[Python-checkins] cpython: Add a function bz2.open(), to match gzip.open().
nadeem.vawda
python-checkins at python.org
Mon Jun 4 23:55:55 CEST 2012
http://hg.python.org/cpython/rev/2143386a17a4
changeset: 77355:2143386a17a4
user: Nadeem Vawda <nadeem.vawda at gmail.com>
date: Mon Jun 04 23:32:38 2012 +0200
summary:
Add a function bz2.open(), to match gzip.open().
files:
Doc/library/bz2.rst | 33 ++++++++-
Lib/bz2.py | 47 +++++++++++-
Lib/test/test_bz2.py | 117 ++++++++++++++++++++++++++++--
Misc/NEWS | 3 +
4 files changed, 184 insertions(+), 16 deletions(-)
diff --git a/Doc/library/bz2.rst b/Doc/library/bz2.rst
--- a/Doc/library/bz2.rst
+++ b/Doc/library/bz2.rst
@@ -14,7 +14,8 @@
The :mod:`bz2` module contains:
-* The :class:`BZ2File` class for reading and writing compressed files.
+* The :func:`.open` function and :class:`BZ2File` class for reading and
+ writing compressed files.
* The :class:`BZ2Compressor` and :class:`BZ2Decompressor` classes for
incremental (de)compression.
* The :func:`compress` and :func:`decompress` functions for one-shot
@@ -26,9 +27,37 @@
(De)compression of files
------------------------
+.. function:: open(filename, mode='r', compresslevel=9, encoding=None, errors=None, newline=None)
+
+ Open a bzip2-compressed file in binary or text mode, returning a :term:`file
+ object`.
+
+ As with the constructor for :class:`BZ2File`, the *filename* argument can be
+ an actual filename (a :class:`str` or :class:`bytes` object), or an existing
+ file object to read from or write to.
+
+ The *mode* argument can be any of ``'r'``, ``'rb'``, ``'w'``, ``'wb'``,
+ ``'a'``, or ``'ab'`` for binary mode, or ``'rt'``, ``'wt'``, or ``'at'`` for
+ text mode. The default is ``'rb'``.
+
+ The *compresslevel* argument is an integer from 1 to 9, as for the
+ :class:`BZ2File` constructor.
+
+ For binary mode, this function is equivalent to the :class:`BZ2File`
+ constructor: ``BZ2File(filename, mode, compresslevel=compresslevel)``. In
+ this case, the *encoding*, *errors* and *newline* arguments must not be
+ provided.
+
+ For text mode, a :class:`BZ2File` object is created, and wrapped in an
+ :class:`io.TextIOWrapper` instance with the specified encoding, error
+ handling behavior, and line ending(s).
+
+ .. versionadded:: 3.3
+
+
.. class:: BZ2File(filename, mode='r', buffering=None, compresslevel=9)
- Open a bzip2-compressed file.
+ Open a bzip2-compressed file in binary mode.
If *filename* is a :class:`str` or :class:`bytes` object, open the named file
directly. Otherwise, *filename* should be a :term:`file object`, which will
diff --git a/Lib/bz2.py b/Lib/bz2.py
--- a/Lib/bz2.py
+++ b/Lib/bz2.py
@@ -4,11 +4,12 @@
(de)compression, and functions for one-shot (de)compression.
"""
-__all__ = ["BZ2File", "BZ2Compressor", "BZ2Decompressor", "compress",
- "decompress"]
+__all__ = ["BZ2File", "BZ2Compressor", "BZ2Decompressor",
+ "open", "compress", "decompress"]
__author__ = "Nadeem Vawda <nadeem.vawda at gmail.com>"
+import builtins
import io
import warnings
@@ -91,7 +92,7 @@
raise ValueError("Invalid mode: {!r}".format(mode))
if isinstance(filename, (str, bytes)):
- self._fp = open(filename, mode)
+ self._fp = builtins.open(filename, mode)
self._closefp = True
self._mode = mode_code
elif hasattr(filename, "read") or hasattr(filename, "write"):
@@ -391,6 +392,46 @@
return self._pos
+def open(filename, mode="rb", compresslevel=9,
+ encoding=None, errors=None, newline=None):
+ """Open a bzip2-compressed file in binary or text mode.
+
+ The filename argument can be an actual filename (a str or bytes object), or
+ an existing file object to read from or write to.
+
+ The mode argument can be "r", "rb", "w", "wb", "a" or "ab" for binary mode,
+ or "rt", "wt" or "at" for text mode. The default mode is "rb", and the
+ default compresslevel is 9.
+
+ For binary mode, this function is equivalent to the BZ2File constructor:
+ BZ2File(filename, mode, compresslevel). In this case, the encoding, errors
+ and newline arguments must not be provided.
+
+ For text mode, a BZ2File object is created, and wrapped in an
+ io.TextIOWrapper instance with the specified encoding, error handling
+ behavior, and line ending(s).
