Loguru

loguru is a drop-in replacement for Python’s logging module with sane defaults: no boilerplate handler/formatter setup, colorized output, structured bind() context, and built-in file rotation.

from loguru import logger
 
logger.info("started")
logger.bind(user_id=42).warning("low balance")

Intercepting stdlib logging

loguru and the standard logging module are separate systems — third-party libraries that call logging.getLogger(__name__) never reach loguru’s sinks unless you bridge them. The standard bridge is a logging.Handler that re-emits every stdlib record through loguru, forwarding the caller’s stack depth so loguru reports the original call site instead of the handler itself.

import logging
from loguru import logger
 
class InterceptHandler(logging.Handler):
    def emit(self, record):
        try:
            level = logger.level(record.levelname).name
        except ValueError:
            level = record.levelno
 
        frame, depth = logging.currentframe(), 2
        while frame.f_code.co_filename == logging.__file__:
            frame = frame.f_back
            depth += 1
 
        logger.opt(depth=depth, exception=record.exc_info).log(
            level, record.getMessage()
        )

Install it on the root logger as early as possible in main(), before importing anything that might configure logging itself:

def main():
    logging.basicConfig(handlers=[InterceptHandler()], level=0, force=True)

• force=True clears any handlers a library already attached to the root logger — without it, basicConfig is a no-op if handlers exist.
• level=0 on the root logger disables stdlib-side filtering, leaving level filtering to loguru’s own sinks.
• Child loggers propagate to root by default, so this catches most libraries automatically.
• A library that disables propagation or attaches its own handler needs an explicit override: logging.getLogger("that.lib").handlers = [InterceptHandler()].

Cheatsheet

Setup

from loguru import logger
logger.add("app.log", rotation="10 MB") # log to file with rotation
logger.remove() # drop the default stderr sink

Intercept stdlib logging

logging.basicConfig(handlers=[InterceptHandler()], level=0, force=True) # call in main(), before other imports