#!/bin/env python

import math     # sqrt
import operator # operators as functions

class Vector(object):
  # constructor
  def __init__(self, coord):
    self.coord = coord  

  # turns the object into string  
  def __str__(self):
    return str(self.coord)
  
  def __abs__(self):
    '''Vector length (Euclidean norm).'''
    return math.sqrt(sum(x*x for x in self.coord))

  def __add__(self, other):
    '''Vector addition.'''
    return map(operator.add, self.coord, other.coord)

if __name__ == "__main__":
    v1 = Vector(range(5))
    print("Vector: ", str(v1));
    print(Vector.__abs__.__doc__, abs(v1))
    print(Vector.__add__.__doc__, v1 + v1)