Code Mess

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]
}

# Add your function below!
def average(values):
    total = float(sum(values))
    count = len(values)
    return total / count

#returns weighted average for a student
def get_average(student):
  total = average(student['homework']) * 0.1 + average(student['quizzes']) * 0.3 + average(student['tests']) * .6
  return total

#returns letter grade from a percentage
def get_letter_grade(percentage):
    grade = 'X'
    if percentage >= 90:
        grade = 'A'
    elif percentage >= 80:
        grade = 'B'
    elif percentage >= 70:
        grade = 'C'
    elif percentage >= 60:
        grade = 'D'
    else:
        grade = 'F'
    return grade

#returns a class average

print get_letter_grade(get_average(lloyd))