Python Basics · Lesson 3

Python Data Types

Learn how Python classifies values as integers, floating-point numbers, strings and booleans, and how to identify a value's data type using type().

What you will learn

• What a data type is
• Integers — int
• Floating-point numbers — float
• Strings — str
• Boolean values — bool
• Using type()
• Identifying data types
• Common type mistakes

Part 1

What is a data type?

A data type tells Python what kind of value it is working with. Different kinds of values can behave differently in a program.

25

Integer

25.5

Float

"25"

String

True

Boolean

CHECK YOUR UNDERSTANDING

What does a data type tell Python?

Part 2

Integers — int

Integers are whole numbers without a decimal part. They can be positive, negative or zero.

age = 25
students = 100
temperature = -5
score = 0

CHECK YOUR UNDERSTANDING

Which value is an integer?

CHECK YOUR UNDERSTANDING

Which value is also an integer?

Part 3

Floating-point numbers — float

A float represents a number containing a decimal component.

price = 99.99
height = 1.75
average = 82.5

CHECK YOUR UNDERSTANDING

Which value is a float?

CHECK YOUR UNDERSTANDING

Which variable contains a float?

Part 4

Strings — str

A string is text. Strings are commonly written inside single or double quotation marks.

"Python"

'Vista Academy'

CHECK YOUR UNDERSTANDING

Which value is a string?

CHECK YOUR UNDERSTANDING

What is the data type of "100"?

Part 5

Boolean values — bool

Boolean values represent one of two states: True or False. Booleans are especially useful when programs need to make decisions.

is_student = True
is_logged_in = False

CHECK YOUR UNDERSTANDING

Which value is a Boolean?

CHECK YOUR UNDERSTANDING

Which statement stores a Boolean value?

Part 6

Finding a data type with type()

Python provides the type() function to inspect the data type of a value.

age = 25
print(type(age))

CHECK YOUR UNDERSTANDING

What does type(age) help you find?

CHECK YOUR UNDERSTANDING

What is the type of "Python"?

CHECK YOUR UNDERSTANDING

What is the type of 25?

CHECK YOUR UNDERSTANDING

What is the type of 25.5?

Predict the output

Can you identify the value?

x = "25"
print(x)

CHECK YOUR UNDERSTANDING

What will print(x) display?

Same-looking values can have different types

a = 10
b = "10"

print(type(a))
print(type(b))

CHECK YOUR UNDERSTANDING

How are a and b different?

Your turn

Complete the answers

Fill in the Blank

The data type of 100 is _____.

Fill in the Blank

The data type of 10.5 is _____.

Fill in the Blank

The data type of "Python" is _____.

Fill in the Blank

The data type of True is _____.

Debug the type mistake

age = "25"
result = age + 5

CHECK YOUR UNDERSTANDING

Why can this code cause a type error?

Mini Challenge

Build a data profile

Create four variables representing a person's name, age, height and student status. Use an appropriate data type for each.

name = "Aman"
age = 21
height = 1.75
is_student = True

Final Challenge

Create and inspect your own variables

Create one integer, one float, one string and one Boolean variable. Then use type() to inspect each one.

age = 25
price = 99.99
name = "Yogesh"
is_student = True

print(type(age))
print(type(price))
print(type(name))
print(type(is_student))

Lesson recap

✓ Data types describe the kind of value being used.
✓ int represents whole numbers.
✓ float represents decimal numbers.
✓ str represents text.
✓ bool represents True or False.
✓ type() can be used to inspect a value's type.
✓ Similar-looking values can have different data types.
✓ Understanding types helps prevent programming errors.