done

lib/python3.11/site-packages/narwhals/stable/__init__.py

@@ -0,0 +1,5 @@
+from __future__ import annotations
+
+from narwhals.stable import v1
+
+__all__ = ["v1"]

lib/python3.11/site-packages/narwhals/stable/v1/_dtypes.py

@@ -0,0 +1,135 @@
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+from narwhals._utils import inherit_doc
+from narwhals.dtypes import (
+    Array,
+    Binary,
+    Boolean,
+    Categorical,
+    Date,
+    Datetime as NwDatetime,
+    Decimal,
+    DType,
+    Duration as NwDuration,
+    Enum as NwEnum,
+    Field,
+    Float32,
+    Float64,
+    FloatType,
+    Int8,
+    Int16,
+    Int32,
+    Int64,
+    Int128,
+    IntegerType,
+    List,
+    NestedType,
+    NumericType,
+    Object,
+    SignedIntegerType,
+    String,
+    Struct,
+    Time,
+    UInt8,
+    UInt16,
+    UInt32,
+    UInt64,
+    UInt128,
+    Unknown,
+    UnsignedIntegerType,
+)
+
+if TYPE_CHECKING:
+    from datetime import timezone
+
+    from narwhals.typing import TimeUnit
+
+
+class Datetime(NwDatetime):
+    @inherit_doc(NwDatetime)
+    def __init__(
+        self, time_unit: TimeUnit = "us", time_zone: str | timezone | None = None
+    ) -> None:
+        super().__init__(time_unit, time_zone)
+
+    def __hash__(self) -> int:
+        return hash(self.__class__)
+
+
+class Duration(NwDuration):
+    @inherit_doc(NwDuration)
+    def __init__(self, time_unit: TimeUnit = "us") -> None:
+        super().__init__(time_unit)
+
+    def __hash__(self) -> int:
+        return hash(self.__class__)
+
+
+class Enum(NwEnum):
+    """A fixed categorical encoding of a unique set of strings.
+
+    Polars has an Enum data type, while pandas and PyArrow do not.
+
+    Examples:
+       >>> import polars as pl
+       >>> import narwhals.stable.v1 as nw
+       >>> data = ["beluga", "narwhal", "orca"]
+       >>> s_native = pl.Series(data, dtype=pl.Enum(data))
+       >>> nw.from_native(s_native, series_only=True).dtype
+       Enum
+    """
+
+    def __init__(self) -> None:
+        super(NwEnum, self).__init__()
+
+    def __eq__(self, other: DType | type[DType]) -> bool:  # type: ignore[override]
+        if type(other) is type:
+            return other in {type(self), NwEnum}
+        return isinstance(other, type(self))
+
+    def __hash__(self) -> int:  # pragma: no cover
+        return super(NwEnum, self).__hash__()
+
+    def __repr__(self) -> str:  # pragma: no cover
+        return super(NwEnum, self).__repr__()
+
+
+__all__ = [
+    "Array",
+    "Binary",
+    "Boolean",
+    "Categorical",
+    "DType",
+    "Date",
+    "Datetime",
+    "Decimal",
+    "Duration",
+    "Enum",
+    "Field",
+    "Float32",
+    "Float64",
+    "FloatType",
+    "Int8",
+    "Int16",
+    "Int32",
+    "Int64",
+    "Int128",
+    "IntegerType",
+    "List",
+    "NestedType",
+    "NumericType",
+    "Object",
+    "SignedIntegerType",
+    "String",
+    "Struct",
+    "Time",
+    "UInt8",
+    "UInt16",
+    "UInt32",
+    "UInt64",
+    "UInt128",
+    "Unknown",
+    "UnsignedIntegerType",
+]

lib/python3.11/site-packages/narwhals/stable/v1/_namespace.py

@@ -0,0 +1,10 @@
+from __future__ import annotations
+
+from narwhals._compliant.typing import CompliantNamespaceT_co
+from narwhals._namespace import Namespace as NwNamespace
+from narwhals._utils import Version
+
+__all__ = ["Namespace"]
+
+
+class Namespace(NwNamespace[CompliantNamespaceT_co], version=Version.V1): ...

