@property
    def size(self):
        if self._is_dirty and self._is_read:
            # Get the size of a file like object
            # Check http://stackoverflow.com/a/19079887
            old_file_position = self.file.tell()
            self.file.seek(0, os.SEEK_END)
            self._size = self.file.tell()
            self.file.seek(old_file_position, os.SEEK_SET)
        if not hasattr(self, '_size'):
            self._size = self._storage.size(self._name)
        return self._size
dataset/ETHPy150Open glasslion/django-qiniu-storage/qiniustorage/backends.py/QiniuFile.size/operator `or` -> `and`