擅长:python、mysql、java
<p>您忘记缩进if语句</p>
<pre><code>count = 0
gradeA = 0
gradeB = 0
gradeC = 0
gradeD = 0
gradeF = 0
score = int(input("Enter an exam score: "))
while score != -1:
count = count + 1
score = int(input("Enter an exam score: "))
if score >= 90 and score <= 100:
gradeA = gradeA + 1
elif score >= 80 and score <= 89:
gradeB = gradeB + 1
elif score >= 70 and score <= 79:
gradeC = gradeC + 1
elif score >= 60 and score <= 69:
gradeD = gradeD + 1
elif score >= 0 and score <= 59:
gradeF = gradeF + 1
print ("You entered " + str(count) + " exam scores.")
print ("Number of A's = " + str(gradeA))
print ("Number of B's = " + str(gradeB))
print ("Number of C's = " + str(gradeC))
print ("Number of D's = " + str(gradeD))
print ("Number of F's = " + str(gradeF))
</code></pre>