Allow string indexing in ItemizedResource.row (#649)

Author: rickwierenga

CHANGELOG.md

@@ -60,6 +60,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 - `location` parameter of `assign_child_resource` is not optional (https://github.com/PyLabRobot/pylabrobot/pull/336)
 - `Resource.get_absolute_location` raises `NoLocationError` instead of `AssertionError` when absolute location is not defined (https://github.com/PyLabRobot/pylabrobot/pull/338)
 - `no_trash` and `no_teaching_rack` were renamed to `with_trash` and `with_teaching_rack` to avoid double negatives (https://github.com/PyLabRobot/pylabrobot/pull/347)
+- `ItemizedResource.row` accepts a string ("A"-"P") in addition to an integer index.
 
 ### Added
 

pylabrobot/resources/itemized_resource.py

@@ -473,6 +473,21 @@ def column(self, column: int) -> List[T]:
     """Get all items in the given column."""
     return self[column * self.num_items_y : (column + 1) * self.num_items_y]
 
-  def row(self, row: int) -> List[T]:
-    """Get all items in the given row."""
+  def row(self, row: Union[int, str]) -> List[T]:
+    """Get all items in the given row.
+
+    Args:
+      row: The row index. Either an integer starting at ``0`` or a letter
+        ``"A"``-``"P"`` (case insensitive) corresponding to ``0``-``15``.
+
+    Raises:
+      ValueError: If ``row`` is a string outside ``"A"``-``"P"``.
+    """
+
+    if isinstance(row, str):
+      letter = row.upper()
+      if letter not in LETTERS[:16]:
+        raise ValueError("Row must be between 'A' and 'P'.")
+      row = LETTERS.index(letter)
+
     return self[row :: self.num_items_y]

pylabrobot/resources/itemized_resource_tests.py

@@ -183,6 +183,22 @@ def test_get_row(self):
       ],
     )
 
+  def test_get_row_str(self):
+    self.assertEqual(
+      [w.name for w in self.plate.row("A")],
+      [w.name for w in self.plate.row(0)],
+    )
+    self.assertEqual(
+      [w.name for w in self.plate.row("d")],
+      [w.name for w in self.plate.row(3)],
+    )
+
+  def test_get_row_str_invalid(self):
+    with self.assertRaises(ValueError):
+      self.plate.row("Q")
+    with self.assertRaises(ValueError):
+      self.plate.row("AA")
+
   def test_get_column(self):
     self.assertEqual(
       [w.name for w in self.plate.column(0)],