Python で平均値と評点を計算する

# Calculate average
def calculate_average(total):
    return total / 5


# Grading scale
def find_score(grade):
    if 90 <= grade <= 100:
        return "A"
    elif 80 <= grade <= 89:
        return "B"
    elif 70 <= grade <= 79:
        return "C"
    elif 60 <= grade <= 69:
        return "D"
    else:
        return "F"


# Enter marks of 5 subjects
scores = []
for i in range(1, 6):
    score = int(input("Enter score {0}: ".format(i)))
    print("That's a(n): " + find_score(score))
    scores.append(score)

# sum of all subject marks
total = sum(scores)
avg_marks = calculate_average(total)
final_grade = find_score(avg_marks)

print("Average grade is: " + str(avg_marks))
print("That's a(n): " + str(final_grade))

Enter score 1: 99
That's a(n): A
Enter score 2: 98
That's a(n): A
Enter score 3: 78
That's a(n): C
Enter score 4: 95
That's a(n): A
Enter score 5: 87
That's a(n): B
Average grade is: 91.4
That's a(n): A