fix(python): Fix dtype parameter in pandas_to_pyseries function (#1…

…5948)

py-polars/polars/_utils/construction/series.py

@@ -404,14 +404,17 @@ def to_series_chunk(values: list[Any], dtype: PolarsDataType | None) -> Series:
 def pandas_to_pyseries(
     name: str,
     values: pd.Series[Any] | pd.Index[Any] | pd.DatetimeIndex,
+    dtype: PolarsDataType | None = None,
     *,
     nan_to_null: bool = True,
 ) -> PySeries:
     """Construct a PySeries from a pandas Series or DatetimeIndex."""
     if not name and values.name is not None:
         name = str(values.name)
     if is_simple_numpy_backed_pandas_series(values):
-        return pl.Series(name, values.to_numpy(), nan_to_null=nan_to_null)._s
+        return pl.Series(
+            name, values.to_numpy(), dtype=dtype, nan_to_null=nan_to_null
+        )._s
     if not _PYARROW_AVAILABLE:
         msg = (
             "pyarrow is required for converting a pandas series to Polars, "

py-polars/polars/series/series.py

@@ -346,7 +346,7 @@ def __init__(
         elif _check_for_pandas(values) and isinstance(
             values, (pd.Series, pd.Index, pd.DatetimeIndex)
         ):
-            self._s = pandas_to_pyseries(name, values)
+            self._s = pandas_to_pyseries(name, values, dtype=dtype)
 
         elif _is_generator(values):
             self._s = iterable_to_pyseries(name, values, dtype=dtype, strict=strict)

py-polars/tests/unit/series/test_series.py

@@ -2337,3 +2337,8 @@ def test_search_sorted(
 
     multiple_s = s.search_sorted(multiple)
     assert_series_equal(multiple_s, pl.Series(multiple_expected, dtype=pl.UInt32))
+
+
+def test_series_from_pandas_with_dtype() -> None:
+    s = pl.Series("foo", pd.Series([1, 2, 3]), pl.Float32)
+    assert_series_equal(s, pl.Series("foo", [1, 2, 3], dtype=pl.Float32))