In IDLE, go to Options -> Configure IDLE -> Keys and there select history-next and then history-previous to change the keys.
Then click on Get New Keys for Selection and you are ready to choose whatever key combination you want.
In IDLE, go to Options -> Configure IDLE -> Keys and there select history-next and then history-previous to change the keys.
Then click on Get New Keys for Selection and you are ready to choose whatever key combination you want.