好的,這是問題所在。我有這樣的代碼如何添加選擇到谷歌數據存儲StringListProperty?
list_categories = [None,"mathematics","engineering","science","other"]
class Books(db.Model)
title = db.StringProperty(required=True)
author = db.StringProperty()
isbn = db.StringProperty()
categories = db.StringListProperty(default=None, choices = set(list_categories))
什麼,我想在這裏做的是有我的book.categories是名單類別的子集,例如 我有一本書,其類別應該是「工程」和「數學」,但當我設置
book.categories = ['engineering','mathematics']
它webapp2的給我一個錯誤
BadValueError: Property categories is ['engineering','mathematics']; must be one of set([None,"mathematics","engineering","science","other"])
我最初這裏的猜測是,我必須將我的list_choices爲[無「mathemat的POWERSET ics「,」engineering「,」science「,」other「],但效率太低。
有沒有人知道這個解決方法?