Attached is a patch to have the rpc marshal exceptions. When used with Martin's patch, IDLE returns 

>>> '\U00010330'
Traceback (most recent call last):
  File "<pyshell#3>", line 1, in <module>
    '\U00010330'
ValueError: character U+10330 is above the range (U+0000-U+FFFF) allowed by Tcl


Martin: I disagree with the approach of raising a UnicodeEncodeError if IDLE can't render the output of a user's program, especially when the program would otherwise run without error if ran from outside of IDLE.

Would replacing these characters with "?" and documenting this limitation in IDLE's docs be an acceptable solution?