Why you can't parse HTML with regex

> HTML is not a regular language and hence cannot be parsed by regular expressions.

But, but! In StackOverflow, "regex" doesn't mean "specification for a finite state automaton which recognizes whether strings belong to a given regular language", but rather "a character matching tool implemented in whatever language or its library that a question is about".

Some so-called regex engines will match nested tags.

The question has a problem because it makes no mention of what concrete tools OP is using to solve a concrete problem.

The second answer is correct, not the top answer. If you have some knowledge about the form of your HTML, then regex might very well be the best tool for the job.

I've spend hours trying to get something to work in BeautifulSoup that could have easily been done in minutes with regex and a few lines of python.