python - 如何使用运算符(operator)进行logging.debug？

Question

我一直在尝试停止使用打印语句进行调试并开始使用logging.debug。我可以在打印中使用运算符，但日志记录似乎没有做同样的事情。

例如，这有效

print('Is between now and then:    ', solar_noon < now < solarnoonplustimeunit )

这这不是。

logger.debug('Is between now and then:    ', solar_noon < now < solarnoonplustimeunit )

后者说:

Traceback (most recent call last):
  File "/usr/lib/python2.7/logging/__init__.py", line 859, in emit
    msg = self.format(record)
  File "/usr/lib/python2.7/logging/__init__.py", line 732, in format
    return fmt.format(record)
  File "/usr/lib/python2.7/logging/__init__.py", line 471, in format
    record.message = record.getMessage()
  File "/usr/lib/python2.7/logging/__init__.py", line 335, in getMessage
    msg = msg % self.args
TypeError: not all arguments converted during string formatting

我应该如何使用日志记录进行运算符(operator)测试？

Answer 1

日志记录模块方法期望第一个参数是格式字符串，并且以下参数属于该格式字符串:logger.debug(fmt_str, arg1,....)。但是您的字符串没有任何迹象表明后面有更多元素。

即logger.debug 函数最终会尝试做这样的事情:

fmt_str % (arg1, arg2, ...)

尝试仅添加格式 str %s:

logger.debug('Is between now and then:    %s', solar_noon < now < solarnoonplustimeunit )

编辑:为什么原始字符串适用于print:

根据docs :

print(*objects, sep=' ', end='\n', file=sys.stdout)

Print objects to the stream file, separated by sep and followed by end. sep, end and file, if present, must be given as keyword arguments.

All non-keyword arguments are converted to strings like str() does and written to the stream, separated by sep and followed by end. Both sep and end must be strings; they can also be None, which means to use the default values. If no objects are given, print() will just write end.

由于默认的 sep 是一个空格，Python 只是将字符串和 bool 值的字符串表示形式混合在一起，并用空格分隔它们。