gh-146044: Fix ctrl-w (unix-word-rubout) to use whitespace word boundaries

Lib/_pyrepl/commands.py

@@ -169,7 +169,7 @@ class unix_word_rubout(KillCommand):
  def do(self) -> None:
  r = self.reader
  for i in range(r.get_arg()):
- self.kill_range(r.bow(), r.pos)
+ self.kill_range(r.bow_ws(), r.pos)
 
 
 class kill_word(KillCommand):

Lib/_pyrepl/reader.py

@@ -417,6 +417,23 @@ def bow(self, p: int | None = None) -> int:
  p -= 1
  return p + 1
 
+ def bow_ws(self, p: int | None = None) -> int:
+ """Return the 0-based index of the whitespace-delimited word break
+ preceding p most immediately.
+
+ p defaults to self.pos; only whitespace is considered a word
+ boundary, matching the behavior of unix-word-rubout in bash/readline.
+ """
+ if p is None:
+ p = self.pos
+ b = self.buffer
+ p -= 1
+ while p >= 0 and b[p] in " \n\t":
+ p -= 1
+ while p >= 0 and b[p] not in " \n\t":
+ p -= 1
+ return p + 1
+
  def eow(self, p: int | None = None) -> int:
  """Return the 0-based index of the word break following p most
  immediately.

Lib/test/test_pyrepl/test_reader.py

@@ -358,6 +358,41 @@ def test_setpos_from_xy_for_non_printing_char(self):
  reader.setpos_from_xy(8, 0)
  self.assertEqual(reader.pos, 7)
 
+ def test_bow_ws_stops_at_whitespace(self):
+ # See https://github.com/python/cpython/issues/146044.
+ reader = prepare_reader(prepare_console([]))
+ reader.buffer = list("foo.bar baz")
+ reader.pos = len(reader.buffer)
+ self.assertEqual(reader.bow_ws(), 8)
+
+ def test_bow_ws_includes_punctuation_in_word(self):
+ reader = prepare_reader(prepare_console([]))
+ buf = "foo.bar(baz) qux"
+ reader.buffer = list(buf)
+ reader.pos = buf.index(")") + 1
+ self.assertEqual(reader.bow_ws(), 0)
+
+ def test_bow_vs_bow_ws(self):
+ reader = prepare_reader(prepare_console([]))
+ reader.buffer = list("foo.bar")
+ reader.pos = len(reader.buffer)
+ # bow() stops at '.' so we return the index of 'b' in "bar"
+ self.assertEqual(reader.bow(), 4)
+ # bow_ws() treats entire "foo.bar" as one word
+ self.assertEqual(reader.bow_ws(), 0)
+
+ def test_bow_ws_with_tabs(self):
+ reader = prepare_reader(prepare_console([]))
+ reader.buffer = list("foo\tbar")
+ reader.pos = len(reader.buffer)
+ self.assertEqual(reader.bow_ws(), 4)
+
+ def test_bow_ws_with_newlines(self):
+ reader = prepare_reader(prepare_console([]))
+ reader.buffer = list("foo\nbar")
+ reader.pos = len(reader.buffer)
+ self.assertEqual(reader.bow_ws(), 4)
+
 @force_colorized_test_class
 class TestReaderInColor(ScreenEqualMixin, TestCase):
  def test_syntax_highlighting_basic(self):

Misc/NEWS.d/next/Library/2026-03-20-00-00-01.gh-issue-146044.WsCtrl.rst

@@ -0,0 +1,3 @@
+Fix ``unix-word-rubout`` (Ctrl-W) in the REPL to use whitespace-only word
+boundaries, matching behavior of the basic REPL. Previously it used
+syntax-table boundaries which treated punctuation as word separators.