Hey I've been looking trough the posts but I haven't seen a solution to my problem. Can anybody help?

Error:

Traceback (most recent call last):

File "python", line 57, in

File "python", line 28, in get_average

TypeError: list indices must be integers, not str

```
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]
}
students = [lloyd, alice, tyler]
# Add your function below!
def average(numbers):
sum(numbers)
total = sum(numbers)
total = float(total)
average = total / len(numbers)
return average
def get_average(student):
homework = average(student["homework"])
quizzes = average(student["quizzes"])
tests = average(student["tests"])
homework = homework * 0.1
quizzes = quizzes * 0.3
tests = tests * 0.6
return float(homework) + float(quizzes) + float(tests)
def get_letter_grade(score):
if (score >= 90):
return "A"
print "A"
elif (score >= 80 and score < 90):
return "B"
print "B"
elif (score >= 70 and score < 80):
return "C"
print "C"
elif (score >= 60 and score < 70):
return "D"
print "D"
else:
return "F"
print "F"
def get_class_average(students):
results = []
for students in students:
results.append(get_average(students))
return average(results)
print get_class_average([lloyd, alice, tyler])
print get_letter_grade(get_average(students))
```