Python 如何获取日志类型错误“字符串格式化期间未转换所有参数”的行号？

如果我使用内置python日志机制，并且犯了一个错误，例如：

logger.debug("The result is", result)

然后我得到一条毫无帮助的错误消息：

Traceback (most recent call last):
File "/usr/lib/python2.6/logging/__init__.py", line 760, in emit
msg = self.format(record)
File "/usr/lib/python2.6/logging/__init__.py", line 644, in format
return fmt.format(record)
File "/usr/lib/python2.6/logging/__init__.py", line 432, in format
record.message = record.getMessage()
File "/usr/lib/python2.6/logging/__init__.py", line 302, in getMessage
msg = msg % self.args
TypeError: not all arguments converted during string formatting

鉴于我有大量的日志记录语句，是否有任何方法可以获得更有用的错误消息—显示出错行号的消息？

多亏了，这很容易做到。无论在何处设置日志代码，请执行以下操作：

import logging

def handleError(self, record):
    raise
logging.Handler.handleError = handleError

堆栈跟踪中的某个地方将出现对logger.debug的错误调用。请注意警告：

请注意，仅插入这样的错误处理程序并不是您想要部署的，因为日志记录中的错误应该会引入应用程序错误。它实际上更多的是为了确保您首先获得正确的日志消息。在将此错误转储代码永久保留在应用程序中之前，请确保阅读并理解有关handleError稍后在消息线程中如何工作的注释

---

在Python的最新版本中，将打印您想要的信息。考虑下面的脚本，LogEX.PY:

使用Python 2.7运行时：

$ python logex.py
Traceback (most recent call last):
  File "/usr/lib/python2.7/logging/__init__.py", line 842, in emit
    msg = self.format(record)
  File "/usr/lib/python2.7/logging/__init__.py", line 719, in format
    return fmt.format(record)
  File "/usr/lib/python2.7/logging/__init__.py", line 464, in format
    record.message = record.getMessage()
  File "/usr/lib/python2.7/logging/__init__.py", line 328, in getMessage
    msg = msg % self.args
TypeError: not all arguments converted during string formatting
Logged from file logex.py, line 6

使用Python 3.2：

$ python3.2 logex.py
Traceback (most recent call last):
  File "/usr/lib/python3.2/logging/__init__.py", line 937, in emit
    msg = self.format(record)
  File "/usr/lib/python3.2/logging/__init__.py", line 812, in format
    return fmt.format(record)
  File "/usr/lib/python3.2/logging/__init__.py", line 551, in format
    record.message = record.getMessage()
  File "/usr/lib/python3.2/logging/__init__.py", line 319, in getMessage
    msg = msg % self.args
TypeError: not all arguments converted during string formatting
Logged from file logex.py, line 6

---

因此，除非您使用的是较旧版本的Python，否则您不应该像Claudiu的回答中建议的那样使用任何技巧。

哦，我不知道！是的，我正在使用Python 2.6。

$ python3.2 logex.py
Traceback (most recent call last):
  File "/usr/lib/python3.2/logging/__init__.py", line 937, in emit
    msg = self.format(record)
  File "/usr/lib/python3.2/logging/__init__.py", line 812, in format
    return fmt.format(record)
  File "/usr/lib/python3.2/logging/__init__.py", line 551, in format
    record.message = record.getMessage()
  File "/usr/lib/python3.2/logging/__init__.py", line 319, in getMessage
    msg = msg % self.args
TypeError: not all arguments converted during string formatting
Logged from file logex.py, line 6