简单示例：
class TestAdmin(admin.ModelAdmin):
def get_some_value(self):
return ", " . join([x.__str__() for x in self.manytomany_field.all()])
list_display(get_some_value)
get_some_value.short_description = 'Title' #sets column header to Title 实际应用代码：
#显示选择的合作区域，此处的city为本模型下manytomany字段
def post_tag(self):
return [pt.__str__() for pt in self.city.all()]
post_tag.short_description = '标签'