# 9. How is everybody doing?

#1

The instructions of this exercise are:

1. Finally, print out the result of calling get_class_average with your students list. Your students should be [lloyd, alice, tyler].

2. Then, print the result of get_letter_grade for the class's average.

The error messages are these:

Traceback (most recent call last):
File "python", line 56, in
File "python", line 53, in get_class_average
File "python", line 28, in get_average
TypeError: string indices must be integers, not str

I didn't convert the variables to string, and even if I put a str(variable), it shows as an invalid syntax. Please anybody can help me to fix this?

``````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]
}

def average(numbers):
total = sum(numbers)
total = float(total)
result = total / len(numbers)
return result

def get_average(student):
homework = average(student["homework"])
quizzes = average(student["quizzes"])
tests = average(student["tests"])
homework = 0.1*homework #retirar parenteses
quizzes = 0.3*quizzes
tests = 0.6*tests
media = sum([homework, quizzes, tests])
return media

#score = get_average(student)
if score >= 90.0:
return "A"
elif score >= 80.0:
return "B"
elif score >= 70.0:
return "C"
elif score >= 60.0:
return "D"
else:
return "F"

def get_class_average(students):
results = []
for student in students:
get = get_average(student)
results.append(get)
return average(results)
print get_class_average(lloyd)
print get_class_average(alice)
print get_class_average(tyler)

#2

where is your `students` list from 3. put it together?

then you can call get_class_average() with students list as arguments

this will give you the average grade for the class, then you can use get_letter_grade to convert this class average grade, into a letter class average grade

#3

I'm sorry, I didn't understand "where is your students list from 3. put it together?"

could you write an example of what you are explaining?

Thank you

#4

put it together is one of the exercises you completed in this track (link), in this you build a list. You are going to need this list. You can use it as argument for get_class_average

#5

Great! It works now.

You are the best!

Thank you!!!

#6