This is a spider for use with Scrapy that crawls for and parses fares for one-way flights on Southwest's website.
Install Scrapy and run from the command line:
scrapy crawl southwest.com -a fromCity=ABC -a toCity=DEF -a "date=01/23/2045" -o output.json -t json
Or, you can run the crawler using the Scrapy API, with an example seen in scraper.py.
Just instantiate a new SWAFareSpider object with fromCity, toCity and date. date can be a string with any common date representation, as it's automatically parsed.
The crawler records the following information for each fare: origin, destination, flight numbers, price, stops, connecting airports, date, and fare validity date.
As with any site scraper, this can break. At any moment. If Southwest tweaks their page layout, things might go astray. If you want to tweak anything, a good place to start would be the information selection XPath in swa/spiders/swa_spider.py.