A class is one of the basic units necessary for supporting object-oriented programming (OOP) in programming languages. A class is used to bundle data (attributes) and methods (functions) for manipulating that data together. Using classes allows you to organize the structure of your code well and make it more reusable.<\/p>\n\n\n\n
A class is a blueprint (design) for creating objects. An object is an entity created based on a class, which occupies memory at runtime and has a state that can act.<\/p>\n\n\n\n
A class is defined using the A constructor is a method that is automatically called when an object is created, and it is mainly used to set the initial state of the object. In Python, the A class variable is a variable that is shared by the class, having the same value for all instances. An instance variable is a variable that can have separate values for each object.<\/p>\n\n\n\n A method is a function defined within a class that defines the behavior of the object. Instance methods are usually used, and the first parameter is Inheritance is a technique for creating new classes based on existing classes, which increases code reusability. It is defined in the form Polymorphism is the ability to handle different data types with the same interface. In Python, polymorphism can be implemented through method overriding.<\/p>\n\n\n\n Encapsulation means restricting outside access to some of the implementation details of an object. In Python, it is conventionally indicated by prefixing the variable name with an underscore (private) to represent encapsulation.<\/p>\n\n\n\n Here, we will create an example that includes all the concepts explained above.<\/p>\n\n\n\nclass<\/code> keyword. Class names usually start with an uppercase letter, and the body of the class should be indented.<\/p>\n\n\n\nclass Car:\n def __init__(self, make, model, year):\n self.make = make\n self.model = model\n self.year = year\n<\/code><\/pre>\n\n\n\n4. Constructor and Destructor<\/h2>\n\n\n\n
__init__<\/code> method serves this purpose. A destructor is called when an object is deleted and can be defined with the __del__<\/code> method.<\/p>\n\n\n\n5. Class Variables and Instance Variables<\/h2>\n\n\n\n
class Car:\n number_of_wheels = 4 # Class variable\n\n def __init__(self, make, model, year):\n self.make = make # Instance variable\n self.model = model # Instance variable\n self.year = year # Instance variable\n<\/code><\/pre>\n\n\n\n6. Defining Methods<\/h2>\n\n\n\n
self<\/code>, which allows access to the object itself.<\/p>\n\n\n\nclass Car:\n def start_engine(self):\n print(\"Engine started\")\n<\/code><\/pre>\n\n\n\n7. Inheritance<\/h2>\n\n\n\n
class DerivedClass(BaseClass):<\/code>.<\/p>\n\n\n\nclass ElectricCar(Car):\n def __init__(self, make, model, year, battery_size):\n super().__init__(make, model, year)\n self.battery_size = battery_size\n<\/code><\/pre>\n\n\n\n8. Polymorphism<\/h2>\n\n\n\n
class Animal:\n def sound(self):\n pass\n\nclass Dog(Animal):\n def sound(self):\n return \"Woof!\"\n\nclass Cat(Animal):\n def sound(self):\n return \"Meow!\"\n<\/code><\/pre>\n\n\n\n9. Encapsulation<\/h2>\n\n\n\n
10. Example of Using Classes<\/h2>\n\n\n\n
class Book:\n def __init__(self, title, author, pages):\n self.title = title\n self.author = author\n self._pages = pages # Private variable\n\n def __str__(self):\n return f\"{self.title} by {self.author}\"\n\n def set_pages(self, pages):\n if pages > 0:\n self._pages = pages\n else:\n raise ValueError(\"The number of pages must be positive.\")\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"