chore: add backend_version param to polars dtype translation utility (#…

…1441)
narwhals-dev · Nov 24, 2024 · 43cd8bf · 43cd8bf
1 parent 8dc9f0a
commit 43cd8bf
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Showing 3 changed files with 25 additions and 15 deletions.
diff --git a/narwhals/_polars/dataframe.py b/narwhals/_polars/dataframe.py
@@ -76,7 +76,7 @@ def __getattr__(self, attr: str) -> Any:
         if attr == "schema":
             schema = self._native_frame.schema
             return {
-                name: native_to_narwhals_dtype(dtype, self._dtypes)
+                name: native_to_narwhals_dtype(dtype, self._dtypes, self._backend_version)
                 for name, dtype in schema.items()
             }
 
@@ -113,12 +113,12 @@ def __array__(self, dtype: Any | None = None, copy: bool | None = None) -> np.nd
     def collect_schema(self) -> dict[str, DType]:
         if self._backend_version < (1,):
             return {
-                name: native_to_narwhals_dtype(dtype, self._dtypes)
+                name: native_to_narwhals_dtype(dtype, self._dtypes, self._backend_version)
                 for name, dtype in self._native_frame.schema.items()
             }
         else:
             return {
-                name: native_to_narwhals_dtype(dtype, self._dtypes)
+                name: native_to_narwhals_dtype(dtype, self._dtypes, self._backend_version)
                 for name, dtype in self._native_frame.collect_schema().items()
             }
 
@@ -351,19 +351,19 @@ def columns(self) -> list[str]:
     def schema(self) -> dict[str, Any]:
         schema = self._native_frame.schema
         return {
-            name: native_to_narwhals_dtype(dtype, self._dtypes)
+            name: native_to_narwhals_dtype(dtype, self._dtypes, self._backend_version)
             for name, dtype in schema.items()
         }
 
     def collect_schema(self) -> dict[str, DType]:
         if self._backend_version < (1,):
             return {
-                name: native_to_narwhals_dtype(dtype, self._dtypes)
+                name: native_to_narwhals_dtype(dtype, self._dtypes, self._backend_version)
                 for name, dtype in self._native_frame.schema.items()
             }
         else:
             return {
-                name: native_to_narwhals_dtype(dtype, self._dtypes)
+                name: native_to_narwhals_dtype(dtype, self._dtypes, self._backend_version)
                 for name, dtype in self._native_frame.collect_schema().items()
             }
 

diff --git a/narwhals/_polars/series.py b/narwhals/_polars/series.py
@@ -90,7 +90,9 @@ def name(self) -> str:
 
     @property
     def dtype(self: Self) -> DType:
-        return native_to_narwhals_dtype(self._native_series.dtype, self._dtypes)
+        return native_to_narwhals_dtype(
+            self._native_series.dtype, self._dtypes, self._backend_version
+        )
 
     @overload
     def __getitem__(self, item: int) -> Any: ...

diff --git a/narwhals/_polars/utils.py b/narwhals/_polars/utils.py
@@ -10,8 +10,6 @@
     from narwhals.dtypes import DType
     from narwhals.typing import DTypes
 
-from narwhals.utils import parse_version
-
 
 def extract_native(obj: Any) -> Any:
     from narwhals._polars.dataframe import PolarsDataFrame
@@ -34,7 +32,11 @@ def extract_args_kwargs(args: Any, kwargs: Any) -> tuple[list[Any], dict[str, An
     return args, kwargs
 
 
-def native_to_narwhals_dtype(dtype: pl.DataType, dtypes: DTypes) -> DType:
+def native_to_narwhals_dtype(
+    dtype: pl.DataType,
+    dtypes: DTypes,
+    backend_version: tuple[int, ...],
+) -> DType:
     import polars as pl  # ignore-banned-import()
 
     if dtype == pl.Float64:
@@ -79,20 +81,26 @@ def native_to_narwhals_dtype(dtype: pl.DataType, dtypes: DTypes) -> DType:
     if dtype == pl.Struct:
         return dtypes.Struct(
             [
-                dtypes.Field(field_name, native_to_narwhals_dtype(field_type, dtypes))
+                dtypes.Field(
+                    field_name,
+                    native_to_narwhals_dtype(field_type, dtypes, backend_version),
+                )
                 for field_name, field_type in dtype  # type: ignore[attr-defined]
             ]
         )
     if dtype == pl.List:
-        return dtypes.List(native_to_narwhals_dtype(dtype.inner, dtypes))  # type: ignore[attr-defined]
+        return dtypes.List(native_to_narwhals_dtype(dtype.inner, dtypes, backend_version))  # type: ignore[attr-defined]
     if dtype == pl.Array:
-        if parse_version(pl.__version__) < (0, 20, 30):  # pragma: no cover
+        if backend_version < (0, 20, 30):  # pragma: no cover
             return dtypes.Array(
-                native_to_narwhals_dtype(dtype.inner, dtypes),  # type: ignore[attr-defined]
+                native_to_narwhals_dtype(dtype.inner, dtypes, backend_version),  # type: ignore[attr-defined]
                 dtype.width,  # type: ignore[attr-defined]
             )
         else:
-            return dtypes.Array(native_to_narwhals_dtype(dtype.inner, dtypes), dtype.size)  # type: ignore[attr-defined]
+            return dtypes.Array(
+                native_to_narwhals_dtype(dtype.inner, dtypes, backend_version),  # type: ignore[attr-defined]
+                dtype.size,  # type: ignore[attr-defined]
+            )
     return dtypes.Unknown()