lib/python3.11/site-packages/narwhals/stable/v1/dependencies.py

@@ -0,0 +1,156 @@
+from __future__ import annotations
+
+import sys
+from typing import TYPE_CHECKING, Any
+
+if TYPE_CHECKING:
+    import cudf
+    import dask.dataframe as dd
+    import ibis
+    import modin.pandas as mpd
+    import pandas as pd
+    import polars as pl
+    import pyarrow as pa
+    from typing_extensions import TypeIs
+
+
+from narwhals.dependencies import (
+    IMPORT_HOOKS,
+    get_cudf,
+    get_dask_dataframe,
+    get_ibis,
+    get_modin,
+    get_numpy,
+    get_pandas,
+    get_polars,
+    get_pyarrow,
+    is_into_dataframe,
+    is_into_series,
+    is_narwhals_dataframe,
+    is_narwhals_lazyframe,
+    is_narwhals_series,
+    is_numpy_array,
+    is_pandas_index,
+)
+
+
+def is_pandas_dataframe(df: Any) -> TypeIs[pd.DataFrame]:
+    """Check whether `df` is a pandas DataFrame without importing pandas."""
+    return ((pd := get_pandas()) is not None and isinstance(df, pd.DataFrame)) or any(
+        (mod := sys.modules.get(module_name, None)) is not None
+        and isinstance(df, mod.pandas.DataFrame)
+        for module_name in IMPORT_HOOKS
+    )
+
+
+def is_pandas_series(ser: Any) -> TypeIs[pd.Series[Any]]:
+    """Check whether `ser` is a pandas Series without importing pandas."""
+    return ((pd := get_pandas()) is not None and isinstance(ser, pd.Series)) or any(
+        (mod := sys.modules.get(module_name, None)) is not None
+        and isinstance(ser, mod.pandas.Series)
+        for module_name in IMPORT_HOOKS
+    )
+
+
+def is_modin_dataframe(df: Any) -> TypeIs[mpd.DataFrame]:
+    """Check whether `df` is a modin DataFrame without importing modin."""
+    return (mpd := get_modin()) is not None and isinstance(df, mpd.DataFrame)
+
+
+def is_modin_series(ser: Any) -> TypeIs[mpd.Series]:
+    """Check whether `ser` is a modin Series without importing modin."""
+    return (mpd := get_modin()) is not None and isinstance(ser, mpd.Series)
+
+
+def is_cudf_dataframe(df: Any) -> TypeIs[cudf.DataFrame]:
+    """Check whether `df` is a cudf DataFrame without importing cudf."""
+    return (cudf := get_cudf()) is not None and isinstance(df, cudf.DataFrame)
+
+
+def is_cudf_series(ser: Any) -> TypeIs[cudf.Series[Any]]:
+    """Check whether `ser` is a cudf Series without importing cudf."""
+    return (cudf := get_cudf()) is not None and isinstance(ser, cudf.Series)
+
+
+def is_dask_dataframe(df: Any) -> TypeIs[dd.DataFrame]:
+    """Check whether `df` is a Dask DataFrame without importing Dask."""
+    return (dd := get_dask_dataframe()) is not None and isinstance(df, dd.DataFrame)
+
+
+def is_ibis_table(df: Any) -> TypeIs[ibis.Table]:
+    """Check whether `df` is a Ibis Table without importing Ibis."""
+    return (ibis := get_ibis()) is not None and isinstance(df, ibis.expr.types.Table)
+
+
+def is_polars_dataframe(df: Any) -> TypeIs[pl.DataFrame]:
+    """Check whether `df` is a Polars DataFrame without importing Polars."""
+    return (pl := get_polars()) is not None and isinstance(df, pl.DataFrame)
+
+
+def is_polars_lazyframe(df: Any) -> TypeIs[pl.LazyFrame]:
+    """Check whether `df` is a Polars LazyFrame without importing Polars."""
+    return (pl := get_polars()) is not None and isinstance(df, pl.LazyFrame)
+
+
+def is_polars_series(ser: Any) -> TypeIs[pl.Series]:
+    """Check whether `ser` is a Polars Series without importing Polars."""
+    return (pl := get_polars()) is not None and isinstance(ser, pl.Series)
+
+
+def is_pyarrow_chunked_array(ser: Any) -> TypeIs[pa.ChunkedArray[Any]]:
+    """Check whether `ser` is a PyArrow ChunkedArray without importing PyArrow."""
+    return (pa := get_pyarrow()) is not None and isinstance(ser, pa.ChunkedArray)
+
+
+def is_pyarrow_table(df: Any) -> TypeIs[pa.Table]:
+    """Check whether `df` is a PyArrow Table without importing PyArrow."""
+    return (pa := get_pyarrow()) is not None and isinstance(df, pa.Table)
+
+
+def is_pandas_like_dataframe(df: Any) -> bool:
+    """Check whether `df` is a pandas-like DataFrame without doing any imports.
+
+    By "pandas-like", we mean: pandas, Modin, cuDF.
+    """
+    return is_pandas_dataframe(df) or is_modin_dataframe(df) or is_cudf_dataframe(df)
+
+
+def is_pandas_like_series(ser: Any) -> bool:
+    """Check whether `ser` is a pandas-like Series without doing any imports.
+
+    By "pandas-like", we mean: pandas, Modin, cuDF.
+    """
+    return is_pandas_series(ser) or is_modin_series(ser) or is_cudf_series(ser)
+
+
+__all__ = [
+    "get_cudf",
+    "get_ibis",
+    "get_modin",
+    "get_numpy",
+    "get_pandas",
+    "get_polars",
+    "get_pyarrow",
+    "is_cudf_dataframe",
+    "is_cudf_series",
+    "is_dask_dataframe",
+    "is_ibis_table",
+    "is_into_dataframe",
+    "is_into_series",
+    "is_modin_dataframe",
+    "is_modin_series",
+    "is_narwhals_dataframe",
+    "is_narwhals_lazyframe",
+    "is_narwhals_series",
+    "is_numpy_array",
+    "is_pandas_dataframe",
+    "is_pandas_index",
+    "is_pandas_like_dataframe",
+    "is_pandas_like_series",
+    "is_pandas_series",
+    "is_polars_dataframe",
+    "is_polars_lazyframe",
+    "is_polars_series",
+    "is_pyarrow_chunked_array",
+    "is_pyarrow_table",
+]

