See http://stackoverflow.com/questions/4534612/what-is-the-point-of-heterogenous-arrays/4534652#4534652

Using arrays as a 'struct'.py

import time
import sys

arg = sys.argv[1];

def testFun():
  pass

if arg == 'class':

  class testClass:
    def __init__(self, a, b):
      self.a = a
      self.b = b

  test = testClass(1, testFun)

  t = time.time()
  for i in xrange(30000000):
    a = test.a
    a = test.b

  print time.time() - t

elif arg == 'array':

  testArr = [1, testFun]

  t = time.time()
  for i in xrange(30000000):
    a = testArr[0]
    a = testArr[1]

  print time.time() - t

else:

  print 'type "class" or "array"'