code: def insert(self, loc, column, value, allow_duplicates=False,
                 inplace=False):
          
          out = self if inplace else self.copy()
          out._frame.insert(loc, column, value,
                            allow_duplicates=allow_duplicates)
          if not inplace:
              return out
docs: Insert column into molecule at specified location.
  
          Wrapper around the :meth:`pandas.DataFrame.insert` method.