Notice: This page requires JavaScript to function properly.
Please enable JavaScript in your browser settings or update your browser.
Leer Attributes Annotations | Encapsulation
Object-Oriented Programming in Python

bookAttributes Annotations

Using annotations starting with @ symbol is a special way to define properties.

  • Write @property to define get() method;
  • Write @attribute.setter to define the set() method for the attribute.

We need to do that to explain to Python what these methods are going to be used for.

1234567891011121314151617181920212223
class Cat: def __init__(self, name = 'Kitty', age = 1): self.name = name self.__age = age self.__number_of_legs = 4 @property def age(self): return self.__age @age.setter def 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) # Adding the wrong value cat.age = -100 cat.age = 5 print(cat.age)
copy

Note

  • First, define getter @property and after that – setter @attribute.setter;
  • Both methods have the same name, that is equal to the attribute name;
  • Now, to access the private attribute __age outside the class, you can use the cat.age expression;
question mark

Сhoose the wrong option.

Select the correct answer

Was alles duidelijk?

Hoe kunnen we het verbeteren?

Bedankt voor je feedback!

Sectie 2. Hoofdstuk 3

Vraag AI

expand

Vraag AI

ChatGPT

Vraag wat u wilt of probeer een van de voorgestelde vragen om onze chat te starten.

Suggested prompts:

Stel mij vragen over dit onderwerp

Vat dit hoofdstuk samen

Toon voorbeelden uit de praktijk

bookAttributes Annotations

Veeg om het menu te tonen

Using annotations starting with @ symbol is a special way to define properties.

  • Write @property to define get() method;
  • Write @attribute.setter to define the set() method for the attribute.

We need to do that to explain to Python what these methods are going to be used for.

1234567891011121314151617181920212223
class Cat: def __init__(self, name = 'Kitty', age = 1): self.name = name self.__age = age self.__number_of_legs = 4 @property def age(self): return self.__age @age.setter def 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) # Adding the wrong value cat.age = -100 cat.age = 5 print(cat.age)
copy

Note

  • First, define getter @property and after that – setter @attribute.setter;
  • Both methods have the same name, that is equal to the attribute name;
  • Now, to access the private attribute __age outside the class, you can use the cat.age expression;
question mark

Сhoose the wrong option.

Select the correct answer

Was alles duidelijk?

Hoe kunnen we het verbeteren?

Bedankt voor je feedback!

Sectie 2. Hoofdstuk 3
some-alt