擅长:python、mysql、java
<p><code>operator</code>只是一个字符串,您仍然需要编写使它有意义的代码。你可以这样做:</p>
<pre><code>if operator in ('+', 'add'):
realanswer = rn1 + rn2
elif operator in ('-', 'subtract'):
realanswer = rn1 - rn2
else:
print operator, "is not valid"
</code></pre>