fix(cli): re-prompt on invalid confirmation answers instead of cancelling

src/kaggle/api/kaggle_api_extended.py

@@ -10130,12 +10130,14 @@ def confirmation(self, action: str = "", default_to_yes: bool = False):
             options[""] = True
         while True:
             sys.stdout.write("{} {} ".format(question, prompt))
-            choice = input().lower()
+            try:
+                choice = input().strip().lower()
+            except EOFError:
+                # Closed stdin can never produce a valid answer; treat it as "no" rather than looping.
+                return False
             if choice in options:
                 return options[choice]
-            else:
-                sys.stdout.write("Please respond with 'yes' or 'no'.\n")
-                return False
+            sys.stdout.write("Please respond with 'y' or 'n'.\n")
 
     def _check_response_version(self, response: Response):
         if self.already_printed_version_warning:

tests/unit/test_confirmation.py

@@ -0,0 +1,28 @@
+from unittest.mock import patch
+
+import pytest
+
+
+@pytest.mark.parametrize(
+    "answer, default_to_yes, expected",
+    [
+        ("", True, True),
+        (" Y \r", True, True),
+        ("NO", True, False),
+    ],
+)
+def test_confirmation_single_answer(api, answer, default_to_yes, expected):
+    with patch("builtins.input", return_value=answer):
+        assert api.confirmation("do it", default_to_yes=default_to_yes) is expected
+
+
+def test_confirmation_reprompts_after_invalid_answer(api):
+    # Without default_to_yes, Enter is not an answer either.
+    with patch("builtins.input", side_effect=["", "x", "y"]) as mock_input:
+        assert api.confirmation("do it") is True
+    assert mock_input.call_count == 3
+
+
+def test_confirmation_closed_stdin_cancels(api):
+    with patch("builtins.input", side_effect=["x", EOFError]):
+        assert api.confirmation("do it") is False