如何使用不同的类和导入即时使用Python登录更改文件句柄

Question

我无法即时执行日志文件处理更改。

例如我有3个班级

one.py

import logging
class One():
    def __init__(self,txt="?"):
        logging.debug("Hey, I'm the class One and I say: %s" % txt)

two.py

import logging
class Two():
    def __init__(self,txt="?"):
        logging.debug("Hey, I'm the class Two and I say: %s" % txt)

config.py

import logging
class Config():
    def __init__(self,logfile=None):
        logging.debug("Reading config")
        self.logfile(logfile)

myapp

from one import One
from two import Two
from config import Config
import logging

#Set default logging
logging.basicConfig( 
    level=logging.getLevelName(DEBUG), 
    format='%(asctime)s - %(name)s - %(levelname)s - %(message)s',
    filename=None
)

logging.info("Starting with stdout")

o=One(txt="STDOUT")
c=Config(logfile="/tmp/logfile")

# Here must be the code that change the logging configuration and set the filehandler

t=One(txt="This must be on the file, not STDOUT")

如果我再试loggin.basicConfig()一次，那是行不通的。

Answer 1

实际上，如果已经设置了处理程序，logging.basicConfig则 什么也不 做：

如果根记录器已经为其配置了处理程序，则此功能不执行任何操作。

您需要 替换 根记录器上的当前处理程序：

    import logging

    fileh = logging.FileHandler('/tmp/logfile', 'a')
    formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
    fileh.setFormatter(formatter)

    log = logging.getLogger()  # root logger
    for hdlr in log.handlers[:]:  # remove all old handlers
        log.removeHandler(hdlr)
    log.addHandler(fileh)      # set the new handler

请参阅“
Python日志记录”操作指南中的“配置日志记录”一章。