+
+ """
+ if "t" in mode:
+ if "b" in mode:
+ raise ValueError("Invalid mode: %r" % (mode,))
+ else:
+ if encoding is not None:
+ raise ValueError("Argument 'encoding' not supported in binary mode")
+ if errors is not None:
+ raise ValueError("Argument 'errors' not supported in binary mode")
+ if newline is not None:
+ raise ValueError("Argument 'newline' not supported in binary mode")
+
+ bz_mode = mode.replace("t", "")
+ binary_file = BZ2File(filename, bz_mode, compresslevel=compresslevel)
+
+ if "t" in mode:
+ return io.TextIOWrapper(binary_file, encoding, errors, newline)
+ else:
+ return binary_file
+
+
def compress(data, compresslevel=9):
"""Compress a block of data.
diff --git a/Lib/test/test_bz2.py b/Lib/test/test_bz2.py
--- a/Lib/test/test_bz2.py
+++ b/Lib/test/test_bz2.py
@@ -48,6 +48,13 @@
TEXT = b''.join(TEXT_LINES)
DATA = b'BZh91AY&SY.\xc8N\x18\x00\x01>_\x80\x00\x10@\x02\xff\xf0\x01\x07n\x00?\xe7\xff\xe00\x01\x99\xaa\x00\xc0\x03F\x86\x8c#&\x83F\x9a\x03\x06\xa6\xd0\xa6\x93M\x0fQ\xa7\xa8\x06\x804hh\x12$\x11\xa4i4\xf14S\xd2<Q\xb5\x0fH\xd3\xd4\xdd\xd5\x87\xbb\xf8\x94\r\x8f\xafI\x12\xe1\xc9\xf8/E\x00pu\x89\x12]\xc9\xbbDL\nQ\x0e\t1\x12\xdf\xa0\xc0\x97\xac2O9\x89\x13\x94\x0e\x1c7\x0ed\x95I\x0c\xaaJ\xa4\x18L\x10\x05#\x9c\xaf\xba\xbc/\x97\x8a#C\xc8\xe1\x8cW\xf9\xe2\xd0\xd6M\xa7\x8bXa<e\x84t\xcbL\xb3\xa7\xd9\xcd\xd1\xcb\x84.\xaf\xb3\xab\xab\xad`n}\xa0lh\tE,\x8eZ\x15\x17VH>\x88\xe5\xcd9gd6\x0b\n\xe9\x9b\xd5\x8a\x99\xf7\x08.K\x8ev\xfb\xf7xw\xbb\xdf\xa1\x92\xf1\xdd|/";\xa2\xba\x9f\xd5\xb1#A\xb6\xf6\xb3o\xc9\xc5y\\\xebO\xe7\x85\x9a\xbc\xb6f8\x952\xd5\xd7"%\x89>V,\xf7\xa6z\xe2\x9f\xa3\xdf\x11\x11"\xd6E)I\xa9\x13^\xca\xf3r\xd0\x03U\x922\xf26\xec\xb6\xed\x8b\xc3U\x13\x9d\xc5\x170\xa4\xfa^\x92\xacDF\x8a\x97\xd6\x19\xfe\xdd\xb8\xbd\x1a\x9a\x19\xa3\x80ankR\x8b\xe5\xd83]\xa9\xc6\x08\x82f\xf6\xb9"6l$\xb8j@\xc0\x8a\xb0l1..\xbak\x83ls\x15\xbc\xf4\xc1\x13\xbe\xf8E\xb8\x9d\r\xa8\x9dk\x84\xd3n\xfa\xacQ\x07\xb1%y\xaav\xb4\x08\xe0z\x1b\x16\xf5\x04\xe9\xcc\xb9\x08z\x1en7.G\xfc]\xc9\x14\xe1B@\xbb!8`'
+ def setUp(self):
+ self.filename = TESTFN
+
+ def tearDown(self):
+ if os.path.isfile(self.filename):
+ os.unlink(self.filename)
+
if has_cmdline_bunzip2:
def decompress(self, data):
pop = subprocess.Popen("bunzip2", shell=True,
@@ -70,13 +77,6 @@
class BZ2FileTest(BaseTest):
"Test BZ2File type miscellaneous methods."
