How did they get this result even though there is a subtraction. P1-P2

Question

class Point:

def __init__(self, x = 0, y = 0):
self.x = x
self.y = y

def __sub__(self, other):
x = self.x + other.x
y = self.y + other.y
return Point(x,y)

p1 = Point(3, 4)
p2 = Point(1, 2)
result = p1-p2
print(result.x, result.y)

result : 4 6

Answer 1

Because you redefined subtraction as addition in sub function, literally you said to - to act as +

Answer 2

This is called 'operator overload': You define what a certain operator is supposed to do with that type.

For example when you add two numbers like 5+5, the result is 10 as you'd expect, but if you write '5' + '5', the result is '55' - because + has been given another meaning.

And __sub__ defines what happens when you use - on that type. (And it can even be nonsense, like in this case.)