title: Finding average length of strings in a list
body: <p>I have a large list containing a lot of data which is read from a csv file.
  For simplicity I will give you a dummy list which will have far less data in it.</p>
  
  <pre><code>list1 = ['foo', 'bar', 'bob', 'jess', 'google', 'alphabet']
  </code></pre>
  
  <p>I want to find the average length of strings within the list. I am currently doing it like this:</p>
  
  <pre><code>all_lengths = []
  num_of_strings = len(list1)
  
  for item in list1:
      string_size = len(item)
      all_lengths.append(string_size)
      total_size = sum(all_lengths)
  ave_size = float(total_size) / float(num_of_strings)
  </code></pre>
  
  <p>The problem is that because the real list is so large it is taking an incredibly long time to perform this.</p>
  
  <p>Is there a more optimal or elegant way to perform this.</p>
  
  <p>Also, for what it's worth, using Python2.7</p>