All 15 Logging questions
More in Logging
How do you format log output to include the timestamp, logger name, level, and message? What is the relationship between Logger, Handler, Formatter, and Filter in the logging module? Why is it recommended to use logging.getLogger(__name__) instead of the root logger in library and module code? How do you configure logging using a dictionary via logging.config.dictConfig? What's the difference between propagate=True and propagate=False on a logger? What's the danger of using %-style, f-string, or .format() interpolation directly in a log call's message argument versus lazy % substitution? How do RotatingFileHandler and TimedRotatingFileHandler prevent log files from growing unbounded? How does logger.exception() differ from logger.error(), and when should you use it? Why is logging generally considered thread-safe, and what should you still be careful about in multiprocessing? How would you write a custom logging.Filter to redact sensitive data like passwords from log messages?
Advertisement
Back to results for “Logging”
Python › Logging

How do you include structured context (like a request ID) in every log message using LoggerAdapter or extra?

Intermediate

Answer

The extra parameter passes custom key-value data into a LogRecord for use in a custom Formatter string, while LoggerAdapter wraps a logger to automatically inject the same contextual data (e.g., request_id, user_id) into every call without repeating extra= at each call site -- useful for correlating logs across a single request's lifecycle.
import logging

logger = logging.getLogger('app')
adapter = logging.LoggerAdapter(logger, {'request_id': 'abc-123'})
adapter.info('Processing request')  # includes request_id in every call automatically
Real-world example A web API creates a LoggerAdapter per incoming request carrying its unique request_id, so every log line during that request's handling can be filtered and correlated in log aggregation tools.

Common follow-ups: How does extra interact with reserved LogRecord attribute names?;What's the alternative using contextvars for async code?

Concurrency (asyncio/threading/multiprocessing);Async Generators & Async Context Managers
All 15 Logging questions