8. part of a whole


#1

i'm a bit confused as to why this code doesn't work? (the error message says: get_class_average(alice) should return a number)

shouldn't we loop over the class_list to get the average grade for each student? /:

thank you so much!

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 = sum(numbers)
    total = float(total)
    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:
        return "B"
    elif score >= 70:
        return "C"
    elif score >= 60:
        return "D"
    else:
        return "F"

students = [lloyd, alice, tyler]

def get_class_average(students):
    results = []
    for student in students:
        return results.append(get_average(student))
    return average(results)

8. Part of the Whole
#2

here:

return results.append(get_average(student))

a function ends the moment a return keyword is reached, the loop is used to append each student average grade to the results list, so no need to use return here


#3

thank you so much! so when should we use the "return" keywords in general? (":

do you have any idea why the error now reflects as: "Oops, try again. get_class_average([alice, lloyd]) returned 91.15 instead of 85.85 as expected"

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 = sum(numbers)
    total = float(total)
    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:
        return "B"
    elif score >= 70:
        return "C"
    elif score >= 60:
        return "D"
    else:
        return "F"
students = [lloyd, alice, tyler]
def get_class_average(students):
    results = []
    for student in students:
        results.append(get_average(student))
        return average(results)

#4

by default, when a function ends, it return None. By using the return keyword, we can let the function return something different then None.

We determined the function ends the moment a return keyword is reached, so your loop now only makes one itration


#5

thank you!!! i get it now!!!! (": so the return average(results) needs to be outside the "for" function?


#6

outside the for loop, yes


#7

This topic was automatically closed 7 days after the last reply. New replies are no longer allowed.