Python中的配置文件以代替日志功能

Question

i have function:

def go_logger(logfilename):
    formatter = logging.Formatter('%(asctime)s - %(levelname)s - %(message)s')
    logging.basicConfig(filemode='a', datefmt='%m-%d-%Y %H:%M:%S')
    logger = logging.getLogger(logfilename)
    logger.setLevel(logging.DEBUG)
    handler = closehandler.ClosingHandler(os.path.join('/path/to/my/logs', logfilename),
                                          mode='a', encoding='utf-8')
    handler.setLevel(logging.DEBUG)
    handler.setFormatter(formatter)
    logger.addHandler(handler)
    return logger

I tried to replace on method:

def get_logger(logfilename):
    config_file = ('/path/to/my/config')
    logging.config.fileConfig(config_file, defaults={'logfilename': logfilename}, disable_existing_loggers=False)
    logger = logging.getLogger("main")

My config:

[loggers]
keys=root

[handlers]
keys=fileHandler

[formatters]
keys=Formatter

[logger_root]
level=DEBUG
handlers=fileHandler
qualname=main

[handler_fileHandler]
class=FileHandler
level=DEBUG
formatter=Formatter
args=('%(filename)s', 'a', 'utf8')

[formatter_Formatter]
format=%(asctime)s - %(levelname)s - %(message)s
datefmt="%Y-%m-%d %H:%M:%S"

But file with log, was not created. When i am using function, everything is ok. I tried to replace function on config and it does not work. Where i have error ? Can you help me ?

Answer 1

Your filename placeholder in the config file doesn't match the logfilename key you're passing in. Make them match, and it works.

Here's a full, runnable example based on yours:

import logging.config


def get_logger(logfilename):
    config_file = ('config.txt')
    logging.config.fileConfig(config_file, defaults={'logfilename': logfilename}, disable_existing_loggers=False)
    logger = logging.getLogger("main")
    return logger

logger = get_logger('scratch.log')
logger.info('Hello, World!')

When I run that with your config file, I get this error:

Traceback (most recent call last):
File "/home/don/.IdeaIC2017.2/config/scratches/scratch.py", line 10, in <module>
logger = get_logger('scratch.log')
File "/home/don/.IdeaIC2017.2/config/scratches/scratch.py", line 6, in get_logger
logging.config.fileConfig(config_file, defaults={'logfilename': logfilename}, disable_existing_loggers=False)
File "/usr/lib/python2.7/logging/config.py", line 85, in fileConfig
handlers = _install_handlers(cp, formatters)
File "/usr/lib/python2.7/logging/config.py", line 161, in _install_handlers
args = cp.get(sectname, "args")
File "/usr/lib/python2.7/ConfigParser.py", line 623, in get
return self._interpolate(section, option, value, d)
File "/usr/lib/python2.7/ConfigParser.py", line 669, in _interpolate
option, section, rawval, e.args[0])
ConfigParser.InterpolationMissingOptionError: Bad value substitution:
section: [handler_fileHandler]
option : args
key    : filename
rawval : ('%(filename)s', 'a', 'utf8')

Bad value substitution means that %(filename)s doesn't match anything. Look carefully, and you see that the defaults you passed in use logfilename .

I change the config file to this, and it works:

[loggers]
keys=root

[handlers]
keys=fileHandler

[formatters]
keys=Formatter

[logger_root]
level=DEBUG
handlers=fileHandler
qualname=main

[handler_fileHandler]
class=FileHandler
level=DEBUG
formatter=Formatter
args=('%(logfilename)s', 'a', 'utf8')

[formatter_Formatter]
format=%(asctime)s - %(levelname)s - %(message)s
datefmt="%Y-%m-%d %H:%M:%S"

Answer 2

Your log file name does not match.

logging.config.fileConfig(config_file, defaults={'logfilename': logfilename}, disable_existing_loggers=False)

>>{'logfilename': logfilename}
And
>>args=('%(filename)s', 'a', 'utf8')

Your file handler should be like this

[handler_fileHandler]
class=FileHandler
level=DEBUG
formatter=Formatter
args=('%(logfilename)s', 'a', 'utf8')