code: def fill_cells(self, dialect, has_header, choices=True):
          
  
          # Get columns from csv
          first_line = get_first_line(self.csvfilepath, dialect)
          self.shape[1] = no_cols = len(first_line)
  
          if no_cols > self.GetNumberCols():
              missing_cols = no_cols - self.GetNumberCols()
              self.AppendCols(missing_cols)
  
          elif no_cols < self.GetNumberCols():
              obsolete_cols = self.GetNumberCols() - no_cols
              self.DeleteCols(pos=no_cols - 1, numCols=obsolete_cols)
  
          # Retrieve type choices
          digest_keys = self.get_digest_keys()
  
          # Is a header present? --> Import as strings in first line
          if has_header:
              for i, header in enumerate(first_line):
                  self.SetCellValue(0, i, header)
  
          if choices:
              # Add Choices
              for col in xrange(self.shape[1]):
                  choice_renderer = ChoiceRenderer(self)
                  choice_editor = wx.grid.GridCellChoiceEditor(
                      self.digest_types.keys(), False)
                  self.SetCellRenderer(has_header, col, choice_renderer)
                  self.SetCellEditor(has_header, col, choice_editor)
                  self.SetCellValue(has_header, col, digest_keys[col])
  
          # Fill in the rest of the lines
  
          self.dtypes = []
          for key in self.get_digest_keys():
              try:
                  self.dtypes.append(self.digest_types[key])
              except KeyError:
                  self.dtypes.append(types.NoneType)
  
          topleft = (has_header + 1, 0)
  
          digest_gen = csv_digest_gen(self.csvfilepath, dialect, has_header,
                                      self.dtypes)
  
          for row, col, val in cell_key_val_gen(digest_gen, self.shape, topleft):
              self.SetCellValue(row, col, val)
  
          self.Refresh()
docs: Fills the grid for preview of csv data
  
          Parameters
          ----------
          dialect: csv,dialect
          \tDialect used for csv reader
          choices: Bool
          \tCreate and show choices