Logging utilities

log.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""Logging utilities."""
import logging

CRITICAL = logging.CRITICAL
ERROR = logging.ERROR
WARNING = logging.WARNING
INFO = logging.INFO
DEBUG = logging.DEBUG
NOTSET = logging.NOTSET


class _Formatter(logging.Formatter):
    """Customized log formatter."""

    def __init__(self):
        datefmt = '%m%d %H:%M:%S'
        super().__init__(datefmt=datefmt, style='{')

    def _get_color(self, level):
        if WARNING <= level:
            return '\x1b[31m'
        elif INFO <= level:
            return '\x1b[32m'
        else:
            return '\x1b[34m'

    def _get_label(self, level):
        if level == CRITICAL:
            return 'C'
        elif level == ERROR:
            return 'E'
        elif level == WARNING:
            return 'W'
        elif level == INFO:
            return 'I'
        elif level == DEBUG:
            return 'D'
        else:
            return 'U'

    def format(self, record):
        fmt = self._get_color(record.levelno)
        fmt += self._get_label(record.levelno)
        fmt += '{asctime} {process:5d} {name}:{funcName}:{lineno}'
        fmt += ']\x1b[0m'
        fmt += ' {message}'
        self._style._fmt = fmt
        return super().format(record)


_handler = logging.StreamHandler()
_handler.setFormatter(_Formatter())


def get_logger(name=None, level=DEBUG):
    """Get customized logger.

    :param str name: Name of the logger.
    :param level: Level to log.
    :return: A logger.
    """
    logger = logging.getLogger(name)
    if getattr(logger, '_init_done', None) is None:
        logger._init_done = True
        logger.addHandler(_handler)
        logger.setLevel(level)
    return logger