[Solved]Python 36 Question Inheritance Polymorphism One Advantage Using Subclasses Ability Use Pol Q37020851

Python 3.6 Question:

Inheritance – Polymorphism

One advantage of using subclasses is the ability to usepolymorphism.

The idea behind polymorphism is that several different types ofobjects can have the same methods, and be treated in the sameway.

For example, have a look at the code we’ve included for thisproblem. We’ve defined Shape as an abstract base class. It doesn’tprovide any functionality by itself, but it does supply aninterface (in the form of .area() and .vertices()methods) which aremeaningful for any type of 2D Shape.

The total_area function makes use of this to calculate the areaof any kind of Shape. We’ve provided an example of this with twoSquare instances.

We want you to write RightAngledTriangle and Rectangle classeswhich implement this interface.

The constructor for RightAngledTriangle accepts one argument,vertices, being a list of the points of the triangle relative toits origin. The first vertex will be at the right angle.

The constructor for Rectangle accepts width and height.

Given Codes:

class Shape():
“””
A representation of a shape.

“””
def __init__(self, origin=(0, 0)):
“””Construct a shape object
  
Parameters:
origin(tuple<int, int>): origin of the shape
  
“””

self.origin = origin

def area(self):
“””
(int) Return the area of the shape.

“””
raise NotImplementedError()

def vertices(self):
“””
Return the vertices of the shape.

Return:
list<tuple<int, int>>: The vertices of the shape, as alist of tuples
representing two dimensional points.
This list may be returned in any order.
  
“””
raise NotImplementedError()

class Square(Shape):
“””A Square object”””
def __init__(self, side_length, origin=(0, 0)):
“””
Construct a square object
  
Parameters:
side_length (int): Length of the sides of the square
origin (tuple<int, int>): Coordinate of topleft corner ofsquare
  
“””
super().__init__(origin=origin)

self.side_length = side_length

def area(self):
“””
(int) Return the area of the shape.
  
“””
return self.side_length * self.side_length

def vertices(self):
“””
Return the vertices of the shape.

Return:
list<tuple<int, int>>: The vertices of the shape, as alist of tuples
representing two dimensional points.
This list may be returned in any order.
  
“””
x, y = self.origin

return [
(x, y),
(x, y + self.side_length),
(x + self.side_length, y + self.side_length),
(x + self.side_length, y),
]

def total_area(shapes):
“””
Return the total area of the given list of shapes.

Parameters:
shapes (list<Shape>): The list of shapes to sum the areafor.

Return:
int: The total area of the list of shapes, being the sum of thearea of
each individual shape.

“””
area = 0.

for shape in shapes:
area += shape.area()

return area

def outer_bounds(shapes):
“””
Return the outer bounds of the given list of shapes.

Parameters:
shapes (list<Shape>): The list of shapes to return the outerbounds for.

Return:
tuple<tuple<int, int>, tuple<int, int>>:

The first element of the tuple is the top-left corner of arectangle
which could enclose every shape in the given list.
The second element of the tuple is the bottom-right corner of thatsame
rectangle.

The top-left corner of the rectangle will be, at minimum, (0,0).

“””
vertices = []

for shape in shapes:
for vertex in shape.vertices():
vertices.append(vertex)

top_left_x = 0
top_left_y = 0
bottom_right_x = 0
bottom_right_y = 0

for x, y in vertices:
if x < top_left_x:
top_left_x = x
elif x > bottom_right_x:
bottom_right_x = x

if y < top_left_y:
top_left_y = y
elif y > bottom_right_y:
bottom_right_y = y

return (top_left_x, top_left_y), (bottom_right_x,bottom_right_y)

# example usage
# note that total_area doesn’t know nor care that we used instancesof Square
shapes = [Square(2), Square(4, origin=(2, 2))]
area = total_area(shapes)

Expert Answer

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Answer to Python 3.6 Question: Inheritance – Polymorphism One advantage of using subclasses is the ability to use polymorphism. Th… . . .