I'm trying to use the python logging module to create a RotatingFileHandler for my program. My log handler logs output to the file: /var/log/pdmd.log and the basic functionality seems to work and log output as desired.
However, I'm trying to format my log string with this format:
"%(levelname)s %(asctime)s %(funcName)s %(lineno)d %(message)s"
But only the message portion of the exception is getting logged. Here is my code to setup the logger:
#class variable declared at the beginning of the class declaration
log = logging.getLogger("PdmImportDaemon")
def logSetup(self):
FORMAT = "%(levelname)s %(asctime)s %(funcName)s %(lineno)d %(message)s"
logging.basicConfig(format=FORMAT)
#logging.basicConfig(level=logging.DEBUG)
self.log.setLevel(logging.DEBUG) #by setting our logger to the DEBUG level (lowest level) we will include all other levels by default
#setup the rotating file handler to automatically increment the log file name when the max size is reached
self.log.addHandler( logging.handlers.RotatingFileHandler('/var/log/pdmd.log', mode='a', maxBytes=50000, backupCount=5) )
Now, when I run a method and make the program output to the log with the following code:
def dirIterate( self ):
try:
raise Exception( "this is my exception, trying some cool output stuff here!")
except Exception, e:
self.log.error( e )
raise e
And the output in the pdmd.log file is just the exception text and nothing else. For some reason, the formatting is not being respected; I expected:
ERROR 2013-09-03 06:53:18,416 dirIterate 89 this is my exception, trying some cool output stuff here!
Any ideas as to why the formatting that I setup in my logging.basicConfig is not being respected?
You have to add the format to the Handler too.
When you run basicConfig(), you are configuring a new Handler for the root Logger.
In this case your custom Handler is getting no format.
Replace
self.log.addHandler( logging.handlers.RotatingFileHandler('/var/log/pdmd.log', mode='a', maxBytes=50000, backupCount=5) )
with:
rothnd = logging.handlers.RotatingFileHandler('/var/log/pdmd.log', mode='a', maxBytes=50000, backupCount=5)
rothnd.setFormatter(logging.Formatter(FORMAT))
self.log.addHandler(rothnd)
Related
I am utilizing try-except statements that utilize logging but, even though the log file is being generated, no logs are being created.
Initially my code worked, but it was incorrectly formatted for production: Try except statements that tried running scripts and, upon their failure, pushing log statements to a log.
I was told "Imports -> Functions -> Run functions" + "Functions should have try-except logging, not the other way around".
I've modified my code for this question to isolate the problem: In this code, we have a script that opens a json. The script opening the JSON works. The logging is the only issue.
Where am I going wrong?
When rearranging the code, the script still runs, excluding the logging portion.
import logging
LOG_FORMAT = "%(levelname)s %(asctime)s - %(message)s"
logging.basicConfig(filename='C:\\Users\\MWSF\\Documents\\log_test.log',
level=logging.INFO,
format=LOG_FORMAT)
logger = logging.getLogger()
def get_filepath():
'''Find the file path, which is partly defined by the file name.'''
try:
return "C:\\Users\\MWSF\\Documents\\filename.json"
except Exception:
logger.error("Error occured while determining current JSON file path.")
else:
logger.info("Successfully determined current JSON file path.")
path = get_filepath()
Intended result: A function that opens a specified file and a log named log_test.log that has this information:
INFO 2019-04-26 14:52:02,260 - Imported current JSON file.
Actual result: A function that opens a specified file and a log named log_test.log that has this information:
Put the return on the "else" clause rather than under "try". It causes the function to exit rather than doing the logging.
def get_filepath():
'''Find the file path, which is partly defined by the file name.'''
try:
#return "C:\\Users\\MWSF\\Documents\\filename.json"
path = "C:\\Users\\MWSF\\Documents\\filename.json"
except Exception:
logger.error("Error occured while determining current JSON file path.")
else:
logger.info("Successfully determined current JSON file path.")
return path
Sample log_test.log:
INFO 2019-04-29 12:58:53,329 - Successfully determined current JSON file path.
I'm using Jupyter Notebook to develop some Python. This is my first stab at logging errors and I'm having an issue where no errors are logged to my error file.