lib/python3.11/site-packages/narwhals/stable/v1/dtypes.py

@@ -0,0 +1,77 @@
+from __future__ import annotations
+
+from narwhals.stable.v1._dtypes import (
+    Array,
+    Binary,
+    Boolean,
+    Categorical,
+    Date,
+    Datetime,
+    Decimal,
+    DType,
+    Duration,
+    Enum,
+    Field,
+    Float32,
+    Float64,
+    FloatType,
+    Int8,
+    Int16,
+    Int32,
+    Int64,
+    Int128,
+    IntegerType,
+    List,
+    NestedType,
+    NumericType,
+    Object,
+    SignedIntegerType,
+    String,
+    Struct,
+    Time,
+    UInt8,
+    UInt16,
+    UInt32,
+    UInt64,
+    UInt128,
+    Unknown,
+    UnsignedIntegerType,
+)
+
+__all__ = [
+    "Array",
+    "Binary",
+    "Boolean",
+    "Categorical",
+    "DType",
+    "Date",
+    "Datetime",
+    "Decimal",
+    "Duration",
+    "Enum",
+    "Field",
+    "Float32",
+    "Float64",
+    "FloatType",
+    "Int8",
+    "Int16",
+    "Int32",
+    "Int64",
+    "Int128",
+    "IntegerType",
+    "List",
+    "NestedType",
+    "NumericType",
+    "Object",
+    "SignedIntegerType",
+    "String",
+    "Struct",
+    "Time",
+    "UInt8",
+    "UInt16",
+    "UInt32",
+    "UInt64",
+    "UInt128",
+    "Unknown",
+    "UnsignedIntegerType",
+]

