log.py

import logging
from logging.handlers import *

import sys
class errorLogFilter(logging.Filter):
     
    def filter(self,record):
        if record.msg.startswith('error'):
            return True
        return False


logger = logging.getLogger(name='error')
logger.setLevel(logging.NOTSET)

f = errorLogFilter()

handle = logging.FileHandler('/tmp/aaa.log')
formatter = logging.Formatter('%(asctime)s %(levelname)s %(message)s')
handle.setLevel(logging.ERROR)
handle.setFormatter(formatter)
handle.addFilter(f)

debug_handler = logging.StreamHandler()
debug_handler.setLevel(logging.DEBUG)
debug_handler.setFormatter(formatter)
logger.addHandler(handle)

if sys.argv[1] == 'debug':
    logger.setLevel(logging.DEBUG)
    logger.addHandler(debug_handler)

logger.error('I am a error log')
logger.debug('I am a debug log')
logger.error('error, this will be log')