gh-94521: Copy or cut current line while no selection

Doc/library/idle.rst

@@ -125,9 +125,11 @@ Select All
 
 Cut
    Copy selection into the system-wide clipboard; then delete the selection.
+   If there is no selection, cut the current line instead.
 
 Copy
    Copy selection into the system-wide clipboard.
+   If there is no selection, copy the current line instead.
 
 Paste
    Insert contents of the system-wide clipboard into the current window.
@@ -371,9 +373,11 @@ Context menus have the standard clipboard functions also on the Edit menu.
 
 Cut
    Copy selection into the system-wide clipboard; then delete the selection.
+   If there is no selection, cut the current line instead.
 
 Copy
    Copy selection into the system-wide clipboard.
+   If there is no selection, copy the current line instead.
 
 Paste
    Insert contents of the system-wide clipboard into the current window.

Lib/idlelib/editor.py

@@ -610,14 +610,21 @@ def python_docs(self, event=None):
         return "break"
 
     def cut(self,event):
-        self.text.event_generate("<<Cut>>")
+        if not self.text.tag_ranges('sel'):
+            self.copy(event)
+            self.text.delete('insert', 'insert+1l')
+        else:
+            self.text.event_generate("<<Cut>>")
         return "break"
 
     def copy(self,event):
-        if not self.text.tag_ranges("sel"):
-            # There is no selection, so do nothing and maybe interrupt.
-            return None
-        self.text.event_generate("<<Copy>>")
+        if not self.text.tag_ranges('sel'):
+            self.text.mark_set('insert', 'insert linestart')
+            line = self.text.get('insert', 'insert+1l')
+            self.text.clipboard_clear()
+            self.text.clipboard_append(line)
+        else:
+            self.text.event_generate("<<Copy>>")
         return "break"
 
     def paste(self,event):

Lib/idlelib/idle_test/test_editor.py

@@ -401,5 +401,51 @@ def test_ignore_choice_clears_mtime(self):
         stub.set_saved.assert_not_called()
 
 
+class CopyCutLineTest(unittest.TestCase):
+
+    @classmethod
+    def setUpClass(cls):
+        requires('gui')
+        cls.root = Tk()
+        cls.root.withdraw()
+        cls.window = Editor(root=cls.root)
+
+    @classmethod
+    def tearDownClass(cls):
+        cls.root.destroy()
+        del cls.root
+
+    def test_copy_no_selection(self):
+        eq = self.assertEqual
+        text = self.window.text
+
+        insert(text, 'hello\nworld')
+        text.mark_set('insert', '1.2')
+        self.window.copy(event=None)
+
+        # Copy current line without being selected
+        eq(text.clipboard_get(), 'hello\n')
+        eq(text.tag_ranges('sel'), ())
+
+        # Cursor move to start of the line
+        eq(text.index('insert'), '1.0')
+
+    def test_cut_no_selection(self):
+        eq = self.assertEqual
+        text = self.window.text
+
+        insert(text, 'hello\nworld')
+        text.mark_set('insert', '1.2')
+        self.window.cut(event=None)
+
+        # Copy current line and remove it
+        eq(text.clipboard_get(), 'hello\n')
+        eq(text.get('1.0', 'end'), 'world\n')
+        eq(text.tag_ranges('sel'), ())
+
+        # Cursor move to start of the line
+        eq(text.index('insert'), '1.0')
+
+
 if __name__ == '__main__':
     unittest.main(verbosity=2)

Misc/NEWS.d/next/IDLE/2026-02-23-17-28-34.gh-issue-94521.vlr8XB.rst

@@ -0,0 +1 @@
+Copy or cut current line while no selection. Patch by Shixian Li.