CODEWITHSUNDEEP
pythonclassparameters
Jett
Jett

Reputation: 2541

How to make the input into a parameter in a class for Python

I'm suppose to find the perimeter of a triangle using a class and a main() function. I just need to somehow make the inputs equal the parameters in the class. I'm not sure how to do this.

Here is the code so far:

class Triangle:
    def __init__(self):
        self.__side1 = 1.0
        self.__side2 = 1.0
        self.__side3 = 1.0
    def getPerimeter(self):
        return self.__side1+self.__side2+self.__side3
    def __str__(self):
        return "side1 : "+str(self.__side1)+" side2 : "+str(self.__side2)+" side3 : "+str(self.__side3)  

def main():
    side1 = input("Enter first side: ")
    side2 = input("Enter second side: ")
    side3 = input("Enter third side: ")
    t1 = Triangle()
    print("The Perimeter of Triangle : ",t1.getPerimeter())
    print(t1)

main()

So basically how do I make the perimeter equal the inputs.

self.__side1 = side1
self.__side2 = side2
self.__side3 = side3

For example lets say I input 

side1 = 4
side2 = 5
side3 = 2

Then the perimeter should be 11

Upvotes: 1

Views: 155

Answers (2)

Pavel Anossov
Pavel Anossov

Reputation: 62928

Like this:

class Triangle:
    def __init__(self, a, b, c):
        self.__side1 = a
        self.__side2 = b
        self.__side3 = c

    def getPerimeter(self):
        return self.__side1 + self.__side2 + self.__side3

    def __str__(self):
        return "side1 : " + str(self.__side1) + " side2 : " + str(self.__side2) + " side3 : " + str(self.__side3)  

def main():
    side1 = input("Enter first side: ")
    side2 = input("Enter second side: ")
    side3 = input("Enter third side: ")
    t1 = Triangle(int(side1), int(side2), int(side3))
    print("The Perimeter of Triangle : ", t1.getPerimeter())
    print(t1)

main()

Note that you have to convert the inputs to integers, or you'll get '4' + '5' + '2' = '452':

t1 = Triangle(int(side1), int(side2), int(side3))

 

PS: The __str__ method can be simplified by using string formatting:

return "side1: {} side2: {} side3: {}".format(self.__side1, self.__side2, self.__side3)

And further if you didn't use name-mangled quasi-private attributes:

class Triangle:
    def __init__(self, a, b, c):
        self.side1 = a
        self.side2 = b
        self.side3 = c

    def getPerimeter(self):
        return self.side1 + self.side2 + self.side3

    def __str__(self):
        return "side1: {0.side1} side2: {0.side2} side3: {0.side3}".format(self)

Upvotes: 2

Benjamin Hodgson
Benjamin Hodgson

Reputation: 44634

def __init__(self, side1, side2, side3):
    self.side1 = side1
    self.side2 = side2
    self.side3 = side3

Then it's called like this:

t = Triangle(3, 4, 5)  # send in the side lengths

Upvotes: 0

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