problem with interpolation and logging.config.dictConfig with python3.6+

[tjwilli58]

I'm having a problem using configobj with interpolation to configure a logger. Everything works fine with python3.4, python3.5, but for python3.5 and above, I get an exception.

Here is my test program:

import sys
import configobj
import logging, logging.config

msg = '***** python version: \n{}\n*****\n'.format(sys.version)
print(msg)

config = configobj.ConfigObj('logtest.ini')
# make version an int
config['logging']['version'] = int(config['logging']['version'])
logging.config.dictConfig(config['logging'])
logger=logging.getLogger('root')
logger.info(msg)

and my INI file:

[logging]
    version = 1
    level = INFO
    [[formatters]]
        [[[fmt1]]]
            format = %(asctime)s: (%(levelname)s)   %(message)s
    [[handlers]]
        [[[console]]]
            class = logging.StreamHandler
            level = INFO
            stream = ext://sys.stderr
            formatter = fmt1
        [[[file]]]
            class = logging.FileHandler
            level = INFO
            mode = a
            formatter = fmt1
            filename = test.log
    [[loggers]]
        [[[root]]]
            level = INFO
            handlers = console, file

running under python3.4 or python 3.5:

(py36) C:\Users\Tim\workspace\CollectionSoftware>conda.bat activate py35

(py35) C:\Users\Tim\workspace\CollectionSoftware>python testlogging.py ***** python version: 3.5.5 | packaged by conda-forge | (default, Jul 24 2018, 01:52:17) [MSC v.1900 64 bit (AMD64)]

---

2019-09-29 12:53:27,027: (INFO) ***** python version: 3.5.5 | packaged by conda-forge | (default, Jul 24 2018, 01:52:17) [MSC v.1900 64 bit (AMD64)]

---

But when I try the same program with python3.6, I get a ValueError when trying to configer my logger format:

(py35) C:\Users\Tim\workspace\CollectionSoftware>conda.bat activate py36

(py36) C:\Users\Tim\workspace\CollectionSoftware>python testlogging.py ***** python version: 3.6.7 (default, Jul 2 2019, 02:21:41) [MSC v.1900 64 bit (AMD64)]

---

Traceback (most recent call last): File "C:\Users\Tim\Miniconda3\envs\py36\lib\logging\config.py", line 545, in configure formatters[name]) File "C:\Users\Tim\Miniconda3\envs\py36\lib\logging\config.py", line 327, in getitem return self.convert_with_key(key, value) File "C:\Users\Tim\Miniconda3\envs\py36\lib\logging\config.py", line 293, in convert_with_key result = self.configurator.convert(value) File "C:\Users\Tim\Miniconda3\envs\py36\lib\logging\config.py", line 446, in convert value = ConvertingDict(value) File "C:\Users\Tim\Miniconda3\envs\py36\lib\site-packages\configobj.py", line 557, in getitem return self._interpolate(key, val) File "C:\Users\Tim\Miniconda3\envs\py36\lib\site-packages\configobj.py", line 549, in _interpolate return engine.interpolate(key, value) File "C:\Users\Tim\Miniconda3\envs\py36\lib\site-packages\configobj.py", line 352, in interpolate value = recursive_interpolate(key, value, self.section, {}) File "C:\Users\Tim\Miniconda3\envs\py36\lib\site-packages\configobj.py", line 330, in recursive_interpolate k, v, s = self._parse_match(match) File "C:\Users\Tim\Miniconda3\envs\py36\lib\site-packages\configobj.py", line 417, in _parse_match value, section = self._fetch(key) File "C:\Users\Tim\Miniconda3\envs\py36\lib\site-packages\configobj.py", line 386, in _fetch raise MissingInterpolationOption(key) configobj.MissingInterpolationOption: missing option "asctime" in interpolation.

During handling of the above exception, another exception occurred:

Traceback (most recent call last): File "testlogging.py", line 11, in logging.config.dictConfig(config['logging']) File "C:\Users\Tim\Miniconda3\envs\py36\lib\logging\config.py", line 802, in dictConfig dictConfigClass(config).configure() File "C:\Users\Tim\Miniconda3\envs\py36\lib\logging\config.py", line 548, in configure 'formatter %r: %s' % (name, e)) ValueError: Unable to configure formatter 'fmt1': missing option "asctime" in interpolation.

It could be a bug in logging.config, but I'm thinking it may be somewhere in configobj.interpolate()

Thanks for any help

[tjwilli58]

I think the source my confusion is that the formatting of the logging module LogRecord attributes Is identical to the 'ConfigParser' interpolation. I changed the interpolation to 'Template', then made sure to change the confiobj key values to have that format, while leaving the format statement alone, e.g.

[MainWindow]
    NumCameras = 1
    RootDir = TestData
    CaptureDrive = "C:/"
    LogFile = ${CaptureDrive}${RootDir)/test.log

[logging]
    version = 1
    level = INFO
    [[formatters]]
        [[[fmt1]]]
            format = %(asctime)s: (%(levelname)s)   %(message)s
            datefmt = 
    [[handlers]]
        [[[console]]]
            class = logging.StreamHandler
            level = INFO
            stream = ext://sys.stderr
            formatter = fmt1
        [[[file]]]
            class = logging.FileHandler
            level = INFO
            mode = a
            formatter = fmt1
            filename = C:/TestData/test_20190530.log
    [[loggers]]
        [[[root]]]
            level = INFO
            handlers = console, file