[issue1295] logging records cache the result of formatException()
Vinay Sajip added the comment: I've updated the docs (Formatter.format) to mention the caching and its effect on multiple formatters. -- nosy: +vsajip __ Tracker [EMAIL PROTECTED] http://bugs.python.org/issue1295 __ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1295] logging records cache the result of formatException()
New submission from Thomas Heller: I needed two logging handlers in my application, one notifiying the user of errors, the other writing errors to a logfile. So I created a custom subclass of logging.Formatter and redefined the formatException() method that returned a summary of the exception like 'ZeroDivisionError' instead of the full traceback. Unfortunately the logging record caches the result of the handler.formatException() call in the exc_text variable, and the formatException() method of the second handler isn't called at all. The attached patch removes the caching and fixes the problem. -- components: Library (Lib) files: logging.patch keywords: patch messages: 56525 nosy: theller severity: normal status: open title: logging records cache the result of formatException() type: behavior versions: Python 2.4, Python 2.5, Python 2.6, Python 3.0 Added file: http://bugs.python.org/file8563/logging.patch __ Tracker [EMAIL PROTECTED] http://bugs.python.org/issue1295 __Index: Lib/logging/__init__.py === --- Lib/logging/__init__.py (revision 58033) +++ Lib/logging/__init__.py (working copy) @@ -247,7 +247,6 @@ self.filename = pathname self.module = Unknown module self.exc_info = exc_info -self.exc_text = None # used to cache the traceback text self.lineno = lineno self.funcName = func self.created = ct @@ -420,14 +419,10 @@ record.asctime = self.formatTime(record, self.datefmt) s = self._fmt % record.__dict__ if record.exc_info: -# Cache the traceback text to avoid converting it multiple times -# (it's constant anyway) -if not record.exc_text: -record.exc_text = self.formatException(record.exc_info) -if record.exc_text: +exc_text = self.formatException(record.exc_info) if s[-1:] != \n: s = s + \n -s = s + record.exc_text +s = s + exc_text return s # ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1295] logging records cache the result of formatException()
Guido van Rossum added the comment: This is tough. On the one hand you are right that different classes that have different formatException() methods aren't treated correctly; on the other hand I think the caching is important for other cases where there are multiple loggers all using the default formatException(). I recommend that instead of getting rid of the cache, you fix your class by overriding format() to reset record.ex c_text and then calling the base class format() method. -- nosy: +gvanrossum __ Tracker [EMAIL PROTECTED] http://bugs.python.org/issue1295 __ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1295] logging records cache the result of formatException()
Thomas Heller added the comment: This is tough. On the one hand you are right that different classes that have different formatException() methods aren't treated correctly; on the other hand I think the caching is important for other cases where there are multiple loggers all using the default formatException(). I recommend that instead of getting rid of the cache, you fix your class by overriding format() to reset record.ex c_text and then calling the base class format() method. That is what I have been doing although I think that I have to reset record.exc_text also AFTER the call to format() for the following handlers, if any. So, should this issue be closed as 'wont fix' ? __ Tracker [EMAIL PROTECTED] http://bugs.python.org/issue1295 __ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1295] logging records cache the result of formatException()
Thomas Heller added the comment: I think that a warning or an example in the docs would be nice, but I have no time to make a patch for that. -- resolution: - wont fix status: open - closed __ Tracker [EMAIL PROTECTED] http://bugs.python.org/issue1295 __ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1295] logging records cache the result of formatException()
Guido van Rossum added the comment: I think so. On 10/18/07, Thomas Heller [EMAIL PROTECTED] wrote: Thomas Heller added the comment: This is tough. On the one hand you are right that different classes that have different formatException() methods aren't treated correctly; on the other hand I think the caching is important for other cases where there are multiple loggers all using the default formatException(). I recommend that instead of getting rid of the cache, you fix your class by overriding format() to reset record.ex c_text and then calling the base class format() method. That is what I have been doing although I think that I have to reset record.exc_text also AFTER the call to format() for the following handlers, if any. So, should this issue be closed as 'wont fix' ? __ Tracker [EMAIL PROTECTED] http://bugs.python.org/issue1295 __ __ Tracker [EMAIL PROTECTED] http://bugs.python.org/issue1295 __ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
