Intermediate Python - 22.2 Practice Help - “Shape Factory”

Question

We are improving our drawing application.
Our application needs to support adding and comparing two Shape objects.
Add the corresponding methods to enable addition + and comparison using the greater than > operator for the Shape class.

The addition should return a new object with the sum of the widths and heights of the operands, while the comparison should return the result of comparing the areas of the objects.

Please help, thanks! Code in comments.

Answer 1

Sorry, Calvin... here it's the complete code:

class Shape:
def __init__(self, w, h):
self.width = w
self.height = h

def area(self):
return self.width*self.height

def __add__(self, other):
return Shape(self.width + other.width, self.height + other.height)

def __gt__(self, other):
return self.width * self.height > other.width * other.height

Answer 2

In class Shape u need to define the magic method __add__
With parameters self and other
Within create a new instance of shape like demanded and return it.
the two heights are self.height and other.height

Answer 3

class Shape:
def __init__(self, w, h):
self.width = w
self.height = h

def area(self):
return self.width*self.height

w1 = int(input())
h1 = int(input())
w2 = int(input())
h2 = int(input())

s1 = Shape(w1, h1)
s2 = Shape(w2, h2)
result = s1 + s2

print(result.area())
print(s1 > s2)

Answer 4

Zach Z You may revisit the concept of magic methods in Python. Also, the question is a bit vague.

Answer 5

Zach Z Here's the solution:

class Shape:
def __init__(self, x, y):
self.length = x
self.width = y
def __add__(self, obj):
return Shape(self.length + obj.length, self.width + obj.width)
def __gt__(self, obj):
return self.length * self.width > obj.length * obj.width

# Hope this helps

Answer 6

Thanks Calvin Thomas but that doesnt work either? Not sure what im doing wrong here?

Answer 7

class Shape:
def __init__(self, w, h):
self.width = w
self.height = h

def area(self):
return self.width*self.height
def __mul__(self,other):
return ((self.width+other.width)*(self.height+other.height))

def __ge__(self,other):
return self.area>other.area

w1 = int(input())
h1 = int(input())
w2 = int(input())
h2 = int(input())

s1 = Shape(w1, h1)
s2 = Shape(w2, h2)
result = s1 * s2

print(result)
print(s1.area() > s2.area())

Answer 8

class Shape:
def __init__(self, w, h):
self.width = w
self.height = h

def area(self):
return self.width*self.height

def __add__(self, other):
return Shape(self.width + other.width, self.height + other.height)

def __gt__(self, other):
return self.width * self.height > other.width * other.height

w1 = int(input())
h1 = int(input())
w2 = int(input())
h2 = int(input())

s1 = Shape(w1, h1)
s2 = Shape(w2, h2)
result = s1 + s2

print(result.area())
print(s1 > s2)

Answer 9

Thanks Calvin Thomas i couldnt get that to work. Not sure what im going wrong here. Any insignt?

Answer 10

What you sent last has no output. What shoukd the full code be?

Answer 11

Oh, I had thought that you were struggling to make just the class. Add this code to complete it:

A = Shape(int(input()), int(input()))
B = Shape(int(input()), int(input()))
print((A + B).area())
print(A > B)

# Hope this helps

Answer 12

Calvin Thomas i tried combining the code from your two comments but still doesnt work. Can you post the full code or at least comments in order of it ? Thanks!

Answer 13

Zach Z Here you go:

class Shape:
def __init__(self, x, y):
self.length = x
self.width = y
def __add__(self, obj):
return Shape(self.length + obj.length, self.width + obj.width)
def __gt__(self, obj):
return self.length * self.width > obj.length * obj.width

A = Shape(int(input()), int(input()))
B = Shape(int(input()), int(input()))
print((A + B).area())
print(A > B)

# Hope this helps

P.S. I'm sorry for the delay in getting the correct answer, as I can't see the question.

Answer 14

Since the method "area" is defined, why can't I use the code below?

def __gt__(self, other):
return self.area > other.area

Is this not the same as this code?

def __gt__(self, other):
return self.width * self.height > other.width * other.height

Answer 15

Calvin Thomas ya i dont always find the questions clear or always clearly related to the previous lesson.

Appreciate that Oma Falk Can you give more direction, not sure what to do next. Thanks

Answer 16

Zach Z Here's a code with 3 magic methods:

class Complex:
def __init__(self, x, y):
self.real = x
self.imag = y
def __add__(self, *p):
a = self.real
b = self.imag
for x in p:
a += x.real
b += x.imag
return Complex(a, b)
def __str__(self):
a = self.real
b = self.imag
return str(a) * bool(a) + f" {'+' * (b > 0) or '-'} " * bool(a and b) + f"{abs(b)}i" * bool(b)

A = Complex(1, 2)
B = Complex(4, 2)
C = Complex(9, 2)

print(A + B + C)
# 14 + 6i

Magic methods are special methods that are can be called without the parentheses format. Here, the "__init__" magic method is called whenever the Complex objects are created. The "__add__" method is called whenever two such objects are added with each other. Finally, the "__str__" method is called whenever an instance of the class "Complex" gets printed. As you can clearly see, these magic methods are bound by double-underscores on either side ("dunder" methods).

Answer 17

The "__add__" and the "__gt__" magic methods are to be used here. I hope that this helps.

Answer 18

Zach Z What's the error shown? How many test cases are passed?

Answer 19

Calvin Thomas no worries or need to apologize, appreciate the help! Still not working though lol. Here is the orignal code again.

class Shape:
def __init__(self, w, h):
self.width = w
self.height = h

def area(self):
return self.width*self.height

#your code goes here

w1 = int(input())
h1 = int(input())
w2 = int(input())
h2 = int(input())

s1 = Shape(w1, h1)
s2 = Shape(w2, h2)
result = s1 + s2

print(result.area())
print(s1 > s2)

Answer 20

Zach Z Damn! I bet that I'll help you with this one. Let me just take a look at the question myself.

Edit: It seems that I won't be able to skip to the code coach in the Intermediate Python course without completing each of the lessons.