Alternation

Lesson 19 of 28 in Coddy's RegEx in Python course.

You can combine alternation with other regex patterns to create more complex expressions. This allows you to match different patterns in different contexts.

import re

text = "The quick brown fox jumps over the lazy dog. The quick blue cat sleeps."
pattern = r"quick (brown|blue)"
matches = re.findall(pattern, text)

print(matches)  # Output: ['brown', 'blue']

In the above example, the pattern quick (brown|blue) matches the word "quick" followed by either "brown" or "blue".

Challenge

Easy

Write a function named find_pet_names that takes a text string as input and returns a list of pet names that are either "dog", "cat", or "fish" followed by a color (black, white, red).

Try it yourself

import re

def find_pet_names(text):
    # Write code here

All lessons in RegEx in Python

1Introduction

Introduction

4Anchors and Quantifiers

Anchors Boundaries Quantifiers Repetitions

7Final Challenges

Extracting Hashtags Finding Email Addresses Valid Phone Numbers Finding Dates Capitalized Words

2re Library

findall search split sub

5Grouping and Advanced Patterns

Grouping Capturing Pipe OperatorAlternationLookaheads Lookbehinds

3Basic Pattern Syntax

Basic Metacharacters Literals Character Classes Ranges Common Predefined Classes Advanced Predefined Classes

6Advanced Techniques

Escape Metacharacters Escape Sequences