title: How to index a middle character in a list in python
body: <p>Complete the get_mid_letter() function which is passed a list of strings as a parameter. The function returns a string made up of the concatenation of the middle letter of each word from the parameter list. The string returned by the function should be in lowercase characters. If the parameter list is an empty list, the function should return an empty string.</p>
  
  <pre><code>def get_mid_letter(a_list):
      middle_list = []
      for item in a_list:
          middle_index = int(len(item) / 2)
          middle_letter = a_list.index(middle_index)
          middle_list = middle_list + [middle_letter] 
      return middle_list.lower()
  
  def test_get_mid_letter():
      print("1.", get_mid_letter(["Jess", "Cain", "Amity", "Raeann"]))
  </code></pre>
  
  <p>In my case, it shows an error message like "2 is not in the list".
  What can I do to run my code successfully? Thanks!</p>