sansio-tld-parser VS psl-problems

Small plug for a random python tool I maintain that uses this.

Parsing domains is a pain in the ass. It can be impossible to know what is part of tld, what is a subdomain etc without a canonical list and parser.

Here's a sansio domain / tld splitter: https://github.com/theelous3/sansio-tld-parser

Usecase: you want to block all edu domains - but tlds like wa.edu.au exists - gotta parse it out.

Ryan Sleevi has written about this before on Hacker News and here's his list https://github.com/sleevi/psl-problems

It's definitely possible that Ryan would consider using this for HN a reasonable choice, because it's mostly cosmetic, but in general you should just not add more dependencies.

Before you begin to make use of the PSL, consider some of its problems: https://github.com/sleevi/psl-problems

FWIW, the link above successfully convinced me and a coworker not to use the PSL.

(googler here, but this is my opinion)

I think there's a big abstraction gap between what we use domains for and what they were supposed to be used for, in a way that we shouldn't assume any ownership only based on the domain itself.

For instance you can have a number of sites that use separate domains but are owned by the same entity (N domains for 1 party). You could also have the same base domain being used for several unrelated parties, think hosting a store on Shopify (1 domain for N parties). This is so ambiguous that even inside the browser you have two different implementations on the way you handle this attribution, one for cookies and one for Single-Origin Policy.

There's a good write up about this problem at https://github.com/sleevi/psl-problems. Sometimes I wonder how the web got here with the amount of kludge that we have to carry.