Ned, Thanks for the detailed example and confirming my gut instinct that Tk was the root cause of the differences seen between the IDLE's Python interactive shell (https://docs.python.org/3.4/library/idle.html) and the interactive interpreter invoked from the command line (https://docs.python.org/3.4/tutorial/interpreter.html#tut-invoking).

As an end user learning Python (such as the elementary education market), the current Standard Library documentation on IDLE guides me to the incorrect conclusion that the "Python shell window (aka interactive interpreter)" in IDLE would behave the same as invoking the interactive interpreter from the command line.

It seems reasonable to explicitly state in the Standard Library doc that:
"In rare cases, such as text handling with certain special characters (i.e. '\b' in a string), the IDLE's interactive Python shell may return a different response than the Python interactive interpreter invoked from the command line. This is due to IDLE's low level dependence on Tk (Tk itself is not part of Python; it is maintained at ActiveState. reference: first paragraph of https://docs.python.org/3.4/library/tkinter.html#module-tkinter)."