擅长:python、mysql、java
<pre><code>Python 2.7.1+ (r271:86832, Apr 11 2011, 18:13:53)
>>> 3 in [1, 2, 3] # To know if a value is in a list
True
>>> 3 in {1: 'one', 2: 'two', 3: 'three'} # To know if a value is in keys of a dict
True
>>> 'three' in {1: 'one', 2: 'two', 3: 'three'}.values() # To know if a value is in values of a dict
True
>>>
</code></pre>
<p>如果要验证值是否在列表/目录中<em>而不是</em>,请使用<code>not in</code>而不是<code>in</code></p>