Python的logging模块基本用法

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import logging

LOG_FILENAME = 'log.txt'
logging.basicConfig(
  filename=LOG_FILENAME,
  level=logging.DEBUG,
)

logging.debug('hello logging!')

with open(LOG_FILENAME, 'rt') as f:
  body = f.read()

print('FILE: ')
print(body)

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import glob
import logging.handlers

LOG_FILENAME = 'log.txt'

my_logger = logging.getLogger('SpecificLogger')
my_logger.setLevel(logging.DEBUG)

# Add the log message handler to the logger
handler = logging.handlers.RotatingFileHandler(
  LOG_FILENAME,
  maxBytes=20,
  backupCount=5,
)
my_logger.addHandler(handler)

# Log some messages
for i in range(20):
  my_logger.debug(f'i = {i}')

# See what files are created
log_files = glob.glob(f'{LOG_FILENAME}*')
for filename in sorted(log_files):
  print(filename)

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import logging
import sys

level = int(sys.argv[1])
logging.basicConfig(
  level=level
)

logging.debug('debug message')
logging.info('info message')
logging.warning('warning message')
logging.error('error message')
logging.critical('critical message')

$ python logging_level.py 10
DEBUG:root:debug message
INFO:root:info message
WARNING:root:warning message
ERROR:root:error message
CRITICAL:root:critical message
$ python logging_level 40
ERROR:root:error message
CRITICAL:root:critical message

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import logging

logging.basicConfig(
  level=logging.WARNING
)

logger1 = logging.getLogger('package1.module1')
logger2 = logging.getLogger('package2.module2')

logger1.warning('hello 1')
logger2.warning('hello 2')