Python 记录器 - 具有多个级别的多个记录器实例 - 最佳实践

Question

I have the following requirements:

1. To have one global logger which you can configure (setup level, additional handlers,..)
2. To have per module logger which you can configure (setup level, additional handlers,..)

In other words we need more logs with different configuration

Therefore I did the following

1. create method to setup logger:

def setup_logger(module_name=None, level=logging.INFO, add_stdout_logger=True):

   print("Clear all loggers")
   for _handler in logging.root.handlers:
       logging.root.removeHandler(_handler)

   if add_stdout_logger:
       print("Add stdout logger")
       stdout_handler = logging.StreamHandler(sys.stdout)
       stdout_handler.setLevel(level)
       stdout_handler.setFormatter(logging.Formatter(fmt='%(asctime)-11s [%(levelname)s] [%(name)s] %(message)s'))
       logging.root.addHandler(stdout_handler)


   print("Set root level log")
   logging.root.setLevel(level)

   if module_name:
       return logging.getLogger(module_name)
   else:
       return logging.getLogger('global')

Then I create logger as following:

logger_global = setup_logger(level=logging.DEBUG)
logger_module_1 = setup_logger(module_name='module1', level=logging.INFO)
logger_module_2 = setup_logger(module_name='module2', level=logging.DEBUG)

logger_global.debug("This is global log and will be visible because it is setup to DEBUG log")

logger_module_1.debug("This is logger_module_1 log and will NOT be visible because it is setup to INFO log") 

logger_module_2.debug("This is logger_module_2 log and will be visible because it is setup to DEBUG log")

Before I will try what works and what not and test it more deeply I want to ask you if this is good practice to do it or do you have any other recommendation how to achieve our requrements?

Thanks for help

Answer 1

Finally I found how to do it:

def setup_logger(module_name=None, level=logging.INFO, add_stdout_logger=True):

   custom_logger = logging.getLogger('global')
   if module_name:
       custom_logger = logging.getLogger(module_name)     

   print("Clear all handlers in logger") # prevent multiple handler creation
   module_logger.handlers.clear()

   if add_stdout_logger:
       print("Add stdout logger")
       stdout_handler = logging.StreamHandler(sys.stdout)
       stdout_handler.setLevel(level)
       stdout_handler.setFormatter(logging.Formatter(fmt='%(asctime)-11s [%(levelname)s] [%(name)s] %(message)s'))
       module_logger.addHandler(stdout_handler)

    # here you can add another handlers ,...

    # because we use custom handlers which have the different type of log level,
    # then our logger has to have the lowest level of logging
    custom_logger.setLevel(logging.DEBUG)

   return custom_logger 

Then simply call the following

logger_module_1 = setup_logger(module_name='module1', level=logging.INFO)
logger_module_2 = setup_logger(module_name='module2', level=logging.DEBUG)

logger_module_1.debug("This is logger_module_1 log and will NOT be visible because it is setup to INFO log") 

logger_module_2.debug("This is logger_module_2 log and will be visible because it is setup to DEBUG log")