By using Cron, we can schedule the running of scripts at a specific date and time. However, it took me a while to figure out how to make it work on AWS EC2 to schedule a python task. Below are steps.
1). Need to add conda activate env_name in bash file, so that conda environment is activated automatically before Cron runs.
2). Create Cron jobs by crontab -e. After setting up the scheduled time following syntax of Crontab, we need to first cd to the path of python script. Finally the command should be:
30 13 * * 1,2,3,4,5 cd /absolute/path/to/script/ && $(which python) /absolute/path/to/script/main.py >> ~/cron.log 2>&1
Notice that, cd command cannot be ignored, even though the absolute path is still needed in the last step. Also, step 1) is also necessary. It won’t run if $(which python) is replaced by the absolute path of the python location.