logging-format-interpolation / W1202

Message emitted:

Use %s formatting in logging functions

Description:

Used when a logging statement has a call form of "logging.<logging method>(format_string.format(format_args...))". Use another type of string formatting instead. You can use % formatting but leave interpolation to the logging function by passing the parameters as arguments. If logging-fstring-interpolation is disabled then you can use fstring formatting. If logging-not-lazy is disabled then you can use % formatting as normal.

Problematic code:

import logging
import sys

# +1: [logging-format-interpolation]
logging.error("Python version: {}".format(sys.version))

Correct code:

import logging
import sys

logging.error("Python version: %s", sys.version)

Additional details:

Another reasonable option is to use f-string. If you want to do that, you need to enable logging-format-interpolation and disable logging-fstring-interpolation.

Related links:

• logging variable data

• Rationale for the message on stackoverflow

Created by the logging checker.