【Python】ロギングのベタープラクティス

実装

同じ階層にmain.pyとlogger.pyがあるとします。

logger.py

import logging
import logging.handlers


def set_logger():
    logger = logging.getLogger()

    streamHandler = logging.StreamHandler()
    fileHandler = logging.handlers.RotatingFileHandler(
        "./logs/app.log", maxBytes=1000000, backupCount=5, encoding="utf-8"
    )

    formatter = logging.Formatter(
        '%(asctime)s| %(levelname)-5s | %(name)s.%(funcName)s.%(lineno)d | %(message)s'
    )

    streamHandler.setFormatter(formatter)
    fileHandler.setFormatter(formatter)

    logger.setLevel(logging.DEBUG)
    streamHandler.setLevel(logging.INFO)
    fileHandler.setLevel(logging.DEBUG)

    logger.addHandler(streamHandler)
    logger.addHandler(fileHandler)

    return logger

main.py

# 最初に定義
from logger import set_logger

if __name__ == "__main__":
    set_logger()

    ...
    ..
    .

各モジュールでの使用例

import logging


logger = logging.getLogger(__name__)


logger.debug("debug")
logger.info("info")
logger.warning("warn")
logger.error("error")
logger.critical("critical")

結果

コンソール

$ python /app/tmp/main.py 
2024-10-25 13:22:45,521| INFO  | functions.apicall_vad.54 | done: ./tmp/target.wav
2024-10-25 13:22:45,523| INFO  | functions._clear_dir.241 | done: clear ./tmp_splitted_wav
2024-10-25 13:22:45,526| INFO  | functions.split_wav_by_vad.132 | done: ./tmp_splitted_wav/0.wav
2024-10-25 13:22:45,527| INFO  | functions.split_wav_by_vad.132 | done: ./tmp_splitted_wav/1.wav

app.log

2024-10-25 13:23:01,511| INFO  | functions.apicall_asr.98 | done: ./tmp_combined_wav/2.wav
2024-10-25 13:23:07,337| DEBUG | functions.apicall_asr.89 | _json_data= {'data': ["brabrabra"], 'errors': []}