def interrupt_guard(msg='<STR_LIT>', reraise=True):
def echo():<EOL><INDENT>print(msg)<EOL><DEDENT>return on_interrupt(echo, reraise=reraise)<EOL>
context for guard keyboardinterrupt
ex)
with interrupt_guard('need long time'):
    critical_work_to_prevent()

:param str msg: message to print when interrupted
:param reraise: re-raise or not when exit
:return: context