model.py 文件源码

def load(cls, f):
      h = cls()

      magic = f.read(8)
      if len(magic) != 8 or magic != cls._MAGIC:
        raise InvalidModelFormatError('invalid magic value: {0}'.format(str(magic)))

      for (key, fmt, _) in cls.fields():
        size = struct.calcsize(fmt)
        raw = f.read(size)
        if len(raw) != size:
          raise InvalidModelFormatError('failed to read {0} in header (expected {1} bytes, got {2} bytes)'.format(key, size, len(raw)))
        try:
          value = struct.unpack(fmt, raw)[0]
        except ValueError:
          raise InvalidModelFormatError('failed to parse {0} value {1} as {2}'.format(key, str(raw), fmt))
        setattr(h, key, value)
      return h