title: How to replace substring in column values?
body: <p>I have this DataFrame:</p>
  <pre><code>feed
  ==========
  garden_1
  garden_2
  equipment
  device
  </code></pre>
  <p>I need to replace <code>garden_*</code> with <code>total_*</code>.</p>
  <p>How ca  I do it?</p>
  <p>This is what I tried?</p>
  <pre><code>df[&quot;feed&quot;] = np.where((&quot;garden&quot; in df.feed), &quot;total&quot;, df.feed)
  </code></pre>