Name mangling với __private

class MyClass:
    def __init__(self):
        self.__private = "secret"
        self._protected = "internal"
        self.public = "open"
 
obj = MyClass()
 
print(obj.public)      # "open" ✅
print(obj._protected)  # "internal" ✅
print(obj.__private)   # AttributeError! ❌
 
# Nhưng...
print(obj._MyClass__private)  # "secret" ✅ What?!

class MyClass:
    def __init__(self):
        self.__x = 10
 
# Python tự động rename
# self.__x → self._MyClass__x

class MyClass:
    def __init__(self):
        self.__private = "secret"
 
obj = MyClass()
print(dir(obj))
# [..., '_MyClass__private', ...]
 
# Access trực tiếp
print(obj._MyClass__private)  # "secret"

class MyClass:
    def __init__(self):
        self.public = "everyone can use"

class MyClass:
    def __init__(self):
        self._protected = "internal use"
        # Convention: Đừng dùng bên ngoài class

class MyClass:
    def __init__(self):
        self.__private = "avoid name collision"
        # Để tránh collision với subclass

class Base:
    def __init__(self):
        self.__id = 1  # Name mangled
 
    def get_id(self):
        return self.__id
 
class Derived(Base):
    def __init__(self):
        super().__init__()
        self.__id = 2  # KHÔNG conflict với Base.__id
 
d = Derived()
print(d.get_id())         # 1 (Base.__id)
print(d._Derived__id)     # 2 (Derived.__id)

class MyClass:
    def __init__(self):
        self._internal = "use with care"  # ✅

class MyClass:
    def __init__(self):
        self.__private = "rarely needed"  # ❌ Overkill