class_docstr: File handler for NUCAPS netCDF4 format.
class_docstr_tok: ["File","handler","for","NUCAPS","netCDF4","format","."]
docstr: Return orbit number for the beginning of the swath.
docstr_tok: ["Return","orbit","number","for","the","beginning","of","the","swath","."]
code: def start_orbit_number(self):
      """Return orbit number for the beginning of the swath."""
      try:
          return int(self["/attr/start_orbit_number"])
      except KeyError:
          return 0
  
imports: import logging
  from collections import defaultdict
  import numpy
  import pandas
  import xarray
  from satpy.readers.netcdf_utils import NetCDF4FileHandler
  from satpy.readers.yaml_reader import FileYAMLReader
label_desc: Use image node_id 6 for calling the NUCAPSFileHandler obj's underlying member method code with example usage: obj.start_orbit_number() and returns: int, int