<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _process_file(self, obj, fobj, field):

 """
 obj is record object
 fobj is data
 field is FileField instance
 """

        from uliweb import settings
        
        paths = []
        upload_to = self.upload_to or self._get_upload_path(field, 'upload_to', obj)
        if upload_to:
            self.fileserving.to_path = upload_to
        upload_to_sub = self.upload_to_sub or self._get_upload_path(field, 'upload_to_sub', obj)
        if upload_to_sub:
            paths.append(upload_to_sub)
        paths.append(fobj['filename'])
        
        return self.fileserving.save_file(os.path.join(*paths), 
            fobj['file'], replace=self.file_replace, 
            convert=self.file_convert)