title: Trying to extract a string value between dots from a string column
body: <p>im trying to extract a default string value from a string column but without sucess.</p>
  <p>This is the column with some string values:</p>
  <pre><code>      Unnamed: 0
  57    PA.SQNTURBO.Bb20.0-Serquinutri Turbo - Bb20 L
  58    PA.SQNTURBO.Fr 1l.0-Serquinutri Turbo - Frasco 1l
  59    PA.SQNZ10.Bb 20.0-Serquinutri Zinco 10 - Bb 20 L
  60    PA.sqnbor.Bb 20.0-Serquinutri Serquibor - Bb 20 L
  61    PA.sqnbor.Bb 5.0-Serquinutri Serquibor - Bb 5l
  </code></pre>
  <p>What im trying to reach:</p>
  <pre><code>      Unnamed: 0
  57    SQNTURBO.Bb20
  58    SQNTURBO.Fr 1l
  59    SQNZ10.Bb 20
  60    sqnbor.Bb 20
  61    sqnbor.Bb 5
  </code></pre>
  <p>this is my unsucess code:</p>
  <pre class="lang-py prettyprint-override"><code>
  all_months[&quot;Unnamed: 0&quot;] = all_months[&quot;Unnamed: 0&quot;].str.extract(r&quot;/.(.*)./&quot;, expand=False)
  all_months
  
  </code></pre>
  <p>and the result...</p>
  <pre><code>      Unnamed: 0
  57    NaN
  58    NaN
  59    NaN
  60    NaN
  61    NaN
  </code></pre>
  <p>Could you guys help me? i have a kinda difficult with regex and it just blow my mind when i have to deal with it.</p>