birdnotes.py: Objects to represent bird note files

# - - -   B i r d N o t e T r e e . _ r e a d M o n t h

    def _readMonth(self, monthKey):
        '''Convert one month's data file into a BirdNoteSet.

          [ monthKey is a month as "YYYY-MM" ->
              if the month file corresponding to monthKey is
              readable and valid ->
                return a BirdNoteSet instance representing
                that file
              else -> raise IOError ]
        '''

First we create an empty BirdNoteSet and assemble the path name to the month file. Then we use the BirdNoteSet.readFile() method to read it. For documentation on the BirdNoteSet class, see the specification.

        #-- 1 --
        # [ birdNoteSet  :=  a new, empty BirdNoteSet instance using
        #                    self.txny for its taxonomy
        #   inFileName  :=  path name for the month file corresponding
        #                   to monthKey ]
        birdNoteSet = BirdNoteSet(self.txny)
        inFileName = os.path.join(self.rootDir,
                        ("%s/%s.xml" % (monthKey[:4], monthKey)))

        #-- 2 --
        # [ if inFileName names a readable file valid against
        #   birdnotes.rnc ->
        #     birdNoteSet  :=  birdNoteSet with that file added
        #   else -> raise IOError ]
        birdNoteSet.readFile(inFileName)

        #-- 3 --
        return birdNoteSet