simple_logging.py

import datetime
import inspect
import os


ERROR = 0
WARNING = 1
INFO = 2
DEBUG = 3

KINDS = ['ERROR', 'WARNING', 'INFO', 'DEBUG']

LINE = '=' * 120

LOG_LEVEL = INFO


def log_impl(msg):
    print(msg)


def log(level, *msg):
    # type(int, str) -> None
    if level <= LOG_LEVEL:
        when = datetime.datetime.utcnow().strftime('%H:%M:%S')
        log_impl('%s %s %s: %s' % (caller_info(), when, KINDS[level], ' '.join(map(str,msg))))


def warning(*msg):
    # type(str) -> None
    log(WARNING, *msg)


def error(*msg):
    # type(str) -> None
    log(ERROR, *msg)


def info(*msg):
    # type(str) -> None
    log(INFO, *msg)


def debug(*msg):
    # type(str) -> None
    log(DEBUG, *msg)


def caller_info(skip=3):
    frame = inspect.stack()[skip][0]
    path = inspect.getfile(frame)
    base = os.path.dirname(__file__)
    return '%s:%d' % (path[len(base) + 1:], inspect.getlineno(frame))


def set_level(level):
    global LOG_LEVEL
    LOG_LEVEL = level


def get_level():
    return LOG_LEVEL


if __name__ == '__main__':
    set_level(WARNING)
    warning('Tell the user about something potentially harmful.')

    set_level(DEBUG)
    debug('Show a highly verbose internal debugging message.')

    set_level(INFO)
    info('Report end-user level events.')
    info('Arg1', 'Arg2', 'Arg3', 1, 2, 3, True, '- Just some multiple args')

    set_level(ERROR)
    error('Something seriously wrong happened, execution probably ends now.')