python classmethod get_by_user returns None

Question

I need help in using the class method example get_by_user My adaptation of the class method is next.

class Pages(ndb.Model):
    user_id = ndb.StringProperty()
    name = ndb.StringProperty()

    @classmethod
    def get_by_user(cls, user):
        return cls.query().filter(cls.user_id == user.user_id()).get()

view.py code is next.

class MainPage(BaseHandler):

    def get(self):
    user = users.get_current_user()
    logging.info("MainPageGet: %s " % user)
    if user: #offer user options 
        isUser = True
        user_ID = user
        for p in Pages.query():
        logging.info("MainPageGet p: %s " % p.user_id)
        logging.info("MainPageGet user_ID: %s " % user_ID)
        page = Pages.get_by_user( user_ID) 
        logging.info("MainPageGet page: %s " % page )

And my log results are the following.

<pre>
INFO     2018-02-10 04:28:21,509 views.py:192] MainPageGet: [email protected] 
INFO     2018-02-10 04:28:21,518 views.py:198] MainPageGet p: [email protected] 
INFO     2018-02-10 04:28:21,519 views.py:198] MainPageGet p: [email protected] 
INFO     2018-02-10 04:28:21,519 views.py:200] MainPageGet user_ID: [email protected] 
INFO     2018-02-10 04:28:21,524 views.py:204] MainPageGet page: None 
INFO     2018-02-10 04:28:21,535 module.py:812] default: "GET / HTTP/1.1" 200 2284
</pre>

My sample ndb data is produced as follows.

page1 = Pages(id='BS',user_id='[email protected]',name='Brian')
page2 = Pages(id='JS',user_id='[email protected]',name='Joan')
page1.put()
page2.put()

So, my question is, what am I doing wrong that is producing the None result in the final logging result instead of locating the test.example.com result for the id='BS'?

Answer 1

The user.user_id() returns an ID, which at least on the development server is a numeric value, like this one: 185804764220139124118.

But when you created your Pages entities you set the values of their user_id property to a string containing an email address: user_id='[email protected]'.

Because of this the query inside get_by_user() won't return any entity, as none matches the filter.

You could modify get_by_user() to something like this (you may want to adjust the actual property name in this case, to avoid confusion):

    @classmethod
    def get_by_user(cls, user):
        return cls.query().filter(cls.user_id == user.email()).get()