Vector.py

from math import sqrt


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

    def __repr__(self):
        return 'Vector({x}, {y})'.format(x=self.x, y=self.y)

    def distance(self, other):
        dx = self.x - other.x
        dy = self.y - other.y
        return sqrt(dx**2 + dy**2)

    def __abs__(self):
        return self.distance(Vector())

    def __add__(self, other):
        dx = self.x + other.x
        dy = self.y + other.y
        return Vector(dx, dy)

    def __mul__(self, n):
        return Vector(self.x*n, self.y*n)


if __name__ == '__main__':
    v = Vector(3, 4)

    # 5.0
    print(abs(v))

    v1 = Vector(2, 4)
    v2 = Vector(2, 1)

    # Vector(4, 5)
    print(v1 + v2)

    # Vector(6, 12)
    print(v1 * 3)