python & django logging 小結

[TOC]

python

基本

一次配置,多處生效

          
            import logging
logging.basicConfig(format='%(asctime)s %(message)s', datefmt='%m/%d/%Y %I:%M:%S %p')
logging.warning('is when this event was logged.')

>>>12/12/2010 11:46:36 AM is when this event was logged.
          
        

高級

• log_record

  filters會用到,一個和log信息有關的對象

• loggers

  接口,被應用層(我們開發者)調用的

• handlers

  寫文件的,掛在logger上

• filters

  過濾文本的, 可以給logger用,也可以給handler用

• formatters

  定義log的格式, 給handler用

formatter

• fmt

  message的格式

• datefmt

  時間格式

• style

  分隔符

  • %(asctime)s - %(levelname)s - %(message)s
  • &(asctime)s - &(levelname)s - &(message)s

例子

my_formater = logging.Formatter(fmt='%(asctime)s - %(levelname)s - %(message)s', datefmt='%m/%d/%Y %I:%M:%S %p', style='%')

詳細參數

源碼里面有,也可以看文檔

filter

• 返回True或者False
• False將會被過濾
• 可以是一個類,也可以是函數.
• 建議用類的形式, 因為帶name,將來想remove filter更方便

• Filter類長這樣

                
                  class Filter(object):
      def __init__(self, name=''):
          self.name = name
          self.nlen = len(name)
      def filter(self, record):
          return True
                
              

• 函數

                
                  def my_filter(record):
      return False
                
              

handler

• logging模塊提供了很多handler.
• logging.StreamHandler(sys.stdout) 和 logging.RotatingFileHandler 常見
• handler.addFilter()
• handler.setFormatter()
• my_handler.setLevel()

logger

• 定義logger

  logger = logging.getLogger('666')

• set level

  logger.setLevel(logging.DEBUG)

• logger.addFilter()
• logger.addHandler()
• logger.info('message')

例子

          
            import logging
logger = logging.getLogger('spam_application')
logger.setLevel(logging.DEBUG)
my_handler = logging.StreamHandler()
my_handler.setLevel(logging.DEBUG)
formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
my_handler.setFormatter(formatter)
logger.addHandler(my_handler)
logger.info('creating an instance of auxiliary_module.Auxiliary')
>>> 2019-07-03 16:02:30,952 - spam_application - INFO - creating an instance of auxiliary_module.Auxiliary
my_filter = lambda record: True
my_handler.addFilter(my_filter)
logger.info('creating an instance of auxiliary_module.Auxiliary')
>>> 2019-07-03 16:03:06,858 - spam_application - INFO - creating an instance of auxiliary_module.Auxiliary
my_filter = lambda record: False
my_handler.addFilter(my_filter)
logger.info('creating an instance of auxiliary_module.Auxiliary')
          
        

配置日志記錄

三種方式

1. 像上面用方法配置

2. dict

                 
                   LOGGING = {
       'version': 1,
       'disable_existing_loggers': True,
       'formatters': {
           'standard': {
               'format': '[%(asctime)s][%(filename)s] - %(funcName)s[line:%(lineno)d] - [%(levelname)s]: %(message)s'
           },
       },
       'filters': {
       },
       'handlers': {
           'security_log': {
               'level': 'DEBUG',
               'class': 'logging.handlers.RotatingFileHandler',
               'filename': os.path.join(cf['log']['path'], 'security_log.log'),
               'maxBytes': 1024 * 1024 * 10,
               'backupCount': 10,
               'formatter': 'standard',
           },
           'event_log': {
               'level': 'DEBUG',
               'class': 'logging.handlers.RotatingFileHandler',
               'filename': os.path.join(cf['log']['path'], 'event_log.log'),
               'maxBytes': 1024 * 1024 * 10,
               'backupCount': 10,
               'formatter': 'standard',
           },
           'console': {
               'level': 'ERROR',
               'class': 'logging.StreamHandler',
               'formatter': 'standard'
           },
       },
       'loggers': {
           'eventLog': {
               'handlers': ['event_log', 'console'],
               'level': 'DEBUG',
               'propagate': False
           },
           'security': {
               'handlers': ['security_log', 'console', 'security_db'],
               'level': 'DEBUG',
               'propagate': False
           },
           'system': {
               'handlers': ['system_log', 'console', 'system_db'],
               'level': 'DEBUG',
               'propagate': False
           },
       }
   }
                 
               

3. file

   略

django

django默認使用dict方式.

logging_settings == settings.LOGGING

logging_config == logging.config.dictConfig

          
            def configure_logging(logging_config, logging_settings):
    if logging_config:
        # First find the logging configuration function ...
        logging_config_func = import_string(logging_config)

        logging.config.dictConfig(DEFAULT_LOGGING)

        # ... then invoke it with the logging settings
        if logging_settings:
            logging_config_func(logging_settings)
          
        

例子

理想情況下,如果在settings中配置了LOGGING,直接使用即可.

          
            # import the logging library
import logging

# Get an instance of a logger
logger = logging.getLogger(__name__)

def my_view(request, arg1, arg):
    ...
    if bad_mojo:
        # Log an error message
        logger.error('Something went wrong!')
          
        

最佳實踐

1. disable_existing_loggers == False

   django本身是有一個logging配置的,這里有一個標志位去決定是否需要取消掉.

2. 靈活運用 propagate 和 logging.getLogger(__name__)

   通過 . 找父親.

   'a.b' 是 ‘a.b.c’的父親. ‘a.b’是logger name