Oops, try again. get_class_average([alice]) resulted in an error: 'function' object has no attribute '**getitem**'

```
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)
def average(numbers):
return sum(numbers) / float(len(numbers))
def get_average(student):
return average(student["homework"]) * 0.1 + average(student["quizzes"]) * 0.3 + average(student["tests"]) * 0.6
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 getclassaverage(students):
results = []
for student in students:
results.append(get_average(student))
return average(results)
```

I'm really not sure what i'm doing wrong, i have checked other forums about this error and it seems that people get it only when they use [] instead of () but i i'm not using []