Introduction to Python Fundamentals

Welcome to Python!

Python is one of the most popular programming languages in the world. It’s used for web development, data science, automation, and much more. This course will teach you the fundamentals through interactive, hands-on exercises that run right in your browser - no installation required!

Each section below includes interactive code editors. Try running the examples, then modify them to experiment and learn!

Module 1: Python Basics

Variables and Data Types

In Python, variables are used to store information. You don’t need to declare variable types - Python figures it out automatically!

# Try running this code!
name = "Python"
version = 3.12
is_awesome = True

print("Language:", name)
print("Version:", version)
print("Is awesome?", is_awesome)
print("Type of version:", type(version))

Basic Arithmetic

Python can perform all standard mathematical operations.

# Calculator operations
x = 10
y = 3

print("Addition:", x + y)
print("Subtraction:", x - y)
print("Multiplication:", x * y)
print("Division:", x / y)
print("Integer Division:", x // y)
print("Modulo (remainder):", x % y)
print("Power:", x ** y)

Exercise: Create Your Own Variables

Now it’s your turn! Create variables for your name, age, and favorite number, then print them out.

# Your code here - create three variables and print them
# Example:
# my_name = "Alex"
# my_age = 25
# favorite_number = 7

Module 2: Lists

Working with Lists

Lists are used to store multiple items in a single variable. Lists are ordered, changeable, and allow duplicate values.

# Creating and accessing lists
fruits = ["apple", "banana", "cherry", "date"]

print("All fruits:", fruits)
print("First fruit:", fruits[0])
print("Last fruit:", fruits[-1])
print("Number of fruits:", len(fruits))

# Slicing - getting multiple elements
print("First two fruits:", fruits[0:2])

List Methods

Lists have built-in methods that let you modify them.

# Modifying lists
numbers = [5, 2, 8, 1, 9]

print("Original list:", numbers)

numbers.append(3)
print("After append(3):", numbers)

numbers.sort()
print("After sort():", numbers)

numbers.reverse()
print("After reverse():", numbers)

Exercise: Build Your Own List

Create a list of your top 5 favorite movies, then use list methods to add one more and sort them alphabetically.

# Create a list of 5 movies
# Add a 6th movie using append()
# Sort the list alphabetically
# Print the final list

movies = []

# Your code here:

Module 3: Functions

Built-in Functions

Python comes with many useful built-in functions that you can use right away.

# Exploring built-in functions
numbers = [4, 2, 9, 7, 5, 1]
greeting = "hello world"

print("Max number:", max(numbers))
print("Min number:", min(numbers))
print("Sum of numbers:", sum(numbers))
print("Length of list:", len(numbers))
print("Uppercase:", greeting.upper())
print("Capitalized:", greeting.capitalize())
print("Absolute value of -42:", abs(-42))

Creating Custom Functions

You can create your own functions using the def keyword. Functions help you reuse code!

# Define a function
def greet(name):
    return f"Hello, {name}! Welcome to Python."

def add_numbers(a, b):
    return a + b

def calculate_area(length, width):
    return length * width

# Use the functions
print(greet("Alice"))
print("5 + 3 =", add_numbers(5, 3))
print("Area of 4x6 rectangle:", calculate_area(4, 6))

Exercise: Create Your Own Function

Write a function that takes a temperature in Celsius and converts it to Fahrenheit. Formula: F = (C × 9/5) + 32

# Write a function to convert Celsius to Fahrenheit
def celsius_to_fahrenheit(celsius):
    # Your code here
    pass

# Test your function
print("0°C is", celsius_to_fahrenheit(0), "°F")
print("100°C is", celsius_to_fahrenheit(100), "°F")
print("25°C is", celsius_to_fahrenheit(25), "°F")

Module 4: Control Flow

Conditional Statements

Use if, elif, and else to make decisions in your code.

# Making decisions with if statements
age = 25

if age < 13:
    print("You are a child")
elif age < 20:
    print("You are a teenager")
elif age < 65:
    print("You are an adult")
else:
    print("You are a senior")

# Comparison operators: ==, !=, <, >, <=, >=
print("Is age exactly 25?", age == 25)

For Loops

Loops let you repeat code multiple times. The for loop is perfect for iterating over lists.

# Looping through lists
colors = ["red", "green", "blue", "yellow"]

for color in colors:
    print(f"I like {color}")

print("\nCounting with range:")
for i in range(5):
    print(f"Count: {i}")

print("\nMultiplication table for 7:")
for i in range(1, 11):
    print(f"7 × {i} = {7 * i}")

While Loops

While loops repeat code as long as a condition is true.

# While loop example
count = 1

while count <= 5:
    print(f"Count is: {count}")
    count += 1

print("Done!")

# Be careful with while loops - make sure they can exit!

Exercise: FizzBuzz Challenge

Write a program that prints numbers from 1 to 20, but:

For multiples of 3, print “Fizz” instead of the number
For multiples of 5, print “Buzz” instead of the number
For multiples of both 3 and 5, print “FizzBuzz”

# FizzBuzz Challenge
for i in range(1, 21):
    # Your code here
    # Hint: Use the modulo operator (%) to check divisibility
    # Hint: Check for 15 first (divisible by both 3 and 5)

    pass

Final Challenge: Putting It All Together

Create a simple program that:

Creates a list of numbers
Defines a function to check if a number is even or odd (returns “even” or “odd”)
Uses a loop to check each number and print the result in the format: x is even or y is odd

Example output:

is even
is odd
is even

# Final Challenge Solution
# Your code here:

# Step 1: Create a list of numbers


# Step 2: Define a function to check even/odd


# Step 3: Loop through and print results

Congratulations!

You’ve completed the Introduction to Python Fundamentals course! You now know:

How to work with variables and data types
How to use and manipulate lists
How to use built-in functions and create your own
How to control program flow with if statements and loops

Next Steps

Keep practicing! Here are some ideas:

Build a simple calculator program
Create a guessing game
Write a program to analyze text (count words, find longest word, etc.)
Explore more advanced Python topics like dictionaries, file handling, and object-oriented programming

Happy coding!