Swapping Variables

Part of the Logic & Flow section of Coddy's Python journey — lesson 3 of 78.

Swapping variables is a common operation where the values of two variables are exchanged. Python offers a simple and elegant way to swap variables without needing a temporary variable, unlike many other programming languages.

Traditional Method (Using a Temporary Variable):

a = 10
b = 20
temp = a
a = b
b = temp
print(a)  # Output: 20
print(b)  # Output: 10

Pythonic Way (Simultaneous Assignment):

a = 10
b = 20
a, b = b, a
print(a)  # Output: 20
print(b)  # Output: 10

In the Pythonic way, the values of b and a are simultaneously assigned to a and b, respectively. This approach is more readable and doesn't require any additional variables.

Challenge

Easy

Write a Python program to swap the values of two variables without using a temporary variable. Initialize two variables, x and y, with the values 5 and 10 respectively. Swap their values and then print them.

Cheat sheet

Python allows swapping variables using simultaneous assignment without needing a temporary variable.

Traditional method using a temporary variable:

a = 10
b = 20
temp = a
a = b
b = temp

Pythonic way using simultaneous assignment:

a = 10
b = 20
a, b = b, a

The simultaneous assignment approach is more readable and doesn't require additional variables.

Try it yourself

# Initialize variables x and y



# Swap the values of x and y


# Print the swapped values
print(f"x: {x}")
print(f"y: {y}")

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 AssignmentsSwapping VariablesPlaceholder 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 Operations Set Methods Recap - 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