Students becomes the teacher: Part of a Whole


#1



Hey all!
Soo, I am stuck at this exercise:

https://www.codecademy.com/courses/python-beginner-en-qzsCL/1/4?curriculum_id=4f89dab3d788890003000096
and would appreciate some help.

The error that keeps showing up:
Oops, try again. get_class_average([alice]) resulted in an error: list indices must be integers, not str


And my code:

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 = 0
    total = float(total) +sum(numbers)
    total = total / len(numbers)
    return total
    
def get_average(student):
    homework = average(student["homework"])
    quizzes = average(student["quizzes"])
    tests = average(student["tests"])
    
    total = homework *0.1 + quizzes*0.3 + tests * 0.6
    return total
    
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"
        
def get_class_average(students):
    results =[]
    for student in students:
        results.append(get_average(students))
    return average(results)


Any help would be greatly appreciated!


#2

you need to define a global variable named students that contains a list with all three dictionaries.

students = ['lloyd', 'alice', 'tyler']

Global variable meaning - before and outside any function.

And on this line, there's a small typo.

It should be student referring to the loop variable and not students reffering to the global variable. :slight_smile:


#3

Thanks in advance, i got it! :slight_smile:


#4

this is the fault

note the

should not be students but student.
BTW this is the code i just wrote it in like 3 min easy peasy.

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) / len(numbers)
    return total
    
def get_average(student):
    homework = average(student["homework"])
    quizzes = average(student["quizzes"])
    tests = average(student["tests"])
    
    return 0.1 * homework + 0.3 * quizzes + 0.6 * tests 
    
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 item in students:
        results.append(get_average(item))
    return average(results)
    
print get_class_average(students)
print get_letter_grade(get_class_average(students))

#5

I manage to get it correct without defining a list that include all the student dictionaries. Using

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

I found out that as long as the parameter in the get_class_average function (def get_class_average(students)) is the same as the variable in the for loop (for i in students:), codeacademy will mark you correct.

However, if I create a global list that is not named the same as the parameter in the function and use that in the for loop , codeacademy will mark you incorrect even though it works as it supposes to be.


#6

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