🏷️ Python Variables and Types: Your Magic Boxes

The Story of Magic Boxes

Imagine you have a room full of magic boxes. Each box has a name tag on it, and you can put different things inside. Some boxes hold numbers, some hold words, some hold true/false answers, and some are empty on purpose.

That’s exactly what variables are in Python!

📦 Variables and Assignment

What is a Variable?

A variable is like a labeled box where you store stuff.

age = 10
name = "Emma"

Here:

• age is the box name (label)
• = means “put inside”
• 10 is what goes in the box

The Magic of =

The = sign doesn’t mean “equals” in Python. It means “put this value into this box”.

score = 100

Think: “Put 100 into the box called score.”

Changing What’s Inside

You can change what’s in a box anytime:

score = 100
score = 200

Now score holds 200. The old 100 is gone!

🔄 Multiple Assignment

One Line, Many Boxes

Python lets you fill many boxes at once:

x, y, z = 1, 2, 3

This creates three boxes:

• x gets 1
• y gets 2
• z gets 3

Same Value, Many Boxes

Want to put the same thing in multiple boxes?

a = b = c = 0

All three boxes (a, b, c) now hold 0.

Swapping Made Easy

Want to swap two boxes? Python makes it magical:

x, y = 10, 20
x, y = y, x

Now x is 20 and y is 10. No extra box needed!

🔢 Numeric Types

Python has different kinds of number boxes.

Integers (int) – Whole Numbers

Numbers without dots:

count = 42
temperature = -5
big_number = 1000000

Floats (float) – Decimal Numbers

Numbers with dots:

price = 19.99
pi = 3.14159
tiny = 0.001

Quick Tip

whole = 5       # int
decimal = 5.0   # float

They look similar but Python treats them differently!

✅ Boolean Type

True or False – That’s It!

Boolean is the simplest type. Only two possible values:

is_sunny = True
is_raining = False

Where Do We Use Them?

Booleans help make decisions:

has_ticket = True
age = 12
can_enter = age >= 10

can_enter becomes True because 12 is greater than 10.

Boolean Values

Capital T and F are important!

🕳️ None Type

The Empty Box

Sometimes you need a box but have nothing to put in it yet:

result = None

None means “nothing here” or “empty on purpose.”

Why Use None?

winner = None

# Later in your game...
winner = "Emma"

It’s like a placeholder. “I’ll fill this box later.”

None is NOT Zero

score = 0      # Has a value: zero
result = None  # Has NO value

Zero is something. None is nothing.

🔍 Type Checking

What’s in My Box?

Use type() to peek at what kind of thing is inside:

age = 10
print(type(age))

Output: <class 'int'>

Examples of Type Checking

type(42)        # <class 'int'>
type(3.14)      # <class 'float'>
type("hello")   # <class 'str'>
type(True)      # <class 'bool'>
type(None)      # <class 'NoneType'>

The isinstance() Function

A fancier way to check types:

age = 10
isinstance(age, int)     # True
isinstance(age, float)   # False

🔄 Type Conversion

Changing Box Types

Sometimes you need to transform what’s inside.

String to Integer

text = "25"
number = int(text)

Now number is 25 (a real number, not text).

Integer to Float

whole = 5
decimal = float(whole)

decimal becomes 5.0

Number to String

age = 10
text = str(age)

text becomes "10" (now it’s text).

Float to Integer

price = 9.99
whole = int(price)

whole becomes 9 (the decimal part is chopped off!).

Conversion Table

⚠️ Watch Out!

Not all conversions work:

int("hello")  # ERROR!

You can’t turn “hello” into a number!

🎯 Quick Summary

graph LR
    A[Variables] --> B[Assignment =]
    A --> C[Multiple Assignment]

    D[Types] --> E[int - Whole Numbers]
    D --> F[float - Decimals]
    D --> G[bool - True/False]
    D --> H[None - Empty]

    I[Operations] --> J[type - Check Type]
    I --> K[Convert - Change Type]

🌟 Key Takeaways

1. Variables are named boxes that store values
2. = means “put this value in this box”
3. Multiple assignment lets you set many variables in one line
4. int = whole numbers, float = decimals
5. bool = only True or False
6. None = empty on purpose
7. type() tells you what kind of value you have
8. Convert using int(), float(), str(), bool()

🎮 Try It Yourself!

# Create your own magic boxes!
my_name = "Your Name"
my_age = 10
my_height = 4.5
loves_python = True
secret = None

# Check their types!
print(type(my_name))
print(type(my_age))
print(type(my_height))
print(type(loves_python))
print(type(secret))

You’re now a Python variable wizard! 🧙‍♂️