Inheritance in Python

Inheritance is one of the key concepts in object-oriented programming (OOP). In Python, inheritance allows you to define a class that inherits all the methods and properties from another class. The class that is being inherited from is called the base class, and the class that inherits from the base class is called the derived class. In this lesson, we'll explore how to use inheritance in Python and how it can help you write more efficient and maintainable code.

Creating a Derived Class in Python

To create a derived class in Python, you simply need to specify the name of the base class in parentheses after the name of the derived class. The derived class will inherit all the attributes (methods and properties) of the base class, and you can also add your own attributes to the derived class.

class BaseClass:
    def __init__(self, name, age):
        self.name = name
        self.age = age
        
    def get_name(self):
        return self.name
    
    def get_age(self):
        return self.age

class DerivedClass(BaseClass):
    def __init__(self, name, age, gender):
        super().__init__(name, age)
        self.gender = gender
        
    def get_gender(self):
        return self.gender

In this example, the DerivedClass is inheriting from the BaseClass . The DerivedClass has an additional attribute, gender , and a method called get_gender() , which is not present in the BaseClass . However, the DerivedClass can still use the methods and attributes of the BaseClass , such as get_name() and get_age() .

Overriding Methods in Python

When you inherit a method from a base class, you can override it in the derived class to provide different functionality. To do this, you simply define a method in the derived class with the same name as the method in the base class. The derived class will use the new implementation of the method instead of the one inherited from the base class.

class BaseClass:
    def say_hello(self):
        print("Hello from the BaseClass")

class DerivedClass(BaseClass):
    def say_hello(self):
        print("Hello from the DerivedClass")

In this example, the DerivedClass is overriding the say_hello() method inherited from the BaseClass . When an object of the DerivedClass calls say_hello() , it will print "Hello from the DerivedClass" instead of "Hello from the BaseClass".

Conclusion

Inheritance is a powerful concept in object-oriented programming that allows you to create new classes based on existing classes. In Python, you can use inheritance to create derived classes that inherit all the methods and properties of a base class, and you can also add your own methods and properties to the derived class. Additionally, you can override methods in the derived class to provide different functionality.

In this lesson, we've covered the basics of inheritance in Python. In the next lessons, we'll explore more advanced topics, such as OOP concepts like polymorphism and encapsulation, iterators, generators and closures. By understanding inheritance and these other advanced concepts, you'll be able to write more efficient, maintainable, and powerful Python code.