class_docstr: VIRR Level 1b reader.
class_docstr_tok: ["VIRR","Level","1b","reader","."]
docstr: Open file and perform initial setup.
docstr_tok: ["Open","file","and","perform","initial","setup","."]
code: def __init__(self, filename, filename_info, filetype_info):
      """Open file and perform initial setup."""
      super(VIRR_L1B, self).__init__(
          filename, filename_info, filetype_info
      )
      LOG.debug(
          "day/night flag for {0}: {1}".format(
              filename, self["/attr/Day Or Night Flag"]
          )
      )
      self.geolocation_prefix = filetype_info["geolocation_prefix"]
      self.platform_id = filename_info["platform_id"]
      self.l1b_prefix = "Data/"
      self.wave_number = "Emissive_Centroid_Wave_Number"
      # Else filename_info['platform_id'] == FY3C.
      if filename_info["platform_id"] == "FY3B":
          self.l1b_prefix = ""
          self.wave_number = "Emmisive_Centroid_Wave_Number"
  
file_path: satpy/satpy/readers/virr_l1b.py
imports: import logging
  from datetime import datetime
  import dask.array
  import numpy
  from pyspectral.blackbody import blackbody_wn_rad2temp
  from satpy.readers.hdf5_utils import HDF5FileHandler
label_desc: Use image node_id 1 to create a new VIRR_L1B object from inherited base classes: HDF5FileHandler with example: obj = VIRR_L1B(filename, filename_info, filetype_info)