Imagine you have this get_logger function in your utils.py file of your library:

import logging

def get_logger():
    logging.basicConfig(
        level=logging.INFO,
        format="%(asctime)s %(name)s %(levelname)s: %(message)s",
    )
    logging.getLogger("another_package").setLevel(logging.WARNING)
    return logging.getLogger(__name__)

While it seems convenient to import a single function from utils.py to get a ready-to-use logger, this approach introduces three significant issues:

Problem	Why it hurts
`basicConfig()` is a one-shot	Only the first call in the entire process has any effect. If someone imported a different module that logged before this helper ran, your formatting/levels never take hold; if you call it later it’s silently ignored.
Pollutes global state	Tweaking `logging.getLogger("another_package").setLevel(...)` from a utility file surprises anyone who actually owns that package. Libraries shouldn’t decide how noisy their siblings are.
Hides provenance	Every log coming through this helper gets the same name (`your_package.utils`), so you can’t tell which module really emitted the message.

Let Each Module Own its Logger

# any_module.py
import logging
logger = logging.getLogger(__name__)

Now the logger name (package.subpackage.any_module) tells you exactly where the record came from and follows the normal hierarchy for filtering.

Configure Logging Once

Your entry-point is the right place to configure your logging. It should look something like:

# main.py (or the CLI / notebook / job driver)
import logging

# Config must run before any other log call. 
logging.basicConfig(
	level=logging.INFO,
    format="%(asctime)s %(name)s %(levelname)s: %(message)s",
)
# If you *really* need to silence a chatty dependency, do it here:
logging.getLogger("another_package").setLevel(logging.WARNING)
# ... rest of your application...

Because this code is the first to touch logging, basicConfig() takes effect exactly once, and you keep all global tweaks in one obvious place.

If you are developing a library, it won’t have an entry point, so avoid configuring logging within the library. Remember:

“A good library is a polite house-guest: it cleans up after itself and never rearranges the furniture.”
— Chat GPT