lib/python3.11/site-packages/narwhals/stable/v1/selectors.py

@@ -0,0 +1,23 @@
+from __future__ import annotations
+
+from narwhals.selectors import (
+    all,
+    boolean,
+    by_dtype,
+    categorical,
+    datetime,
+    matches,
+    numeric,
+    string,
+)
+
+__all__ = [
+    "all",
+    "boolean",
+    "by_dtype",
+    "categorical",
+    "datetime",
+    "matches",
+    "numeric",
+    "string",
+]

lib/python3.11/site-packages/narwhals/stable/v1/typing.py

@@ -0,0 +1,192 @@
+from __future__ import annotations
+
+from typing import TYPE_CHECKING, Any, Protocol, TypeVar, Union
+
+if TYPE_CHECKING:
+    import sys
+    from collections.abc import Iterable, Sized
+
+    from narwhals.stable.v1 import DataFrame, LazyFrame
+
+    if sys.version_info >= (3, 10):
+        from typing import TypeAlias
+    else:
+        from typing_extensions import TypeAlias
+
+    from narwhals.stable.v1 import Expr, Series
+
+    # All dataframes supported by Narwhals have a
+    # `columns` property. Their similarities don't extend
+    # _that_ much further unfortunately...
+    class NativeFrame(Protocol):
+        @property
+        def columns(self) -> Any: ...
+
+        def join(self, *args: Any, **kwargs: Any) -> Any: ...
+
+    class NativeDataFrame(Sized, NativeFrame, Protocol): ...
+
+    class NativeLazyFrame(NativeFrame, Protocol):
+        def explain(self, *args: Any, **kwargs: Any) -> Any: ...
+
+    class NativeSeries(Sized, Iterable[Any], Protocol):
+        def filter(self, *args: Any, **kwargs: Any) -> Any: ...
+
+    class DataFrameLike(Protocol):
+        def __dataframe__(self, *args: Any, **kwargs: Any) -> Any: ...
+
+
+IntoExpr: TypeAlias = Union["Expr", str, "Series[Any]"]
+"""Anything which can be converted to an expression.
+
+Use this to mean "either a Narwhals expression, or something
+which can be converted into one". For example, `exprs` in `DataFrame.select` is
+typed to accept `IntoExpr`, as it can either accept a `nw.Expr`
+(e.g. `df.select(nw.col('a'))`) or a string which will be interpreted as a
+`nw.Expr`, e.g. `df.select('a')`.
+"""
+
+
+IntoDataFrame: TypeAlias = Union["NativeDataFrame", "DataFrameLike"]
+"""Anything which can be converted to a Narwhals DataFrame.
+
+Use this if your function accepts a narwhalifiable object but doesn't care about its backend.
+
+Examples:
+    >>> import narwhals as nw
+    >>> from narwhals.typing import IntoDataFrame
+    >>> def agnostic_shape(df_native: IntoDataFrame) -> tuple[int, int]:
+    ...     df = nw.from_native(df_native, eager_only=True)
+    ...     return df.shape
+"""
+
+IntoLazyFrame: TypeAlias = "NativeLazyFrame"
+
+IntoFrame: TypeAlias = Union["IntoDataFrame", "IntoLazyFrame"]
+"""Anything which can be converted to a Narwhals DataFrame or LazyFrame.
+
+Use this if your function can accept an object which can be converted to either
+`nw.DataFrame` or `nw.LazyFrame` and it doesn't care about its backend.
+
+Examples:
+    >>> import narwhals as nw
+    >>> from narwhals.typing import IntoFrame
+    >>> def agnostic_columns(df_native: IntoFrame) -> list[str]:
+    ...     df = nw.from_native(df_native)
+    ...     return df.collect_schema().names()
+"""
+
+Frame: TypeAlias = Union["DataFrame[Any]", "LazyFrame[Any]"]
+"""Narwhals DataFrame or Narwhals LazyFrame.
+
+Use this if your function can work with either and your function doesn't care
+about its backend.
+
+Examples:
+    >>> import narwhals as nw
+    >>> from narwhals.typing import Frame
+    >>> @nw.narwhalify
+    ... def agnostic_columns(df: Frame) -> list[str]:
+    ...     return df.columns
+"""
+
+IntoSeries: TypeAlias = "NativeSeries"
