Python计算字母等级

Question

I'm having trouble getting the letter grade to output anything but F for any value of input that is put into the scores. Can anyone figure out what the problem is. It could be something in my if statement isn't correct but I am not sure if that is true.

score1=float(input("Enter score 1: "))
score2=float(input("Enter score 2: "))
score3=float(input("Enter score 3: "))
score4=float(input("Enter score 4: "))
score5=float(input("Enter score 5: "))
scores=[score1, score2, score3, score4, score5]

def determine_grade(scores):

    if score >=90:
        return 'A'
    elif score >=80:
        return 'B'
    elif score >=70:
        return "C"
    elif score >=60:
        return "D"
    elif score <60:
        return "F"

determine_grade(scores)

print("scores \t numeric grade \t letter grade") 
print("-------------------------------------------------------------") 
print("Score 1: ","\t", score1,"\t", determine_grade(score1))
print("Score 2: ","\t", score2,"\t", determine_grade(score2))
print("Score 3: ","\t", score3,"\t", determine_grade(score3))
print("Score 4: ","\t", score4,"\t", determine_grade(score4))
print("Score 5: ","\t", score5,"\t", determine_grade(score5))
print("-------------------------------------------------------------")
calc_average= sum(scores)/len(scores)
print("Average Score: {0:.2f}".format(calc_average))

Answer 1

First, function determine_grade() is expecting a float parameter; but you passed a list of float scores .

Second, within function determine_grade() , there is a mismatch between parameter scores and score .

Moreover, the code can be written in a cleaner way:

num_scores = 5
scores = []
for i in range(num_scores):
    score = float(input("Enter score {}: ".format(i)))
    scores.append(score)


def determine_grade(scores):
    if score >= 90:
        return 'A'
    elif score >= 80:
        return 'B'
    elif score >= 70:
        return "C"
    elif score >= 60:
        return "D"
    elif score < 60:
        return "F"


print("scores\tnumeric grade\tletter grade")
print('-' * 40)
for i in range(num_scores):
    print("Score {}:\t{}\t{}".format(i, scores[i], determine_grade(scores[i])))
print('-' * 40)
calc_average = sum(scores) / len(scores)
print("Average Score: {0:.2f}".format(calc_average))

Answer 2

You should say what the problem is and what the output looks like. Having said that, from a quick glance, I think this is your problem.

def determine_grade(scores):

    if score >=90:
        return 'A'
    elif score >=80:

In your determine_grade function you are passing 'scores' but inside it you are checking the variable 'score' which will throw up an "undefined" error.

Also you don't need this line. You're not really using the return value.

determine_grade(scores)

Answer 3

Other than the issue pointed out by hikerjobs, the line

determine_grade(scores)

will not do what you want it to do, because in that scope, scores is a list, becaues of the line:

scores=[score1,score2,score3,score4,score5]

But your determine_grade function expects a float.

(On that note, I recommend you get into the habit of writing docstrings for your code. It will help catch a lot of simple errors.)

Answer 4

How about this?

grades = {60:'D',70:'C',80:'B',90:'A',100:'A'}

myscore = 72

print(grades.get(int(myscore/10)*10,'F'))