feat: add wait argument to Model.delete_table

This adds a `wait` argument that will make the `delete_table` call block
until the DynamoDB table is fully deleted if set to `True`. It defaults
to `False` to not break the existing behavior.

Author: ryancausey

pynamodb/models.py

@@ -760,11 +760,21 @@ def exists(cls: Type[_T]) -> bool:
             return False
 
     @classmethod
-    def delete_table(cls) -> Any:
+    def delete_table(cls, wait: bool = False) -> Any:
         """
         Delete the table for this model
+
+        :param wait: If set, then this call will block until the table is deleted
         """
-        return cls._get_connection().delete_table()
+        result = cls._get_connection().delete_table()
+        if not wait:
+            return result
+
+        while True:
+            if not cls.exists():
+                return result
+
+            time.sleep(2)
 
     @classmethod
     def describe_table(cls) -> Any:

tests/test_model.py

@@ -3438,3 +3438,18 @@ def test_delete(add_version_condition: bool) -> None:
         }
         args = req.call_args[0][1]
         assert args == expected
+
+@patch.object(target=Model, attribute="exists", autospec=True)
+@patch.object(target=Model, attribute="_get_connection", autospec=True)
+def test_delete_with_wait(mock__get_connection, mock_exists):
+    """Test that the wait argument works as expected on the delete."""
+    # Make the first two exists calls show the table as still existing, then have the
+    # last call show it has been deleted.
+    mock_exists.side_effect = (True, True, False)
+
+    result = Model.delete_table()
+
+    # Should have returned the delete value.
+    assert result == mock__get_connection.return_value.delete_table.return_value
+    # Should have called exists 3 times.
+    assert mock_exists.call_count == 3