title: How to check if lowercase letters exist?
body: <p>I have been observing unusual behavior with the .<code>islower()</code> and <code>.isupper()</code> methods in Python.  For example:</p>
  
  <pre><code>&gt;&gt;&gt; test = '8765iouy9987OIUY'
  &gt;&gt;&gt; test.islower()
  False
  &gt;&gt;&gt; test.isupper()
  False
  </code></pre>
  
  <p>However, the following mixed string value seems to work:</p>
  
  <pre><code>&gt;&gt;&gt; test2 = 'b1'
  &gt;&gt;&gt; test2.islower()
  True
  &gt;&gt;&gt; test2.isupper()
  False
  </code></pre>
  
  <p>I do not understand this anomaly.  How can I detect lower case letters  as in <code>test</code>?</p>