Set Methods

Part of the Logic & Flow section of Coddy's Python journey — lesson 31 of 78.

Here are even more essential set methods:

discard(element): Removes the specified element from the set if it exists. Does not raise an error if the element is not found.

my_set = {1, 2, 3}
my_set.discard(3)    # Removes 3 from the set
my_set.discard(4)    # No error, even though 4 is not in the set
print(my_set)
# Output: {1, 2}

pop(): Removes and returns an arbitrary element from the set. Raises a KeyError if the set is empty.

my_set = {1, 2, 3}
element = my_set.pop()  # Removes and returns an arbitrary element
print(element)
# Output: 1 (or another element, as it's arbitrary)
print(my_set)
# Output: {2, 3} (or a different set, depending on the popped element)

clear(): Removes all elements from the set, making it empty.

my_set = {1, 2, 3}
my_set.clear()       # Removes all elements
print(my_set)
# Output: set()

Challenge

Easy

Write a program that performs the following tasks:

Create a set called numbers containing the values 10, 20, 30, 40, 50.
Use the discard() method to remove 35 from the set.
Use the pop() method to remove an arbitrary element and store it in a variable called popped_element.
Use the clear() method to empty the set.
Print the following:
- The set after using discard().
- The value of popped_element.
- The set after using clear().

Cheat sheet

Essential set methods for removing elements:

discard(element): Removes the specified element from the set if it exists. Does not raise an error if the element is not found.

my_set = {1, 2, 3}
my_set.discard(3)    # Removes 3 from the set
my_set.discard(4)    # No error, even though 4 is not in the set

pop(): Removes and returns an arbitrary element from the set. Raises a KeyError if the set is empty.

my_set = {1, 2, 3}
element = my_set.pop()  # Removes and returns an arbitrary element

clear(): Removes all elements from the set, making it empty.

my_set = {1, 2, 3}
my_set.clear()       # Removes all elements
print(my_set)        # Output: set()

Try it yourself

# Write code here

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

All lessons in Logic & Flow

1Variables Exploration

Constants Multiple Variable Assignments Swapping Variables Placeholder Variables Round Numbers List Casting

4Contact Book Application

Display Menu Add Contact

7Sets Part 2

Mathematical Operations Part 1 Mathematical Operations Part 2 Recap - Treasure Hunt Subsets and Supersets Iterating Over Sets Recap - Tournament Tracker

10Basic List Comprehensions

The Syntax Creating Simple Lists Adding Conditions Using Data Aggregation Recap - House Of Lists Recap - Elements Of Freedom

13Inventory Management System

Project Overview Add Item

Update Stock

Check Availability

Generate Report

2Dictionaries Part 1

What is a Dictionary?Creating a Dictionary Accessing Values Modifying Dictionaries Recap - Recipe Manager

5Advanced Decision Making

Ternary Operator Membership Checks Identity Checks Indentation Errors Recap - Vacation Filter

8Student Records Manager

Project Overview Add Student

11Advanced Functions

Returning Multiple Values Lambda Functions Part 1 Lambda Functions Part 2 Recap Challenge - Lambda Sort Recursive Functions Part 1 Recursive Functions Part 2 Recap - Sum Nested List

14Higher-Order Functions

The Map Function The Filter Function Recap - Email Validator Recap - Number Processor

3Dictionaries Part 2

Dictionary Methods Nested Dictionaries Checking for Keys Looping Through Dictionaries Recap - Frequency Counter

6Sets Part 1

What is a Set?Basic OperationsSet MethodsRecap - Remove Duplicates

9Advanced Data Aggregation

Using Sum Finding Minimum and Maximum Sorting Data Efficiently Recap - Dictionary Sorter

12Basic Error Handling

What is Error Handling?The Try and Except Block Handling Multiple Exceptions Recap - Shopping Cart Errors

15Final Challenges

Smart Contact Manager Word Analytics Data Transformer