Introduction 🌟
**Single Inheritance** is the simplest form of inheritance in Python. It allows a **child class** to inherit from **one parent class**, gaining its attributes and methods. This promotes **code reuse**, **clean structure**, and **modular design**.
Note
💡 Parent Class = Base Class
💡 In Single Inheritance → One Parent → One Child
1. Basic Example of Single Inheritance 🧱
basic_single_inheritance.py
class Parent:
def display(self):
print("This is the Parent class")
class Child(Parent):
pass
c = Child()
c.display()✔ Child inherits the display() method
✔ No need to rewrite parent methods
2. Adding New Methods in Child Class ✨
child_methods.py
class Parent:
def display(self):
print("Parent class method")
class Child(Parent):
def show(self):
print("Child class method")
c = Child()
c.display()
c.show()✔ Child can have its own unique methods too.
3. Overriding Parent Methods (Polymorphism) 🔄
override_method.py
class Parent:
def greet(self):
print("Hello from Parent")
class Child(Parent):
def greet(self):
print("Hello from Child")
c = Child()
c.greet()✔ Same method name, new behavior
✔ Demonstrates polymorphism in inheritance
4. Using super() to Call Parent Methods 🧠
super_example.py
class Parent:
def greet(self):
print("Hello from Parent")
class Child(Parent):
def greet(self):
super().greet()
print("Hello from Child")
c = Child()
c.greet()✔ super() allows you to extend parent functionality instead of replacing it
5. Constructor Inheritance & super() in __init__ 🚀
constructor_inheritance.py
class Parent:
def __init__(self, name):
self.name = name
class Child(Parent):
def __init__(self, name, age):
super().__init__(name)
self.age = age
c = Child("Sathish", 23)
print(c.name, c.age)✔ Parent constructor is reused
✔ Child class extends functionality with new attributes
6. Real-World Example — Employee System 🧑💼
employee_example.py
class Employee:
def __init__(self, name, salary):
self.name = name
self.salary = salary
def details(self):
print(f"Name: {self.name}, Salary: {self.salary}")
class Developer(Employee):
def __init__(self, name, salary, language):
super().__init__(name, salary)
self.language = language
def show_language(self):
print("Coding in:", self.language)
d = Developer("Sathish", 50000, "Python")
d.details()
d.show_language()✔ Child class inherits common details
✔ Adds specialized behavior
7. Example: Vehicle → Car 🚗
vehicle_example.py
class Vehicle:
def start(self):
print("Vehicle starting...")
class Car(Vehicle):
def start(self):
super().start()
print("Car engine roaring...")
c = Car()
c.start()8. Benefits of Single Inheritance 🌟
- ✔ Reduces code repetition
- ✔ Improves code structure & readability
- ✔ Easy to maintain and extend
- ✔ Encourages modular and logical design
- ✔ Foundation for advanced OOP concepts
9. When to Use Single Inheritance? 🎯
- ✔ When you want a simple parent → child relationship
- ✔ When child needs most features of parent
- ✔ When extending functionality with minimal changes
10. Common Mistakes ❌
- ❌ Forgetting to call super().__init__() when overriding constructor
- ❌ Overriding methods unnecessarily
- ❌ Adding unrelated behavior inside child class
Conclusion 🎉
You now fully understand Single Inheritance in Python! Want the next topic? Try Multilevel Inheritance, Multiple Inheritance, Hierarchical Inheritance, Constructor Overriding, or MRO. Just tell me! 😊