Python set copy() - Duplicate Set

Introduction

In Python, sets are used to store multiple items in a single variable, and these items are unordered, unchangeable, and do not allow duplicate values. The copy() method is a valuable tool when you need to create a duplicate of a set, ensuring that modifications to the new set do not affect the original set. This feature is especially useful in scenarios where you need a working copy of a set to perform operations without altering the original data.

In this article, you will learn how to utilize the copy() method to duplicate a set in Python. Discover the importance of copying sets for data manipulation and ensure that your operations on the duplicate set do not impact the original data.

Creating and Copying Sets

Understand the usage of the copy() method for duplicating Python sets while keeping the original set unchanged.

Duplicate a Basic Set

1. Define an original set of elements.

2. Use the copy() method to create a duplicate set.

   python Copy

   original_set = {1, 2, 3, 4}
   copied_set = original_set.copy()
   print(copied_set)
   

   Here, copied_set becomes a complete copy of original_set. Any modifications to copied_set will not affect original_set.

Modify the Copied Set

1. Add or remove elements from the copied set to see if the original set remains unaffected.

2. Print both sets to verify their independence.

   python Copy

   copied_set.add(5)
   copied_set.remove(1)
   print('Original Set:', original_set)
   print('Copied Set:', copied_set)
   

   After modifying the copied_set by adding 5 and removing 1, the original_set remains unchanged, demonstrating that the copy() method creates a truly independent copy.

Verify the Copy Is Shallow

1. Include mutable objects like lists in a set and copy it to understand the depth of the copy created.

2. Modify the mutable object in the copied set and check if it affects the original set.

   python Copy

   set_with_list = {1, 2, (3, 4)}
   copied_set_with_list = set_with_list.copy()
   # Modify element in the tuple, if it was a mutable object like a list
   # This section is to illustrate that modifying the mutable elements would have been reflected in the original set
   print('Original Set with List:', set_with_list)
   print('Copied Set with List:', copied_set_with_list)
   

   This code clearly shows both sets, neither of which is modified because tuples are immutable. If you replace the tuple with a mutable object like a list, changes to the mutable object in the copied set would also appear in the original set.

Conclusion

The copy() method in Python is crucial for creating independent duplicates of sets, ensuring that manipulations on the copied set do not interfere with the original set. Implement this method for safer operations in scenarios where the original data integrity is paramount, and use it to perform tests or experiments on duplicate data sets without affecting the original. By understanding and using the copy() method appropriately, you maintain clean, manageable, and error-free code in Python applications.