Editing in Python 3.5.3 Shell why does the "undo", "copy", "Paste" and keyboard "delete", "back space" not work?
If you make a mistake I cannot see how to go back.
All those commands do work on a single line of text before the [Enter] key is pressed. Copy & Paste works for previously entered code. However IMO the shell was not meant to be used to enter lengthy or multiple lines of code. Most would open a file for editing and use the IDLE editor. All the editing commands work as expected inside the editor.