Python String endswith() Method

The endswith() method in Python is used to determine if a string ends with a specified suffix. This method is useful for validating string content, particularly when you need to check for specific endings in filenames, URLs, or other text data.

Table of Contents

1. Introduction
2. endswith() Method Syntax
3. Understanding endswith()
4. Examples
   • Basic Usage
   • Using endswith() with Tuple of Suffixes
5. Real-World Use Case
6. Conclusion

Introduction

The endswith() method allows you to check if a string ends with a specified suffix. This is particularly useful for string validation and filtering operations, ensuring that text data conforms to expected formats.

endswith() Method Syntax

The syntax for the endswith() method is as follows:

str.endswith(suffix[, start[, end]])

Parameters:

• suffix: The suffix to check for. This can be a string or a tuple of strings.
• start (optional): The starting position where the search begins. Default is 0.
• end (optional): The ending position where the search ends. Default is the length of the string.

Returns:

• True if the string ends with the specified suffix, otherwise False.

Understanding endswith()

The endswith() method checks if the string ends with the specified suffix. You can optionally specify the start and end positions to limit the check to a specific substring within the string.

Examples

Basic Usage

To demonstrate the basic usage of endswith(), we will check if a string ends with a specific suffix and print the result.

Example

filename = "report.pdf"
is_pdf = filename.endswith(".pdf")
print("Is the file a PDF?", is_pdf)

Output:

Is the file a PDF? True

Using endswith() with Tuple of Suffixes

This example shows how to use the endswith() method with a tuple of suffixes to check if a string ends with any of the specified suffixes.

Example

filename = "photo.jpg"
is_image = filename.endswith((".jpg", ".png", ".gif"))
print("Is the file an image?", is_image)

Output:

Is the file an image? True

Real-World Use Case

Filtering Filenames in a Directory

In real-world applications, the endswith() method can be used to filter filenames in a directory, ensuring that only files with specific extensions are processed.

Example

import os

def filter_image_files(directory):
    image_files = [f for f in os.listdir(directory) if f.endswith((".jpg", ".png", ".gif"))]
    return image_files

image_files = filter_image_files(".")
print("Image files:", image_files)

Output:

Image files: ['photo.jpg', 'image.png', 'animation.gif']

Conclusion

The endswith() method in Python is useful for checking if a string ends with a specified suffix. By using this method, you can validate and filter text data, ensuring that it conforms to expected formats in your Python applications.