Python - Student Becomes the Teacher 9/9


#1

No clue what is wrong, the error message says:
Traceback (most recent call last):
File "python", line 67, in
TypeError: cannot concatenate 'str' and 'float' objects

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) / float(len(numbers))
    return total

def get_average(student):
    homework = average(student["homework"])* 0.1
    quizzes = average(student["quizzes"])* 0.3
    tests = average(student["tests"])* 0.6

    avrg = homework + quizzes + tests
    return avrg

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 "Lloyd:  " + get_letter_grade(get_average(lloyd))
print
print "Alice:  " + get_letter_grade(get_average(alice))
print
print "Tyler:  " + get_letter_grade(get_average(tyler))

students = [lloyd, alice, tyler]

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


print
print
print "Class number average:  " + get_class_average(students)
print "Class letter average:  " + get_letter_grade(get_class_average(students))

#2

Take a look at this line:

print "Class number average:  " + get_class_average(students)

"Class number average: " is a string, get_class_average(students) is a float. You can't add a float to the string. You need to convert the numerical value to string using str function:

print "Class number average:  " + str(get_class_average(students))

Or print both values without concatenation:

print "Class number average:  ", get_class_average(students)

#3

Ohhhhhhhhh very helpful thankyou!


#4

You're very welcome :slight_smile:


#5

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