class_docstr: Reader class for SEVIRI L2 products in GRIB format.
docstr: Read the parameter attributes from the message and create the projection and area dictionaries.
docstr_tok: ["Read","the","parameter","attributes","from","the","message","and","create","the","projection","and","area","dictionaries","."]
code: def _read_attributes(self, gid):
      """Read the parameter attributes from the message and create the projection and area dictionaries."""
      # Read SSP and date/time
      self._ssp_lon = self._get_from_msg(
          gid, "longitudeOfSubSatellitePointInDegrees"
      )
  
      # Read number of points on the x and y axes
      self._nrows = self._get_from_msg(gid, "Ny")
      self._ncols = self._get_from_msg(gid, "Nx")
  
      # Creates the projection and area dictionaries
      self._pdict, self._area_dict = self._get_proj_area(gid)
  
imports: import logging
  from datetime import timedelta
  import dask.array
  import numpy
  import xarray
  from satpy.readers._geos_area import get_area_definition, get_geos_area_naming
  from satpy.readers.eum_base import get_service_mode
  from satpy.readers.file_handlers import BaseFileHandler
  from satpy.readers.seviri_base import PLATFORM_DICT, REPEAT_CYCLE_DURATION, calculate_area_extent
  from satpy.utils import get_legacy_chunk_size
label_desc: Use image node_id 6 for calling the SeviriL2GribFileHandler obj's underlying member method code with example usage: obj._read_attributes(gid) without return types