Various Pyright warnings

[Molkree]

I have only just started using pandas-stubs but I am getting a bunch of warnings from Pyright. Am I doing something wrong?
Examples:
1.

import pandas as pd

s = pd.Series([1.0, 2.0, -3.0], dtype=float)
pd.to_numeric(s)

This raises

Type of "to_numeric" is partially unknown
  Type of "to_numeric" is "Overload[(arg: str | bytes | date | datetime | timedelta | bool | int | float | Timestamp | Timedelta | complex, errors: Literal['raise', 'coerce'] = ..., downcast: Literal['integer', 'signed', 'unsigned', 'float'] | None = ...) -> float, (arg: str | bytes | date | datetime | timedelta | bool | int | float | Timestamp | Timedelta | complex, errors: Literal['ignore'], downcast: Literal['integer', 'signed', 'unsigned', 'float'] | None = ...) -> (str | bytes | date | datetime | timedelta | bool | int | float | Timestamp | Timedelta | complex), (arg: list[Unknown] | tuple[Unknown, ...] | ndarray[Unknown, Unknown], errors: Literal['ignore', 'raise', 'coerce'] = ..., downcast: Literal['integer', 'signed', 'unsigned', 'float'] | None = ...) -> ndarray[Any, dtype[Unknown]], (arg: Series[Unknown], errors: Literal['ignore', 'raise', 'coerce'] = ..., downcast: Literal['integer', 'signed', 'unsigned', 'float'] | None = ...) -> Series[Unknown]]"

import pandas as pd

pd.read_csv("data.csv")

