One Pager Cheat Sheet

• Search engines and text editors use **regular expressions** to quickly locate data and filter out the relevant information.
• Regular expressions, or regex, are a special sequence of characters that define a pattern to match text, which can be more powerful and shorter than the ‘equal’ operator (==), indexing, or other string methods.
• The import keyword is used to load the re module in Python, and therefore import re is a valid statement.
• The re module provides a basic search method, .search(regex, string), which scans through a string and looks for a match to the provided regular expression, as demonstrated in a simple example.
• Using special characters (or metacharacters) in regular expressions adds unique meaning to the expression, typically demonstrated by defining a character class with square brackets ([ ]).
• Using Square Brackets, [a-z], [0-9], and . we can create Regex patterns to match character ranges, digits, and consecutive characters to achieve desired results.
• The ^ metacharacter allows us to match multiple strings that start with the same characters.
• The metacharacter + checks if the previous character appears one or more times.
• By using the * metacharacter, one can avoid having to specify the preceding character when searching for a repeating character in a string.
• The basics of regular expressions were just covered, but with metacharacters such as Square Brackets, Period, Caret, Dollar, Asterisk, Plus, \w, \W, \s, \S, \d, \D, \t and \n, one can match complex patterns in text.