求linux主机每隔半小时自动运行一个python脚本的方法

Question

写了一个python脚本，查询网上某款商品的价格，想挂在云主机上每隔半小时运行一次，求这种定时循环运行python脚本的方法 ：）

Answer 1

$ cat /etc/crontab

SHELL=/bin/bash
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MAILTO=root
HOME=/

# For details see man 4 crontabs

# Example of job definition:
# .---------------- minute (0 - 59)
# |  .------------- hour (0 - 23)
# |  |  .---------- day of month (1 - 31)
# |  |  |  .------- month (1 - 12) OR jan,feb,mar,apr ...
# |  |  |  |  .---- day of week (0 - 6) (Sunday=0 or 7) OR sun,mon,tue,wed,thu,fri,sat
# |  |  |  |  |
# *  *  *  *  * user-name command to be executed

Half an hour is:

*/30 * * * *　xx.py

Thanks @Drazzi

There are many specific usages online, you can refer to: http://www.cnblogs.com/peida/archive/2013/01/08/2850483.html

Answer 2

Give you a keyword: cron

Answer 3

Crontab writes a scheduled task

Answer 4

Python
Give me an informal
Write an infinite loop, and then the loop body sleeps for the last 30 minutes