title: Use string variable in Python dataframe function
body: <p>If I use </p>
  
  <pre><code>df.loc[(origFull['abc'] == 111)]
  </code></pre>
  
  <p>it will work of course. </p>
  
  <p>Then </p>
  
  <pre><code>test = '(origFull[\'abc\'] == 111)'
  
  df.loc[@test]
  </code></pre>
  
  <p>or</p>
  
  <pre><code>df.loc['@test']
  </code></pre>
  
  <p>Neither worked. </p>