- def setUp(self):
- self.filename = TESTFN
-
- def tearDown(self):
- if os.path.isfile(self.filename):
- os.unlink(self.filename)
-
def createTempFile(self, streams=1):
with open(self.filename, "wb") as f:
f.write(self.DATA * streams)
@@ -650,9 +650,7 @@
decompressed = None
-class FuncTest(BaseTest):
- "Test module functions"
-
+class CompressDecompressTest(BaseTest):
def testCompress(self):
data = bz2.compress(self.TEXT)
self.assertEqual(self.decompress(data), self.TEXT)
@@ -672,12 +670,109 @@
text = bz2.decompress(self.DATA * 5)
self.assertEqual(text, self.TEXT * 5)
+
+class OpenTest(BaseTest):
+ def test_binary_modes(self):
+ with bz2.open(self.filename, "wb") as f:
+ f.write(self.TEXT)
+ with open(self.filename, "rb") as f:
+ file_data = bz2.decompress(f.read())
+ self.assertEqual(file_data, self.TEXT)
+ with bz2.open(self.filename, "rb") as f:
+ self.assertEqual(f.read(), self.TEXT)
+ with bz2.open(self.filename, "ab") as f:
+ f.write(self.TEXT)
+ with open(self.filename, "rb") as f:
+ file_data = bz2.decompress(f.read())
+ self.assertEqual(file_data, self.TEXT * 2)
+
+ def test_implicit_binary_modes(self):
+ # Test implicit binary modes (no "b" or "t" in mode string).
+ with bz2.open(self.filename, "w") as f:
+ f.write(self.TEXT)
+ with open(self.filename, "rb") as f:
+ file_data = bz2.decompress(f.read())
+ self.assertEqual(file_data, self.TEXT)
+ with bz2.open(self.filename, "r") as f:
+ self.assertEqual(f.read(), self.TEXT)
+ with bz2.open(self.filename, "a") as f:
+ f.write(self.TEXT)
+ with open(self.filename, "rb") as f:
+ file_data = bz2.decompress(f.read())
+ self.assertEqual(file_data, self.TEXT * 2)
+
+ def test_text_modes(self):
+ text = self.TEXT.decode("ascii")
+ text_native_eol = text.replace("\n", os.linesep)
+ with bz2.open(self.filename, "wt") as f:
+ f.write(text)
+ with open(self.filename, "rb") as f:
+ file_data = bz2.decompress(f.read()).decode("ascii")
+ self.assertEqual(file_data, text_native_eol)
+ with bz2.open(self.filename, "rt") as f:
+ self.assertEqual(f.read(), text)
+ with bz2.open(self.filename, "at") as f:
+ f.write(text)
+ with open(self.filename, "rb") as f:
+ file_data = bz2.decompress(f.read()).decode("ascii")
+ self.assertEqual(file_data, text_native_eol * 2)
+
+ def test_fileobj(self):
+ with bz2.open(BytesIO(self.DATA), "r") as f:
+ self.assertEqual(f.read(), self.TEXT)
+ with bz2.open(BytesIO(self.DATA), "rb") as f:
+ self.assertEqual(f.read(), self.TEXT)
+ text = self.TEXT.decode("ascii")
+ with bz2.open(BytesIO(self.DATA), "rt") as f:
+ self.assertEqual(f.read(), text)
+
+ def test_bad_params(self):
+ # Test invalid parameter combinations.
+ with self.assertRaises(ValueError):
+ bz2.open(self.filename, "wbt")
+ with self.assertRaises(ValueError):
+ bz2.open(self.filename, "rb", encoding="utf-8")
+ with self.assertRaises(ValueError):
+ bz2.open(self.filename, "rb", errors="ignore")
+ with self.assertRaises(ValueError):
+ bz2.open(self.filename, "rb", newline="\n")
+
+ def test_encoding(self):
+ # Test non-default encoding.
+ text = self.TEXT.decode("ascii")
+ text_native_eol = text.replace("\n", os.linesep)
+ with bz2.open(self.filename, "wt", encoding="utf-16-le") as f:
+ f.write(text)
+ with open(self.filename, "rb") as f:
+ file_data = bz2.decompress(f.read()).decode("utf-16-le")
+ self.assertEqual(file_data, text_native_eol)
+ with bz2.open(self.filename, "rt", encoding="utf-16-le") as f:
+ self.assertEqual(f.read(), text)
+
+ def test_encoding_error_handler(self):
+ # Test with non-default encoding error handler.
+ with bz2.open(self.filename, "wb") as f:
+ f.write(b"foo\xffbar")
+ with bz2.open(self.filename, "rt", encoding="ascii", errors="ignore") \
+ as f:
+ self.assertEqual(f.read(), "foobar")
+
+ def test_newline(self):
+ # Test with explicit newline (universal newline mode disabled).
+ text = self.TEXT.decode("ascii")
+ with bz2.open(self.filename, "wt", newline="\n") as f:
+ f.write(text)
+ with bz2.open(self.filename, "rt", newline="\r") as f:
+ self.assertEqual(f.readlines(), [text])
+
+
def test_main():
support.run_unittest(
BZ2FileTest,
BZ2CompressorTest,
BZ2DecompressorTest,
- FuncTest
+ CompressDecompressTest,
+ OpenTest,
)
support.reap_children()
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -15,6 +15,9 @@
Library
-------
+- The bz2 module now contains an open() function, allowing compressed files to
+ conveniently be opened in text mode as well as binary mode.
+
- BZ2File.__init__() now accepts a file object as its first argument, rather
than requiring a separate "fileobj" argument.
--
Repository URL: http://hg.python.org/cpython
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