What are Data Types?
In the previous lesson, you learned how to store information inside variables. But have you noticed that not all information is the same?
Look at these three examples from real life:
- Your name is text (e.g., "Rahul").
- Your age is a number (e.g., 21).
- Whether you passed an exam is either Yes or No (e.g., True).
These are three completely different kinds of information. The computer needs to know exactly what kind of information you are giving it, so it can handle it correctly.
The "kind" of information stored inside a variable is called its Data Type.
The 3 Basic Data Types in Python
For now, you only need to know three types. We will explore each one in detail in the next few lessons:
| Data Type | What it stores | Example |
|---|---|---|
String (str) | Text, words, sentences | "Rahul", "Hello World" |
Integer (int) | Whole numbers (no decimals) | 25, 100, -5 |
Float (float) | Decimal numbers | 19.99, 3.14, -2.5 |
Boolean (bool) | True or False | True, False |
Why Do Data Types Matter?
Because the computer treats different types differently!
For example, the + sign behaves differently depending on the data type:
# With numbers, + does math (addition)
print(5 + 3) # Output: 8
# With text, + joins the text together
print("Hello" + "World") # Output: HelloWorld
If you try to mix types without converting them, Python will crash:
# This will cause an ERROR!
# You cannot add a number to text directly.
print("My age is " + 25)
We will learn how to handle this properly in upcoming lessons.
Checking the Data Type of a Variable
Python has a built-in command called type() that tells you exactly what kind of data a variable is holding:
name = "Rahul"
age = 21
price = 99.5
passed = True
print(type(name)) # <class 'str'>
print(type(age)) # <class 'int'>
print(type(price)) # <class 'float'>
print(type(passed)) # <class 'bool'>
Don't worry about the <class '...'> part for now. Just look at the word inside the quotes - it tells you the data type (str, int, float, or bool).
What's Next?
Let's start exploring the first data type - Strings (Text) in the next lesson!