将日志记录语句放在模块级别和类级别之间有什么区别吗？

Question

module1.py

#!/usr/bin/env python
import logging
LOGGER = logging.getLogger(__main__)
class MyClass()
    def __init__(self):
        LOGGER.info('test')

Versus

module2.py

#!/usr/bin/env python
import logging
class MyClass()
    def __init__(self):
        self.LOGGER = logging.getLogger(__main__)
        self.LOGGER.info('test')

Seems to me like module2.py will give some unpredictable outcome when imported by other modules. I'm not sure though.

Answer 1

logging.getLogger() returns a singleton (per given name); there's no difference in storing it as a module global or as an instance attribute. Your code is referencing the same object in both cases.

Quoting the documentation :

Multiple calls to getLogger() with the same name will always return a reference to the same Logger object.

and from the logging.getLogger() function itself:

All calls to this function with a given name return the same logger instance. This means that logger instances never need to be passed between different parts of an application.