class_docstr: SEVIRI L1B handler for HDF4 files.
class_docstr_tok: ["SEVIRI","L1B","handler","for","HDF4","files","."]
docstr: Get the satellite longitude.
docstr_tok: ["Get","the","satellite","longitude","."]
code: def satlon(self):
      """Get the satellite longitude."""
      attr = self["/attr/Sub_Satellite_Longitude"]
      if isinstance(attr, np.ndarray):
          attr = float(attr.astype(str))
      return attr
  
imports: from datetime import datetime
  import numpy
  from satpy.readers._geos_area import get_area_definition, get_area_extent
  from satpy.readers.hdf4_utils import HDF4FileHandler
label_desc: Use image node_id 3 for calling the SEVIRI_ICARE obj's underlying member method code with example usage: obj.satlon() and returns: attr