Python Logging with a common logger class mixin and class inheritance

Question

I would like to create a Python logging class that can be inherited as a common means of logging configuration, yet seperately control the logging level of the base class from t

Answer 1

A metaclass would be more appropriate. When a class is defined it will get its own logger. Name mangling ensures each class uses its own logger.

import logging
import sys

logging.basicConfig(stream=sys.stdout)

class MetaBase(type):
    def __init__(cls, *args):
        super().__init__(*args)

        # Explicit name mangling
        logger_attribute_name = '_' + cls.__name__ + '__logger'

        # Logger name derived accounting for inheritance for the bonus marks
        logger_name = '.'.join([c.__name__ for c in cls.mro()[-2::-1]])

        setattr(cls, logger_attribute_name, logging.getLogger(logger_name))

class Base(metaclass=MetaBase):
    def __init__(self):
        self.__logger.error('init base')

    def func_base(self):
        self.__logger.error('func base')

class Parent(Base):
    def func_parent(self):
        self.__logger.error('func parent')

p = Parent()
p.func_base()
p.func_parent()

Results in:

ERROR:Base:init base
ERROR:Base:func base
ERROR:Base.Parent:func parent

This approach has a few additional benifites over mix in.

• The logger for each class is created at class definition and accessed via a direct attribute reference. Avoids property and getLogger call
• Subclasses only need to inherit base, no need to remember to add MixIn

I've simplified the example to demonstrate the key concept. Should work across files and with a config file.