How to create daily log folder in python logging

Question

I want to make the log file output into daily folder in python.

I can make the log path in hander like "../myapp/logs/20150514/xx.log" through current date. But the problem is that the log path doesn't change when the date changes.

I create the log instance while i start my long-running python script xx.py, and now the instance's log path is "../myapp/logs/20150514/xx.log". But on tomorrow, as the instance is not changed, so its path is still "../myapp/logs/20150514/xx.log" which should be "../myapp/logs/20150515/xx.log".

How can i make the log output into daily folder?

My get log instance codes:

import os
import utils
import logging
from logging.handlers import RotatingFileHandler
import datetime

def getInstance(file=None):
    global logMap
    if file is None:
        file = 'other/default.log'
    else:
        file = file + '.log'
    if(logMap.has_key(file)):
        return logMap.get(file)
    else:
        visit_date = datetime.date.today().strftime('%Y-%m-%d')
        date_file = os.path.join(visit_date,file)
        log_path = utils.read_from_ini('log_path').strip()
        log_path = os.path.join(log_path,date_file);
        if not os.path.isdir(os.path.dirname(log_path)):
            os.makedirs(os.path.dirname(log_path))
        logging.basicConfig(datefmt='%Y-%m-%d %H:%M:%S',level=logging.INFO)
        log_format = '[%(asctime)s][%(levelname)s]%(filename)s==> %(message)s'
        formatter = logging.Formatter(log_format)
        log_file = RotatingFileHandler(log_path, maxBytes=10*1024*1024,backupCount=5)
        log_file.setLevel(logging.INFO)
        log_file.setFormatter(formatter)
        instance = logging.getLogger(file)
        instance.addHandler(log_file)
        logMap[file] = instance
        return instance

Answer 1

Your RotatingFileHandler doesn't rotate on a time basis, but rather a size basis. That's what the maxBytes argument is for. If you want to rotate based on time, use a TimedRotatingFileHandler instead. Note that this works with filenames, but not paths (as far as I know). You can have 20150505.log, 20150506.log, but not 20150505/mylog.log, 20150506/mylog.log.

If you want to rotate folder names you could probably do it by subclassing the TimedRotatingFileHandler and adding your own logic.