擅长:python、mysql、java
<p>首先,您的条件需要是<code>and</code>s,而不是{<cd2>}s</p>
<pre><code>if 100 >= average >= 90: # same as if 100 >= average and average >= 90
print('A')
elif 89 >= average >=80:
print('B')
elif 79 >= average >= 70:
print('C')
elif 69 >= average >= 60:
print('D')
else:
print('F')
</code></pre>