logger.py

import os
import logging
import datetime

import inspect

class Logger(logging.Logger):
    _instance = None

    def __new__(cls, **kwargs):
        if not len(kwargs) or 'args' not in kwargs:
            return cls._instance

        if cls._instance is None:
            print('Creating the object')
            cls._instance = super(Logger, cls).__new__(cls)

        return cls._instance


    def __init__(self, **kwargs):
        if not len(kwargs) \
            or 'args' not in kwargs :
            print('There is no args parameter passed to Logger')
            return

        print("Initializing the log...")
        args =  kwargs['args']
        self.__log_level = logging._nameToLevel.get(args.log_level.upper())

        log_file_name = 'git_diff'
        if hasattr(args, 'log_dir') and args.log_dir:
            if not os.path.exists(args.log_dir):
                print('Log dir does not exists. Creating directory:{}'.format(
                    args.log_dir))
                os.makedirs(args.log_dir)

            log_file_name = "{}/git_diff_{}.log".format(
                args.log_dir, datetime.datetime.now().strftime("_%Y_%m_%d"))

            super().__init__(log_file_name, self.__log_level)
            self.fh = logging.FileHandler(log_file_name, encoding='utf-8')
            self.fh.encoding='utf-8'
            self.fh.setFormatter(logging.Formatter(
                fmt=u'%(asctime)s.%(msecs)03d [%(levelname)-8s] %(message)s'
                , datefmt="%H:%M:%S"))
            self.addHandler(self.fh)
        else:
            super().__init__(log_file_name, self.__log_level)

        self.sh = logging.StreamHandler()
        self.sh.setFormatter(logging.Formatter(
            fmt=u'%(asctime)s.%(msecs)03d [%(levelname)-8s] %(message)s'
            , datefmt="%H:%M:%S"))
        self.addHandler(self.sh)

        self.debug('Logger initialized, log_level={} -- {}, file={}'.format(
                self.__log_level, self.get_level_name(), log_file_name))


    # logger interface
    def dbg(self, info):
        # if log_level > 'debug' then exit
        calframe = inspect.getouterframes(inspect.currentframe(), 2)
        frame = calframe[1]
        file = frame.filename
        current_dir = os.path.abspath(os.getcwd())
        if current_dir not in file:
            file = f'{current_dir}/{file}'
        self.debug(
            'file "{}:{}", in {}\n' \
            '===> {}'.format(file, frame.lineno, frame.function, info))


    def get_level_name(self) -> str:
        """
        param could be self or the string value one of
                'notset|debug|info|warn|error|critical'
        """
        return logging.getLevelName(self.__log_level).lower()


    def get_level_value(self) -> int:
        return self.__log_level



log = Logger()