为什么 cron 作业不编译 python 文件？

Question

Cron doesn't compile my.py file and I can't get an e-mail from Cron to understand why Cron doesn't work. But if I just run the command ~/t/test.sh in terminal everything works fine.

Code in the cron:

SHELL=/bin/bash
MAILTO=mymail@gmail.com
30 0-23 1-31 1-12 0-6 ~/t/test.sh

I ty to run a script test.sh which has the code:

#!/bin/bash
cd /home/alex/t && python3.8 ./test.py

Code in the test.py :

from datetime import datetime
current_time = datetime.now()
f = open("text.txt", 'w+')
f.write("Hello world! Now is {0}\n".format(current_time))
f.close()

I Launched Cron via the sudo crontab-e and crontab-e commands. I Put Cron in the first line MAILTO=mymail@gmail.com . I Installed yum install mailx . I tried adding the command >/dev/null 2>&1 to Cron, ie writing * * * * * ~/t/test.sh >/dev/null 2>&1 Nothing helps I Use Ubuntu 18.04 Python3.8.2 Here is what the logs for the grep CRON /var/log/syslog command show:

Apr 30 15:35:01 av CRON[2130]: (alex) CMD (~/t/test.sh)

Apr 30 15:35:01 av CRON[2129]: (alex) MAIL (mailer 68 bytes of output put get status 0x004b from MTA#012)

Has anyone encountered this problem? Can you help?

Answer 1

your test.sh should be something like this: (needs full path)

#!/bin/bash
/"location where python is installed"/python/bin/python /home/alex/t/test.py

Answer 2

The weakest link in you code is the fact that you invoke the Python 3.8 interpreter without a full path. You invoke bash using a full absolute path, cd to an absolute path, and access your script through a path to the directory into which you cd-ed. Only Python is assuming the existence of some directories in the PATH environment variable.

Try accessing Python 3.8 through the full path to its location.