What is the use of the "copy.copy" function in Python?

Table of Contents

• Introduction
• What is copy.copy()?
  • 1. Definition of copy.copy()
  • 2. When to Use copy.copy()
• Key Points about copy.copy()
• Conclusion

Introduction

In Python, the copy module provides various functions to create copies of objects. One of the key functions is copy.copy(), which performs a shallow copy of an object. Understanding how this function works is crucial for managing object references, especially when dealing with mutable objects like lists, dictionaries, or custom objects.

What is copy.copy()?

1. Definition of copy.copy()

The copy.copy() function in Python creates a shallow copy of the provided object. A shallow copy means that it creates a new object, but only copies the references to the original object’s elements. If the original object contains mutable objects, such as lists or dictionaries, the shallow copy will still reference those mutable objects, and changes to them will affect both the original and copied object.

• Syntax:

2. When to Use copy.copy()

You use copy.copy() when you need to duplicate an object, but you don't need to create an entirely independent deep copy of nested or mutable elements within it. This is particularly useful when working with simple objects or when performance and memory efficiency are concerns.

In the example above, since copy.copy() performs a shallow copy, both the original list and the copied list share references to the same inner lists. Therefore, modifying the inner list in the shallow copy also affects the original list.

Key Points about copy.copy()

• Mutable Objects: For mutable objects like lists, dictionaries, or sets, copy.copy() creates a new outer object but shares references to the original inner objects.
• Immutable Objects: If the object contains immutable elements (e.g., integers, strings, or tuples), they are copied directly since immutable objects cannot be changed after creation.

In this case, since tuples are immutable, copy.copy() returns a reference to the original tuple, rather than creating a new copy.

Conclusion

The copy.copy() function in Python is used for creating shallow copies of objects. It duplicates the outer object but keeps references to the same inner elements, which is useful when you want to avoid creating a full deep copy of an object. However, be mindful of how changes to mutable objects inside the shallow copy will reflect in the original object.