BZ2File objects do not have name attribute

[jojkosivek]

BPO	24258
Nosy	@stestagg, @hrik2001
Files	bz2file.tar: tar ball with test and example of bz2 behaviour bz2.name.patch

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2015-05-21.09:16:55.969>
labels = ['type-bug', '3.8', '3.9', '3.10', '3.11', 'library']
title = 'BZ2File objects do not have name attribute'
updated_at = <Date 2021-04-27.13:05:23.760>
user = 'https://bugs.python.org/jojkosivek'

bugs.python.org fields:

activity = <Date 2021-04-27.13:05:23.760>
actor = 'roysmith'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2015-05-21.09:16:55.969>
creator = 'jojko.sivek'
dependencies = []
files = ['39452', '49991']
hgrepos = ['311']
issue_num = 24258
keywords = ['patch']
message_count = 7.0
messages = ['243743', '244095', '244622', '244623', '392035', '392059', '392069']
nosy_count = 7.0
nosy_names = ['roysmith', 'nadeem.vawda', 'jcd', 'jojko.sivek', 'Hasan Diwan', 'stestagg', 'hrik2001']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue24258'
versions = ['Python 3.8', 'Python 3.9', 'Python 3.10', 'Python 3.11']

[jojkosivek]

Unlike GzipFile the BZ2File does not have defined name attribute. The reading of this attribute results in: "AttributeError: 'BZ2File' object has no attribute 'name'".

This is truly missing feature and wrong behaviour, compare:
https://hg.python.org/releasing/3.4.3/file/933c3041d548/Lib/gzip.py
and
https://hg.python.org/releasing/3.4.3/file/933c3041d548/Lib/bz2.py

In addition to that the BZ2File did have name attribute in python 2.7.* .

In attachment there is tar ball with example files, expected results in python 3 and results in python 2.

[jcd]

I'd be happy to take a look at this one, if no one else is working on it.

[jcd]

I've got a fix for this now. In working on it, I've discovered that not all file-like objects have a .name attribute. io.BytesIO (which is used all over the test suite) does not. I've written a patch that always creates a .name attribute on BZ2File, but sets it to None if the associated file-like object has no .name.

See the linked branch

[jcd]

It's probably too late for this to get into 3.5, since we're already in betas. Pushing back to 3.6.

[HasanDiwan]

Patch adds a bz2.BZ2File.name property corresponding to the filename passed in.

[stestagg]

Please may you add a test that uses "io.BytesIO()" as the filename argument. BytesIO() objects do not have a 'name' attribute

[roysmith]

The https://bitbucket.org/cliff/cpython#python24258 URL 404's

Looking at the attached bz2.py diff, I would change:

 if isinstance(filename, (str, bytes, os.PathLike)):
 self._fp = _builtin_open(filename, mode)
+ self.filename = filename
 self._closefp = True
 self._mode = mode_code

to special-case os.PathLike and do:

 self.filename = str(filename)

I would expect BZ2File.name to be a string. Returning a PathLike means lots of legitimate string methods will not work on it. Also, it should be "name" as an attribute, not "name()" as a method, to match other existing interfaces.