How do I change the format of a Python log message on a per-logger basis?

Question

After reading the documentation on `logging`, I know I can use code like this to perform simple logging: ``` import logging def main(): logging.basicConfig(filename="messages.log", level=logging.WARNING, format='%(filename)s: ' '%(levelname)s: ' '%(funcName)s(): ' '%(lineno)d:	' '%(message)s') logging.debug("Only for debug purposes
") logging.shutdown() main() ``` However, I realised I don't know how to change the format of log messages on a per-logger basis, since `basicConfig` is a module-level function. This code works for creating different loggers with different levels, names, etc. but is there a way to change the format of those log messages on a per-logger basis as well, in a way similar to `basicConfig`? ``` import inspect import logging def function_logger(level=logging.DEBUG): function_name = inspect.stack()[1][3] logger = logging.getLogger(function_name) logger.setLevel(level) logger.addHandler(logging.FileHandler("{0}.log".format(function_name))) return logger def f1():…

Accepted Answer

Try this

```
import logging

logger = logging.getLogger('simple_example')
logger.setLevel(logging.DEBUG)
# create file handler that logs debug and higher level messages
fh = logging.FileHandler('spam.log')
fh.setLevel(logging.DEBUG)
# create console handler with a higher log level
ch = logging.StreamHandler()
ch.setLevel(logging.ERROR)
# create formatter and add it to the handlers
formatter = logging.Formatter(
    '%(asctime)s - %(name)s - %(levelname)s - %(message)s')
ch.setFormatter(formatter)
fh.setFormatter(formatter)
# add the handlers to logger
logger.addHandler(ch)
logger.addHandler(fh)

# 'application' code
logger.debug('debug message')
logger.info('info message')
logger.warn('warn message')
logger.error('error message')
logger.critical('critical message')
```

See http://docs.python.org/howto/logging-cookbook.html#multiple-handlers-and-formatters for more information

How do I change the format of a Python log message on a per-logger basis?

Solution

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