Property: when reading a variable isn't just reading a variable

 

Ever felt limited by plain variables in your Python classes? Fear not, the @property decorator swoops in like a superhero to add some superpowers ‍* to your code!

With @property, accessing a variable becomes an action, not just a read. Let's see how it elevates our humble Fraction class:

class Fraction:
  def __init__(self, numerator, denominator):
    self.numerator = numerator
    self.denominator = denominator

  @property
  def value(self):
    """Calculates and returns the actual fraction value."""
    if self.denominator == 0:
      raise ZeroDivisionError("Oops! Denominator can't be zero.")  # Handle division by zero
    return self.numerator / self.denominator

  @value.setter  # Setter for the "value" property
  def value(self, new_value_tuple):
    """Sets the numerator and denominator based on the provided value."""
    numerator, denominator = new_value_tuple 
    self.numerator = numerator
    self.denominator = denominator

 

Usage:

frac1=Fraction(1,2)

print( frac1.value ) #no need to use empty-braces "frac1.value()"

#call the "value" method decorated with @value.getter;

frac1.value = ( 3,4 ) #this is not name binding

#this calls the "value" method decorated with @value.setter and modifies the frac1 object 

interactive example:

https://colab.research.google.com/drive/1eLdmgflqqG2UlUgbOyLzHM_8266T-NMr