Can I customize log format on top of loguru format

I am trying to figure out if I could customize log message in addition to the log format provided by loguru.

For example: Log message from Loguru : 2019-07-01 16:21:16.733 | INFO | __main__:run_server:50 - Tornado server starting on port 5000

Can I change this format to include correlation ID as well like 👇 [2019-06-28 09:51:59] [application_name] [correlationID] [INFO] - __main__:run_server:50 Tornado server starting on port 5000

Thanks

[Delgan]

I forgot to precise: you need first to remove() the default handler, otherwise, logs will be printed twice as you saw!

The thing is that, for convenience, Loguru adds a pre-configured handler which sends messages to stderr. This is why you can do from loguru import logger then logger.info("A message") and it works out of the box.

If you want to customize the log format, you have to remove the default handler first.

logger.remove()  # All configured handlers are removed
logger.add(sys.stderr, format=your_format)
logger.info("Logged message")

Note that the default format used by Loguru is as follow:

"<green>{time:YYYY-MM-DD HH:mm:ss.SSS}</green> | <level>{level: <8}</level> | <cyan>{name}</cyan>:<cyan>{function}</cyan>:<cyan>{line}</cyan> - <level>{message}</level>"

[AnesBenmerzoug]

Another way to do the same, which I use myself, is to directly configure the logger with the handler(s) you desire which also takes care of removing the default handler.

import sys
from loguru import logger

fmt = "[{time}] [application_name] [correlationId] [{level}] - {name}:{function}:{line} - {message}"
config = {
    "handlers": [
        {"sink": sys.stderr, "format": fmt},
    ],
}
logger.configure(**config)

logger.info("Logged message")

Which would give you the desired output:

[2019-07-06T11:35:07.697112+0200] [application_name] [correlationId] [INFO] - __main__:<module>:14 - Logged message