Ranges

Lesson 9 of 28 in Coddy's RegEx in Python course.

Ranges are a shorthand way of specifying a sequence of characters.

Here are some examples of using ranges in character classes:

[a-z]: Matches any lowercase letter from a to z.
[A-Z]: Matches any uppercase letter from A to Z.
[0-9]: Matches any digit from 0 to 9.
[a-zA-Z]: Matches any letter from a to z or from A to Z.

import re

text = "A1, B2, C3, D4"
pattern = "[A-D][1-4]"

matches = re.findall(pattern, text)

print(matches)  # Output: ['A1', 'B2', 'C3', 'D4']

In the above example, the pattern [A-D][1-4] matches any two-character string where the first character is an uppercase letter from A to D, and the second character is a digit from 1 to 4.

Challenge

Easy

Write a function named find_letter_digit_pairs that takes a text string as input and returns a list of two-character strings where the first character is a lowercase letter from a to c and the second character is a digit from 1 to 3.

Try it yourself

import re

def find_letter_digit_pairs(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 Operator Alternation Lookaheads Lookbehinds

3Basic Pattern Syntax

Basic Metacharacters Literals Character ClassesRangesCommon Predefined Classes Advanced Predefined Classes

6Advanced Techniques

Escape Metacharacters Escape Sequences