Guido Neumann BLOG

from math import sqrt
class vector:
  def __init__(self, data):
    self.data = data
  def __repr__(self):
    return repr(self.data)  
  def __add__(self, other):
    data = []
    for j in range(len(self.data)):
      data.append(self.data[j] + other.data[j])
    return vector(data)  
  def __sub__(self, other):
    data = []
    for j in range(len(self.data)):
      data.append(self.data[j] - other.data[j])
    return vector(data)  
  def __mul__(self, other):
    data = []
    for j in range(len(self.data)):
      data.append(self.data[j] * other.data[j])
    return vector(data)
  def __getitem__(self, data):
    return vector(self.data[data])
  def length(self):
    coll = 0
    for j in range(len(self.data)):
      coll += self.data[j] * self.data[j]
    return sqrt(coll)
###### Examples ######
a = [1, 2, 3]
b = [5, 6, 7]
c = vector(a) + vector(b)
print c
print c[0]
print c.length()