code: def split(self, pat, side='left'):
          
          check_type(pat, str)
          check_type(side, str)
  
          # don't want this made with the object
          _split_mapping = {
              'left': 0,
              'right': 1
          }
  
          if side not in _split_mapping:
              raise ValueError('Can only select left or right side of split')
  
          return _series_str_result(self, weld_str_split, pat=pat, side=_split_mapping[side])
docs: Split once each element from the left and select a side to return.
  
          Note this is unlike pandas split in that it essentially combines the split with a select.
  
          Parameters
          ----------
          pat : str
          side : {'left', 'right'}
              Which side of the split to select and return in each element.
  
          Returns
          -------
          Series