Fix various conversion issues.

The R package polars introduced a few changes in
its class definition.

The fixes highlighted an issue in rpy2 (conversion
rules for R environment) that will be fixed in rpy2-robjects 3.6.3.
That fix is required.

Author: lgautier

pyproject.toml

@@ -25,7 +25,7 @@ classifiers = [
 ]
 dependencies = [
     "pyarrow",
-    "rpy2 >= 3.5.15"
+    "rpy2-robjects >= 3.6.3"
 ]
 dynamic = ["version"]
 

rpy2_arrow/polars.py

@@ -58,18 +58,29 @@ def pypolars_to_rpolars_dataframe(
     rpack_polars = ensure_r_polars()
     # TODO: There appear to be an odd shortcircuiting that requires toggling
     # additional conversion off.
-    with rpy2.robjects.default_converter.context():
+    with rpy2arrow.converter.context():
         return rpack_polars.as_polars_df(r_arrow_table)
 
-
 # TODO: rpy2.rinterface.SexpExtPtr should have an robjects-level wrapper?
 def rpolar_to_pypolars_dataframe(
         dataf: rpy2.rinterface.SexpExtPtr
 ) -> polars.DataFrame:
     # R polars to R arrow.
     rpack_arrow = ensure_r_arrow()
     ensure_r_polars()
-    r_arrow_table = rpack_arrow.as_arrow_table(dataf)
+    with rpy2.robjects.default_converter.context():
+        r_arrow_table = rpack_arrow.as_arrow_table(dataf)
+    return rarrow_to_pypolars_dataframe(r_arrow_table)
+
+
+def rpolars_env_to_pypolars_dataframe(
+        dataf: rpy2.rinterface.sexp.SexpEnvironment
+) -> polars.DataFrame:
+    # R polars to R arrow.
+    rpack_arrow = ensure_r_arrow()
+    ensure_r_polars()
+    with rpy2.robjects.default_converter.context():
+        r_arrow_table = rpack_arrow.as_arrow_table(dataf)
     return rarrow_to_pypolars_dataframe(r_arrow_table)
 
 
@@ -92,12 +103,14 @@ def rpolar_to_pypolars_dataframe(
 
 converter._rpy2py_nc_map[rpy2.rinterface.SexpEnvironment].update(
     {
-        'Table': rarrow_to_pypolars_dataframe,
+        'polars_data_frame': rpolars_env_to_pypolars_dataframe,
+        'Table': rarrow_to_pypolars_dataframe
     }
 )
 
 converter._rpy2py_nc_map[rpy2.rinterface.SexpExtPtr].update(
     {
+        # TODO: is this still needed?
         'polars_data_frame': rpolar_to_pypolars_dataframe,
     }
 )

rpy2_arrow/tests_polars.py

@@ -97,7 +97,7 @@ def test_rpolar_to_pypolars_dataframe(self):
             ([1, 2], polars.Int64, 'Int64', _cmp_simple),  # Fails.
             ([1.1, 2.1], polars.Float32, 'Float32', _cmp_float),
             ([1.1, 2.1], polars.Float64, 'Float64', _cmp_float),
-            (['wx', 'yz'], polars.Utf8, 'Utf8', _cmp_simple),
+            (['wx', 'yz'], polars.Utf8, 'String', _cmp_simple),
             (['wx', 'yz', 'wx'], polars.Categorical,
              'Categorical', _cmp_simple)
         ])
@@ -169,6 +169,6 @@ def test_rpl_to_pl(self, rstr, cls):
 
     def test_pl_to_rpl(self):
         plobj = polars.DataFrame({'a': [1, 2, 3]})
-        cls = rpy2.robjects.ExternalPointer
+        cls = rpy2.robjects.environments.Environment
         rplobj = rpy2polars.pl_to_rpl(plobj)
         assert isinstance(rplobj, cls)