Recommend exc_info=True over formatting exception in message

[adamchainz]

Description

Hastily-written log messages often use the exception in the message:

try:
    float()
except Exception as exc:
    logging.info("Floating failed: %s", exc)

This is not a great pattern as str(exc) reveals little info - no stack trace! Better to use exc_info=True.

Let’s detect exc or str(exc) used in arguments and recommend exc_info=True instead. type(exc) is okay as a parameter.