False positive "Argument missing for parameter "self"?

[sergeykorablin]

I see annoying error message "Argument missing for parameter "self". Is it a bug?

import asyncio
import telegram

bot = telegram.Bot(token="some-token")
async def send_msg():
    await bot.send_message(chat_id="channel-id", text="Hello World")  # Argument missing for parameter "self"

asyncio.run(send_msg())

$ .local/share/nvim/mason/bin/pyright --version
pyright 1.1.339

$ python -V          
Python 3.10.12

$ pip freeze
python-telegram-bot==20.7

[erictraut]

This is a bug in the python-telegram-bot library. The send_message function is decorated with @_log, and the _log function is not properly annotated. If it were completely unannotated, pyright would infer its type correctly, but it is partially annotated, so pyright assumes that it shouldn't override the intent of the author.

The correct way to type _log is to use a TypeVar bound to a Callable or a Callable with a ParamSpec.

    # Option 1: TypeVar bound to a Callable
    T = TypeVar("T", bound=Callable[..., Any])

    def _log(func: T) -> T: ...

    # Option 2: Callable with a ParamSpec
    P = ParamSpec("P")
    R = TypeVar("R")

    def _log(func: Callable[P, R]) -> Callable[P, R]: ...

A third option is to remove all annotations for _log. Pyright will then correctly infer the return type. However, this won't work with other type checkers like mypy, which don't support return type inference.

I recommend that you file a bug with the maintainers of this library.

[sergeykorablin]

Thanks for the detailed explanation!

[leakedby]

file: pyproject.toml

[tool.pyright]
venvPath = "./"
venv = ".venv"
reportMissingImports = true
reportMissingTypeStubs = false
reportMissingParameterType = false
typeCheckingMode = "off"
pythonVersion = "3.11.6"

Turn off this by set reportMissingParameterType = false