title: python pandas column conditional on two other column values
body: <p>Is there a way in python pandas to apply a conditional if one or another column have a value?</p>
  
  <p>For one column, I know I can use the following code, to apply a test flag if the column Title includes the word "test". </p>
  
  <pre><code>df['Test_Flag'] = np.where(df['Title'].str.contains("test|Test"), 'Y', '')
  </code></pre>
  
  <p>But if I would like to say if column title or column subtitle include the word "test", add the test flag, how could I do that?</p>
  
  <p>This obviously didn't work</p>
  
  <pre><code>df['Test_Flag'] = np.where(df['Title'|'Subtitle'].str.contains("test|Test"), 'Y', '')
  </code></pre>