traverseda
/
cpython
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Issue #15677: Document that zlib and gzip accept a compression level of 0 to mean 'no compression'. 

Patch by Brian Brazil.
This commit is contained in:
Nadeem Vawda 2012-11-11 14:04:14 +01:00
parent 12489d98e6
commit 19e568d254
5 changed files with 22 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
Doc/library/gzip.rst
View File

@ -50,9 +50,10 @@ The module defines the following items:
supported. If you need to read a compressed file in text mode, wrap your
:class:`GzipFile` with an :class:`io.TextIOWrapper`.
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 *compresslevel* argument is an integer from ``0`` to ``9`` controlling
the level of compression; ``1`` is fastest and produces the least
compression, and ``9`` is slowest and produces the most compression. ``0``
is no compression. The default is ``9``.
The *mtime* argument is an optional numeric timestamp to be written to
the stream when compressing. All :program:`gzip` compressed streams are

15
Doc/library/zlib.rst
View File

@ -51,19 +51,20 @@ The available exception and functions in this module are:
.. function:: compress(data[, level])
Compresses the bytes in *data*, returning a bytes object containing compressed data.
*level* is an integer from ``1`` to ``9`` controlling the level of compression;
``1`` is fastest and produces the least compression, ``9`` is slowest and
produces the most. The default value is ``6``. Raises the :exc:`error`
exception if any error occurs.
Compresses the bytes in *data*, returning a bytes object containing
compressed data. *level* is an integer from ``0`` to ``9`` controlling the
level of compression; ``1`` is fastest and produces the least compression,
``9`` is slowest and produces the most. ``0`` is no compression. The default
value is ``6``. Raises the :exc:`error` exception if any error occurs.
.. function:: compressobj([level])
Returns a compression object, to be used for compressing data streams that won't
fit into memory at once. *level* is an integer from ``1`` to ``9`` controlling
fit into memory at once. *level* is an integer from ``0`` to ``9`` controlling
the level of compression; ``1`` is fastest and produces the least compression,
``9`` is slowest and produces the most. The default value is ``6``.
``9`` is slowest and produces the most. ``0`` is no compression. The default
value is ``6``.
.. function:: crc32(data[, value])

7
Lib/gzip.py
View File

@ -137,9 +137,10 @@ class GzipFile(io.BufferedIOBase):
A mode of 'r' is equivalent to one of 'rb', and similarly for 'w' and
'wb', and 'a' and 'ab'.
The compresslevel argument is an integer from 1 to 9 controlling the
The compresslevel argument is an integer from 0 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.
and 9 is slowest and produces the most compression. 0 is no compression
at all. The default is 9.
The mtime argument is an optional numeric timestamp to be written
to the stream when compressing. All gzip compressed streams
@ -573,7 +574,7 @@ class GzipFile(io.BufferedIOBase):
def compress(data, compresslevel=9):
"""Compress data in one shot and return the compressed string.
Optional argument is the compression level, in range of 1-9.
Optional argument is the compression level, in range of 0-9.
"""
buf = io.BytesIO()
with GzipFile(fileobj=buf, mode='wb', compresslevel=compresslevel) as f:

3
Misc/NEWS
View File

@ -714,6 +714,9 @@ Tools/Demos
Documentation
-------------
- Issue #15677: Document that zlib and gzip accept a compression level of 0 to
mean 'no compression'. Patch by Brian Brazil.
- Issue #8040: added a version switcher to the documentation. Patch by
Yury Selivanov.

6
Modules/zlibmodule.c
View File

@ -81,7 +81,7 @@ zlib_error(z_stream zst, int err, char *msg)
PyDoc_STRVAR(compressobj__doc__,
"compressobj([level]) -- Return a compressor object.\n"
"\n"
"Optional arg level is the compression level, in 1-9.");
"Optional arg level is the compression level, in 0-9.");
PyDoc_STRVAR(decompressobj__doc__,
"decompressobj([wbits]) -- Return a decompressor object.\n"
@ -115,7 +115,7 @@ newcompobject(PyTypeObject *type)
PyDoc_STRVAR(compress__doc__,
"compress(string[, level]) -- Returned compressed string.\n"
"\n"
"Optional arg level is the compression level, in 1-9.");
"Optional arg level is the compression level, in 0-9.");
static PyObject *
PyZlib_compress(PyObject *self, PyObject *args)
@ -1135,7 +1135,7 @@ PyDoc_STRVAR(zlib_module_documentation,
"zlib library, which is based on GNU zip.\n"
"\n"
"adler32(string[, start]) -- Compute an Adler-32 checksum.\n"
"compress(string[, level]) -- Compress string, with compression level in 1-9.\n"
"compress(string[, level]) -- Compress string, with compression level in 0-9.\n"
"compressobj([level]) -- Return a compressor object.\n"
"crc32(string[, start]) -- Compute a CRC-32 checksum.\n"
"decompress(string,[wbits],[bufsize]) -- Decompresses a compressed string.\n"