Python Script On Webserver

Question

I have python script which downloads N number of images from website. I run it on webserver ubuntu 10.04. For example download.py downloads 10000 images from website, prints to file about occured errors. After downloading N images it exits. Usually on local machine I run it like:

sudo python download.py

How can I run it on webserver to be always running and when it finished it should stop? I run it manually when I need(cron jobs is not necessary). for loop in script:

for i in range(1, N):
   #do download

If script is stopped by some errors, I will need to run again from beginning, while I do not save any data to run from stop place.

Answer 1

On your server, you can use an Event loop provided by Twisted and make it run at regular intervals.

from twisted.internet import task
from twisted.internet import reactor

timeout = 60.0 

def downloadlinks():
    # Have a logic to start download.
    # One previous download is over.
    if num_images_downloaded < 1000:
       pass  # previous download still in progress
    else:
       start_download()


    #do work here
    pass

l = task.LoopingCall(doWork)
l.start(timeout) # call every sixty seconds

reactor.run()

Answer 2

您可以创建将运行脚本的python守护程序服务

Answer 3

使用诸如Supervisor之类的流程管理器。

Answer 4

在我的情况下，我可以像这样运行它： sudo nohup python download.py