What methods are used to minimize errors when designing systems using object-oriented principles?

To minimize errors in system design using object-oriented principles, the following methods are used:

• Encapsulation — hiding the internal implementation of an object and providing access only through methods, which prevents incorrect usage.
• Inheritance and polymorphism — allow creating extendable and flexible structures, reducing code duplication.
• SOLID principles — a set of rules that help write maintainable and extendable code.
• Use of interfaces and abstract classes — to define contracts and reduce coupling.
• Unit testing — testing individual components to detect errors early.
• Refactoring — regularly improving the code structure without changing its behavior.

Example: applying encapsulation to protect class data.

class BankAccount:
    def __init__(self, balance):
        self.__balance = balance  # private field

    def deposit(self, amount):
        if amount > 0:
            self.__balance += amount

    def get_balance(self):
        return self.__balance

Thus, direct access to the balance is impossible, reducing the risk of errors.