new_contents: import pysal as ps
  import numpy as np
  import unittest as ut
  
  class Test_Table(ut.TestCase):
      def setUp(self):
          self.filehandler = ps.open(ps.examples.get_path('columbus.dbf'))
          self.df = self.filehandler.to_df()
          self.filehandler.seek(0)
          self.shapefile = ps.open(ps.examples.get_path('columbus.shp'))
          self.csvhandler = ps.open(ps.examples.get_path('usjoin.csv'))
          self.csv_df = self.csvhandler.to_df()
          self.csvhandler.seek(0)
  
      def test_to_df(self):
          for column in self.csv_df.columns:
              if column.lower() == 'name':
                  continue
              np.testing.assert_allclose(self.csvhandler.by_col(column), 
                                         self.csv_df[column].values)
          for column in self.df.columns:
              if column == 'geometry':
                  continue
              np.testing.assert_allclose(self.filehandler.by_col(column), 
                                         self.df[column])
  
  
subject: add tests for to_df table method