python3 log to file AND stdout
import logging
logging.basicConfig(handlers=[logging.FileHandler('/var/log/runner/process1.log'),logging.StreamHandler()],format='%(asctime)s %(levelname)s %(message)s',level=logging.INFO)

logging.info('foo')

Encore mieux pour supporter le logrotate sans copytruncate :
import logging.handlers
logging.basicConfig(handlers=[logging.handlers.WatchedFileHandler('/var/log/worker/worker1.log'),logging.StreamHandler()],format='%(asctime)s %(levelname)s %(message)s',level=logging.INFO)

/var/log/worker/*.log {
monthly
rotate 12
compress
delaycompress
missingok
notifempty
create 644 root root
}

Python 2:

import logging as loggingg

logging = loggingg.getLogger('simple_example')
logging.setLevel(loggingg.INFO)

formatter = loggingg.Formatter('%(asctime)s %(levelname)s %(message)s')

console_handler = loggingg.StreamHandler()
console_handler.setLevel(loggingg.INFO)
console_handler.setFormatter(formatter)

file_handler = loggingg.FileHandler('/var/log/worker/worker3.log')
file_handler.setLevel(loggingg.INFO)
file_handler.setFormatter(formatter)

logging.addHandler(console_handler)
logging.addHandler(file_handler)

Dans l'urgence on peut avoir besoin de forcer la rotation de logs un peu trop fat ^^

logrotate --force $CONFIG_FILE