What is the difference between "append" and "extend" in Python?

Table of Contents

• Introduction
• Key Differences Between append and extend
  • 1. Functionality
  • Example:
  • 2. Argument Type
  • Example:
  • 3. Use Cases
• Practical Examples
  • Example : Using append to Add a Single Item
  • Example : Using extend to Add Multiple Items
• Conclusion

Introduction

In Python, lists are a versatile data structure that allows you to store and manipulate collections of items. Two common methods used to modify lists are append and extend. Although both methods add elements to a list, they do so in different ways. Understanding the differences between append and extend is crucial for effective list manipulation in Python. This article will clarify how each method works and provide practical examples to illustrate their usage.

Key Differences Between append and extend

1. Functionality

• append: The append method adds its argument as a single element to the end of the list. This means that the argument is treated as a single entity, regardless of its type (e.g., whether it is a number, string, or another list).
• extend: The extend method iterates over its argument and adds each element to the end of the list. The argument must be an iterable (such as a list, tuple, or set), and its elements are added individually to the list.

Example:

2. Argument Type

• append: Accepts a single argument of any data type and adds it as a single element.
• extend: Accepts an iterable (e.g., list, tuple, or set) and adds each element of the iterable to the list.

Example:

3. Use Cases

• append: Use append when you need to add a single item to the end of a list, regardless of its type. This method is ideal for adding elements where you don’t need to unpack or decompose the item.
• extend: Use extend when you want to add multiple items to a list from another iterable. This method is suitable for merging lists or adding elements from iterable collections.

Practical Examples

Example : Using append to Add a Single Item

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Example : Using extend to Add Multiple Items

Conclusion

The append and extend methods in Python both serve to add elements to a list, but they do so in different ways. append adds its argument as a single element, while extend iterates over its argument and adds each element individually. By understanding these differences, you can choose the appropriate method based on whether you need to add single items or multiple items from an iterable to your list.