Python - operator overloading in vector math

Question

Code:

class Vector:
    def __init__(self):
        self.x = 0.0
        self.y = 0.0

    def __mul__(self, scalar):
        v = Vector()
        v.x = self.x * scalar
        v.y = self.y * scalar
        return v    


v = Vector()
v.x = 2
v.y = 5
v = v * 2

Question: is there a way to overload mul operator in a way that this becomes possible:

v = 2 * v

?

Answer 1

Use __rmul__ :

def __rmul__(self, scalar):  # self: right operand (Vector)
    v = Vector()
    v.x = self.x * scalar
    v.y = self.y * scalar
    return v    

__rmul__ called when the left-hand operand does not support the corresponding operation ( __mul__ ).