Data Types

Data types define what kind of value a variable stores. Python provides several built-in data types that are used to work with numbers, text, collections, and logical values.

What is a Data Type?

A data type tells Python what kind of data a value represents and what operations can be performed on it.

For example, 25 is an integer, 25.5 is a floating-point number, and "Python" is a string.

Built-in Data Types in Python

Python has several built-in data types. Some of the most commonly used ones are:

1. Integer (int)

The int data type is used to store whole numbers without decimal points.

age = 25
students = 50
marks = -10

print(age)
print(type(age))

Output

25
<class 'int'>

2. Float (float)

The float data type is used for numbers containing decimal values.

price = 499.99
percentage = 85.5

print(price)
print(type(price))

Output

499.99
<class 'float'>

3. Complex (complex)

Python supports complex numbers using the j notation for the imaginary part.

number = 3 + 4j

print(number)
print(type(number))

Output

(3+4j)
<class 'complex'>

4. String (str)

A string is a sequence of characters used to represent text. Strings can be written using single or double quotes.

name = "Samadhan"
course = 'Python'

print(name)
print(type(name))

Output

Samadhan
<class 'str'>

5. Boolean (bool)

The bool data type represents one of two values: True or False.

is_student = True
is_completed = False

print(is_student)
print(type(is_student))

Output

True
<class 'bool'>

6. List (list)

A list is an ordered and changeable collection. Lists can contain multiple values.

courses = ["Python", "C#", "Java"]

print(courses)
print(type(courses))

Output

['Python', 'C#', 'Java']
<class 'list'>

7. Tuple (tuple)

A tuple is an ordered collection that cannot be changed after it is created.

languages = ("Python", "Java", "C#")

print(languages)
print(type(languages))

Output:

('Python', 'Java', 'C#')
<class 'tuple'>

8. Set (set)

A set is a collection of unique values. Duplicate values are automatically removed.

numbers = {10, 20, 30, 20}

print(numbers)
print(type(numbers))

Output:

{10, 20, 30}
<class 'set'>

Notice that the duplicate value 20 is stored only once.

9. Dictionary (dict)

A dictionary stores data in key-value pairs.

student = {
    "name": "Samadhan",
    "course": "Python",
    "institute": "CIIT Training Institute 🫠👀.."
}

print(student)
print(type(student))

Output:

{'name': 'Samadhan', 'course': 'Python', 'institute': 'CIIT Training Institute 🫠👀..'}
<class 'dict'>

10. NoneType

None represents the absence of a value. It is commonly used when a variable currently has no meaningful value.

result = None

print(result)
print(type(result))

Output

None
<class 'NoneType'>

Checking Data Type using type()

The type() function tells us the type of a value or variable.

name = "Samadhan"
age = 25
salary = 45000.50
is_active = True

print(type(name))
print(type(age))
print(type(salary))
print(type(is_active))

Output:

<class 'str'>
<class 'int'>
<class 'float'>
<class 'bool'>

Data Type Conversion

Python provides functions such as int(), float(), and str() to convert values from one data type to another.

age = "25"

age_number = int(age)

print(age_number)
print(type(age_number))

Output:

25
<class 'int'>

Detailed type conversion will be covered in the next topic: Type Conversion.

age = 25
percentage = 85.5
name = "Samadhan"
is_student = True
courses = ["Python", "C#", "Java"]
student = {"name": "Samadhan", "age": 25}

print(age, type(age))
print(percentage, type(percentage))
print(name, type(name))
print(is_student, type(is_student))
print(courses, type(courses))
print(student, type(student))

25 <class 'int'>
85.5 <class 'float'>
Samadhan <class 'str'>
True <class 'bool'>
['Python', 'C#', 'Java'] <class 'list'>
{'name': 'Samadhan', 'age': 25} <class 'dict'>