exercise link : https://www.codecademy.com/courses/python-beginner-en-qzsCL/1/5?curriculum_id=4f89dab3d788890003000096#

codeacademy give me green light to move on **Congratulations, you've finished this course!**, but python give me **Error**

the error is :

Traceback (most recent call last):

File "python", line 62, in

File "python", line 28, in get_average

TypeError: list indices must be integers, not str

i was expect it will work but it not

```
<html>
<head>
How is Everybody Doing?
</head>
<body>
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(number):
total = sum(number)
total = float(total)/len(number)
return total
def get_average(students):
homework = average(students["homework"])
quizzes = average(students["quizzes"])
tests = average(students["tests"])
homework *= 0.1
quizzes *= 0.3
tests *= 0.6
n= tests + quizzes + homework
return n
def get_letter_grade(score):
if score>= 90:
return "A"
elif score >= 80:
return "B"
elif score >= 70:
return "C"
elif score >= 60:
return "D"
else:
return "F"
print get_letter_grade(get_average(lloyd))
def get_class_average(student):
result = []
for l in student:
t = get_average(l)
result.append(t)
return average(result)
students = [lloyd, alice, tyler]
print get_class_average(students)
for b in students:
print get_letter_grade(get_average(students))
</body>
</html>
```