I believe you said elsewhere that you would like to try the refactoring that splits a window+frame class into a window class and a frame class. It would be great if you became good at doing this.

If the current class name is used externally, I might consider reusing it for the window class.  But since the external interface for textview is the two wrapper functions, 'TextView' is not used externally.

F:\dev\cpython\lib\idlelib\idle_test\test_textview.py: 3: Since all methods and functions create (or destroy) a TextViewer, which
F:\dev\cpython\lib\idlelib\idle_test\test_textview.py: 31: # If we call TextViewer or wrapper functions with defaults
F:\dev\cpython\lib\idlelib\idle_test\test_textview.py: 36: class TV(tv.TextViewer):  # Used in TextViewTest.
F:\dev\cpython\lib\idlelib\idle_test\test_textview.py: 73: # Call TextViewer with modal=False.
F:\dev\cpython\lib\idlelib\idle_test\test_textview.py: 88:         self.assertIsInstance(view, tv.TextViewer)
F:\dev\cpython\lib\idlelib\idle_test\test_textview.py: 93:         self.assertIsInstance(view, tv.TextViewer)
F:\dev\cpython\lib\idlelib\idle_test\test_textview.py: 113: # Call TextViewer with _utest=True.
F:\dev\cpython\lib\idlelib\pyshell.py: 895:             # XXX KBK 27Dec07 use TextViewer someday, but must work w/o subproc
F:\dev\cpython\lib\idlelib\textview.py: 11: class TextViewer(Toplevel):
F:\dev\cpython\lib\idlelib\textview.py: 78:     """Create TextViewer for given text.
F:\dev\cpython\lib\idlelib\textview.py: 87:     return TextViewer(parent, title, text, modal, _utest=_utest)
F:\dev\cpython\lib\idlelib\textview.py: 91:     """Create TextViewer for text in filename.
F:\dev\cpython\lib\idlelib\textview.py: 116:     run(TextViewer)

So lets try TextviewWindow and TextviewFrame.  Make the obvious substitutions, except in the PyShell and line 78 and 91 comments, 'TextViewer' should become a generic 'text viewer' that would apply to TextviewFrame if that became the main entry point.

If you want to show me an incomplete patch, you can still upload diffs here.