LogRecord attributes are not tuple, when logging only dict

[sejvlond]

BPO	25508
Nosy	@vsajip, @bitdancer

^{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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assignee = None
closed_at = <Date 2015-11-24.23:24:33.249>
created_at = <Date 2015-10-29.10:22:02.659>
labels = []
title = 'LogRecord attributes are not tuple, when logging only dict'
updated_at = <Date 2015-11-24.23:24:33.247>
user = 'https://bugs.python.org/sejvlond'

bugs.python.org fields:

activity = <Date 2015-11-24.23:24:33.247>
actor = 'python-dev'
assignee = 'none'
closed = True
closed_date = <Date 2015-11-24.23:24:33.249>
closer = 'python-dev'
components = []
creation = <Date 2015-10-29.10:22:02.659>
creator = 'sejvlond'
dependencies = []
files = []
hgrepos = []
issue_num = 25508
keywords = []
message_count = 3.0
messages = ['253673', '253676', '255303']
nosy_count = 4.0
nosy_names = ['vinay.sajip', 'r.david.murray', 'python-dev', 'sejvlond']
pr_nums = []
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = None
url = 'https://bugs.python.org/issue25508'
versions = ['Python 2.7', 'Python 3.4']

[sejvlond]

Hi,

in doc https://docs.python.org/3.4/library/logging.html#logrecord-attributes there is
args You shouldn’t need to format this yourself. The tuple of arguments merged into msg to produce message.

But when I log message with 1 arg - a dict - in record.args will be this dict

import logging

class H(logging.Handler):
    def emit(self, record):
        print(record.args, type(record.args))

lgr = logging.getLogger()
lgr.addHandler(H())
lgr.error("msg", 1)
lgr.error("msg", dict(a=1))
lgr.error("msg", dict(a=1), 2)

output:

(1,) <class 'tuple'>
{'a': 1} <class 'dict'>
({'a': 1}, 2) <class 'tuple'>

[bitdancer]

I believe this is due to the way % formatting works, and so is a doc bug. Vinay will know for sure, of course :)

[python-dev]

New changeset a365fb0dd5e1 by Vinay Sajip in branch '2.7':
Issue bpo-25508: Clarify documentation on LogRecord args attribute.
https://hg.python.org/cpython/rev/a365fb0dd5e1

New changeset 01998efb605a by Vinay Sajip in branch '3.4':
Issue bpo-25508: Clarify documentation on LogRecord args attribute.
https://hg.python.org/cpython/rev/01998efb605a

New changeset ca512b568368 by Vinay Sajip in branch '3.5':
Issue bpo-25508: Merged documentation fix from 3.4.
https://hg.python.org/cpython/rev/ca512b568368

New changeset 1da622f4630b by Vinay Sajip in branch 'default':
Closes bpo-25508: Merged documentation fix from 3.5.
https://hg.python.org/cpython/rev/1da622f4630b