copy | Python Standard Library – Real Python

The Python copy module provides functionality to create shallow copy and deep copies of objects in Python.

This module is useful when you need to duplicate objects while ensuring that the original and the copy can be modified independently.

Here’s a quick example:

Key Features

  • Creates shallow copies of objects
  • Creates deep copies of objects
  • Ensures independent modification of copies from originals

Frequently Used Classes and Functions

Object Type Description
copy.copy() Function Creates a shallow copy of an object
copy.deepcopy() Function Creates a deep copy of an object

Examples

Creating a shallow copy of a list:

Creating a deep copy of a nested list:

Common Use Cases

  • Duplicating complex objects without shared references
  • Ensuring that modifications to copies don’t affect the original object
  • Creating backup states of objects for undo functionality

Real-World Example

Suppose you’re working on a project where you need to maintain versions of a configuration dictionary. You can use the copy module to create deep copies of the configuration at different states:

By using copy.deepcopy(), you ensure that modifications to config_user don’t affect config, allowing for independent version management.

Shallow vs Deep Copying of Python Objects

For additional information on related topics, take a look at the following resources: