fix: enforce TypeError for DataFrame registration in SessionContext

Author: kosiew

python/datafusion/context.py

@@ -24,6 +24,8 @@
 
 import pyarrow as pa
 
+from datafusion import EXPECTED_PROVIDER_MSG
+
 try:
     from warnings import deprecated  # Python 3.13+
 except ImportError:
@@ -767,8 +769,13 @@ def register_table(
                 implementing ``__datafusion_table_provider__`` to add to the session
                 context.
         """
-        provider = _normalize_table_provider(table)
-        self.ctx.register_table(name, provider)
+        if isinstance(table, DataFrame):
+            raise TypeError(EXPECTED_PROVIDER_MSG)
+
+        if isinstance(table, Table):
+            self.ctx.register_table(name, table.table)
+        else:
+            self.ctx.register_table(name, table)
 
     def deregister_table(self, name: str) -> None:
         """Remove a table from the session."""

python/tests/test_context.py

@@ -423,7 +423,7 @@ def test_table_provider_from_capsule_invalid():
 
 def test_register_table_with_dataframe_errors(ctx):
     df = ctx.from_pydict({"a": [1]})
-    with pytest.raises(Exception) as exc_info:
+    with pytest.raises(TypeError) as exc_info:
         ctx.register_table("bad", df)
 
     assert str(exc_info.value) == EXPECTED_PROVIDER_MSG