Last summer I worked on a project where I needed a search engine that supported simple Boolean queries and key-value parameters. This was to be used on a Python site, so I wanted to write the query parser in Python too. At the time, Lepl seemed like a good choice. I figured out the grammar necessary to support the search query language I wanted, and all was good. I went to check out Lepl just now and I see it has been discontinued, which is a little disheartening. Regardless, I figured better late than never to post this since it still works and Lepl did the job.