如何在python中优雅地记录多个非常相似的事件？

您应该编写消息聚合/统计类而不是尝试挂钩日志系统的单例,但我想您可能有一个使用日志记录的现有代码库.

我还建议你应该实例化你的记录器,而不是总是使用默认的root.在Python记录食谱具有广泛的解释和例子.

以下课程应该按照你的要求做.

import logging
import atexit
import pprint

class Aggregator(object):
    logs = {}

    @classmethod
    def _aggregate(cls, record):
        id = '{0[levelname]}:{0[name]}:{0[msg]}'.format(record.__dict__)
        if id not in cls.logs: # first occurrence
            cls.logs[id] = [1, record]
        else: # subsequent occurrence
            cls.logs[id][0] += 1

    @classmethod
    def _output(cls):
        for count, record in cls.logs.values():
            record.__dict__['msg'] += ' (occured {} times)'.format(count)
            logging.getLogger(record.__dict__['name']).handle(record)

    @staticmethod
    def filter(record):
        # pprint.pprint(record)
        Aggregator._aggregate(record)
        return False

    @staticmethod
    def exit():
        Aggregator._output()



logging.getLogger().addFilter(Aggregator)
atexit.register(Aggregator.exit)

for i in range(99999): 
    try:
        asdf[i]   # not defined!
    except NameError:
        logging.exception('foo') # generates large number of logging events
    else: pass

# ... more code with more logging ...
for i in range(88888): logging.error('more of the same')

# ... and so on ...    

请注意,在程序退出之前,您不会获得任何日志.

运行它的结果是:

    ERROR:root:foo (occured 99999 times)
    Traceback (most recent call last):
      File "C:\work\VEMS\python\logcount.py", line 38, in 
        asdf[i]   # not defined!
    NameError: name 'asdf' is not defined
    ERROR:root:more of the same (occured 88888 times)