checks.py 文件源码

def _check_exclude(self, obj):
        """ Check that exclude is a sequence without duplicates. """

        if obj.exclude is None:  # default value is None
            return []
        elif not isinstance(obj.exclude, (list, tuple)):
            return must_be('a list or tuple', option='exclude', obj=obj, id='admin.E014')
        elif len(obj.exclude) > len(set(obj.exclude)):
            return [
                checks.Error(
                    "The value of 'exclude' contains duplicate field(s).",
                    obj=obj.__class__,
                    id='admin.E015',
                )
            ]
        else:
            return []