Are typing errors in fastapi/starlite templates normal ?

[StitiFatah]

Hi,

I'm trying piccolo with the Starlite template and have some typing errors (from pyright/pylance in both vscodium and neovim), for example with the /tasks endpoint :

@get("/tasks", tags=["Task"])
async def tasks() -> t.List[Task]:
    tasks = await Task.select().order_by(Task.id, ascending=False)
    return tasks

I get Cannot access member "id" for type "Type[Task]" Member "id" is unknown , Is that because id isn't manually specified on the Table ? Why does the auto completion works fine in ipython ?

I also get Expression of type "Any | list[Table] | Table | Unknown | str | list[Unknown]" cannot be assigned to return type "List[Task]" is unknown` for tasks. Is that intended and should we use typing.cast for the moment ?

I also get errors when using Band.objects(Band.all_related()) with models that have foreign keys.

But maybe that's an editor problem on my side ?

Thanks in advance.

[dantownsend]

I get Cannot access member "id" for type "Type[Task]" Member "id" is unknown , Is that because id isn't manually specified on the Table ? Why does the auto completion works fine in ipython ?

If a primary key isn't manually specified then Piccolo automatically adds id.

To fix this type error, you can add this to your table class:

from piccolo.columns.column_types import Serial

class MyTable(Table):
    id: Serial
    ...

I also get Expression of type "Any | list[Table] | Table | Unknown | str | list[Unknown]" cannot be assigned to return type "List[Task]" is unknown` for tasks. Is that intended and should we use typing.cast for the moment ?

Piccolo's select query returns a list of dictionaries. So the response type is something like t.List[t.Dict].

To get a list of Task objects you need to use objects instead.

@get("/tasks", tags=["Task"])
async def tasks() -> t.List[Task]:
    tasks = await Task.objects().order_by(Task.id, ascending=False)
    return tasks

We're working on improving the type annotations for Piccolo - you might need to add something like this for now:

@get("/tasks", tags=["Task"])
async def tasks() -> t.List[Task]:
    tasks: t.List[Task] = await Task.objects().order_by(Task.id, ascending=False)
    return tasks

I have quite a large PR underway at the moment which uses Python's generics to improve the type responses of queries, so should help.

[StitiFatah]

Thanks for the response,

Piccolo's select query returns a list of dictionaries. So the response type is something like t.List[t.Dict].
To get a list of Task objects you need to use objects instead.

Yes it makes sense, I tried that but got the same error, but shouldn't the template replace select with objects ? I've just copy pasted it.

We're working on improving the type annotations for Piccolo - you might need to add something like this for now:

@get("/tasks", tags=["Task"])
async def tasks() -> t.List[Task]:
    tasks: t.List[Task] = await Task.objects().order_by(Task.id, ascending=False)
    return tasks

Ok I'll use that for now.

Thanks for this library by the way, I'm considering switching from Django/DRF to Starlite and I really like Piccolo so far.

[dantownsend]

Thanks for this library by the way, I'm considering switching from Django/DRF to Starlite and I really like Piccolo so far.

No worries, glad you're enjoying it.