17. Public, Protected and Private in Python Classes (Video in Khmer)

Hello friend! 👋 Python use naming rules for public, protected, and private class data. They help show how you should use an attribute.

Important: Python does not fully block access to these attributes. The names show how you should use them.

🌍 Public Attribute

Public attribute can be used inside and outside the class. Use a normal name.

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

student = Student("Dara")
print(student.name)      # Dara

name is public. You can read or change it outside the class.

🛡️ Protected Attribute

Start the name with one underscore _. This means: use it inside the class, or in a child class. It is a Python convention, not a strict rule.

class Student:
    def __init__(self, name):
        self._name = name

    def show_name(self):
        print(self._name)

student = Student("Dara")
student.show_name()      # Dara

_name can still be accessed outside the class, but it is better not to do that.

🔒 Private Attribute

Start the name with two underscores __. Python changes the name inside the class to help avoid accidental access or name conflicts.

class Student:
    def __init__(self, score):
        self.__score = score

    def get_score(self):
        return self.__score

student = Student(95)
print(student.get_score())    # 95

Use a method like get_score() to read the private attribute.

Python does not make it truly private. The double underscore is not a security feature.

🏫 Example: Manage a Classroom

Keep the student list in a class and use methods to add and show students.

class Classroom:
    def __init__(self):
        self.__students = []

    def add_student(self, name):
        self.__students.append(name)

    def show_students(self):
        for student in self.__students:
            print(student)

room = Classroom()
room.add_student("Dara")
room.add_student("Mina")
room.show_students()

Output:

Dara
Mina

🎥 Video: Example Manage Classroom with List of Students (Khmer)

🎥 Video: Using Private, Protected and Public in a Class (Khmer)

📊 Quick Table

Name style	Example	Meaning
Public	`name`	Use it anywhere
Protected	`_name`	Internal use by convention
Private	`__name`	Python changes the name to avoid accidental access

💡 Tips

Use public names for data that is okay to access directly.
One underscore _name means internal use by convention.
Two underscores __name help avoid accidental access and name conflicts.
Use methods when you want to control how data is read or changed.
Python naming conventions do not provide security or fully block access.
Use clear names so your code is easy to understand.

❓ Any Question?

Tell us in comment below! 👇

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