[issue16110] Provide logging.config.configParserConfig

[thbach]

New submission from thbach:

Currently logging.config provides a fileConfig function which reads a ini-style 
file via configparser.ConfigParser. I would like to have a function e.g. 
configParserConfig which accepts a ConfigParser instance and configures logging 
directly from the settings found in there. The main reasons for this are:

1) I think it is rather common for an application that provides an interface to 
configure its logging via an ini file to use this ini file also for further 
application configuration. With the current implementation the file is read 
twice and ConfigParser is initialized two times.

2) Currently it is not idiomatic how to alter an ini-file configuration e.g. by 
options passed in via command-line. The new function provides a clear solution: 
create a ConfigParser instance, parse the ini file, alter the configuration and 
pass it on to logging.config.configParserConfig.

In fact, the new functionality is easy to achieve by refactoring logging.config 
a bit (see attached patch).

--
components: Library (Lib)
files: configParserConfig.patch
keywords: patch
messages: 171812
nosy: thbach
priority: normal
severity: normal
status: open
title: Provide logging.config.configParserConfig
Added file: http://bugs.python.org/file27386/configParserConfig.patch

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue16110] Provide logging.config.configParserConfig

[R. David Murray]

Changes by R. David Murray :


--
nosy: +vinay.sajip
type:  -> enhancement
versions: +Python 3.4

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue16110] Provide logging.config.configParserConfig

[Vinay Sajip]

Vinay Sajip added the comment:

Thanks for the suggestion - I'm sorry, but I'm not inclined to add this. My 
reasoning is as follows:

1. I want to encourage usage of the dictConfig() API, as fileConfig() does not 
cover as much of the logging API as dictConfig() does (for example, Filters). 
I'd like to minimise the maintenance I have to do for fileConfig()-related 
code, and would prefer not to add any auxiliary APIs around fileConfig().
2. The file reading time and ConfigParser instantiation time are not likely to 
be a performance problem in practice, as logging  configuration is an 
infrequent operation (a one-off operation in most cases).
3. You can also pass in a file-like object rather than a filename, and in that 
case, fileConfig() will use readfp() if available. While you might have to seek 
to the beginning of the file to pass it to another ConfigParser instance, that 
is likely to be just a pointer adjustment in a buffer rather than actual disk 
I/O (config files are usually pretty small).

I hope you will agree. I'll leave the issue as pending for now, and close it in 
a day or two.

--
assignee:  -> vinay.sajip
resolution:  -> wont fix
status: open -> pending

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue16110] Provide logging.config.configParserConfig

[R. David Murray]

R. David Murray added the comment:

Vinay, you missed one use case in his request: reading the program's 
configuration, *modifying it* (based on command line args), and then passing it 
to logging.  How would you suggest he handle that use case?  Is there an easy 
way to get from a loaded configuration file to a dictionary for use in 
dictConfig?

--
nosy: +r.david.murray
status: pending -> open

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue16110] Provide logging.config.configParserConfig

[thbach]

thbach added the comment:

vinay: I understand your preference of dictConfig over fileConfig as 
maintainer. But as an application developer I want to provide my user an easy 
way to adjust logging herself. In the end of the day she is the one knowing 
what has to be logged in which place. Therefor, having something like 
fileConfig is essential.

david: The modified configuration can be passed to fileConfig via a StringIO 
instance. 

The downside is that ConfigParser instances with e.g. 'allow_no_value' set to 
True are currently difficult to handle – e.g.:

>>> sys.version
'3.2.3 (default, Jun 25 2012, 23:10:56) \n[GCC 4.7.1]'
>>> cp = configparser.ConfigParser(allow_no_value=True)
>>> cp.read_string('[foo]\nbar')
>>> buf = io.StringIO()
>>> cp.write(buf)
>>> buf.seek(0)
0
>>> logging.config.fileConfig(buf)
---
ParsingError  Traceback (most recent call last)
 in ()
> 1 logging.config.fileConfig(buf)

/usr/lib/python3.2/logging/config.py in fileConfig(fname, defaults, 
disable_existing_loggers)
 64 cp = configparser.ConfigParser(defaults)
 65 if hasattr(fname, 'readline'):
---> 66 cp.read_file(fname)
 67 else:
 68 cp.read(fname)

/usr/lib/python3.2/configparser.py in read_file(self, f, source)
706 except AttributeError:
707 source = ''
--> 708 self._read(f, source)
709 
710 def read_string(self, string, source=''):

/usr/lib/python3.2/configparser.py in _read(self, fp, fpname)
   1079 # if any parsing errors occurred, raise an exception
   1080 if e:
-> 1081 raise e
   1082 self._join_multiline_values()
   1083 

ParsingError: Source contains parsing errors: 
[line  2]: 'bar\n'

Hence, logging.config.fileConfig should at least provide a way to pass in 
arguments for the ConfigParser initialization. Anyways, I think it is much 
cleaner to provide a function which gets the configuration directly from the 
ConfigParser instance.

--

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue16110] Provide logging.config.configParserConfig

[Vinay Sajip]

Vinay Sajip added the comment:

I could consider relaxing the parameters on fileConfig such that instead of 
accepting just a string or a file-like object, it additionally accepts a 
ConfigParser instance. More specifically:

def fileConfig(file_or_fname_or_cp, defaults=None):
if isinstance(file_or_fname_or_cp, RawConfigParser):
cp = file_or_filename_or_cp
else:
cp = ConfigParser.ConfigParser(defaults)
if hasattr(cp, 'readfp') and\
hasattr(file_or_fname_or_cp, 'readline'):
cp.readfp(file_or_fname_or_cp)
else:
cp.read(file_or_fname_or_cp)

formatters = _create_formatters(cp)

This will only require (in addition to the above) small tweaks to docs
and tests. It would appear to fit the bill for your use case. Do you agree?

--

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue16110] Provide logging.config.configParserConfig

[Vinay Sajip]

Changes by Vinay Sajip :


--
resolution: wont fix -> 

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue16110] Provide logging.config.configParserConfig

[Thomas Bach]

Thomas Bach added the comment:

Yeah, the change you suggest sounds reasonable.

Thanks for reconsidering the case!

--

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue16110] Provide logging.config.configParserConfig

[Roundup Robot]

Roundup Robot added the comment:

New changeset ce0d0d052494 by Vinay Sajip in branch 'default':
Closes #16110: fileConfig now accepts a pre-initialised ConfigParser instance.
http://hg.python.org/cpython/rev/ce0d0d052494

--
nosy: +python-dev
resolution:  -> fixed
stage:  -> committed/rejected
status: open -> closed

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue16110] Provide logging.config.configParserConfig

[Roundup Robot]

Roundup Robot added the comment:

New changeset 113341605247 by R David Murray in branch 'default':
whatsnew: logging.fileConfig accepts ConfigParser instances. (#16110)
http://hg.python.org/cpython/rev/113341605247

--

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com