Logging as the caller module in Python

Question

I have the following application structure:

./utils.py
def do_something(logger=None):
    if not logger:
        logger = logging.getLogger(__name__)

    print(         


        

Answer 1

Passing the logger as an argument looks fine to me. But if you have many calls to do_something then passing the same logger in each call is not only too verbose but prone to errors --you might pass the wrong logger by mistake. Also, while you do need to make do_something aware of the logger, doing it at the point where you are calling it probably does not make sense --you want to do something, not mess with loggers. OOP to the rescue: make do_something a method of a class and pass the logger when instantiating the class, then you do not need to pass it to the method.

# utils.py
class UsefulObject:
    def __init__(self, logger):
        self._logger = logger

    def do_something(self):
        print('hello')
        self._logger.debug('test')

Now in the client module you create an instance of UsefulObject and you can call .do_something on it without passing the logger every time.

# one.py
from utils import UsefulObject
logger = logging.getLogger(__name__)
useful_object = UsefulObject(logger)  # do this once
# ...
useful_object.do_something()  # do this many times, do not pass the logger