Magic Methods, Operator Overloads, and Union Types

For this challenge question, you’re going to modify the Point class you previously wrote to add more functionality! (This will mean modifying the point.py file inside lessons/CQ07. If you weren’t able to get full points for CQ07, you can use this file as a baseline.)

0: __str__()

First, you are going to write a __str__ magic method to print out points in a readable way! It should print

x: <x value>; y: <y value>

where <x value> and <y value> are the x and y attributes of the Point, respectively.

Example Usage

$ python 
>>> from lessons.CQ07.point import Point
>>> my_point: Point = Point(1.0, 2.0)
>>> print(str(my_point))
x: 1.0; y: 2.0

1: __mul__()

Now, you are going to add a __mul__() method to overload the multiplication * operator!

The goal is that when multiplying a Point object with a factor: int, it should create a new Point where both the x and y attributes should be the previous points attributes multiplied by factor. (Hint: This is the same functionality as a method you’ve already written in Point!)

Example Usage:

$ python 
>>> from lessons.CQ07.point import Point
>>> my_point: Point = Point(1.0, 2.0)
>>> new_point: Point = my_point * 3
>>> print(new_point)
x: 3.0; y: 6.0

1.1: Union Types

Now, modify __mul__ so that the factor parameter can be either a float or an int!

Example Usage:

$ python 
>>> from lessons.CQ07.point import Point
>>> my_point: Point = Point(1.0, 2.0)
>>> new_point: Point = my_point * 3.0
>>> print(new_point)
x: 3.0; y: 6.0

2: __add__()

Now, you are going to add an __add__() method to overload the addition + operator!

It should behave similarly to multiplication, where it creates a new Point, but now adds to the x and y attributes.

$ python 
>>> from lessons.CQ07.point import Point
>>> my_point: Point = Point(1.0, 2.0)
>>> new_point: Point = my_point + 3.0
>>> print(new_point)
x: 4.0; y: 5.0

2.1: Union Types

Now, modify __add__ so that the factor parameter can be either a float or an int!

3: Default Parameters

Now, you are going to set default parameters for Point() so that when no arguments are given to the constructor, the default values of the x and y attributes are 0.0.

Example Usage

$ python 
>>> from lessons.CQ07.point import Point
>>> my_point: Point = Point()
>>> print(my_point)
x: 0.0; y: 0.0
>>> my_other_point: Point = Point(2.0, 1.0)
>>> print(my_other_point)
x: 2.0; y: 1.0

4: Submission

Create your submission with the following command:

python -m tools.submission lessons/CQ07