CODEWITHSUNDEEP
pythonloggingpython-2.7timerotation
demorphica
demorphica

Reputation: 123

class based on timerotatingfilehandler does not write anything in logs

I wrote this from help from the logging cookbook here this code was supposed to write a line for each "device". It creates the log files, but nothing is written inside.

#!/usr/bin/env python

from __future__ import unicode_literals

import json
import logging
import glob
import logging.handlers

# This next bit is to ensure the script runs unchanged on 2.x and 3.x
try:
    unicode
except NameError:
    unicode = str

class LogWriter:
    Name = 'LogWriter'
    def __init__(self, Device_ID, Severity, Message):
        self.id = Device_ID
        self.severity = Severity
        self.message = Message
        self.logfile = './log/log_'+self.id+'.log'

    def log(self):
        # Set up a specific logger with our desired output level
        logwriter = logging.getLogger('LogWriter')
        logwriter.setLevel(logging.INFO)

        # Add the log message handlers to the logger
        timedRotatingLogFileHandler = logging.handlers.TimedRotatingFileHandler(self.logfile, when = 'midnight', backupCount=2)
        #setup formatting
        formatter = logging.Formatter('%(asctime)s %(processName)-10s %(name)s %(levelname)-8s %(message)s')
        timedRotatingLogFileHandler.setFormatter(formatter)
        logwriter.addHandler(timedRotatingLogFileHandler)

        try:
            logging.info(self.message, self.severity)
        except:
            return 1
        return 0

def main():
    for i in range(20):
        logger = LogWriter(str(i), 'INFO', 'hello'+str(i))
        logger.log()


if __name__ == '__main__':
    main()

Can anyone tell me why this is not working please?

Upvotes: 1

Views: 136

Answers (2)

demorphica
demorphica

Reputation: 123

Both cox and Vinay were correct, but no explicit solution was provided. cox's solution didn't fully work because his suggested definition would hard code the severity not allowing modification by the calls

so I'm no longer passing the device_ID, severity and message to the class, but directly to the log() function

This was the easiest way i got this done. 

a = getattr(logwriter, severity) 
a(message)

replacing

logging.info(self.message, self.severity)

Best practices are to not create handlers inside the class definition as Vinay said. The solution i found for that is to define a separate logger module, attach the handlers outside the class definition in the module, create the new logger only once in the calling program, and then each new logger request can log to a child log as explained in the logging cookbook.

Upvotes: 0

Vinay Sajip
Vinay Sajip

Reputation: 99365

You're adding a handler to the 'LogWriter' logger, but logging to the root logger, which has no handlers added to it.

It's not good practice to add handlers and set levels except just once from a if __name__ == '__main__' clause, it's not really clear from your posted code whether you're following the right practice.

Upvotes: 1

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