This raises

Type of "read_csv" is partially unknown
  Type of "read_csv" is "Overload[(filepath_or_buffer: str | PathLike[str] | ReadCsvBuffer[bytes] | ReadCsvBuffer[str], *, sep: str | None = ..., delimiter: str | None = ..., header: int | Sequence[int] | Literal['infer'] | None = ..., names: list[str] | None = ..., index_col: int | str | Sequence[str | int] | Literal[False] | None = ..., usecols: list[str] | tuple[str, ...] | Sequence[int] | Series[Unknown] | Index | ndarray[Any, dtype[Unknown]] | ((str) -> bool) | None = ..., dtype: ExtensionDtype | str | dtype[generic] | Type[str] | Type[complex] | Type[bool] | Type[object] | dict[Any, ExtensionDtype | str | dtype[generic] | Type[str] | Type[complex] | Type[bool] | Type[object]] | defaultdict[Unknown, Unknown] | None = ..., engine: Literal['c', 'python', 'pyarrow', 'python-fwf'] | None = ..., converters: Mapping[int | str, (str) -> Any] | Mapping[int, (str) -> Any] | Mapping[str, (str) -> Any] | None = ..., true_values: list[str] = ..., false_values: list[str] = ..., skipinitialspace: bool = ..., skiprows: int | Sequence[int] | ((int) -> bool) = ..., skipfooter: int = ..., nrows: int | None = ..., na_values: Sequence[str] | Mapping[str, Sequence[str]] = ..., keep_default_na: bool = ..., na_filter: bool = ..., verbose: bool = ..., skip_blank_lines: bool = ..., parse_dates: bool | list[int] | list[str] | Sequence[Sequence[int]] | Mapping[str, Sequence[int | str]] = ..., infer_datetime_format: bool = ..., keep_date_col: bool = ..., date_parser: (...) -> Unknown = ..., dayfirst: bool = ..., cache_dates: bool = ..., iterator: Literal[True], chunksize: int | None = ..., compression: dict[str, Any] | Literal['infer', 'gzip', 'bz2', 'zip', 'xz', 'zstd'] | None = ..., thousands: str | None = ..., decimal: str = ..., lineterminator: str | None = ..., quotechar: str = ..., quoting: Literal[0, 1, 2, 3] = ..., doublequote: bool = ..., escapechar: str | None = ..., comment: str | None = ..., encoding: str | None = ..., encoding_errors: str | None = ..., dialect: str | Dialect = ..., on_bad_lines: ((list[str]) -> (list[str] | None)) | Literal['error', 'warn', 'skip'] = ..., delim_whitespace: bool = ..., low_memory: bool = ..., memory_map: bool = ..., float_precision: Literal['high', 'legacy', 'round_trip'] | None = ..., storage_options: dict[str, Any] | None = ...) -> TextFileReader, (filepath_or_buffer: str | PathLike[str] | ReadCsvBuffer[bytes] | ReadCsvBuffer[str], *, sep: str | None = ..., delimiter: str | None = ..., header: int | Sequence[int] | Literal['infer'] | None = ..., names: list[str] | None = ..., index_col: int | str | Sequence[str | int] | Literal[False] | None = ..., usecols: list[str] | tuple[str, ...] | Sequence[int] | Series[Unknown] | Index | ndarray[Any, dtype[Unknown]] | ((str) -> bool) | None = ..., dtype: ExtensionDtype | str | dtype[generic] | Type[str] | Type[complex] | Type[bool] | Type[object] | dict[Any, ExtensionDtype | str | dtype[generic] | Type[str] | Type[complex] | Type[bool] | Type[object]] | defaultdict[Unknown, Unknown] | None = ..., engine: Literal['c', 'python', 'pyarrow', 'python-fwf'] | None = ..., converters: Mapping[int | str, (str) -> Any] | Mapping[int, (str) -> Any] | Mapping[str, (str) -> Any] | None = ..., true_values: list[str] = ..., false_values: list[str] = ..., skipinitialspace: bool = ..., skiprows: int | Sequence[int] | ((int) -> bool) = ..., skipfooter: int = ..., nrows: int | None = ..., na_values: Sequence[str] | Mapping[str, Sequence[str]] = ..., keep_default_na: bool = ..., na_filter: bool = ..., verbose: bool = ..., skip_blank_lines: bool = ..., parse_dates: bool | list[int] | list[str] | Sequence[Sequence[int]] | Mapping[str, Sequence[int | str]] = ..., infer_datetime_format: bool = ..., keep_date_col: bool = ..., date_parser: (...) -> Unknown = ..., dayfirst: bool = ..., cache_dates: bool = ..., iterator: bool = ..., chunksize: int, compression: dict[str, Any] | Literal['infer', 'gzip', 'bz2', 'zip', 'xz', 'zstd'] | None = ..., thousands: str | None = ..., decimal: str = ..., lineterminator: str | None = ..., quotechar: str = ..., quoting: Literal[0, 1, 2, 3] = ..., doublequote: bool = ..., escapechar: str | None = ..., comment: str | None = ..., encoding: str | None = ..., encoding_errors: str | None = ..., dialect: str | Dialect = ..., on_bad_lines: ((list[str]) -> (list[str] | None)) | Literal['error', 'warn', 'skip'] = ..., delim_whitespace: bool = ..., low_memory: bool = ..., memory_map: bool = ..., float_precision: Literal['high', 'legacy', 'round_trip'] | None = ..., storage_options: dict[str, Any] | None = ...) -> TextFileReader, (filepath_or_buffer: str | PathLike[str] | ReadCsvBuffer[bytes] | ReadCsvBuffer[str], *, sep: str | None = ..., delimiter: str | None = ..., header: int | Sequence[int] | Literal['infer'] | None = ..., names: list[str] | None = ..., index_col: int | str | Sequence[str | int] | Literal[False] | None = ..., usecols: list[str] | tuple[str, ...] | Sequence[int] | Series[Unknown] | Index | ndarray[Any, dtype[Unknown]] | ((str) -> bool) | None = ..., dtype: ExtensionDtype | str | dtype[generic] | Type[str] | Type[complex] | Type[bool] | Type[object] | dict[Any, ExtensionDtype | str | dtype[generic] | Type[str] | Type[complex] | Type[bool] | Type[object]] | defaultdict[Unknown, Unknown] | None = ..., engine: Literal['c', 'python', 'pyarrow', 'python-fwf'] | None = ..., converters: Mapping[int | str, (str) -> Any] | Mapping[int, (str) -> Any] | Mapping[str, (str) -> Any] | None = ..., true_values: list[str] = ..., false_values: list[str] = ..., skipinitialspace: bool = ..., skiprows: int | Sequence[int] | ((int) -> bool) = ..., skipfooter: int = ..., nrows: int | None = ..., na_values: Sequence[str] | Mapping[str, Sequence[str]] = ..., keep_default_na: bool = ..., na_filter: bool = ..., verbose: bool = ..., skip_blank_lines: bool = ..., parse_dates: bool | list[int] | list[str] | Sequence[Sequence[int]] | Mapping[str, Sequence[int | str]] = ..., infer_datetime_format: bool = ..., keep_date_col: bool = ..., date_parser: (...) -> Unknown = ..., dayfirst: bool = ..., cache_dates: bool = ..., iterator: Literal[False] = ..., chunksize: None = ..., compression: dict[str, Any] | Literal['infer', 'gzip', 'bz2', 'zip', 'xz', 'zstd'] | None = ..., thousands: str | None = ..., decimal: str = ..., lineterminator: str | None = ..., quotechar: str = ..., quoting: Literal[0, 1, 2, 3] = ..., doublequote: bool = ..., escapechar: str | None = ..., comment: str | None = ..., encoding: str | None = ..., encoding_errors: str | None = ..., dialect: str | Dialect = ..., on_bad_lines: ((list[str]) -> (list[str] | None)) | Literal['error', 'warn', 'skip'] = ..., delim_whitespace: bool = ..., low_memory: bool = ..., memory_map: bool = ..., float_precision: Literal['high', 'legacy', 'round_trip'] | None = ..., storage_options: dict[str, Any] | None = ...) -> DataFrame]"

I am using Pylance v2023.2.30 and have installed pandas-stubs-1.5.3.230214 in my venv.

[Dr-Irv]

@Molkree We test with pyright. Can you check if you are using the "basic" or "strict" setting within pylance? We are not yet supporting "strict" .

[Molkree]

Yup, that's with a "strict" setting. Okay, that makes sense then if you don't yet support strict checking.

[Dr-Irv]

We support a subset of "strict". See the settings we use here (and the lines below):

pandas-stubs/pyproject.toml

Line 176 in 00ab656

[tool.pyright]

The "partially unknown" messages are occurring because in pandas-stubs, a Series is generic. For pd.to_numeric(), we can't tell whether we will get Series[int] or Series[float] as a result, so we return Series[Unknown]. Similarly, for pd.read_csv(), we don't know if we will get a Series or DataFrame. So any pandas function/method that returns a Series will have the "partially unknown" type, unless we can infer what is "inside" the Series.

[davetapley]

Here's another weird one with strict:

from pandas import to_datetime

will complain about the import itself 🤯

error: Type of "to_datetime" is partially unknown

[twoertwein]

As mentioned by @Dr-Irv, I would only recommend a small subset of the strict ruleset. In the case of to_datetime, one overload allows Series as an input without specifying the type (Series[Unknown]): so the entire function is partially unknown.