Overview of regex

There are plenty of cases when it’s quite hard or even impossible to locate some web-based content or elements with XPath and CSS selectors. Fortunately, we can overcome such situations using a regex. A regex is an expression built using strings that is used to find or search content by identifying an existing pattern.

In web scraping and extraction-related activities, a regex is also used as a final or firsthand pattern-matching option. Patterns can be defined using various steps, often accompanied by special notations that represent predefined rules. A regex is like grouping and writing plain text, and many libraries and text-related features exist that use these expressions, providing us with handy, easy-to-use functions.

The latest code editors, document readers, and writing programs all provide facilities such as searching in files, multiple pages, and inside project folders, and using find and replace. To use these options, we need to input text...