psycopg2: RealDictCursor cursor is type checking as untyped #14417
Description
Problem
cursors using the RealDictCursor cursor factory are being caught as untyped in mypy strict mode.
Versions
mypy==1.17.0 psycopg2==2.9.10 types-psycopg2==2.9.21.20250516
Issue not present in types-psycopg2==2.9.21.20250318 and still "reveals" as Any
Replication
Save the below script
import psycopg2
from psycopg2.extras import RealDictCursor
def main(conn: psycopg2.extensions.connection) -> None:
with conn.cursor(cursor_factory=RealDictCursor) as cursor:
reveal_type(cursor.execute("SELECT * FROM users"))run mypy --strict
↳ mypy --strict . main.py:7: error: Call to untyped function "execute" in typed context [no-untyped-call] main.py:7: note: Revealed type is "Any" Found 1 error in 1 file (checked 1 source file)
Activity
srittau commented on Jul 16, 2025
Yes, RealDictCursor.execute() is untyped in typeshed. We don't keep issues about untyped items open in typeshed, as this is a rather frequent and "expected" situation. That said, PRs that add or fix annotations are always welcome!
Don-Burns commented on Jul 16, 2025
Understood. I only raised it as previously "ok" code is now not safely checking on the newer version, since whatever changed now surfaces an untyped func rather than a func returning Any.
Of course the Any is a "lie" too.
srittau commented on Jul 16, 2025
The issue was probably hidden before #14063 since vars was previously annotated as Incomplete | None = None, which made type checkers believe that execute was partly annotated (when it wasn't really).