GH-121584: Toggle helper instead of nesting instances when using key bindings

Lib/_pyrepl/commands.py

@@ -435,9 +435,14 @@ def do(self) -> None:
 class help(Command):
     def do(self) -> None:
         import _sitebuiltins
-
-        with self.reader.suspend():
-            self.reader.msg = _sitebuiltins._Helper()()  # type: ignore[assignment, call-arg]
+        if self.reader.help_mode:
+            self.reader.help_mode = False
+            raise KeyboardInterrupt
+        else:
+            self.reader.help_mode = True
+            with self.reader.suspend():
+                self.reader.msg = _sitebuiltins._Helper()()  # type: ignore[assignment, call-arg]
+            self.reader.help_mode = False
 
 
 class invalid_key(Command):

Lib/_pyrepl/reader.py

@@ -234,6 +234,7 @@ class Reader:
     dirty: bool = False
     finished: bool = False
     paste_mode: bool = False
+    help_mode: bool = False
     in_bracketed_paste: bool = False
     commands: dict[str, type[Command]] = field(default_factory=make_default_commands)
     last_command: type[Command] | None = None
@@ -665,7 +666,7 @@ def suspend(self) -> SimpleContextManager:
             self.restore()
             yield
         finally:
-            for arg in ("msg", "ps1", "ps2", "ps3", "ps4", "paste_mode"):
+            for arg in ("msg", "ps1", "ps2", "ps3", "ps4", "paste_mode", "help_mode"):
                 setattr(self, arg, prev_state[arg])
             self.prepare()
 

Lib/test/test_pyrepl/support.py

@@ -58,6 +58,7 @@ def prepare_reader(console: Console, **kwargs):
     reader = ReadlineAlikeReader(console=console, config=config)
     reader.more_lines = partial(more_lines, namespace=None)
     reader.paste_mode = True  # Avoid extra indents
+    reader.help_mode = False
 
     def get_prompt(lineno, cursor_on_line) -> str:
         return ""

Lib/test/test_pyrepl/test_reader.py

@@ -175,6 +175,20 @@ def test_up_arrow_after_ctrl_r(self):
         reader, _ = handle_all_events(events)
         self.assert_screen_equals(reader, "")
 
+    def test_help_toggles_instead_of_nesting(self):
+
+        events = [
+            Event(evt="key", data="f1", raw=bytearray(b"")),
+        ]
+
+        no_paste_reader = functools.partial(
+            prepare_reader,
+            paste_mode=False,
+            help_mode=True,
+        )
+        reader, _ = handle_all_events(events, prepare_reader=no_paste_reader)
+        self.assertFalse(reader.help_mode)
+
     def test_newline_within_block_trailing_whitespace(self):
         # fmt: off
         code = (

Misc/NEWS.d/next/Library/2025-01-21-19-46-20.gh-issue-121584.O3lEdm.rst

@@ -0,0 +1,2 @@
+Toggle helper instead of nesting instances when using key bindings in the
+new REPL.