What is encapsulation in Python?

Encapsulation is an OOP principle where an object's internal data is hidden from direct outside access.

Naming conventions:

In Python, there are no strict access modifiers (private, public). Instead, conventions are used:

• name — public attribute, accessible to everyone.
• _name — "protected" (by convention), intended for internal use only.
• __name — "private", Python applies name mangling (changing the name).

class BankAccount:
    def __init__(self, balance):
        self.__balance = balance  # "Private" attribute

    def get_balance(self):
        return self.__balance

account = BankAccount(1000)
# print(account.__balance)  # AttributeError
print(account.get_balance())  # 1000

# Name mangling — the attribute is accessible via the modified name
print(account._BankAccount__balance)  # 1000

@property — controlled access:

Allows using methods as if they were attributes:

class Temperature:
    def __init__(self, celsius):
        self._celsius = celsius

    @property
    def celsius(self):
        return self._celsius

    @celsius.setter
    def celsius(self, value):
        if value < -273.15:
            raise ValueError("Below absolute zero!")
        self._celsius = value

    @property
    def fahrenheit(self):
        return self._celsius * 9 / 5 + 32

temp = Temperature(25)
print(temp.celsius)     # 25
print(temp.fahrenheit)  # 77.0
temp.celsius = 30       # Uses the setter