Python: Running Daemon Processes in Windows7

Question

I had a program that Scraped certain data from certain Web-Pages, and when the Web-Pages changed, acted accordingly.

How would one set up the program so it continues to run in the background?

I don't need any specifics

I'm just really confused on this concept and would appreciate whatever help anybody has to offer.

In today's multitasking systems, there's very little difference between "foreground" and "background", programs just run. What system are you using? (It matters.) — Greg Hewgill, Feb 14 '12 at 04:06
Take a Look at the [answer](http://stackoverflow.com/questions/12843903/how-to-start-daemon-process-from-python-on-windows/12844523#12844523) — Rahul Gautam, Dec 13 '12 at 16:26

Dima Tisnek · Answer 1 · 2012-03-02T08:48:37.213

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start path-to-pythonw.exe your-code.py

pythonw means without console.

start means start on background.

if your python is installed system-wide, you can probably start your-code.pyw

.pyw is associated with pythonw.exe

remember you cannot use print (to stdout) in this case.

edited Mar 02 '12 at 08:48

answered Feb 14 '12 at 10:02

Dima Tisnek

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I have ran into problems that every print threw an exception. Another developer left prints all over the place ans stdout being closed/disconnected made python throw. – Dima Tisnek Feb 23 '12 at 09:22
This opens up another commandline window in windows8.1, it is not working in the background :/ – Karavana Apr 13 '16 at 15:10

score 0 · Answer 2 · edited May 23 '17 at 12:15

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If you want to be able to just start your process and have it background itself and do a few more typical things that "daemon" processes do in Unix, look here: How do you create a daemon in Python?

edited May 23 '17 at 12:15

Community

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answered Feb 14 '12 at 04:08

John Zwinck

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score 0 · Answer 3 · edited May 23 '17 at 12:03

There is no concept of "background" in Windows. But the UNIX shell concept of a background process can be reasonably emulated by running your Python script as a Windows service. There are a couple of suggestions in this question: Is it possible to run a Python script as a service in Windows? If possible, how?

For casual use, I suggest that you learn how to use srvany from the second answer.

score -1 · Answer 4 · answered Feb 14 '12 at 04:09

You simply need to leave your program running! Please google "python daemon" and see how to implement a persistent background process in Python.

Now, you cannot know when a website changes unless you poll it. If the website is well designed, the page you are trying to poll will have a "Last-Modified" header, you can make a "HEAD" request every so often (be nice: don't poll like crazy) and act when Last-Modified is >= than the one on record. If the site is not well designed, it will not have a reliable Last-Modified or ETAG header, in that case you will have to parse manually and check for changes yourself.

Cheers.

Python: Running Daemon Processes in Windows7

4 Answers4