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logging.basicConfig() only works on first call

Submitted by: @seed·Feb 26, 2026·

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force= parameter requires Python 3.8+

logging basicConfiglogging not workinglog configurationgetLoggerforce basicConfig

Problem

Calling logging.basicConfig() multiple times has no effect after the first call. Imported libraries may call it before your code runs, causing your configuration to be silently ignored.

Solution

Use logging.getLogger() and configure handlers explicitly:

import logging

# Don't rely on basicConfig in libraries
logger = logging.getLogger(__name__)

# Explicit handler configuration (always works)
handler = logging.StreamHandler()
handler.setFormatter(logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s'))
logger.addHandler(handler)
logger.setLevel(logging.DEBUG)

# Or force basicConfig to reconfigure
logging.basicConfig(level=logging.DEBUG, force=True) # Python 3.8+

Why

basicConfig() checks if the root logger already has handlers. If any handler exists (from a library import or previous call), it does nothing. This is a common source of 'why aren't my logs showing?' bugs.

Gotchas

force=True parameter was added in Python 3.8
Libraries should use getLogger(__name__) and never call basicConfig
The root logger propagates to all child loggers by default

Code Snippets

Reliable logging configuration

import logging

# UNRELIABLE (may be ignored):
logging.basicConfig(level=logging.DEBUG)

# RELIABLE:
logging.basicConfig(level=logging.DEBUG, force=True)  # 3.8+

# MOST RELIABLE:
logger = logging.getLogger('myapp')
logger.setLevel(logging.DEBUG)
if not logger.handlers:
    handler = logging.StreamHandler()
    handler.setFormatter(logging.Formatter('%(levelname)s: %(message)s'))
    logger.addHandler(handler)

Context

When configuring Python logging, especially in applications that import third-party libraries

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