title: Using counter on array for one value while keeping index of other values
body: <p>After reading the answers on this question <a href="https://stackoverflow.com/questions/2161752/how-to-count-the-frequency-of-the-elements-in-a-list">How to count the frequency of the elements in a list?</a> I was wondering how to count the frequency of something, and at the same time retreive some extra information, through something like an index.  For example</p>
  
  <pre><code>a = ['fruit','Item#001']
  b = ['fruit','Item#002']
  c = ['meat','Item#003']
  foods = [a,b,c]
  </code></pre>
  
  <p>Now I want to count how many times fruit is in the list foods.  If I use counter on the first index of each array a,b, and c, the results will have the number of fruit, but I can not access which item it was.  In essence, if I use <code>most_common</code>, I will get a list of the number of times fruit appears, like ('fruit',2), how can I get all the items from both of those occurrences. </p>
  
  <p>I would like to avoid using the attributes like this question <a href="https://stackoverflow.com/questions/28306700/python-how-to-use-counter-on-objects-according-to-attributes">Python how to use Counter on objects according to attributes</a> </p>
  
  <p>Example, where it would be doing what I would like, not necessarily what the Counter method actually does.</p>
  
  <pre><code>counts = Counter(foods)
  counts.most_common(10)
  print counts
  -&gt; (('fruit',2)('meat',1))
  print counts[0].Something_Like_Expand_Method()
  -&gt; ['fruit','Item#001'],['fruit','Item#002']
  </code></pre>