I’m trying to run a simple python script that writes data from a subprocess to my log file using my class logger.

I’ve got the following right now, which does works:

import logging
from itertools import repeat

from multiprocessing import Process, Pool, Queue, cpu_count
from multiprocessing.managers import BaseManager, NamespaceProxy


class SharedObj:
    def __init__(self):
        self.attr1 = 0

class SharedProxy(NamespaceProxy):
    _exposed_ = ("__getattribute__", "__setattr__", "__delattr__")


class QueueManager(BaseManager):
    BaseManager.register("Queue", Queue)
    BaseManager.register("SharedObj", SharedObj, SharedProxy)

class Main:
    def __init__(self):
        self.logger = logging.getLogger(__name__)

    def _loggingSubprocess(self, queue):
        while True:
            try:
                logData = queue.get()
                if logData is None:
                    break
            except EOFError:
                break
            queuedLogger = getattr(self.logger, logData[1])

            queuedLogger(logData[0])

    def _subProc(self, iterNum, sharedObj, queue):
        queue.put((f"In subproc {iterNum}", "debug"))
        sharedObj.attr1 += iterNum

    def run(self):
        with QueueManager() as manager:
            queue = manager.Queue()
            shObj = manager.SharedObj()
            _ = Process(target=self._loggingSubprocess, args=(queue,)).start()
            

            pool = Pool(processes=cpu_count() - 2)
            pool.starmap(
                self._subProc,
                zip(
                    range(10),
                    repeat(shObj),
                    repeat(queue),
                )
            )



def setupLogger():
    logConfig = {   
        "format": "%(asctime)s %(filename)s->%(funcName)s():%(lineno)s %(levelname)s: %(message)s",
        "datefmt": "%m/%d/%Y %I:%M:%S",
        "encoding": "utf-8",
        "loglevel": "DEBUG",
        "warnings": True
    }

    logLevels = {
        "CRITICAL": logging.CRITICAL,
        "DEBUG": logging.DEBUG,
        "ERROR": logging.ERROR,
        "INFO": logging.INFO,
        "WARNING": logging.WARNING,
    }

    logging.basicConfig(
            filename="logs/logFile.log",
            format=logConfig["format"],
            datefmt=logConfig["datefmt"],
            encoding=logConfig["encoding"],
            level=logLevels[logConfig["loglevel"]],
        )

    logging.captureWarnings(logConfig["warnings"])
    
setupLogger()
if __name__ == "__main__":
    
    Main().run()

but if I move the setupLogger() call to inside the __main__ namescape it no longer works correctly.

if __name__ == "__main__":
    setupLogger()
    Main().run()

Why can’t the setupLogger call happen inside __main__?