How do I schedule a Scrapy spider?

Scheduling a Scrapy spider involves running your spider at specific intervals of time. The typical way of doing this is via a task scheduler.

For instance, in a Unix-based system, you can use cron to schedule your tasks. If you are working on Windows, you can use Task Scheduler.

Here's a step-by-step guide on how to schedule a Scrapy spider using cron:

1. Open your terminal.
2. Type crontab -e to edit the crontab file.

$ crontab -e

1. Add a new line to schedule your Scrapy spider. Here's the basic syntax of a cron job:

* * * * * command_to_execute

• The first * field is for minutes (0 - 59)
• The second * field is for hours (0 - 23)
• The third * field is for days of the month (1 - 31)
• The fourth * field is for months (1 - 12)
• The fifth * field is for days of the week (0 - 7) where both 0 and 7 are for Sunday.

For instance, if you want to run your spider every day at 5 PM, you would do something like this:

0 17 * * * cd /path/to/your/spider && scrapy crawl your_spider_name

Remember to replace /path/to/your/spider with the actual path to your spider and your_spider_name with the actual name of your spider.

1. Save and close the file. Your cron job is now scheduled.

For Windows users, you can use Task Scheduler:

1. Open Task Scheduler
2. Click on Create Basic Task
3. Name the task and provide a description
4. Choose when you want the task to start
5. Choose Start a program option
6. Browse the Python executable file (python.exe) and add arguments as the path of your scrapy spider script
7. Click finish to set up the task

Please note that you should have your Scrapy spider set up as a script for this to work. You can achieve this by using the runspider command provided by Scrapy.

from scrapy import cmdline
cmdline.execute("scrapy runspider my_spider.py".split())

In the above code, replace my_spider.py with the actual name of your spider file.

Also, you can use Python libraries like schedule or APScheduler for in-script scheduling. However, using system-level task schedulers like cron or Task Scheduler is more reliable and recommended for production systems.