typing related issues to custom record class.

[iyad-f]

so i just type hinted a user record like

class User(asyncpg.Record):
    if TYPE_CHECKING:
        id: int
        username: str
        password: str

    def __getattr__(self, name: str) -> Any:
        return self[name]

but i get the following error from pyright

so do i need to do some additional stuff for this?

[ltianyi992]

The issue is that asyncpg.Record uses __slots__ and its attributes are accessed via __getitem__, not __getattr__. Pyright sees Record has no fields named id, username, etc., so it reports the type error even with the TYPE_CHECKING guard.

The cleaner approach is to use a TypedDict or Protocol for type hints instead of subclassing asyncpg.Record:

Option 1 — TypedDict (recommended for query results)

from typing import TypedDict
import asyncpg

class UserRecord(TypedDict):
    id: int
    username: str
    password: str

# Cast the result
row = await conn.fetchrow("SELECT id, username, password FROM users WHERE id = $1", user_id)
user: UserRecord = dict(row)  # type: ignore[assignment]
print(user["username"])  # fully typed

Option 2 — Keep subclassing but suppress the Pyright error

Pyright does not support __getattr__ as a dynamic attribute resolver for Record subclasses. You need to declare the attributes as class variables directly (not inside TYPE_CHECKING):

from typing import Any
import asyncpg

class User(asyncpg.Record):
    id: int          # declare directly
    username: str
    password: str

    def __getattr__(self, name: str) -> Any:
        return self[name]

Declaring them outside TYPE_CHECKING makes Pyright aware of the attributes at analysis time. The attributes will not actually exist as instance vars at runtime (access goes through __getattr__ → __getitem__), but type checking will work.

Option 3 — Use record_class parameter

Asyncpg supports passing a custom record_class to query methods, but that class must be a Record subclass. Combine with a Protocol for typing:

from typing import Protocol

class UserLike(Protocol):
    @property
    def id(self) -> int: ...
    @property
    def username(self) -> str: ...

For most cases, Option 1 (TypedDict) is the least friction and works well with type checkers.