Disabling specific logger in pytest

Question

In my project I'm parsing some PDF files using pdfplumber. During tests execution (pytest) I sometimes would like to see logs from my code for debugging purposes. This can be done by setting --log-cli-level=DEBUG. However, this turns on messages from all code, also pdfplumber - which is very verbose and makes debugging difficult. Is there a way to selectively enable/disable loggers during test run?

pytest 4.6.3
python 3.7.3

Thanks for help!

Answer 1

Pytest does not support this by default, but you can add a custom option to your conftest.py to turn off specific loggers.

import pytest
import logging

def pytest_addoption(parser):
    """Add a command line option to disable logger."""
    parser.addoption(
        "--log-disable", action="append", default=[], help="disable specific loggers"
    )

def pytest_configure(config):
    """Disable the loggers."""
    for name in config.getoption("--log-disable", default=[]):
        logger = logging.getLogger(name)
        logger.propagate = False

For pytest 7.3.0 and later:

pytest now supports --log-disable without a custom option. https://docs.pytest.org/en/7.4.x/how-to/logging.html