Python new operation

 

self.sides = [0 for i in range(no_of_sides)]

This will create the list of initial values zero.

 

class Polygon:

    def __init__(self, no_of_sides):

        self.n = no_of_sides

        self.sides = [0 for i in range(no_of_sides)]

    def inputSides(self):

        self.sides = [float(input("Enter side "+str(i+1)+" : ")) for i in range(self.n)]

    def dispSides(self):

        for i in range(self.n):

            print("Side",i+1,"is",self.sides[i])

class Triangle(Polygon):

    def __init__(self):

        Polygon.__init__(self,3)

    def findArea(self):

        a, b, c = self.sides

        # calculate the semi-perimeter

        s = (a + b + c) / 2

        area = (s*(s-a)*(s-b)*(s-c)) ** 0.5

        print('The area of the triangle is %0.2f' %area)

t = Triangle()

t.inputSides()

print(t.sides1)