How to run a Python package as a scheduled daemon job?

Question

I have created a Python package and released it on PyPI, say spamandeggs . This package is cross-platform (Windows,GNU/Linux, MacOSX) aimed at updating the user with certain information periodically (say every 5 minutes). The package can be run from command-line through the command spamtheeggs .

Here are the issues I am facing:

Question 01 : How to daemonize the script running through the spamtheeggs command?

Problem : Following this answer, I tried using schedule in my script. This works fine for scheduling but the execution is not daemonized. The terminal is busy for the entirety of the process.
I would like to know a way to daemonise the Python package.

Question 02 : How to add the command as a cron job for scheduled execution ?

Solution 01 : One way to do this would be to write an installation guide describing the process (editing crontab using crontab -e , etc.). Drawback : Not appealing.

Solution 02 : As the author of the package, I want to be able to add this command to the user's crontab (after getting user's confirmation, obviously).

Options:

1. Write a Python script to schedule another script (Is this even possible?)
2. Use a task scheduler which can also daemonize.

I would like to know which option is suitable(if any) and any tips on how can I go about working on them.

List of resources I have read so far:

• How to run a python background process periodically
• Scheduling Python Script to run every hour accurately
• How to package a Python daemon with setuptools
• Execute python Script on Crontab
• running a python script with cron
• Creating a Cron Job - Linux / Python
• How to make Python script run as service?

Note: I would appreciate if the solution is applicable over all the 3 platforms.
PS: This is my first attempt at cron and daemon jobs.

Answer 1

python-deamon package can help you, it works in 2 modes:

• using a runner (I think is just what you want): http://www.gavinj.net/2012/06/building-python-daemon-process.html

• or running using daemon.DaemonContext directly (a more traditional way)

python-deamon has no documentation, but I've found some code that may help you http://www.programcreek.com/python/example/10392/daemon.DaemonContext