如何在Python日志记录中格式化异常堆栈跟踪?

问题描述

我在Python中创建的日志旨在临时存储为文件，这些文件又将被处理成日志数据库.他们采用管道描述的格式来指示如何处理日志，但是logging.exception()通过添加太多字段和太多换行符来破坏我的标准.

The logs I am creating in Python are intended to be temporarily stored as files which will, in turn, be processed into a log database. They take a pipe-delineated format to dictate how the logs will be processed, but logging.exception() is breaking my standard by adding one too many fields and way too many newlines.

import logging
logging.basicConfig(filename='output.txt',
                    format='%(asctime)s|%(levelname)s|%(message)s|',
                    datefmt='%m/%d/%Y %I:%M:%S %p',
                    level=logging.DEBUG)
logging.info('Sample message')

try:
    x = 1 / 0
except ZeroDivisionError as e:
    logging.exception('ZeroDivisionError: {0}'.format(e))

# output.txt
01/27/2015 02:09:01 PM|INFO|Sample message|
01/27/2015 02:09:01 PM|ERROR|ZeroDivisionError: integer division or modulo by zero|
Traceback (most recent call last):
  File "C:\Users\matr06586\Desktop\ETLstage\Python\blahblah.py", line 90, in <module>
    x = 1 / 0
ZeroDivisionError: integer division or modulo by zero

如何最好地使用空白和换行符来处理或格式化回溯?这些消息是，但是当我尝试记录异常实例时，绕过该功能感到很奇怪.如何记录我的回溯并设置其格式?应该忽略回溯吗?

How can I best handle or format tracebacks with the whitespace and newlines? These messages are part and parcel in logging.exception(), but it feels odd to circumvent the function when I am attempting to document instances of exceptions. How do I record my tracebacks and format them too? Should the tracebacks be ignored?

谢谢您的时间！

推荐答案

您可以定义自己的Formatter，您可以重写其方法以完全按照所需的格式格式化异常信息.这是一个简单(但可行)的示例:

You can define your own Formatter whose methods you can override to format exception information exactly how you want it. Here is a simplistic (but working) example:

import logging

class OneLineExceptionFormatter(logging.Formatter):
    def formatException(self, exc_info):
        result = super(OneLineExceptionFormatter, self).formatException(exc_info)
        return repr(result) # or format into one line however you want to

    def format(self, record):
        s = super(OneLineExceptionFormatter, self).format(record)
        if record.exc_text:
            s = s.replace('\n', '') + '|'
        return s

fh = logging.FileHandler('output.txt', 'w')
f = OneLineExceptionFormatter('%(asctime)s|%(levelname)s|%(message)s|', '%m/%d/%Y %I:%M:%S %p')
fh.setFormatter(f)
root = logging.getLogger()
root.setLevel(logging.DEBUG)
root.addHandler(fh)
logging.info('Sample message')

try:
    x = 1 / 0
except ZeroDivisionError as e:
    logging.exception('ZeroDivisionError: {0}'.format(e))

这仅产生两行:

01/28/2015 07:28:27 AM|INFO|Sample message|
01/28/2015 07:28:27 AM|ERROR|ZeroDivisionError: integer division or modulo by zero|'Traceback (most recent call last):\n  File "logtest2.py", line 23, in <module>\n    x = 1 / 0\nZeroDivisionError: integer division or modulo by zero'|

当然，您可以在此示例的基础上进行精确的操作，例如通过traceback模块.

Of course, you can build on this example to do precisely what you want, e.g. via the traceback module.

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