John Joseph
John Joseph

Reputation: 199

python global name not defined-homework

from math import *
class GeometricObject():
     def __init__(self, color = "green", filled = True):
        self.color = color
        self.filled = filled

    def __str__(self):
        return "color: " + self.__color + \
               " and filled: " + str(self.__filled)


class Triangle(GeometricObject):
    def __init__(self, side1 = 1, side2 = 1, side3 = 1):
        super().__init__()
        self.side1 = float(side1)
        self.side2 = float(side2)
        self.side3 = float(side3)

    def getArea(self):
        return self.area

    def setArea(self, side1, side2, side3):
        s = (side1 + side2 + side3)/2
        area = sqrt(s*(s-side1)*(s-side2)*(s-side3))
        self.area = area

    def getPerimeter(self):
        return self.perimeter

    def setPerimeter(self, side1, side2, side3):
        perimeter = side1 + side2 + side3
        self.perimeter = perimeter

    def __str__(self):
        return "Triangle: " + "side 1 = " + str(self.side1)+ \
               " " + "side 2 = " + str(self.side2) + " " + \
                "side 3 = " + str(self.side3)

def main():
    side1 = eval(input("Enter a value for side 1: "))
    side2 = eval(input("Now enter a value for side 2: "))
    side3 = eval(input("Now enter a value for side 3: "))
    color = input("Enter the color of the triangle: ")
    filled = input("Enter true(filled) or false(not filled) " + \
                   "for the triangle being filled: ")
    go = GeometricObject(color, filled)
    tri = Triangle(side1, side2, side3)
    tri.setArea(side1, side2, side3)
    tri.setPerimeter(side1, side2, side3)

    print("\n\n")
    print("A Triangle: ", tri.__str__(), go.__str__())
    print("The area is: ", tri.getArea())
    print("The perimeter is: ", tri.getPerimeter())

main()

Above is my code and the error I am getting I don't understand, most of the code is direct from the book examples and adjusted to fit my program. What can I do to get this to work the way I need it to. This is for homework and I could really use some help to figure out what is wrong in my code.

This it not really an error but how can I get the GeometricObject color and filled properties to display after the other triangle information.

Enter a value for side 1: 3
Now enter a value for side 2: 4
Now enter a value for side 3: 5
Enter the color of the triangle: blue
Enter 1(filled) or 0(not filled) for the triangle being filled: 1



A Triangle:  Triangle: side 1 = 3.0 side 2 = 4.0 side 3 = 5.0 <__main__.GeometricObject object at 0x000000000312EA20>
The area is:  6.0
The perimeter is:  12

Upvotes: 0

Views: 2024

Answers (2)

David C
David C

Reputation: 7484

Your problem is in this function:

def __str__(self):
  return "Triangle: " + "side 1 = " + str(side1) +\
    "side 2 = " + str(side2) + "side 3 = " + str(side3)

The NameError is saying that it doesn't recognize the variable 'side1' because 'side1' is never declared in that scope.

Now, a question: where are side1, side2, and side3 getting referenced from? How can you change them?

Upvotes: 1

Moshe
Moshe

Reputation: 9839

The problem is that the instance variables in tri.__str__ are not being accessed properly. In order to access a variable belonging to an instance of the class, you need to preface the name with self.

The variables names are also incorrect within the function: they should be __side1, __side2, and __side3.

Replace your __str__ function with this, and it should work:

def __str__(self):
    return "Triangle: " + "side 1 = " + str(self.__side1) +\
            "side 2 = " + str(self.__side2) + "side 3 = " + str(self.__side3)

Upvotes: 1

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