Message 323734 - Python tracker

IDLE avoids the problem of calculating a location for a '^' below the bad line by instead asking tk to give the marked character (and maybe more) a 'ERROR' tag, which shows as a red background.  So it marks the '$' of 'A_I_U_E_O$' and the 'alid' slice of 'inv\u200balid' (from duplicate #10384).  When the marked character is '\n', the space following the line is tagged.  Is it possible to do something similar with any of the major system consoles?