Introducting regular expressions

A regular expression, or regex for short, is simply a sequence of characters that specifies a certain search pattern. Regular expressions have been around for quite a while and are a field of computer science in and of themselves.

In Python, regular expression operations are handled using Python's built in re module. In this section, I will walk through the basics of creating regular expressions and using them to  You can implement a regular expression with the following steps:

1. Specify a pattern string.
2. Compile the pattern string to a regular expression object.
3. Use the regular expression object to search a string for the pattern.
4. Optional: Extract the matched pattern from the string.

Writing and using a regular expression

The first step to creating a regular expression in Python is to import the re module:

import re

Python regular expressions are expressed using pattern strings, which are strings that specify the desired search pattern. In its simplest form, a pattern...