code: def read(self):
          
          if self.getiddname() == None:
              errortxt = ("IDD file needed to read the idf file. "
                          "Set it using IDF.setiddname(iddfile)")
              raise IDDNotSetError(errortxt)
          readout = idfreader1(
              self.idfname, self.iddname, self,
              commdct=self.idd_info, block=self.block)
          (self.idfobjects, block, self.model,
              idd_info, idd_index, idd_version) = readout
          self.__class__.setidd(idd_info, idd_index, block, idd_version)
docs: Read the IDF file and the IDD file. If the IDD file had already been
          read, it will not be read again.
  
          Read populates the following data structures:
  
          - idfobjects : list
          - model : list
          - idd_info : list
          - idd_index : dict