title: Conditional searches on pandas Dataframe
body: <p>I'm trying to filter a Pandas dataframe. The format of the data is a block of data with whitespace in between.</p>
  
  <pre><code>data1, data2
  
  val1,  val2
  val1,  val2
  
  val1,  val2
  </code></pre>
  
  <p>I want to filter the blocks but keep the whitespace in the dataframe. My code that should do this is:</p>
  
  <pre><code>df = df.loc[(df['data2'] &gt;= threshold) and (df['data2'] == '')]
  </code></pre>
  
  <p>but this returns the error:</p>
  
  <pre><code>ValueError: The truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all().
  </code></pre>
  
  <p>I've tried inserting these methods into my line, but nothing seems to work, it's probably my sleeop-deprived brain but if anyone </p>