I have a remote cron job that scrapes data using selenium every 30 minutes. Roughly 1 in 10 times the selenium script fails. When the script fails, I get an error output instead (various selenium error messages). Does this cause the cron job to stop? Shouldn't crontab try to run the script again in 30 minutes?
After a failed attempt, when I type crontab -l, it still shows my cron job. 
How do I ensure that the crontab tries again in 30 minutes?
ANSWER: The website I was scraping was sophisticated enough to find out I was using selenium because cron was running the job every 30 minutes on the dot. So they flagged my VM's IP address after the 4-5th attempt. 
My solution was simple: add randomness to the interval with which I scrapped the website using random.uniform and time.sleep - now I have no issues scraping.
Does cron job persist/run again if the python script fails?