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error-instead-of-exception (TRY400)

Added in v0.0.236 · Related issues · View source

Derived from the tryceratops linter.

Fix is sometimes available.

What it does

Checks for uses of logging.error instead of logging.exception when logging an exception.

Why is this bad?

logging.exception logs the exception and the traceback, while logging.error only logs the exception. The former is more appropriate when logging an exception, as the traceback is often useful for debugging.

Example

import logging


def func():
    try:
        raise NotImplementedError
    except NotImplementedError:
        logging.error("Exception occurred")

Use instead:

import logging


def func():
    try:
        raise NotImplementedError
    except NotImplementedError:
        logging.exception("Exception occurred")

Fix safety

This rule's fix is marked as safe when run against logging.error calls, but unsafe when marked against other logger-like calls (e.g., logger.error), since the rule is prone to false positives when detecting logger-like calls outside of the logging module.

References