Python日志：仅记录到处理器而不记录到根日志

Question

我有一个这样的类：

class Log(object):

# class new
#new is used instead of init because __new__ is able to return (where __init__ can't)
def __new__(self, name, consolelevel, filelevel):

    formatter = logging.Formatter('%(asctime)s %(levelname)s: %(name)s: %(message)s')

    #Create consolehandler and set formatting (level is set in the ROOT)
    consolehandler = StreamHandler()
    consolehandler.setFormatter(formatter)

    #Create filehandler, set level and set formatting
    filehandler = FileHandler(name + '.log')
    filehandler.setLevel(filelevel)
    filehandler.setFormatter(formatter)

    #Create the root logger, add console and file logger. Set the rootlevel == consolelevel.
    self.root = logging.getLogger(name)

    #causing me problems....
    self.root.setLevel(consolelevel)

    self.root.addHandler(consolehandler)
    self.root.addHandler(filehandler)
    self.root.propagate = True

    return self.root

# Close the logger object
def close():
    # to be implemented
    pass

我用这个类来记录信息到控制台和文件（根据设置的级别来决定）。问题是，根级别似乎对添加处理程序有影响。有没有办法禁用这个功能？现在我把根级别设置成和控制台级别一样，但这样做并没有效果……

有什么建议吗？

提前感谢，祝好，

JR

Answer 1

这是我正在制作的模块的简化版本。这个模块里有几个类，它们都需要记录日志的功能。每个类都记录到不同的文件里，而且还应该可以在类之间改变文件处理器的级别（比如，游戏手柄类用console.debug和filehandler.info，而MQTT类用console info和filehandler.debug）。

因此，我觉得设置一个日志类是最简单的方法。请记住，我通常做电子产品，现在是结合了Python，所以我的技能还比较基础……

#!/bin/env python2.7

from future import division from operator import * import logging from logging import FileHandler from logging import StreamHandler import pygame import threading from pygame.locals import * import mosquitto import time from time import sleep import sys

class ConsoleFileLogger(object):

# class constructor
def __init__(self, filename, loggername, rootlevel, consolelevel, filelevel):

    # logger levels: DEBUG, INFO, WARNING, ERROR, CRITICAL

    # define a root logger and set its ROOT logging level
    logger = logging.getLogger(loggername)
    logger.setLevel(rootlevel)

    # define a Handler which writes messages or higher to the sys.stderr (Console)
    self.console = logging.StreamHandler()
    # set the logging level
    self.console.setLevel(consolelevel)

    # define a Handler which writes messages to a logfile
    self.logfile = logging.FileHandler(filename + '.log')
    # set the logging level
    self.logfile.setLevel(filelevel)

    # create formatter and add it to the handlers
    formatter = logging.Formatter('%(asctime)s %(levelname)s: %(name)s: %(message)s')
    self.console.setFormatter(formatter)
    self.logfile.setFormatter(formatter)

    # add the handlers to the root logger
    logger.addHandler(self.console)
    logger.addHandler(self.logfile)

    self._logger = logger

# set a net instance of the logger
def set(self):
    return self._logger

# Stop and remove the ConsoleFileLogger object
def remove(self):
    self._logger.removeHandler(self.console)
    self._logger.removeHandler(self.logfile)
    self._logfile.FileHandler().close()

class Gamepad():

# class constructor
def __init__(self, mqttgamepad):
    self.logger = ConsoleFileLogger('BaseLogFiles/Gamepad', 'Gamepad', logging.INFO, logging.INFO, logging.INFO).set()

    if joystickcount == 0:
        self.logger.error('No gamepad connected')
    elif joystickcount == 1:
        self.gamepad = pygame.joystick.Joystick(0)
        self.gamepad.init()
        self.logger.debug('Joystick name %s', self.gamepad.get_name())
        self.logger.debug('nb of axes = %s', self.gamepad.get_numaxes())
        self.logger.debug('nb of balls = %s', self.gamepad.get_numballs())
        self.logger.debug('nb of buttons = %s', self.gamepad.get_numbuttons())
        self.logger.debug('nb of mini joysticks = %s', self.gamepad.get_numhats())
    elif joystickcount > 1:
        self.logger.error('only one gamepad is allowed')

def run(self):
    self.logger.debug('gamepad running')

class MQTTClient():

def __init__(self, clientname):
    self.logger = ConsoleFileLogger('BaseLogFiles/MQTT/Pub', clientname, logging.DEBUG, logging.DEBUG, logging.DEBUG).set()
    self.logger.debug('test')

def run(self):
       self.logger.info('Connection MQTT Sub OK')

def main(): logger = ConsoleFileLogger('BaseLogFiles/logControlCenterMain', 'ControlCenterMain', logging.DEBUG, logging.DEBUG, logging.DEBUG).set()

mqttclient = MQTTClient("MQTTClient")
mqttclient.connect()

gamepad = Gamepad(mqttclient)

if gamepad.initialized():
    gamepadthread = threading.Thread(target=gamepad.run)
    gamepadthread.start()

    mqtttpubhread = threading.Thread(target=mqttclient.run)
    mqtttpubhread.start()

logger.info('BaseMain started')

# Monitor the running program for a KeyboardInterrupt exception
# If this is the case all threads and other methods can be closed the correct way :)
while 1:
    try:
        sleep(1)
    except KeyboardInterrupt:
        logger.info('Ctrl-C pressed')
        gamepad.stop()
        mqttclient.stop()
        logger.info('BaseMain stopped')
        sys.exit(0)

if name == 'main': main()

Answer 2

我看到你代码中的一个问题是，每次你创建一个 Log 类的实例时，它都会添加更多的处理器。你可能并不想这样。

记住，getLogger 在用相同的参数调用时总是返回同一个实例，这基本上实现了单例模式。所以当你后面调用 addHandler 时，每次都会添加一个新的处理器。

处理 logging 的正确方式是，在模块级别创建一个记录器并使用它。

另外，我建议你不要使用 __new__。在你的情况下，可以用一个简单的函数来代替。而且要注意，你的 Log.close 方法不会起作用，因为你的 __new__ 方法没有返回一个 Log 实例，因此返回的记录器没有这个方法。

关于记录器的级别，我不明白为什么你不在 consolehandler 上设置级别，而是在整个记录器上设置。