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Logging
Python’s logging module provides a flexible framework for tracking events in your applications. It’s used to log messages to various outputs (console, files, etc.) with different severity levels like DEBUG, INFO, WARNING, ERROR, and CRITICAL.
Use Cases of Logging
Debugging: Identify issues during development. Monitoring: Track events in production to monitor behavior. Audit Trails: Capture what has been executed for security or compliance. Error Tracking: Store errors for post-mortem analysis. Rotating Log Files: Prevent logs from growing indefinitely using size or time-based rotation.
Python Logging Levels
| Level | Usage | Numeric Value | Description |
|---|---|---|---|
DEBUG | Detailed information for diagnosing problems. | 10 | Useful during development and debugging stages. |
INFO | General information about program execution. | 20 | Highlights normal, expected behavior (e.g., program start, process completion). |
WARNING | Indicates something unexpected but not critical. | 30 | Warns of potential problems or events to monitor (e.g., deprecated functions, nearing limits). |
ERROR | An error occurred that prevented some part of the program from working. | 40 | Represents recoverable errors that might still allow the program to continue running. |
CRITICAL | Severe errors indicating a major failure. | 50 | Marks critical issues requiring immediate attention (e.g., system crash, data corruption). |
INFO
import logging
logging.basicConfig(level=logging.INFO) # Set the logging level to INFO
logging.debug("This is a debug message.")
logging.info("This is an info message.")
logging.warning("This is a warning message.")
logging.error("This is an error message.")
logging.critical("This is a critical message.")
Error
import logging
logging.basicConfig(level=logging.ERROR) # Set the logging level to ERROR
logging.debug("This is a debug message.")
logging.info("This is an info message.")
logging.warning("This is a warning message.")
logging.error("This is an error message.")
logging.critical("This is a critical message.")
import logging
logging.basicConfig(
level=logging.DEBUG,
format = '%(asctime)s - %(name)s - %(levelname)s - %(message)s'
)
logging.debug("This is a debug message.")
logging.info("This is an info message.")
logging.warning("This is a warning message.")
More Examples
git clone https://github.com/gchandra10/python_logging_examples.git