Python implementation of vector class from 'Math for Game Developers Video Series by Jorge Rodriguez' http://www.youtube.com/watch?v=DxmGxkhhluU&list=PLW3Zl3wyJwWOpdhYedlD-yCB7WQoHf-My

1. vector.py

import math
class Vector(object):
    def __init__(self, x, y):
        self.x = float(x)
        self.y = float(y)
    
    def __add__(self, vector):
        return Vector(vector.x + self.x, vector.y + self.y)        
    
    def __sub__(self, vector):
        return Vector(self.x - vector.x, self.y - vector.y)
    
    def __mul__(self, scalar):
        return Vector(self.x * scalar, self.y * scalar)
    
    def __div__(self, scalar):
        return Vector(self.x / scalar, self.y / scalar)

    @property
    def length(self):
        return math.hypot(self.x, self.y)

    @property
    def length_sqr(self):
        return self.x * self.x + self.y* self.y
    
    def normalized(self):
        return Vector(self.x / self.length, self.y / self.length)

2. Example

'''
Python implementation of vector class from 'Math for Game Developers Video Series by Jorge Rodriguez'
http://www.youtube.com/watch?v=DxmGxkhhluU&list=PLW3Zl3wyJwWOpdhYedlD-yCB7WQoHf-My
''' 

p = Vector(0, -1)
i = Vector(1, 1)
c = Vector(2, -1)

cp = p - c
ip = p - i 

print 'cp length: {}, squared: {}'.format(cp.length, cp.length_sqr)
print 'ip length: {}, squared: {}'.format(ip.length, ip.length_sqr)

3. output

cp length: 2.0, squared: 4.0
ip length: 2.2360679775, squared: 5.0