+"""Anything which can be converted to a Narwhals Series.
+
+Use this if your function can accept an object which can be converted to `nw.Series`
+and it doesn't care about its backend.
+
+Examples:
+    >>> from typing import Any
+    >>> import narwhals as nw
+    >>> from narwhals.typing import IntoSeries
+    >>> def agnostic_to_list(s_native: IntoSeries) -> list[Any]:
+    ...     s = nw.from_native(s_native)
+    ...     return s.to_list()
+"""
+
+IntoFrameT = TypeVar("IntoFrameT", bound="IntoFrame")
+"""TypeVar bound to object convertible to Narwhals DataFrame or Narwhals LazyFrame.
+
+Use this if your function accepts an object which is convertible to `nw.DataFrame`
+or `nw.LazyFrame` and returns an object of the same type.
+
+Examples:
+    >>> import narwhals as nw
+    >>> from narwhals.typing import IntoFrameT
+    >>> def agnostic_func(df_native: IntoFrameT) -> IntoFrameT:
+    ...     df = nw.from_native(df_native)
+    ...     return df.with_columns(c=nw.col("a") + 1).to_native()
+"""
+
+IntoDataFrameT = TypeVar("IntoDataFrameT", bound="IntoDataFrame")
+"""TypeVar bound to object convertible to Narwhals DataFrame.
+
+Use this if your function accepts an object which can be converted to `nw.DataFrame`
+and returns an object of the same class.
+
+Examples:
+    >>> import narwhals as nw
+    >>> from narwhals.typing import IntoDataFrameT
+    >>> def agnostic_func(df_native: IntoDataFrameT) -> IntoDataFrameT:
+    ...     df = nw.from_native(df_native, eager_only=True)
+    ...     return df.with_columns(c=df["a"] + 1).to_native()
+"""
+
+IntoLazyFrameT = TypeVar("IntoLazyFrameT", bound="IntoLazyFrame")
+
+FrameT = TypeVar("FrameT", "DataFrame[Any]", "LazyFrame[Any]")
+"""TypeVar bound to Narwhals DataFrame or Narwhals LazyFrame.
+
+Use this if your function accepts either `nw.DataFrame` or `nw.LazyFrame` and returns
+an object of the same kind.
+
+Examples:
+    >>> import narwhals as nw
+    >>> from narwhals.typing import FrameT
+    >>> @nw.narwhalify
+    ... def agnostic_func(df: FrameT) -> FrameT:
+    ...     return df.with_columns(c=nw.col("a") + 1)
+"""
+
+DataFrameT = TypeVar("DataFrameT", bound="DataFrame[Any]")
+"""TypeVar bound to Narwhals DataFrame.
+
+Use this if your function can accept a Narwhals DataFrame and returns a Narwhals
+DataFrame backed by the same backend.
+
+Examples:
+    >>> import narwhals as nw
+    >>> from narwhals.typing import DataFrameT
+    >>> @nw.narwhalify
+    >>> def func(df: DataFrameT) -> DataFrameT:
+    ...     return df.with_columns(c=df["a"] + 1)
+"""
+
+IntoSeriesT = TypeVar("IntoSeriesT", bound="IntoSeries")
+"""TypeVar bound to object convertible to Narwhals Series.
+
+Use this if your function accepts an object  which can be converted to `nw.Series`
+and returns an object of the same class.
+
+Examples:
+    >>> import narwhals as nw
+    >>> from narwhals.typing import IntoSeriesT
+    >>> def agnostic_abs(s_native: IntoSeriesT) -> IntoSeriesT:
+    ...     s = nw.from_native(s_native, series_only=True)
+    ...     return s.abs().to_native()
+"""
+
+
+__all__ = [
+    "DataFrameT",
+    "Frame",
+    "FrameT",
+    "IntoDataFrame",
+    "IntoDataFrameT",
+    "IntoExpr",
+    "IntoFrame",
+    "IntoFrameT",
+    "IntoSeries",
+    "IntoSeriesT",
+]

lib/python3.11/site-packages/narwhals/stable/v2/_namespace.py

@@ -0,0 +1,10 @@
+from __future__ import annotations
+
+from narwhals._compliant.typing import CompliantNamespaceT_co
+from narwhals._namespace import Namespace as NwNamespace
+from narwhals._utils import Version
+
+__all__ = ["Namespace"]
+
+
+class Namespace(NwNamespace[CompliantNamespaceT_co], version=Version.V2): ...

