Data Types in Python

In the last lesson, you learned how to create variables and store values in them. But Python needs to know what kind of value you’re storing, a number, a word, a true/false answer, before it can work with it correctly. That’s what a data type is: a label that tells Python how to treat a piece of data.
Get this wrong, and your program breaks in confusing ways. Try to add the number 5 to the text “5” and Python will stop you cold. So before going further, it’s worth spending a few minutes actually understanding the main types you’ll use every day.

The Main Data Types in Python

Python has several built-in data types, but as a beginner, you really only need to know these four well:

1. Integer (int)

Whole numbers, positive or negative, with no decimal point.

int_datatype.py

age = 15
year = 2026
temperature = -5

2. Float (float)

Numbers that have a decimal point.

float_datatype.py

price = 99.50
pi_value = 3.14159
height = 5.6

3. String (str)

Text. Anything wrapped in single or double quotes.

str_datatype.py

name = "Sujan"
city = 'Kathmandu'
message = "I am learning Python"

4. Boolean (bool)

Only two possible values: True or False. Used constantly in decision-making, which you’ll see when we get to conditional statements.

bool_datatype.py

is_student = True
has_passed = False

Checking a Data Type

Python gives you a built-in function,type(), to check what type a variable is. This is genuinely useful when you’re debugging and not sure why something isn’t working.

checking_datatype.py

x = 10
y = "Hello"
z = 3.14
w = True

print(type(x))   # <class 'int'>
print(type(y))   # <class 'str'>
print(type(z))   # <class 'float'>
print(type(w))   # <class 'bool'>

A Common Mistake Beginners Make

This one trips up almost everyone starting:

num1 = "10"
num2 = 5
result = num1 + num2

Run this, and Python throws a TypeError. Why? Because num1 is a string, not a number, even though it looks like a number. Python won’t guess what you meant. You’d need to convert num1 into an integer first using,int(num1), something we’ll cover properly in the next lesson on type conversion.

Quick Example: Putting It Together

name = "Priya"
age = 16
gpa = 3.8
is_school_topper = True

print(name, "is", age, "years old.")
print("GPA:", gpa)
print("School topper:", is_school_topper)

Nothing fancy here, but notice how each variable holds a different type, and Python handles printing all of them together without complaint, as long as you’re not trying to combine a string and a number with +.

Frequently Asked Questions