尝试从 ubuntu crontab 运行 python 脚本 [英] Trying to run a python script from ubuntu crontab

问题描述

嘿，我在尝试使用来自 ubuntu 的 Python 脚本运行 cron 作业时遇到了问题.这就是我所做的:

Hey I am running into an issue when trying to run a cron job with a python script from ubuntu. This is what I have done:

1.) 编写了一个简单的 tkinter 应用程序:代码来源来自这个 url - http://www.ittc.ku.edu/~niehaus/classes/448-s04/448-standard/simple_gui_examples/sample.py

1.) Wrote a simple tkinter app: source for the code is from this url - http://www.ittc.ku.edu/~niehaus/classes/448-s04/448-standard/simple_gui_examples/sample.py

#!/usr/bin/python
from Tkinter import *
class App:
    def __init__(self,parent):
        f = Frame(parent)
        f.pack(padx=15,pady=15)
        self.entry = Entry(f,text="enter your choice")
        self.entry.pack(side= TOP,padx=10,pady=12)
        self.button = Button(f, text="print",command=self.print_this)
        self.button.pack(side=BOTTOM,padx=10,pady=10)
        self.exit = Button(f, text="exit", command=f.quit)
        self.exit.pack(side=BOTTOM,padx=10,pady=10)

    def print_this(self):
        print "this is to be printed"

root  = Tk()
root.title('Tkwidgets application')
app = App(root)
root.mainloop()

2.) 将脚本更改为可执行:

2.) changed the script to become executable:

chmod 777 sample.py

3.) 将脚本添加到我的 cronjob 中，每分钟运行一次以进行测试.我打开 crontab -e 并将以下内容添加到我的文件中:

3.) Added the script to my cronjob to be run every minute for testing purposes. I opened crontab -e and added the following to my file:

 * * * * * /home/bbc/workspace/python/tkinter/sample.py 

4.) 免责声明:我没有为 tkinter 添加任何额外的环境变量，也没有在/etc/init.d/cron 中更改我的 cronjob 脚本

4.) Disclaimer: I did not add any additional environment variables for tkinter nor did I change my cronjob script at /etc/init.d/cron

5.) 我通过执行 tail -f/var/log/syslog

5.) I was tracking the cron job by doing a tail -f /var/log/syslog

$ tail -f /var/log/syslog
Jul  7 18:33:01 bbc CRON[11346]: (bbc) CMD (/home/bbc/workspace/python/tkinter/sample.py)
Jul  7 18:33:01 bbc CRON[11343]: (CRON) error (grandchild #11344 failed with exit status 1)
Jul  7 18:33:01 bbc CRON[11343]: (CRON) info (No MTA installed, discarding output)
Jul  7 18:33:01 bbc CRON[11342]: (CRON) error (grandchild #11346 failed with exit status 1)
Jul  7 18:33:01 bbc CRON[11342]: (CRON) info (No MTA installed, discarding output)

任何有关调试此问题的帮助将不胜感激...

Any help on debugging this issue will be most appreciated...

推荐答案

我不确定您希望在这里发生什么.cronjob 将无法访问可以显示 GUI 的显示器，因此永远不会显示按钮，因此永远不会运行 print_this

I'm not sure what you expect to happen here. The cronjob won't have access to a display where it can display the GUI, so the button will never be displayed, so print_this will never be run

FWIW，当我尝试运行您的代码时出现错误:

FWIW, when I tried to run your code I got an error:

  File "./t.py", line 4
    def __init__(self,parent):
      ^
IndentationError: expected an indented block

不确定这是否只是由复制/粘贴到页面中引起的，或者是否是您的代码的真正问题.

Not sure if that's just caused by copy/paste into the page or if it's a real problem with your code.

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