gh-151876: Add tkinter Canvas methods rotate and rchars (GH-151877)

Wrap the Tk canvas commands "rchars" (replace the text or coordinates of
items, since Tk 8.6) and "rotate" (rotate the coordinates of items about
an origin, new in Tk 9.0) as the methods Canvas.rchars() and
Canvas.rotate(), complementing the existing dchars/insert and move/scale
methods.

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Author: serhiy-storchaka

Doc/library/tkinter.rst

@@ -3743,6 +3743,15 @@ Widget classes
       *yOrigin* changes by a factor of *yScale* (a factor of ``1.0`` leaves the
       coordinate unchanged).
 
+   .. method:: rotate(tagOrId, xOrigin, yOrigin, angle, /)
+
+      Rotate the coordinates of all items given by *tagOrId* in canvas
+      coordinate space about the origin (*xOrigin*, *yOrigin*) by *angle*
+      degrees anticlockwise.
+      Negative values of *angle* rotate clockwise.
+
+      .. versionadded:: next
+
    .. method:: delete(*tagOrIds)
 
       Delete each of the items given by the *tagOrIds* arguments.
@@ -3762,6 +3771,17 @@ Widget classes
       For line and polygon items *string* must be a valid sequence of
       coordinates.
 
+   .. method:: rchars(tagOrId, first, last, string, /)
+
+      Replace the characters (for text items) or coordinates (for line and
+      polygon items) in the range from *first* to *last* inclusive of each of
+      the items given by *tagOrId* with *string*.
+      For line and polygon items *string* must be a valid sequence of
+      coordinates.
+      Items that do not support indexing ignore this operation.
+
+      .. versionadded:: next
+
    .. method:: itemcget(tagOrId, option)
 
       Return the current value of the configuration option *option* for the

Doc/whatsnew/3.16.rst

@@ -173,6 +173,11 @@ tkinter
   synchronization of the displayed view with the underlying text.
   (Contributed by Serhiy Storchaka in :gh:`151675`.)
 
+* Added new :class:`!tkinter.Canvas` methods :meth:`~tkinter.Canvas.rchars`
+  which replaces the text or coordinates of canvas items, and
+  :meth:`~tkinter.Canvas.rotate` which rotates the coordinates of canvas items.
+  (Contributed by Serhiy Storchaka in :gh:`151876`.)
+
 * Added a :meth:`!validate` method to the :class:`!tkinter.Entry` and
   :class:`!tkinter.Spinbox` widgets, which forces an evaluation of the
   validation command.

Lib/test/test_tkinter/test_widgets.py

@@ -1409,6 +1409,34 @@ def test_scale(self):
         self.assertRaises(TclError, c.scale, rect, 0, 0, 'spam', 2)
         self.assertRaises(TclError, c.scale, rect, 0, 0)  # missing factors
 
+    @requires_tk(8, 6)
+    def test_rchars(self):
+        c = self.create()
+        # On a line item, rchars replaces a range of the coordinate list.
+        line = c.create_line(0, 0, 10, 10, 20, 0)
+        c.rchars(line, 2, 5, (30, 30, 40, 40))
+        self.assertEqual(c.coords(line), [0.0, 0.0, 30.0, 30.0, 40.0, 40.0])
+        # On a text item, rchars replaces a range of characters.
+        text = c.create_text(10, 10, text='hello')
+        c.rchars(text, 0, 2, 'HE')
+        self.assertEqual(c.itemcget(text, 'text'), 'HElo')
+        self.assertRaises(TclError, c.rchars)
+
+    @requires_tk(9, 0)
+    def test_rotate(self):
+        c = self.create()
+        line = c.create_line(10, 0, 20, 0)
+        # The canvas y-axis points down, so an anticlockwise rotation about
+        # the origin maps (x, y) to (y, -x).
+        c.rotate(line, 0, 0, 90)
+        for got, expected in zip(c.coords(line), [0, -10, 0, -20]):
+            self.assertAlmostEqual(got, expected, places=3)
+        # A negative angle rotates clockwise, restoring the original position.
+        c.rotate(line, 0, 0, -90)
+        for got, expected in zip(c.coords(line), [10, 0, 20, 0]):
+            self.assertAlmostEqual(got, expected, places=3)
+        self.assertRaises(TclError, c.rotate, line, 0, 0, 'spam')
+
     def test_delete(self):
         c = self.create()
         r1 = c.create_rectangle(10, 10, 30, 30)

Lib/tkinter/__init__.py

@@ -3270,6 +3270,22 @@ def tag_raise(self, *args):
 
     lift = tkraise = tag_raise  # overrides Misc.tkraise
 
+    def rchars(self, *args):
+        """Replace the text or coordinates between indices FIRST and LAST of
+        the items identified by TAGORID with STRING.
+
+        Text items replace their text; line and polygon items replace their
+        coordinates, in which case STRING is a list of coordinates. Other
+        items ignore this operation."""
+        self.tk.call((self._w, 'rchars') + args)
+
+    def rotate(self, *args): # new in Tk 9.0
+        """Rotate the coordinates of the items identified by TAGORID about the
+        origin (XORIGIN, YORIGIN) by ANGLE degrees anticlockwise.
+
+        Negative values of ANGLE rotate clockwise."""
+        self.tk.call((self._w, 'rotate') + args)
+
     def scale(self, *args):
         """Scale item TAGORID with XORIGIN, YORIGIN, XSCALE, YSCALE."""
         self.tk.call((self._w, 'scale') + args)

Misc/NEWS.d/next/Library/2026-06-22-00-55-07.gh-issue-151876.sVe0xx.rst

@@ -0,0 +1,2 @@
+Add the :class:`tkinter.Canvas` methods :meth:`!rchars` and :meth:`!rotate`,
+wrapping the ``rchars`` and ``rotate`` Tk canvas commands.