title: Codecademy's python - Student Becomes the Teacher - 8/9
body: <p>I guess many of you know the python codecademy course, 
  and there is a specific section, that I saw, many people have trouble with,
  the "Student Becomes the Teacher - 8/9"
  the instructions are a bit unclear, 
  and the problems met by others on the net are not exactly the same as mine here...</p>
  
  <p>when I run this code, I get the correct answer - 83.8666666667
  (I checked the result manually),
  but I still get an error:
  <em>"Oops, try again. get_class_average([alice]) resulted in an error: unsupported operand type(s) for +: 'int' and 'dict'"</em></p>
  
  <p>WHAT AM I MISSING HERE??</p>
  
  <p>Thanks...</p>
  
  <pre><code>lloyd = {
      "name": "Lloyd",
      "homework": [90.0, 97.0, 75.0, 92.0],
      "quizzes": [88.0, 40.0, 94.0],
      "tests": [75.0, 90.0]
  }
  alice = {
      "name": "Alice",
      "homework": [100.0, 92.0, 98.0, 100.0],
      "quizzes": [82.0, 83.0, 91.0],
      "tests": [89.0, 97.0]
  }
  tyler = {
      "name": "Tyler",
      "homework": [0.0, 87.0, 75.0, 22.0],
      "quizzes": [0.0, 75.0, 78.0],
      "tests": [100.0, 100.0]
  }
  
  
  def average(numbers):
      total = sum(numbers)
      total = float(total)
      new_total = total / len(numbers)
      return new_total
  
  #print(average(alice["homework"]))
  
  def get_average(student):
      homework = average(student["homework"])
      quizzes = average(student["quizzes"])
      tests = average(student["tests"])
      return 0.1 * homework + 0.3 * quizzes + 0.6 * tests
  
  #print get_average(tyler)
  
  def get_letter_grade(score):
      if score &gt;= 90:
          return "A"
      elif score &gt;= 80:
          return "B"
      elif score &gt;= 70:
          return "C"
      elif score &gt;= 60:
          return "D"
      else:
          return "F"
  
  #print get_letter_grade(get_average(tyler))
  
  
  def get_class_average(students):
  
      return average(students)
  
  results = []
  results.append(get_average(lloyd))
  results.append(get_average(alice))
  results.append(get_average(tyler))
  
  print get_class_average(results)
  </code></pre>