A regular expression is a particular sequence of characters that uses a specialised syntax to help you match or find other strings or collections of strings. In the UNIX realm, regular expressions are commonly employed. In Python, the re module provides full support for Perl-style regular expressions. If an error occurs while compiling or utilising a regular expression, the re module throws the re.error exception. We'll go over two key routines that are utilised to deal with regular expressions. But first, a minor point: there are a number of letters that have unique meaning when employed in regular expression. We'll utilise Raw Strings as r'expression' to avoid any confusion while working with regular expressions.