title: Pandas GenericGBQException
body: <p>I'm trying to use try/except to query BigQuery tables, sometimes the query may not be correct in which case pandas raises a GenericGBQException error. </p>
  
  <p>My problem is I get name 'GenericGBQException' is not defined when trying to handle this error, example code below:</p>
  
  <pre><code>try:
      df = pd.read_gbq(query, projID)
      query_fail = 0
  except GenericGBQException:
      query_fail = 1
  if query_fail == 1:
      do some stuff
  </code></pre>
  
  <p>I can get by with catching all exceptions though obviously it's not ideal.</p>