**Python - Student Becomes the Teacher - Part of the Whole**

I just completed 'Part of the Whole' after being stuck on it for a while. I finished it by using a line of code that I took from another forum post; specifically line 46:

`for student in students:`

What I don't understand is how the get_class_average function, well... functions.

From my current understanding, the function begins by creating an empty list, then searching for a variable, 'student', in the argument 'students'. My question is how does the program know what a student is? I don't see where in my code the variable 'student' is defined. Unless it's defined when the get_class_average function calls on the get_average function, which uses 'student' as an argument? But then how is that argument defined?

I'm missing something. I can't seem to trace back where some of the inputs to these arguments are coming from.

Any insight you guys can shed on this would be greatly appreciated!

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