# Chapter 27 example: Point class.

import math

class Point:
    def __init__(self, x, y):
        self.x = x
        self.y = y

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

a = Point(0, 0)
b = Point(3, 4)
print(a.distance(b))   # 5.0

# Try-this: add a move(dx, dy) method and call it on `a`.