Please clarify it better

Question

*Please clarify it better (step 1/4 - Python OO/Magic Methods)*

Considering the code below, why are x and y used in the __add__ magic method?

Is it because class Vector2D exposes x and y to all its underlying methods despite they (x and y) are local to __init__?

Please forgive my ignorance. I believe that should be a bit clearer as this is Python.

class Vector2D:
def __init__(self, x, y):
self.x = x
self.y = y
def __add__(self, other):
return Vector2D(self.x + other.x, self.y + other.y)

Answer 1

I'm not totally sure what you are asking, but I'll give it a shot!

The `__add__` method doesn't use `x` and `y`, rather it uses `self.x` and `self.y`, which were set in the `__init__` method. The `x` and `y` variables are not visible inside `__add__`.

`self` is a special variable that refers to the current object, and you can set variables on it. That is not really related to magic methods though - a lot of variable setting happens in `__init__` because it is the first thing that happens after object creation, but you can do it from everywhere.

class Foo:
def __init__(self):
self.x = 4
def not_init(self):
self.y = 10 # totally works

bar = Foo() # __init__ is called here
bar.not_init()
bar.z = 5 # totally works too

print(bar.x + bar.y + bar.z) # 19

Hope this helps!