Learn Web Development with Python

Me, myself, and I – using the self variable

From within a class method, we can refer to an instance by means of a special argument, called self by convention. self is always the first attribute of an instance method. Let's examine this behavior together with how we can share, not just attributes, but methods with all instances:

# oop/class.self.pyclass Square:    side = 8    def area(self):  # self is a reference to an instance        return self.side ** 2sq = Square()print(sq.area())  # 64 (side is found on the class)print(Square.area(sq))  # 64 (equivalent to sq.area())sq.side = 10print(sq.area())  # 100 (side is found on the instance)

Note how the area method is used by sq. The two calls, Square.area(sq) and sq.area(), are equivalent, and teach us ...