Property Decorator in Python

Introduction

• The property decorator allows defining a method as a property.
• Access methods like attributes.
• Benefits: Add additional logic when reading, writing, or deleting attributes.

Components of Property Decorator

• getter method: To read the attribute.
• setter method: To write the attribute.
• deleter method: To delete the attribute.

Example: Rectangle Class

Constructor

• Initialize with width and height. def __init__(self, width, height): self._width = width self._height = height

Creating Rectangle Object

• Creating a rectangle object and printing attributes: rectangle = Rectangle(3, 4) print(rectangle.width) # Access width attribute print(rectangle.height) # Access height attribute

Private Attributes

• Prefix attributes with _ to make them private: self._width = width self._height = height
  • Indicates attributes meant to be internal and protected.
  • Access through getter methods.

Getter Methods

• Define getter methods using @property decorator: @property def width(self): return f"{self._width:.1f} cm" @property def height(self): return f"{self._height:.1f} cm"

Setter Methods

• Define setter methods using attribute_name.setter decorator: @width.setter def width(self, new_width): if new_width > 0: self._width = new_width else: print("Width must be greater than zero") @height.setter def height(self, new_height): if new_height > 0: self._height = new_height else: print("Height must be greater than zero")

Deleter Methods

• Define deleter methods using attribute_name.deleter decorator: @width.deleter def width(self): del self._width print("Width has been deleted") @height.deleter def height(self): del self._height print("Height has been deleted")

Summary

• Property decorator (@property) allows methods to be accessed as attributes.
• Benefits:
  • Adding logic when reading, writing, and deleting.
• Getter, setter, and deleter methods provide control over attribute access.