revert Dataset.pl; it needs pyarrow after all

Author: liquidcarbon

affinity.py

@@ -348,7 +348,7 @@ def arrow(self) -> "pa.Table":
 
     @property
     def pl(self) -> "pl.DataFrame":
-        return pl.DataFrame(self.dict)
+        return pl.DataFrame(dict(self))
 
     def is_dataset(self, key):
         attr = getattr(self, key, None)

pyproject.toml

@@ -19,13 +19,9 @@ dependencies = [
 
 [dependency-groups]
 dev = [
-    "pytest>=8",
-]
-polars = [
     "polars>=1",
-]
-pyarrow = [
     "pyarrow>=17",
+    "pytest>=8",
 ]
 
 [tool.hatch.build]

test_affinity.py

@@ -259,13 +259,15 @@ class aDataset(af.Dataset):
 
 
 @pytest.mark.skipif(NO_POLARS, reason="polars is not installed")
+@pytest.mark.skipif(NO_PYARROW, reason="pyarrow is not installed")
 def test_to_polars():
     class aDataset(af.Dataset):
         v1 = af.VectorBool("")
         v2 = af.VectorF32("")
         v3 = af.VectorI16("")
 
     data = aDataset(v1=[True], v2=[1 / 2], v3=[999])
+    # this requires polars AND pyarrow because conversion goes via pd.Series
     polars_df = data.pl
     assert str(polars_df.dtypes) == "[Boolean, Float32, Int16]"