擅长:python、mysql、java
<p>你需要这样的东西:</p>
<pre><code>StudentGrades = {
"Alcott": [5, 9, 7],
"Jerry": [3, 5, 2],
"David": [8, 9, 8, 9]
}
print("Students:")
for x, y in StudentGrades.items():
print(x, y)
while True:
print("Select a student: ")
name = str(input())
if name in StudentGrades.keys():
print("You have chosen: " + name)
print( sum(StudentGrades[name]) / len(StudentGrades[name]) ). # This is the part of your code that was wrong.
else:
print('You chosen wrong!')
break
</code></pre>
<p>此外,要添加新学生,不应使用<code>student = {'Name': 10}</code>,而应使用<code>student = {'Name': [10]}</code>。与所有其他值一样,该值必须是一个列表</p>