Anchors

Lesson 12 of 28 in Coddy's RegEx in Python course.

Anchors are special characters in regex that match positions rather than actual characters. The two most common anchors are ^ and $.

<strong>^</strong>: Matches the start of a string.
<strong>$lt;/strong>: Matches the end of a string.

import re

text = "Hello, world!"
pattern_start = r"^Hello"
pattern_end = r"world!$"

match_start = re.search(pattern_start, text)
match_end = re.search(pattern_end, text)

if match_start:
    print("Start anchor match found:", match_start.group())  # Output: Start anchor match found: Hello
else:
    print("No start anchor match found")

if match_end:
    print("End anchor match found:", match_end.group())  # Output: End anchor match found: world!
else:
    print("No end anchor match found")

In the above example, the pattern ^Hello matches "Hello" at the start of the string, and the pattern world!$ matches "world!" at the end of the string

Challenge

Easy

Write a function named find_lines_starting_with that takes a list of strings and a word as input, and returns a list of strings that start with the given word.

Try it yourself

import re

def find_lines_starting_with(lines, word):
    # Write code here

All lessons in RegEx in Python

1Introduction

Introduction

4Anchors and Quantifiers

AnchorsBoundaries 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 Classes Ranges Common Predefined Classes Advanced Predefined Classes

6Advanced Techniques

Escape Metacharacters Escape Sequences