fixup?

puffin/__init__.py

@@ -0,0 +1,8 @@
+from puffin import containers
+from puffin.translate import get_namespace
+from puffin.translate import to_original_object
+from puffin.translate import to_polars_api
+
+__version__ = "0.2.6"
+
+__all__ = ["to_polars_api", "to_original_object", "get_namespace", "containers"]

puffin/containers.py

@@ -0,0 +1,102 @@
+try:
+    import polars as pl
+except ModuleNotFoundError:
+    POLARS_AVAILABLE = False
+    pl = object  # type: ignore[assignment]
+else:
+    POLARS_AVAILABLE = True
+try:
+    import pandas as pd
+except ModuleNotFoundError:
+    PANDAS_AVAILABLE = False
+    pd = object
+else:
+    PANDAS_AVAILABLE = True
+try:
+    import cudf
+except ModuleNotFoundError:
+    CUDF_AVAILABLE = False
+    cudf = object
+else:
+    CUDF_AVAILABLE = True
+try:
+    import modin.pandas as mpd
+except ModuleNotFoundError:
+    MODIN_AVAILABLE = False
+    mpd = object
+else:
+    MODIN_AVAILABLE = True
+
+
+from typing import Any
+
+
+def is_lazyframe(obj: Any) -> bool:
+    if hasattr(obj, "__lazyframe_namespace__"):
+        return True
+    if POLARS_AVAILABLE and isinstance(
+        obj, (pl.DataFrame, pl.LazyFrame, pl.Expr, pl.Series)
+    ):
+        return isinstance(obj, pl.LazyFrame)
+    return False
+
+
+def is_dataframe(obj: Any) -> bool:
+    if hasattr(obj, "__dataframe_namespace__"):
+        return True
+    if POLARS_AVAILABLE and isinstance(
+        obj, (pl.DataFrame, pl.LazyFrame, pl.Expr, pl.Series)
+    ):
+        return isinstance(obj, pl.DataFrame)
+    return False
+
+
+def is_expr(obj: Any) -> bool:
+    if hasattr(obj, "__expr_namespace__"):
+        return True
+    if POLARS_AVAILABLE and isinstance(
+        obj, (pl.DataFrame, pl.LazyFrame, pl.Expr, pl.Series)
+    ):
+        return isinstance(obj, pl.Expr)
+    return False
+
+
+def is_series(obj: Any) -> bool:
+    if hasattr(obj, "__series_namespace__"):
+        return True
+    if POLARS_AVAILABLE and isinstance(
+        obj, (pl.DataFrame, pl.LazyFrame, pl.Expr, pl.Series)
+    ):
+        return isinstance(obj, pl.Series)
+    return False
+
+
+def get_implementation(obj: Any) -> str:
+    if POLARS_AVAILABLE and isinstance(
+        obj, (pl.DataFrame, pl.LazyFrame, pl.Expr, pl.Series)
+    ):
+        return "polars"
+    if PANDAS_AVAILABLE and isinstance(obj, (pd.DataFrame, pd.Series)):
+        return "pandas"
+    if CUDF_AVAILABLE and isinstance(obj, (cudf.DataFrame, cudf.Series)):
+        return "cudf"
+    if MODIN_AVAILABLE and isinstance(obj, mpd.DataFrame):
+        return "modin"
+    msg = f"Unknown implementation: {obj}"
+    raise TypeError(msg)
+
+
+def is_pandas(obj: Any) -> bool:
+    return get_implementation(obj) == "pandas"
+
+
+def is_polars(obj: Any) -> bool:
+    return get_implementation(obj) == "polars"
+
+
+def is_cudf(obj: Any) -> bool:
+    return get_implementation(obj) == "cudf"
+
+
+def is_modin(obj: Any) -> bool:
+    return get_implementation(obj) == "modin"