lib/python3.11/site-packages/narwhals/stable/v2/dependencies.py

@@ -0,0 +1,3 @@
+from __future__ import annotations
+
+from narwhals.dependencies import *  # noqa: F403

lib/python3.11/site-packages/narwhals/stable/v2/dtypes.py

@@ -0,0 +1,3 @@
+from __future__ import annotations
+
+from narwhals.dtypes import *  # noqa: F403

lib/python3.11/site-packages/narwhals/stable/v2/selectors.py

@@ -0,0 +1,3 @@
+from __future__ import annotations
+
+from narwhals.selectors import *  # noqa: F403

lib/python3.11/site-packages/narwhals/stable/v2/typing.py

@@ -0,0 +1,186 @@
+from __future__ import annotations
+
+from typing import TYPE_CHECKING, Any, Protocol, TypeVar, Union
+
+if TYPE_CHECKING:
+    import sys
+    from collections.abc import Iterable, Sized
+
+    from narwhals.stable.v2 import DataFrame, LazyFrame
+
+    if sys.version_info >= (3, 10):
+        from typing import TypeAlias
+    else:
+        from typing_extensions import TypeAlias
+
+    from narwhals.stable.v2 import Expr, Series
+
+    # All dataframes supported by Narwhals have a
+    # `columns` property. Their similarities don't extend
+    # _that_ much further unfortunately...
+    class NativeFrame(Protocol):
+        @property
+        def columns(self) -> Any: ...
+
+        def join(self, *args: Any, **kwargs: Any) -> Any: ...
+
+    class NativeDataFrame(Sized, NativeFrame, Protocol): ...
+
+    class NativeLazyFrame(NativeFrame, Protocol):
+        def explain(self, *args: Any, **kwargs: Any) -> Any: ...
+
+    class NativeSeries(Sized, Iterable[Any], Protocol):
+        def filter(self, *args: Any, **kwargs: Any) -> Any: ...
+
+
+IntoExpr: TypeAlias = Union["Expr", str, "Series[Any]"]
+"""Anything which can be converted to an expression.
+
+Use this to mean "either a Narwhals expression, or something
+which can be converted into one". For example, `exprs` in `DataFrame.select` is
+typed to accept `IntoExpr`, as it can either accept a `nw.Expr`
+(e.g. `df.select(nw.col('a'))`) or a string which will be interpreted as a
+`nw.Expr`, e.g. `df.select('a')`.
+"""
+
+IntoDataFrame: TypeAlias = "NativeDataFrame"
+"""Anything which can be converted to a Narwhals DataFrame.
+
+Use this if your function accepts a narwhalifiable object but doesn't care about its backend.
+
+Examples:
+    >>> import narwhals as nw
+    >>> from narwhals.typing import IntoDataFrame
+    >>> def agnostic_shape(df_native: IntoDataFrame) -> tuple[int, int]:
+    ...     df = nw.from_native(df_native, eager_only=True)
+    ...     return df.shape
+"""
+
+IntoLazyFrame: TypeAlias = "NativeLazyFrame"
+
+IntoFrame: TypeAlias = Union["IntoDataFrame", "IntoLazyFrame"]
+"""Anything which can be converted to a Narwhals DataFrame or LazyFrame.
+
+Use this if your function can accept an object which can be converted to either
+`nw.DataFrame` or `nw.LazyFrame` and it doesn't care about its backend.
+
+Examples:
+    >>> import narwhals as nw
+    >>> from narwhals.typing import IntoFrame
+    >>> def agnostic_columns(df_native: IntoFrame) -> list[str]:
+    ...     df = nw.from_native(df_native)
+    ...     return df.collect_schema().names()
+"""
+
+Frame: TypeAlias = Union["DataFrame[Any]", "LazyFrame[Any]"]
+"""Narwhals DataFrame or Narwhals LazyFrame.
+
+Use this if your function can work with either and your function doesn't care
+about its backend.
+
+Examples:
+    >>> import narwhals as nw
