Get and Set

Getter and setter are methods for non-direct access to the attributes:

get() (getter) returns the value of the private attribute;
set() (setter) sets the value.

These methods are called properties.

You can implement them by defining two additional methods:


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class Cat:
  def __init__(self, name = 'Kitty', age = 1):
    self.name = name
    self.__age = age
    self.__children = 0 

  # Getter
  def get_age(self):
    return self.__age

  # Setter
  def set_age(self, age):
    if isinstance(age, int) and 0 <= age <= 30:
      self.__age = age
    else:
      print('Invalid value of attribute age')

cat = Cat('Maggie', 3)
# Wrong value
cat.set_age(-23) 
cat.set_age(8)
print(cat.get_age())

Note

We added data validation inside the set_age() method. Only the correct integer value can be assigned to the attribute.

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Cursusinhoud

Object-Oriented Programming in Python

1. Classes and Objects

Classes Objects Implementation Unique Object Constructor

2. Encapsulation

Private and Public Concepts Get and Set Attributes Annotations

3. Inheritance

Inheritance Challenge Method super()

4. Polymorphism

Polymorphism Challenge