Encapsulation Principle

Encapsulation is one of the 4 main OOP principles.

It protects the class data from access outside the class body.

Members that are supposed to be accessed only in the class are labeled with __ prefix.

Example of encapsulation

class Car: # Getter and setters that control access # to the private members: def getModel(self): return self.__model def setModel(self, value): self.__model = value def getManifactureYear(self): return self.__manifactureYear def setManifactureYear(self, value): self.__manifactureYear = value car = Car() car.setModel("Toyota Corolla") car.setManifactureYear(2020) print("Year:", car.getManifactureYear()) print("Model:", car.getModel())

Result:

Year: 2020 Model: Toyota Corolla

Explanation:

• The private members (__model and __manifactureYear) are supposed to be accessed / modified by functions defined inside the class (in this case getters and setters).
• Access outside the class is done via the getters and setters.

Example of no encapsulation

class Car: pass car = Car() car.model = "Toyota Corolla" car.manifactureYear = 2020 print("Year:", car.manifactureYear) print("Model:", car.model)

Output:

Year: 2020 Model: Toyota Corolla

All members are accessed outside the class body.