Data Types & Conversions

Strings, integers, floats and booleans — learn what kind of data you are working with.

🎯 What you will learn

Recognize str, int, float and bool
Check types with type()
Convert between types

👋 Let’s get started!

Every value in Python has a TYPE. “42” in quotes is text, 42 without quotes is a number — and Python treats them very differently. Knowing types prevents tons of bugs! 🐛

🪜 Step by step

1. 🔤 The big four

str is text, int is a whole number, float has a decimal point, bool is True or False.

name = "Kai"      # str
level = 7         # int
speed = 3.5       # float
is_ready = True   # bool

2. 🕵️ type()

Ask Python what type something is.

print(type(7))
print(type("7"))
print(type(7.0))

3. 🔄 Converting

Use int(), float(), str() and bool() to change types.

age = int("12")
print(age + 1)
print("Level " + str(5))

🧪 Try it!

Change the code and press ▶ Run to see what happens. You can’t break anything!

Type detective

values = [42, "42", 4.2, True]
for v in values:
    print(v, "is a", type(v).__name__)

Fix the type mix-up

coins = input("Coins? ")
coins = int(coins)
coins = coins * 2
print("Doubled:", coins)

📖 Key words

Tap a card to flip it over!

str: Text, inside quotes 🔤
int: Whole number 🔢
float: Number with a decimal point 🌊
bool: True or False ✅❎

🏆 Challenge

Fix the bug so the program prints: Next year I will be 13

Challenge

age = "12"
print("Next year I will be " + (age + 1))

Knowledge Check Quiz

What type is 3.14?
What prints?
What prints?