title: pandas select from Dataframe using startswith
body: <p>This works (using Pandas 12 dev)</p>
  
  <pre><code>table2=table[table['SUBDIVISION'] =='INVERNESS']
  </code></pre>
  
  <p>Then I realized I needed to select the field using "starts with" Since I was missing a bunch.
  So per the Pandas doc as near as I could follow I tried </p>
  
  <pre><code>criteria = table['SUBDIVISION'].map(lambda x: x.startswith('INVERNESS'))
  table2 = table[criteria]
  </code></pre>
  
  <p>And got AttributeError: 'float' object has no attribute 'startswith'</p>
  
  <p>So I tried an alternate syntax with the same result</p>
  
  <pre><code>table[[x.startswith('INVERNESS') for x in table['SUBDIVISION']]]
  </code></pre>
  
  <p>Reference <a href="http://pandas.pydata.org/pandas-docs/stable/indexing.html#boolean-indexing">http://pandas.pydata.org/pandas-docs/stable/indexing.html#boolean-indexing</a>
  Section 4: List comprehensions and map method of Series can also be used to produce more complex criteria:</p>
  
  <p>What am I missing?</p>