如何在Google App Engine expando类中创建动态字段? [英] How to create dynamic fields in Google App Engine expando class?
问题描述
我有一个名为widget的db expando类。
我传递一个json字符串并将其转换为字典,然后将其添加到数据存储。 / p>
我的问题是如何循环执行字典以创建动态字段。
widget = Widget.get_by_key_name(key_name)
widget.name = self.request.get('wname')
fields = simplejson.loads(self.request.get('wcontents'))
for k,v in fields.iteritems():
widget.k = v
这使得k成为我的字段名称,与dict中的k值相反。 code> widget.k 引用属性 k
对象小部件
。动态 选择您设置的属性,请使用内置的 setattr
方法:
setattr(widget,k,v )
动态设置像这样的属性将创建该特定实体上的字段。 b $ b
I have a db expando class called widget.
I'm passing in a json string and converting it to a dict and then adding it to the datastore.
My question is how can I loop through my dict to create dynamic fields.
widget = Widget.get_by_key_name(key_name)
widget.name = self.request.get('wname')
fields = simplejson.loads(self.request.get('wcontents'))
for k,v in fields.iteritems():
widget.k = v
This renders "k" as my field name as oppose to the k value in the dict.
The syntax widget.k
references the attribute k
on object widget
. To dynamically choose which attribute you set, use the built-in setattr
method:
setattr(widget, k, v)
Dynamically setting an attribute like this will create the field on that particular entity.
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