Python logging

logger.py

# ref https://realpython.com/python-logging/
import logging


# filter for logging handler - console_handler_debugs
def show_only_debugs(record):
    return record.levelname == 'DEBUG'


# instantiate logger and handlers
logger = logging.getLogger(__name__)
logger.setLevel('DEBUG')  # set to lowest so handlers can start from there


# formatter that can be used on handlers or use multiple formatters for different handlers
formatter = logging.Formatter(
    "{asctime} - {levelname} - {message}",
    style="{",
    datefmt="%Y-%m-%d %H:%M",
)


# create handlers
# console handler
console_handler = logging.StreamHandler()
console_handler.setLevel("DEBUG")
console_handler.setFormatter(formatter)
logger.addHandler(console_handler)


# console handler only debugs filter
console_handler_debugs = logging.StreamHandler()
console_handler_debugs.setLevel('DEBUG')
console_handler_debugs.setFormatter(formatter)
console_handler_debugs.addFilter(show_only_debugs)
logger.addHandler(console_handler_debugs)


# file handler 1
file_handler_1 = logging.FileHandler(
    './decorators/log_file_1.log', mode='a', encoding='utf-8'
)
file_handler_1.setLevel('DEBUG')
file_handler_1.setFormatter(formatter)
logger.addHandler(file_handler_1)


# file handler 2
file_handler_2 = logging.FileHandler(
    './decorators/log_file_2.log', mode='a', encoding='utf-8'
)
file_handler_2.setLevel('WARNING')
file_handler_2.setFormatter(formatter)
logger.addHandler(file_handler_2)


# add handlers to logger
logger.addHandler(console_handler)
logger.addHandler(console_handler_debugs)
logger.addHandler(file_handler_1)
logger.addHandler(file_handler_2)


# logger info things
logger.handlers  # look at loggers handlers
logger  # look at logger
logger.getEffectiveLevel()  # int representation of log level
logger.parent  # logger parent



# logs and their int representation
logger.debug('hello debug')  # 10
logger.info('hello info')  # 20
logger.warning('hello warning')  # 30
logger.error('hello error')  # 40
logger.critical('hello critical')  # 50