gh-134746: implement Ctrl+Alt+L clear display keymap in pyREPL

Lib/_pyrepl/commands.py

@@ -135,6 +135,13 @@ def do(self) -> None:
         r.dirty = True
 
 
+class clear_display(Command):
+    def do(self) -> None:
+        r = self.reader
+        r.console.clear_all()
+        r.dirty = True
+
+
 class refresh(Command):
     def do(self) -> None:
         self.reader.dirty = True

Lib/_pyrepl/console.py

@@ -114,6 +114,10 @@ def clear(self) -> None:
         """Wipe the screen"""
         ...
 
+    def clear_all(self) -> None:
+        """Clear screen and scrollback buffer."""
+        ...
+
     @abstractmethod
     def finish(self) -> None:
         """Move the cursor to the end of the display and otherwise get

Lib/_pyrepl/reader.py

@@ -75,6 +75,7 @@ def make_default_commands() -> dict[CommandName, type[Command]]:
         (r"\<return>", "accept"),
         (r"\C-k", "kill-line"),
         (r"\C-l", "clear-screen"),
+        (r"\C-\M-l", "clear-display"),
         (r"\C-m", "accept"),
         (r"\C-t", "transpose-characters"),
         (r"\C-u", "unix-line-discard"),

Lib/_pyrepl/unix_console.py

@@ -561,6 +561,11 @@ def clear(self):
         self.posxy = 0, 0
         self.screen = []
 
+    def clear_all(self) -> None:
+        """Clear screen and scrollback buffer."""
+        self.__write("\x1b[3J\x1b[2J\x1b[H")
+        self.clear()
+
     @property
     def input_hook(self):
         # avoid inline imports here so the repl doesn't get flooded

Lib/_pyrepl/windows_console.py

@@ -111,6 +111,7 @@ def __init__(self, err: int | None, descr: str | None = None) -> None:
 MOVE_UP = "\x1b[{}A"
 MOVE_DOWN = "\x1b[{}B"
 CLEAR = "\x1b[H\x1b[J"
+CLEAR_ALL= "\x1b[3J\x1b[2J\x1b[H"
 
 # State of control keys: https://learn.microsoft.com/en-us/windows/console/key-event-record-str
 ALT_ACTIVE = 0x01 | 0x02
@@ -516,6 +517,12 @@ def clear(self) -> None:
         self.posxy = 0, 0
         self.screen = [""]
 
+
+    def clear_all(self) -> None:
+        """Clear screen and scrollback buffer."""
+        self.__write(CLEAR_ALL)
+        self.clear()
+
     def finish(self) -> None:
         """Move the cursor to the end of the display and otherwise get
         ready for end.  XXX could be merged with restore?  Hmm."""

Misc/NEWS.d/next/Library/2025-09-05-15-02-20.gh-issue-134746.9kiF6K.rst

@@ -0,0 +1,5 @@
+Added a new ``clear_display`` command in the REPL. ``Ctrl+Alt+L`` now clears
+the screen and, if possible, the terminal’s scrollback buffer, then redraws
+the current line at the top of the screen.
+
+Manually tested on Unix; Windows behavior not yet verified.