I'm using:
import logging
logger = logging.getLogger('error')
logger.propagate = False
hdlr = logging.FileHandler("error.log")
formatter = logging.Formatter('%(asctime)s %(message)s')
hdlr.setFormatter(formatter)
logger.addHandler(hdlr)
logger.setLevel(logging.DEBUG)
to create the logger.
I'm then using a try/Except block which is being called on purpose (for testing) by using a column that doesn't exist in my database:
try:
some_bad_call_to_the_database('start',group_id)
except Exception as e:
logger.exception("an error I would like to log")
print traceback.format_exc(limit=1)
and the exception is called as can be seen from my output in my notebook:
Traceback (most recent call last):
File "<ipython-input-10-ef8532b8e6e0>", line 19, in <module>
some_bad_call_to_the_database('start',group_id)
InternalError: (1054, u"Unknown column 'start_times' in 'field list'")
However, error.log is not being written to. Any thoughts would be appreciated.
try:
except Exception as e:
excep = logger.info("an error I would like to log")
for more information please look at the docs https://docs.python.org/2/library/logging.html
have a great day!
You're using logging.exception, which delegates to the root logger, instead of using logger.exception, which would use yours (and write to error.log).
I have written this piece of code to get namespace from xml document.
I am trying to handle exception, and write full trace to the log. however trace is not getting written with custom message in log (though i can see it on screen).
I believe, i am missing somthing in Logger handler config. is there any specific configuration we need to deal with? below is my logger config so far.
Any help will be appreciated.!
logger = logging.getLogger(__name__)
hdlr = logging.FileHandler(r'C:\link.log')
formatter = logging.Formatter('%(asctime)s %(levelname)s %(message)s')
hdlr.setFormatter(formatter)
logger.addHandler(hdlr)
logger.setLevel(logging.INFO)
def get_ns(xmlroot):
"""Retrieve XML Document Namespace """
try:
logger.info("Trying to get XML namespace detail")
nsmap = xmlroot.nsmap.copy()
logger.info("Creating XML Namespace Object, {0}".format(nsmap))
nsmap['xmlns'] = nsmap.pop(None)
except (KeyError, SystemExit):
logging.exception("XML files does not contain namespace, Halting Program! ")
sys.exit()
else:
for ns in nsmap.values():
logger.info("Retrieved XML Namespace {0}".format(ns))
return ns
output on screen:
ERROR:root:XML files does not contain namespace, Halting Program!
Traceback (most recent call last):
File "C:\link.log", line 28, in get_ns
nsmap['xmlns'] = nsmap.pop(None)
KeyError: None
Change
logging.exception("XML files does not contain namespace, Halting Program! ")
to
logger.exception("XML files does not contain namespace, Halting Program! ")
Since it's logger that you have configured to write to file C:\link.log.
Using logging.exception uses the "root logger", which outputs to the console by default.
I'm trying to catch a warning message, print the warning message, and then exit out of a test case with a passing state. Within the test case, I have the following code:
testcase.py:
try:
warnings.filterwarnings('error')
activeConfig(driver, url, None, None, True).confirmConfigSet()
except Warning as e:
print e.message
return
As I'm able to catch the warning without any issues, I'll only display the warning that's actually caught:
code-where-warning-is-caught.py:
.
.
.
except (Exception, NoSuchElementException, TimeoutException):
global_vars.attemptedToEnableDatabase = True
warnings.warn("\nWARNING : DATABASE PACKAGES HAVE NOT BEEN INSTALLED SO THE DATABASE CANNOT BE ENABLED.", UserWarning)
return
I can catch the warning just fine, but I keep getting the following error:
E DeprecationWarning: BaseException.message has been deprecated as of
Python 2.6
If I remove the 'e' parts of the test case code to look like...
try:
warnings.filterwarnings('error')
activeConfig(driver, url, None, None, True).confirmConfigSet()
except Warning:
return
...the test case runs EXACTLY the way I want it to, except it doesn't print the warning message. How do I catch the exception, print the warning message, and exit out of the test case with a passing state? I'm also open to any improvement ideas a more experienced coder may have.
