title: Pandas dataframe column names seem wrong
body: <p>I'm a student and therefore a rookie.  I'm trying to create a Pandas dataframe of crime statistics by neighborhood in San Francisco.  My problem is that I want the column names to be simply "Neighborhood" and "Count".  Instead I seem to be stuck with a separate line that says "('Neighborhood', 'count')" instead of the proper labels.  Here's the code:</p>
  
  <pre><code>df_counts = df_incidents.copy()
  df_counts.rename(columns={'PdDistrict':'Neighborhood'}, inplace=True)
  df_counts.drop(['IncidntNum', 'Category', 'Descript', 'DayOfWeek', 'Date', 'Time', 'Location', 'Resolution', 'Address', 'X', 'Y', 'PdId'], axis=1, inplace=True)
  df_totals=df_counts.groupby(['Neighborhood']).agg({'Neighborhood':['count']})
  df_totals.columns = list(map(str, df_totals.columns)) # Not sure if I need this
  df_totals
  </code></pre>
  
  <p>Output:</p>
  
  <pre><code>('Neighborhood', 'count')
  Neighborhood    
  BAYVIEW     14303
  CENTRAL     17666
  INGLESIDE   11594
  MISSION     19503
  NORTHERN    20100
  PARK        8699
  RICHMOND    8922
  SOUTHERN    28445
  TARAVAL     11325
  TENDERLOIN  9942
  </code></pre>