Class Properties in Python

« Previous Next »

Class Properties in Python

Properties are variables that store data inside a class or its objects. Each object created from a class can have its own set of properties.

Defining Properties in a Class

Most properties are defined inside the __init__() method. These are called instance properties because they belong to individual objects.

Example: Create a Class with Properties

class Employee: def __init__(self, emp_id, salary): self.emp_id = emp_id self.salary = salary e1 = Employee(101, 45000) print(e1.emp_id) print(e1.salary)

101 45000

Accessing Object Properties

You can access properties using dot notation: object_name.property_name

Example: Access Properties

class Phone: def __init__(self, brand, price): self.brand = brand self.price = price p1 = Phone("Samsung", 30000) print(p1.brand) print(p1.price)

Samsung 30000

Modifying Properties

Object properties can be updated after the object is created.

Example: Update a Property Value

class User: def __init__(self, name, points): self.name = name self.points = points u1 = User("Amit", 80) print(u1.points) u1.points = 95 print(u1.points)

80 95

Deleting Properties

You can remove a property from an object using the del keyword.

Example: Delete a Property

class Player: def __init__(self, username, level): self.username = username self.level = level p1 = Player("Neo", 7) del p1.level print(p1.username) # print(p1.level) # This will raise an AttributeError

Neo

Class Properties vs Instance Properties

Python supports two types of properties:

[Image contrasting Class Properties shared among all instances versus Instance Properties unique to each object]

Property Type	Description
Instance Properties	Defined inside __init__() and are unique to each object.
Class Properties	Defined directly inside the class body and are shared by all objects.

Example: Class vs Instance Property

class Animal: category = "Mammal" # Class property def __init__(self, name): self.name = name # Instance property a1 = Animal("Dog") a2 = Animal("Cat") print(a1.name) print(a2.name) print(a1.category) print(a2.category)

Dog Cat Mammal Mammal

Modifying Class Properties

When a class property is modified using the class name, the change affects all objects created from that class.

Example: Update a Class Property

class Company: country = "India" def __init__(self, name): self.name = name c1 = Company("TechSoft") c2 = Company("InnoLabs") # Modifying the class property globally Company.country = "USA" print(c1.country) print(c2.country)

USA USA

Adding New Properties to Objects

Python allows you to add new properties to objects dynamically, even after they have been created. This newly added property will only exist for that specific object.

Example: Add Properties at Runtime

class Customer: def __init__(self, name): self.name = name c1 = Customer("Rahul") # Adding properties dynamically c1.email = "rahul@example.com" c1.balance = 1200 print(c1.name) print(c1.email) print(c1.balance)

Rahul rahul@example.com 1200

« Previous Next »

AI Code Explanation Python

Powered by Gocourse AI