code: def __shpFileLength(self):
          
          # Remember starting position
          start = self.shp.tell()
          # Calculate size of all shapes
          self.shp.seek(0,2)
          size = self.shp.tell()
          # Calculate size as 16-bit words
          size //= 2
          # Return to start
          self.shp.seek(start)
          return size
docs: Calculates the file length of the shp file.