>>> print("\N{ROCKET}")
Traceback (most recent call last):
  File "<pyshell#1>", line 1, in <module>
    print("\N{ROCKET}")
  File "idlelib/PyShell.py", line 1352, in write
    return self.shell.write(s, self.tags)
UnicodeEncodeError: 'UCS-2' codec can't encode character '\U0001f680' in position 0: Non-BMP character not supported in Tk

Shouldn't IDLE replace non-encodable characters with "\uFFFD"?

I think

>>> "\N{ROCKET}"
�

is user-friendlier than the traceback.

See also #14304.