Python Encapsulation

Encapsulation is one of the major concept in object oriented programming. It helps to wrap up data and methods into a single unit. Through encapsulation, we can achieve the security and prevent the accidental modification of any attributes in a class

Access Modifiers

Below are the three different types of access modifiers available in python

1. Public Members
2. Private Members
3. Protected Members

Access Modifiers	Own class access	Derived class access	object access
private member	YES	NO	NO
protected member	YES	YES	NO
public member	YES	YES	YES

Public Members

Public members can be accessed from anywhere in the program

#ENCAPSULATION
class Department:
    department = "CS"

class Student(Department):
    def __init__(self, name, age):
        self.name = name
        self.age = 18

    def get_student_age(self):
        return "Age of the student is : {}".format(self.age)

    def get_department_name(self):
        return "Department of the student is : {}".format(self.department)

student = Student("John", 18)
#Public members can access from anywhere
print("Name of the student is : {}".format(student.name))
print(student.get_student_age())
print(student.get_department_name())

Output

Name of the student is : John
Age of the student is : 18
Department of the student is : CS

Protected Members

Protected members cannot be accessed in the child class like the below example

#ENCAPSULATION
class Department:
    _department = "CS"

class Student(Department):
    def __init__(self, name, age):
        self.name = name
        self.age = 18

    def get_student_age(self):
        return "Age of the student is : {}".format(self.age)

    #Child accessing parent protected member- raises exception 
    def get_department_name(self):
        return "Department of the student is : {}".format(self.department)

student = Student("John", 18)
print("Name of the student is : {}".format(student.name))
print(student.get_student_age())
print(student.get_department_name())

Output

Name of the student is : John
Age of the student is : 18
Traceback (most recent call last):
File "<string>", line 21, in <module>
File "<string>", line 15, in get_department_name
AttributeError: 'Student' object has no attribute 'department'

Private Members

Private members cannot be accessed in the child class and its own objects too

#ENCAPSULATION
class Department:
    department = "CS"

class Student(Department):
    def __init__(self, name, age):
        self.__name = name
        self.__age = 18

    def get_student_age(self):
        return "Age of the student is : {}".format(self.__age)

    #Child accessing parent protected member- raises exception 
    def get_department_name(self):
        return "Department of the student is : {}".format(self.department)

student = Student("John", 18)
print(student.get_student_age())
#Raises Exception - Private members cannot access via object
print("Name of the student is : {}".format(student.__name))
print(student.get_department_name())

Output

Age of the student is : 18
Traceback (most recent call last):
File "<string>", line 20, in <module>
AttributeError: 'Student' object has no attribute '__name'