python logging module no output while running in crontab

Question

I hava executable a.py file worked fine when running in CLI. But after I wrote a a.sh script /root/a.py >> /root/a.log and start a crontab * * * * * /bin/sh /root/a.sh, it worked fine except no outputting in the log file.
The logging part of a.py was configured as follows:

DATE_FORMAT = '%a, %d %b %Y %H:%M:%S'
LOG_FILE = 'log'
RESULT_LOG_FILE = 'result.log'
LOG_FORMAT = '[%(asctime)s] [%(filename)s:%(lineno)d] [%(levelname)s] [%(threadName)s] [%(process)d] %(message)s'
logging.basicConfig(format=LOG_FORMAT, datefmt=DATE_FORMAT, level=logging.INFO, filename=LOG_FILE)  
logging.error('ERROR')

I have tried to add /usr/local/bin/python in front of /root/a.py in a.sh but it did not work. I have no idea why this happened.

what log file did you check? the result.log or the a.log? according to your code the log file will be result.log and a.log should be empty. — Srgrn
– Srgrn, Commented Dec 10, 2015 at 1:46
Both of them no log outputting. In the code listed above it should be 'log' file, I configured in logging.basicConfig(filename=LOG_FILE) — J.Wang
– J.Wang, Commented Dec 10, 2015 at 2:01
I mean both of 'log' and 'result.log' no output, there are some print statement output in a.log — J.Wang
– J.Wang, Commented Dec 10, 2015 at 2:11

aneroid · Accepted Answer · 2015-12-10 02:42:24Z

7

The command /root/a.py >> /root/a.log does output redirection into the file /root/a.log. The >> = append, whereas > would overwrite.

Your script is logging to result.log, not a.log. And unless you have a print statement, nothing is going to go into a.log.

In your logging.basicConfig, log events are not output to console, only to the log file, so there is no "output" to re-direct to a.log.

(Add a print 'hello console' in your script, you should see that in a.log.)

Edit from comments:

result.log may not be where you think. Since its path is determined by where it's executed from, not where the script is. Change RESULT_LOG_FILE = 'result.log' to RESULT_LOG_FILE = '/root/result.log'

edited Dec 10, 2015 at 2:42

answered Dec 10, 2015 at 1:58

aneroid

16.7k3 gold badges42 silver badges77 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

J.Wang Over a year ago

Actually I have print statement in a.py file and it shown in a.log. But the output of logging.error('ERROR') did not record in the log(LOG_FILE) as what I configured in logging.basicConfig.

aneroid Over a year ago

result.log may not be where you think. Since its path is determined by where it's executed from, not where the script is. Change RESULT_LOG_FILE = 'result.log' to RESULT_LOG_FILE = '/root/result.log' and try.

Collectives™ on Stack Overflow

python logging module no output while running in crontab

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related