class Geeks: 
     def __init__(self): 
          self._age = 0
 
     # using property decorator 
     # a getter function 
     @property
     def age(self): 
         print("getter method called") 
         return self._age 
 
     # a setter function 
     @age.setter 
     def age(self, a): 
         if(a < 18): 
            raise ValueError("Sorry you age is below eligibility criteria") 
         print("setter method called") 
         self._age = a 
 
mark = Geeks() 
 
mark.age = 19
 
print(mark.age)

Source : https://www.geeksforgeeks.org/getter-and-setter-in-python/