Testing invalid index and keys in DataTable.get_row*

src/textual/widgets/_data_table.py

@@ -644,7 +644,7 @@ class DataTable(ScrollView, Generic[CellType], can_focus=True):
         row_key, column_key = self.coordinate_to_cell_key(coordinate)
         return self.get_cell(row_key, column_key)
 
-    def get_row(self, row_key: RowKey) -> list[CellType]:
+    def get_row(self, row_key: RowKey | str) -> list[CellType]:
         """Get the values from the row identified by the given row key.
 
         Args:
@@ -656,6 +656,8 @@ class DataTable(ScrollView, Generic[CellType], can_focus=True):
         Raises:
             RowDoesNotExist: When there is no row corresponding to the key.
         """
+        if row_key not in self._row_locations:
+            raise RowDoesNotExist(f"Row key {row_key!r} is not valid.")
         cell_mapping: dict[ColumnKey, CellType] = self._data.get(row_key, {})
         ordered_row: list[CellType] = []
         for column in self.ordered_columns:
@@ -677,10 +679,12 @@ class DataTable(ScrollView, Generic[CellType], can_focus=True):
         Raises:
             RowDoesNotExist: If there is no row with the given index.
         """
+        if not self.is_valid_row_index(row_index):
+            raise RowDoesNotExist(f"Row index {row_index!r} is not valid.")
         row_key = self._row_locations.get_key(row_index)
         return self.get_row(row_key)
 
-    def get_column(self, column_key: ColumnKey) -> list[CellType]:
+    def get_column(self, column_key: ColumnKey | str) -> list[CellType]:
         """Get the values from the column identified by the given column key.
 
         Args:

src/textual/widgets/data_table.py

@@ -5,21 +5,25 @@ from ._data_table import (
     CellKey,
     CellType,
     Column,
+    ColumnDoesNotExist,
     ColumnKey,
     CursorType,
     DuplicateKey,
     Row,
+    RowDoesNotExist,
     RowKey,
 )
 
 __all__ = [
-    "Column",
-    "Row",
-    "RowKey",
-    "ColumnKey",
-    "CellKey",
-    "CursorType",
-    "CellType",
     "CellDoesNotExist",
+    "CellKey",
+    "CellType",
+    "Column",
+    "ColumnDoesNotExist",
+    "ColumnKey",
+    "CursorType",
     "DuplicateKey",
+    "Row",
+    "RowDoesNotExist",
+    "RowKey",
 ]

tests/test_data_table.py

@@ -11,8 +11,16 @@ from textual.events import Click, MouseMove
 from textual.message import Message
 from textual.message_pump import MessagePump
 from textual.widgets import DataTable
-from textual.widgets._data_table import DuplicateKey
+from textual.widgets.data_table import (
-from textual.widgets.data_table import CellDoesNotExist, CellKey, ColumnKey, Row, RowKey
+    CellDoesNotExist,
+    CellKey,
+    ColumnDoesNotExist,
+    ColumnKey,
+    DuplicateKey,
+    Row,
+    RowDoesNotExist,
+    RowKey,
+)
 
 ROWS = [["0/0", "0/1"], ["1/0", "1/1"], ["2/0", "2/1"]]
 
@@ -363,6 +371,14 @@ async def test_get_row():
         assert table.get_row(second_row) == [3, 2, 1]
 
 
+async def test_get_row_invalid_row_key():
+    app = DataTableApp()
+    async with app.run_test():
+        table = app.query_one(DataTable)
+        with pytest.raises(RowDoesNotExist):
+            table.get_row("abc")
+
+
 async def test_get_row_at():
     app = DataTableApp()
     async with app.run_test():
@@ -381,6 +397,18 @@ async def test_get_row_at():
         assert table.get_row_at(1) == [2, 4, 1]
 
 
+@pytest.mark.parametrize("index", (-1, 2))
+async def test_get_row_at_invalid_index(index):
+    app = DataTableApp()
+    async with app.run_test():
+        table = app.query_one(DataTable)
+        table.add_columns("A", "B", "C")
+        table.add_row(2, 4, 1)
+        table.add_row(3, 2, 1)
+        with pytest.raises(RowDoesNotExist):
+            table.get_row_at(index)
+
+
 async def test_update_cell_cell_exists():
     app = DataTableApp()
     async with app.run_test():