title: cannot unpack non-iterable object / iteraing through array of objects in python
body: <p>I want to iterate through all objects in an array of URL objects I've got </p>
  
  <pre><code>class Url(object):
      pass
  
  a = Url()
  a.url = 'http://www.heroku.com'
  a.result = 0
  b = Url()
  b.url = 'http://www.google.com'
  b.result = 0
  c = Url()
  c.url = 'http://www.wordpress.com'
  c.result = 0
  
  urls = [a, b, c]
  
  for i, u in urls:
      print(i)
      print(u)
  </code></pre>
  
  <p>However, when I run this script, it comes back with the following error:</p>
  
  <pre><code>TypeError: cannot unpack non-iterable Url object
  </code></pre>
  
  <p>How do I fix this? </p>