+    >>> from narwhals.typing import Frame
+    >>> @nw.narwhalify
+    ... def agnostic_columns(df: Frame) -> list[str]:
+    ...     return df.columns
+"""
+
+IntoSeries: TypeAlias = "NativeSeries"
+"""Anything which can be converted to a Narwhals Series.
+
+Use this if your function can accept an object which can be converted to `nw.Series`
+and it doesn't care about its backend.
+
+Examples:
+    >>> from typing import Any
+    >>> import narwhals as nw
+    >>> from narwhals.typing import IntoSeries
+    >>> def agnostic_to_list(s_native: IntoSeries) -> list[Any]:
+    ...     s = nw.from_native(s_native)
+    ...     return s.to_list()
+"""
+
+IntoFrameT = TypeVar("IntoFrameT", bound="IntoFrame")
+"""TypeVar bound to object convertible to Narwhals DataFrame or Narwhals LazyFrame.
+
+Use this if your function accepts an object which is convertible to `nw.DataFrame`
+or `nw.LazyFrame` and returns an object of the same type.
+
+Examples:
+    >>> import narwhals as nw
+    >>> from narwhals.typing import IntoFrameT
+    >>> def agnostic_func(df_native: IntoFrameT) -> IntoFrameT:
+    ...     df = nw.from_native(df_native)
+    ...     return df.with_columns(c=nw.col("a") + 1).to_native()
+"""
+
+IntoDataFrameT = TypeVar("IntoDataFrameT", bound="IntoDataFrame")
+"""TypeVar bound to object convertible to Narwhals DataFrame.
+
+Use this if your function accepts an object which can be converted to `nw.DataFrame`
+and returns an object of the same class.
+
+Examples:
+    >>> import narwhals as nw
+    >>> from narwhals.typing import IntoDataFrameT
+    >>> def agnostic_func(df_native: IntoDataFrameT) -> IntoDataFrameT:
+    ...     df = nw.from_native(df_native, eager_only=True)
+    ...     return df.with_columns(c=df["a"] + 1).to_native()
+"""
+
+FrameT = TypeVar("FrameT", "DataFrame[Any]", "LazyFrame[Any]")
+"""TypeVar bound to Narwhals DataFrame or Narwhals LazyFrame.
+
+Use this if your function accepts either `nw.DataFrame` or `nw.LazyFrame` and returns
+an object of the same kind.
+
+Examples:
+    >>> import narwhals as nw
+    >>> from narwhals.typing import FrameT
+    >>> @nw.narwhalify
+    ... def agnostic_func(df: FrameT) -> FrameT:
+    ...     return df.with_columns(c=nw.col("a") + 1)
+"""
+
+DataFrameT = TypeVar("DataFrameT", bound="DataFrame[Any]")
+"""TypeVar bound to Narwhals DataFrame.
+
+Use this if your function can accept a Narwhals DataFrame and returns a Narwhals
+DataFrame backed by the same backend.
+
+Examples:
+    >>> import narwhals as nw
+    >>> from narwhals.typing import DataFrameT
+    >>> @nw.narwhalify
+    >>> def func(df: DataFrameT) -> DataFrameT:
+    ...     return df.with_columns(c=df["a"] + 1)
+"""
+
+IntoSeriesT = TypeVar("IntoSeriesT", bound="IntoSeries")
+"""TypeVar bound to object convertible to Narwhals Series.
+
+Use this if your function accepts an object  which can be converted to `nw.Series`
+and returns an object of the same class.
+
+Examples:
+    >>> import narwhals as nw
+    >>> from narwhals.typing import IntoSeriesT
+    >>> def agnostic_abs(s_native: IntoSeriesT) -> IntoSeriesT:
+    ...     s = nw.from_native(s_native, series_only=True)
+    ...     return s.abs().to_native()
+"""
+
+
+__all__ = [
+    "DataFrameT",
+    "Frame",
+    "FrameT",
+    "IntoDataFrame",
+    "IntoDataFrameT",
+    "IntoExpr",
+    "IntoFrame",
+    "IntoFrameT",
+    "IntoSeries",
+    "IntoSeriesT",
+]