擅长:python、mysql、java
<pre><code>servqual != "great" or "good" or "lacking" or "poor"
</code></pre>
<p>相当于</p>
^{pr2}$
<p>而且由于字符串被认为是<code>True</code>,所以它总是正确的</p>
<p>正确的方法是</p>
<pre><code>servqual != "great" and servqual != "good" and servqual != "lacking" and servqual != "poor"
</code></pre>
<p>或者</p>
<pre><code>servqual not in ("great", "good", "lacking", "poor")
</code></pre>
<p>你的最终代码看起来像</p>
<pre><code>servqual = raw_input(">").lower()
while servqual not in ("great", "good", "lacking", "poor"):
print "I didn't understand that. Please try again."
servqual = raw_input(">").lower()
</code></pre>
<p>您可以使用以下构造进一步改进它。在</p>
<pre><code>while raw_input(">").lower() not in ("great", "good", "lacking", "poor"):
print "I didn't understand that. Please try again."
</code></pre>