The word 'self' is used to represent the instance of a class. By using the "self" keyword we access the attributes and methods of the class in python.
"__init__" is a reseved method in python classes. It is called as a constructor in object oriented terminology. This method is called when an object is created from a class and it allows the class to initialize the attributes of the class.
Find out the cost of a rectangular field with breadth(b=120), length(l=160). It costs x (2000) rupees per 1 square unit
class Rectangle: def __init__(self, length, breadth, unit_cost=0): self.length = length self.breadth = breadth self.unit_cost = unit_cost def get_area(self): return self.length * self.breadth def calculate_cost(self): area = self.get_area() return area * self.unit_cost # breadth = 120 units, length = 160 units, 1 sq unit cost = Rs 2000 r = Rectangle(160, 120, 2000) print("Area of Rectangle: %s sq units" % (r.get_area()))
This gives the output
Area of Rectangle: 19200 sq units Cost of rectangular field: Rs.38400000