title: print an array as a tree
body: <p>I have an array(tree) like:</p>
  
  <pre><code>['Humidity\n', ['High', ['Outlook\n', ['Sunny', ['Temp\n', ['Hot', ['Wind\n', ['Weak', ['No']], ['Strong', ['No']]]], ['Mild', ['No']]]], ['Overcast', ['Temp\n', ['Hot', ['Yes']], ['Mild', ['Yes']]]], ['Rain', ['Temp\n', ['Mild', ['Wind\n', ['Weak', ['Yes']], ['Strong', ['No']]]]]]]], ['Normal', ['Wind\n', ['Weak', ['Outlook\n', ['Rain', ['Yes']], ['Overcast', ['Temp\n', ['Cool', ['Yes']], ['Hot', ['Yes']]]], ['Sunny', ['Yes']]]], ['Strong', ['Temp\n', ['Cool', ['No']], ['Mild', ['Outlook\n', ['Rain', ['Yes']], ['Sunny', ['Yes']]]]]]]]]
  </code></pre>
  
  <p>I want to print it as a tree. Here is my attempt</p>
  
  <pre><code>def printTree(treeToPrint, tab):
      print tab + treeToPrint[0]
      newTab = tab + "--"
      nextTree = treeToPrint[1:]
      for tree in nextTree:
          print newTab + tree[0]
          printTree(tree[1], newTab + "--")
  </code></pre>
  
  <p>It is printing output like:</p>
  
  <pre><code>Humidity
  
  --High
  ----Outlook
  
  ------Sunny
  --------Temp
  
  ----------Hot
  ------------Wind
  
  --------------Weak
  ----------------No
  --------------Strong
  ----------------No
  ----------Mild
  ------------No
  ------Overcast
  --------Temp
  
  ----------Hot
  ------------Yes
  ----------Mild
  ------------Yes
  ------Rain
  --------Temp
  
  ----------Mild
  ------------Wind
  
  --------------Weak
  ----------------Yes
  --------------Strong
  ----------------No
  --Normal
  ----Wind
  
  ------Weak
  --------Outlook
  
  ----------Rain
  ------------Yes
  ----------Overcast
  ------------Temp
  
  --------------Cool
  ----------------Yes
  --------------Hot
  ----------------Yes
  ----------Sunny
  ------------Yes
  ------Strong
  --------Temp
  
  ----------Cool
  ------------No
  ----------Mild
  ------------Outlook
  
  --------------Rain
  ----------------Yes
  --------------Sunny
  ----------------Yes
  </code></pre>
  
  <p>Can somebody help me represent this tree in a pretty format.</p>