Please take a read here. They have everything explained, you can experiment with them a bit.
https://docs.python.org/2/library/traceback.html
In my recent project, I managed to write critical only messages to a text file by doing this,
logging.basicConfig(level=logging.CRITICAL,
format = '%(asctime)s %(name)-12s %(levelname)-8s %(message)s',
datefmt = '%m-%d %H:%M',
filename = self.testResultRecord,
filemode = 'w')
lines below are my personal formatting configurations, which have nothing to do with logging level.
format = '%(asctime)s %(name)-12s %(levelname)-8s %(message)s',
datefmt = '%m-%d %H:%M',
Regards
When I have lots of different modules using the standard python logging module, the following stack trace does little to help me find out where, exactly, I had a badly formed log statement:
Traceback (most recent call last):
File "/usr/lib/python2.6/logging/__init__.py", line 768, in emit
msg = self.format(record)
File "/usr/lib/python2.6/logging/__init__.py", line 648, in format
return fmt.format(record)
File "/usr/lib/python2.6/logging/__init__.py", line 436, in format
record.message = record.getMessage()
File "/usr/lib/python2.6/logging/__init__.py", line 306, in getMessage
msg = msg % self.args
TypeError: not all arguments converted during string formatting
I'm only starting to use python's logging module, so maybe I am overlooking something obvious. I'm not sure if the stack-trace is useless because I am using greenlets, or if this is normal for the logging module, but any help would be appreciated. I'd be willing to modify the source, anything to make the logging library actually give a clue as to where the problem lies.
Rather than editing installed python code, you can also find the errors like this:
def handleError(record):
raise RuntimeError(record)
handler.handleError = handleError
where handler is one of the handlers that is giving the problem. Now when the format error occurs you'll see the location.
The logging module is designed to stop bad log messages from killing the rest of the code, so the emit method catches errors and passes them to a method handleError. The easiest thing for you to do would be to temporarily edit /usr/lib/python2.6/logging/__init__.py, and find handleError. It looks something like this:
def handleError(self, record):
"""
Handle errors which occur during an emit() call.
This method should be called from handlers when an exception is
encountered during an emit() call. If raiseExceptions is false,
exceptions get silently ignored. This is what is mostly wanted
for a logging system - most users will not care about errors in
the logging system, they are more interested in application errors.
You could, however, replace this with a custom handler if you wish.
The record which was being processed is passed in to this method.
"""
if raiseExceptions:
ei = sys.exc_info()
try:
traceback.print_exception(ei[0], ei[1], ei[2],
None, sys.stderr)
sys.stderr.write('Logged from file %s, line %s\n' % (
record.filename, record.lineno))
except IOError:
pass # see issue 5971
finally:
del ei
Now temporarily edit it. Inserting a simple raise at the start should ensure the error gets propogated up your code instead of being swallowed. Once you've fixed the problem just restore the logging code to what it was.
It's not really an answer to the question, but hopefully it will be other beginners with the logging module like me.
My problem was that I replaced all occurrences of print with logging.info ,
so a valid line like print('a',a) became logging.info('a',a) (but it should be logging.info('a %s'%a) instead.
This was also hinted in How to traceback logging errors? , but it doesn't come up in the research
Alternatively you can create a formatter of your own, but then you have to include it everywhere.
class DebugFormatter(logging.Formatter):
def format(self, record):
try:
return super(DebugFormatter, self).format(record)
except:
print "Unable to format record"
print "record.filename ", record.filename
print "record.lineno ", record.lineno
print "record.msg ", record.msg
print "record.args: ",record.args
raise
FORMAT = '%(levelname)s %(filename)s:%(lineno)d %(message)s'
formatter = DebugFormatter(FORMAT)
handler = logging.StreamHandler()
handler.setLevel(logging.DEBUG)
handler.setFormatter(formatter)
logger = logging.getLogger(__name__)
logger.setLevel(logging.DEBUG)
logger.addHandler(handler)
Had same problem
Such a Traceback arises due to the wrong format name. So while creating a format for a log file, check the format name once in python documentation: "https://docs.python.org/3/library/logging.html#formatter-objects"