title: Why does this give me the error string indices must be integers?
body: <pre><code>lloyd = {
  "name": "Lloyd",
  "homework": [90, 97, 75, 92],
  "quizzes": [88, 40, 94],
  "tests": [75, 90]
  }
  alice = {
      "name": "Alice",
      "homework": [100, 92, 98, 100],
      "quizzes": [82, 83, 91],
      "tests": [89, 97]
  }
  tyler = {
      "name": "Tyler",
      "homework": [0, 87, 75, 22],
      "quizzes": [0, 75, 78],
      "tests": [100, 100]
  }
  def average(stuff):
      return sum(stuff)/len(stuff)
  
  def getLetterGrade(score):
      score = round(score)
      if  score &gt;= 90: return "A"
      elif  90 &gt; score &gt;= 80: return "B"
      elif  80 &gt; score &gt;= 70: return "C"
      elif  70 &gt; score &gt;= 60: return "D"
      elif  60 &gt; score: return "F"
  
  def getAverage(kid):
      bar = average
      return bar(kid["homework"])*.1 + bar(kid["quizzes"])*.3 + bar(kid["tests"])*.6
  
  students = ["lloyd","alice","tyler"]
  
  #takes students list
  def getClassAverage(list, total = 0):
      for x in list:
          total += getAverage(x)
      return total / len(list)
  
  #takes students list
  def classAvgFull(list):
      print getClassAverage(list)
      print getLetterGrade(getClassAverage(list))
  
  classAvgFull(students)
  </code></pre>
  
  <p>I honestly just can't figure out where I've gone wrong here.  Any help would be greatly appreciated.  I'm sure it is just something simple.  Very very beginning of my learning, using codeacademy.com  Thank you in advance!</p>