cqlengine collections with missing/null values set to empty

[Michael]

Hello,

I'm using a model with collections, e.g. a list

class mytable(Model):

    key = columns.Text(primary_key=True)

    coll = columns.List(columns.Integer, default=None)

When I instantiate an object, or query for such objects, coll is always initialized to [] even if these values are absent in mytable:

In [1]: mytable(key='123', coll=None)

Out[1]: mytable(key='123', coll=[])

In [2]: mytable(key='123')

Out[2]: mytable(key='123', coll=[])

I've also tried without the default argument, or setting it to types.NoneType (fails with stdlib error cannot create 'NoneType' instances).

For a query it's the same. I've logged mytable.__init__ and it gets the coll=None kwarg same way.

The contents of the table are:

cqlsh:myspace> select * from mytable;

 key                                  | coll

--------------------------------------+------

 2381fcdb-5634-4fd8-a94f-b632d0b57dac | null

I wonder if this is the intended behavior? Shouldn't a non-existent value and an empty collection be treated different?

I've checked this in driver version 3.7.1 and 2.7.2

For my application, I could live with an empty list but there are currently API tests that assert certain keys as None that I would need to change. This means also potentially affecting application logic too albeit unlikely.

Thanks,

Michael

[Alan Boudreault]

Hello Michael,

Ideally, this should be treated differently. This is a little misconception since the first release of cqlengine. Unfortunately, modifying this behavior will potentially affect many users. It would be preferable to find a workaround for your API tests at the application level.

Regards,

Alan

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Alan Boudreault

Software Engineer (Drivers) | alan.bo...@datastax.com