code: def insert_column(self, data_array, ckey='temp', index=None):
          
  
          # if it's an integer, use the ckey from the list
          if type(ckey) in [int, int]: ckey = self.ckeys[ckey]
  
          # append/overwrite the column value
          self.columns[ckey] = _n.array(data_array)
          if not ckey in self.ckeys:
              if index is None: self.ckeys.append(ckey)
              else:             self.ckeys.insert(index, ckey)
          
          return self
docs: This will insert/overwrite a new column and fill it with the data from the
          the supplied array.
          
          Parameters
          ----------
          data_array  
              Data; can be a list, but will be converted to numpy array
          ckey        
              Name of the column; if an integer is supplied, uses self.ckeys[ckey]
          index       
              Where to insert this column. None => append to end.