python application logging code example

Example 1: python log to file and console

import logging

logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s [%(levelname)s] %(message)s",
    handlers=[
        logging.FileHandler("debug.log"),
        logging.StreamHandler()
    ]
)

Example 2: python logging to console exqmple

import sys
# ...
logging.getLogger().addHandler(logging.StreamHandler(sys.stdout))

Example 3: testing logging python

# can be done by using unittest's assertLogs

from unittest import TestCase

class MyTest(TestCase):
  
  def test_logs(self):
    with self.assertLogs('foo', level='INFO') as cm:
        logging.getLogger('foo').info('first message')
        logging.getLogger('foo.bar').error('second message')
        self.assertEqual(cm.output, ['INFO:foo:first message',
                                 'ERROR:foo.bar:second message'])