Raise KeyError from table_provider for consistency with table()

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: timsaucer

crates/core/src/context.rs

@@ -1086,8 +1086,10 @@ impl PySessionContext {
         self.ctx.remove_optimizer_rule(name)
     }
 
-    pub fn table_provider(&self, name: &str, py: Python) -> PyDataFusionResult<PyTable> {
-        let provider = wait_for_future(py, self.ctx.table_provider(name))??;
+    pub fn table_provider(&self, name: &str, py: Python) -> PyResult<PyTable> {
+        let provider = wait_for_future(py, self.ctx.table_provider(name))
+            .map_err(|e| PyKeyError::new_err(e.to_string()))?
+            .map_err(|e| PyKeyError::new_err(e.to_string()))?;
         Ok(PyTable { table: provider })
     }
 

python/tests/test_context.py

@@ -593,6 +593,11 @@ def test_table_provider(ctx):
     assert tbl.schema == pa.schema([("x", pa.int64())])
 
 
+def test_table_provider_not_found(ctx):
+    with pytest.raises(KeyError):
+        ctx.table_provider("nonexistent_table")
+
+
 def test_read_json(ctx):
     path = pathlib.Path(__file__).parent.resolve()