Issue #3488: Provide convenient shorthand functions `gzip.compress`

and `gzip.decompress`.  Original patch by Anand B. Pillai.
This commit is contained in:
Antoine Pitrou 2010-08-17 21:10:05 +00:00
parent 852823d731
commit 79c5ef11d5
5 changed files with 58 additions and 1 deletions

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@ -82,6 +82,17 @@ The module defines the following items:
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.
.. function:: decompress(data)
Decompress the *data*, returning a :class:`bytes` object containing the
uncompressed data.
.. _gzip-usage-examples:
@ -112,6 +123,11 @@ Example of how to GZIP compress an existing file::
f_out.close()
f_in.close()
Example of how to GZIP compress a binary string::
import gzip
s_in = b"Lots of content here"
s_out = gzip.compress(s_in)
.. seealso::

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@ -10,7 +10,7 @@ import zlib
import builtins
import io
__all__ = ["GzipFile","open"]
__all__ = ["GzipFile", "open", "compress", "decompress"]
FTEXT, FHCRC, FEXTRA, FNAME, FCOMMENT = 1, 2, 4, 8, 16
@ -476,6 +476,23 @@ class GzipFile(io.BufferedIOBase):
return b''.join(bufs) # Return resulting line
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.
"""
buf = io.BytesIO()
with GzipFile(fileobj=buf, mode='wb', compresslevel=compresslevel) as f:
f.write(data)
return buf.getvalue()
def decompress(data):
"""Decompress a gzip compressed string in one shot.
Return the decompressed string.
"""
with GzipFile(fileobj=io.BytesIO(data)) as f:
return f.read()
def _test():
# Act like gzip; with -d, act like gunzip.
# The input file is not deleted, however, nor are any other gzip

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@ -265,6 +265,26 @@ class TestGzip(unittest.TestCase):
d = f.read()
self.assertEqual(d, data1 * 50, "Incorrect data in file")
# Testing compress/decompress shortcut functions
def test_compress(self):
for data in [data1, data2]:
for args in [(), (1,), (6,), (9,)]:
datac = gzip.compress(data, *args)
self.assertEqual(type(datac), bytes)
with gzip.GzipFile(fileobj=io.BytesIO(datac), mode="rb") as f:
self.assertEqual(f.read(), data)
def test_decompress(self):
for data in (data1, data2):
buf = io.BytesIO()
with gzip.GzipFile(fileobj=buf, mode="wb") as f:
f.write(data)
self.assertEqual(gzip.decompress(buf.getvalue()), data)
# Roundtrip with compress
datac = gzip.compress(data)
self.assertEqual(gzip.decompress(datac), data)
def test_main(verbose=None):
support.run_unittest(TestGzip)

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@ -634,6 +634,7 @@ Neale Pickett
Jim St. Pierre
Dan Pierson
Martijn Pieters
Anand B. Pillai
François Pinard
Zach Pincus
Michael Piotrowski

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@ -95,6 +95,9 @@ Extensions
Library
-------
- Issue #3488: Provide convenient shorthand functions ``gzip.compress``
and ``gzip.decompress``. Original patch by Anand B. Pillai.
- Issue #8807: poplib.POP3_SSL class now accepts a context parameter, which is a
ssl.SSLContext object allowing bundling SSL configuration options,
certificates and private keys into a single (potentially long-lived)