title: Search and filter pandas dataframe with regular expressions
body: <p>I'd appreciate your help. I have a pandas dataframe. I want to search 3 columns of the dataframe using a regular expression, then return all rows that meet the search criteria, sorted by one of my columns. I would like to write this as a function so I can implement this logic with other criteria if possible, but am not quite sure how to do this. </p>
  
  <p>For example, I know how pull the results of a search thusly (with col1 being a column name):</p>
  
  <pre><code>idx1 = df.col1.str.contains(r'vhigh|high', flags=re.IGNORECASE, regex=True, na=False)
  
  print df[~idx1]
  </code></pre>
  
  <p>but I can't figure out how to take this type of action, and perform it with multiple columns and then sort. Anyone have any tips?</p>