Access Set Items in Python

In Python, sets are unique collections that do not support indexing or key access. Instead, you can loop through the set items or check for the presence of a specific value using the in keyword. This lesson will cover how to access items in a set and how to modify the set by adding new items.

1. Accessing Items in a Set

You cannot access items in a set using an index or a key because sets are unordered collections. However, there are effective methods to interact with set items.

1.1 Checking for Presence of an Item

You can use the in keyword to check if a specific value is present in a set.

Example: Check if "apple" is Present in the Set

1# Creating a set
2fruits_set = {"apple", "banana", "cherry"}
3
4# Checking for the presence of "apple"
5print("apple" in fruits_set)  # Output: True

Example: Check if "apple" is NOT Present in the Set

1# Creating a set
2fruits_set = {"apple", "banana", "cherry"}
3
4# Checking if "apple" is NOT present
5print("apple" not in fruits_set)  # Output: False

2. Modifying Set Items

While you cannot change existing items in a set directly, you can add new items to the set.

Adding New Items

You can use the add() method to insert a single item into the set.

Example: Add a New Item to the Set

1# Creating a set
2fruits_set = {"apple", "banana", "cherry"}
3
4# Adding a new item
5fruits_set.add("orange")
6
7print(fruits_set)  # Output: {'banana', 'cherry', 'orange', 'apple'} (Order may vary)

Adding Multiple Items

If you want to add multiple items at once, you can use the update() method.

Example: Add Multiple Items to the Set

1# Creating a set
2fruits_set = {"apple", "banana", "cherry"}
3
4# Adding multiple items
5fruits_set.update(["kiwi", "mango"])
6
7print(fruits_set)  # Output: {'banana', 'cherry', 'mango', 'apple', 'kiwi'} (Order may vary)