Getter or setter?

Question

class ComplexNum:
    def __init__(self, x, y):
        self.x = x
        self.y = y
    def real(self):
        return self.x
    def imag(self):
        return self.y
    def get_r(self):
        return math.sqrt(self.y*self.y + self.x*self.x)
    def sqrt(self):
        complexA = cmath.sqrt(complex(self.x, self.y))
        A = ComplexT(complexA.real, complexA.imag)
        return A
    def sub(self, complexNum):
        a = complex(self.x,self.y)
        b = complex(complexNum.x, complexNum.y)
        c = a - b
        return ComplexT(c.real, c.imag)

I am a bit confused about the concept of getters and setters at the moment, What are the methods considered as? getters or setters or something else?

Don't write getters and setters in Python. But these are all getters — juanpa.arrivillaga, Jan 28 '21 at 17:00
Are you looking for [`@property`](https://docs.python.org/3/library/functions.html#property) ? — aneroid, Jan 28 '21 at 17:06
Does this answer your question? [What's the pythonic way to use getters and setters?](https://stackoverflow.com/questions/2627002/whats-the-pythonic-way-to-use-getters-and-setters) — Tomerikoo, Jan 28 '21 at 17:11

score 3 · Answer 1 · answered Jan 28 '21 at 17:00

You only have getters and instance methods here. Nothing is updating self.? = ? outside the constructor

That being said, if you are just doing return self.?, then it's not really necessary as you can access complex_num_instance.? directly without any function calls

score 2 · Answer 2 · edited Jan 28 '21 at 17:04

the methods shown in your code above would be 'getters' as they 'get' some sort of value once they are ran. Notice how they all return something.

IE: number = complexnum.real()

the 'real' method would return self.x and store it in the 'number' variable. the number variable GOT a value from the real method. One convention that is commonly used is to name these methods with the prefix of 'get'. So this method would become 'get_real(self)'

A setter does kind of the opposite. A setter will 'set' a value.

IE: If we wanted to SET the value of self.x you could have a method like this. complexnum.set_x(3). This would set x's value to 3.

Here is your code retyped using these ideas:

# Code 
class ComplexNum:
    def __init__(self, x, y):
        self.x = x
        self.y = y
    def get_real(self):
        return self.x
    def get_imag(self):
        return self.y
    def get_r(self):
        return math.sqrt(self.y*self.y + self.x*self.x)
    def get_sqrt(self):
        complexA = cmath.sqrt(complex(self.x, self.y))
        A = ComplexT(complexA.real, complexA.imag)
        return A

    # Adding a setter
    def set_x(self, value):
        self.x = value

@killderich111 yes because it only returns some value and doesn't set any attributes. A setter is when you have something like `self.attribute = ...` — Tomerikoo, Jan 28 '21 at 17:10
@killderich111 Sorry, a typo. I meant that. "No, it is a getter, because ...". Sorry — Tomerikoo, Jan 28 '21 at 17:20

Getter or setter?

2 Answers2