I wrote some code to handle and log exceptions in my application.
It works well, but it produces double output for each exception.
How can I fix this?
Here's the pared-down code:
----- main.py
import exceptionLogger
import doStuff
exlog = exceptionLogger.exceptionLogger()
stuff = doStuff.doStuff()
try:
stuff.doit()
except Exception,msg:
exlog.logException()
----- exceptionLogger.py
import traceback
import logging
import os
class exceptionLogger:
loggingLevel = ""
logger = None
def __init__(self):
self.logger = logging.getLogger("foo")
self.loggingLevel = "DEBUG"
if self.loggingLevel == "DEBUG":
self.logger.setLevel(logging.DEBUG)
handler = logging.FileHandler("error.txt")
format = "%(asctime)s %(levelname)-8s %(message)s"
formatter = logging.Formatter(format)
handler.setFormatter(formatter)
self.logger.addHandler(handler)
def logMsg(self,message):
try:
if self.loggingLevel == "DEBUG":
self.logger.debug(message)
except:
self.stopLogging()
def logException(self):
"""Write an exception traceback to the logfile."""
# save the stack trace to a file and then copy the contents of that
# file to the log. (traceback.format_exc would allow us to avoid
# using a temporary file, but it is not available in python 2.3)
TMPFILE = os.tmpfile()
traceback.print_exc(None, TMPFILE)
TMPFILE.flush()
self.logMsg(" ************** EXCEPTION BEGINS **************")
self.logMsgFromFile(TMPFILE)
self.logMsg(" ************** EXCEPTION ENDS **************")
TMPFILE.close()
def logMsgFromFile(self,file):
"""Read the contents of a file into a string and log the string."""
file.seek(0)
msg = ""
for line in file:
msg = msg + line
self.logMsg(msg)
def stopLogging(self):
logging.shutdown()
----- doStuff.py
import exceptionLogger
class doStuff:
def doit(self):
exlog = exceptionLogger.exceptionLogger()
try:
raise ValueError, "hi there"
except Exception:
exlog.logException()
And here's the contents of error.txt:
----- errror.txt
2009-09-24 14:22:23,288 DEBUG ************** EXCEPTION BEGINS **************
2009-09-24 14:22:23,288 DEBUG ************** EXCEPTION BEGINS **************
2009-09-24 14:22:23,288 DEBUG Traceback (most recent call last):
File "/home/gordonj/exception/doStuff.py", line 8, in doit
raise ValueError, "hi there"
ValueError: hi there
2009-09-24 14:22:23,288 DEBUG Traceback (most recent call last):
File "/home/gordonj/exception/doStuff.py", line 8, in doit
raise ValueError, "hi there"
ValueError: hi there
2009-09-24 14:22:23,288 DEBUG ************** EXCEPTION ENDS **************
2009-09-24 14:22:23,288 DEBUG ************** EXCEPTION ENDS **************
As you can see, all of the output is doubled. Header lines, footer lines,
and body text.
Why is this happening? I suspect it's because I'm declaring two instances
of the exceptionLogger class, which ends up calling logger.addHandler()
twice. Is that right?
What would be a better way to handle this?
Thanks.
--
John Gordon A is for Amy, who fell down the stairs
gor...@panix.com B is for Basil, assaulted by bears
-- Edward Gorey, "The Gashlycrumb Tinies"
--
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