sequence of bytes (such as a :class:`bytes` object) containing subsequences that are expected to occur frequently in the data that is to be compressed. Those subsequences that are expected to be most common should come at the end of the dictionary. .. versionchanged:: 3.3 Added the *zdict* parameter and keyword argument support. .. function:: crc32(data[, value]) .. index:: single: Cyclic Redundancy Check single: checksum; Cyclic Redundancy Check Computes a CRC (Cyclic Redundancy Check) checksum of *data*. The result is an unsigned 32-bit integer. If *value* is present, it is used as the starting value of the checksum; otherwise, a default value of 0 is used. Passing in *value* allows computing a running checksum over the concatenation of several inputs. The algorithm is not cryptographically strong, and should not be used for authentication or digital signatures. Since the algorithm is designed for use as a checksum algorithm, it is not suitable for use as a general hash algorithm. .. versionchanged:: 3.0 Always returns an unsigned value. To generate the same numeric value across all Python versions and platforms, use ``crc32(data) & 0xffffffff``. .. function:: decompress(data, wbits=MAX_WBITS, bufsize=DEF_BUF_SIZE) Decompresses the bytes in *data*, returning a bytes object containing the uncompressed data. The *wbits* parameter depends on the format of *data*, and is discussed further below. If *bufsize* is given, it is used as the initial size of the output buffer. Raises the :exc:`error` exception if any error occurs. .. _decompress-wbits: The *wbits* parameter controls the size of the history buffer (or "window size"), and what header and trailer format is expected. It is similar to the parameter for :func:`compressobj`, but accepts more ranges of values: * +8 to +15: The base-two logarithm of the window size. The input must include a zlib header and trailer. * 0: Automatically determine the window size from the zlib header. Only supported since zlib 1.2.3.5. * −8 to −15: Uses the absolute value of *wbits* as the window size logarithm. The input must be a raw stream with no header or trailer. * +24 to +31 = 16 + (8 to 15): Uses the low 4 bits of the value as the window size logarithm. The input must include a gzip header and trailer. * +40 to +47 = 32 + (8 to 15): Uses the low 4 bits of the value as the window size logarithm, and automatically accepts either the zlib or gzip format. When decompressing a stream, the window size must not be smaller than the size originally used to compress the stream; using a too-small value may result in an :exc:`error` exception. The default *wbits* value corresponds to the largest window size and requires a zlib header and trailer to be included. *bufsize* is the initial size of the buffer used to hold decompressed data. If more space is required, the buffer size will be increased as needed, so you don't have to get this value exactly right; tuning it will only save a few calls to :c:func:`malloc`. .. versionchanged:: 3.6 *wbits* and *bufsize* can be used as keyword arguments. .. function:: decompressobj(wbits=MAX_WBITS[, zdict]) Returns a decompression object, to be used for decompressing data streams that won't fit into memory at once. The *wbits* parameter controls the size of the history buffer (or the "window size"), and what header and trailer format is expected. It has the same meaning as `described for decompress() <#decompress-wbits>`__. The *zdict* parameter specifies a predefined compression dictionary. If provided, this must be the same dictionary as was used by the compressor that produced the data that is to be decompressed. .. note:: If *zdict* is a mutable object (such as a :class:`bytearray`), you must not modify its contents between the call to :func:`decompressobj` and the first call to the decompressor's ``decompress()`` method. .. versionchanged:: 3.3 Added the *zdict* parameter. Compression objects support the following methods: .. method:: Compress.compress(data) Compress *data*, returning a bytes object containing compressed data for at least part of the data in *data*. This data should be concatenated to the output produced by any preceding calls to the :meth:`compress` method. Some input may be kept in internal buffers for later processing. .. method:: Compress.flush([mode]) All pending input is processed, and a bytes object containing the remaining compressed output is returned. *mode* can be selected from the constants :const:`Z_NO_FLUSH`, :const:`Z_PARTIAL_FLUSH`, :const:`Z_SYNC_FLUSH`, :const:`Z_FULL_FLUSH`, :const:`Z_BLOCK` (zlib 1.2.3.4), or :const:`Z_FINISH`, defaulting to :const:`Z_FINISH`. Except :const:`Z_FINISH`, all constants allow compressing further bytestrings of data, while :const:`Z_FINISH` finishes the compressed stream and prevents compressing any more data. After calling :meth:`flush` with *mode* set to :const:`Z_FINISH`, the :meth:`compress` method cannot be called again; the only realistic action is to delete the object. .. method:: Compress.copy() Returns a copy of the compression object. This can be used to efficiently compress a set of data that share a common initial prefix. Decompression objects support the following methods and attributes: .. attribute:: Decompress.unused_data A bytes object which contains any bytes past the end of the compressed data. That is, this remains ``b""`` until the last byte that contains compression data is available. If the whole bytestring turned out to contain compressed data, this is ``b""``, an empty bytes object. .. attribute:: Decompress.unconsumed_tail A bytes object that contains any data that was not consumed by the last :meth:`decompress` call because it exceeded the limit for the uncompressed data buffer. This data has not yet been seen by the zlib machinery, so you must feed it (possibly with further data concatenated to it) back to a subsequent :meth:`decompress` method call in order to get correct output. .. attribute:: Decompress.eof A boolean indicating whether the end of the compressed data stream has been reached. This makes it possible to distinguish between a properly-formed compressed stream, and an incomplete or truncated one. .. versionadded:: 3.3 .. method:: Decompress.decompress(data, max_length=0) Decompress *data*, returning a bytes object containing the uncompressed data corresponding to at least part of the data in *string*. This data should be concatenated to the output produced by any preceding calls to the :meth:`decompress` method. Some of the input data may be preserved in internal buffers for later processing. If the optional parameter *max_length* is non-zero then the return value will be no longer than *max_length*. This may mean that not all of the compressed input can be processed; and unconsumed data will be stored in the attribute :attr:`unconsumed_tail`. This bytestring must be passed to a subsequent call to :meth:`decompress` if decompression is to continue. If *max_length* is zero then the whole input is decompressed, and :attr:`unconsumed_tail` is empty. .. versionchanged:: 3.6 *max_length* can be used as a keyword argument. .. method:: Decompress.flush([length]) All pending input is processed, and a bytes object containing the remaining uncompressed output is returned. After calling :meth:`flush`, the :meth:`decompress` method cannot be called again; the only realistic action is to delete the object. The optional parameter *length* sets the initial size of the output buffer. .. method:: Decompress.copy() Returns a copy of the decompression object. This can be used to save the state of the decompressor midway through the data stream in order to speed up random seeks into the stream at a future point. Information about the version of the zlib library in use is available through the following constants: .. data:: ZLIB_VERSION The version string of the zlib library that was used for building the module. This may be different from the zlib library actually used at runtime, which is available as :const:`ZLIB_RUNTIME_VERSION`. .. data:: ZLIB_RUNTIME_VERSION The version string of the zlib library actually loaded by the interpreter. .. versionadded:: 3.3 .. seealso:: Module :mod:`gzip` Reading and writing :program:`gzip`\ -format files. http://www.zlib.net The zlib library home page. http://www.zlib.net/manual.html The zlib manual explains the semantics and usage of the library's many functions.