code: def dim_lower_extent(self, *args, **kwargs):
          
  
          # The lower extent of any integral dimension is 0 by default
          args = tuple(0 if isinstance(a, (int, np.integer))
              else a for a in args)
          return self._dim_attribute('lower_extent', *args, **kwargs)
docs: Returns the lower extent of the dimensions in args.
  
          .. code-block:: python
  
              t_ex, bl_ex, ch_ex = cube.dim_lower_extent('ntime', 'nbl', 'nchan')
  
          or
  
          .. code-block:: python
  
              t_ex, bl_ex, ch_ex, src_ex = cube.dim_lower_extent('ntime,nbl:nchan nsrc')