Macports Python IDLE 3.4 not opening
Macports version of IDLE needs X11 to be installed on the computer

Check you've X11 installed and if not download and install it here - https://www.xquartz.org/

If installed check it is version 2.7.9 .. if not update it using the link above

If it is installed and up to date and IDLE still gives the above error run the following command in a terminal window to get X11 to autolaunch
     launchctl load -w /Library/LaunchAgents/org.macosforge.xquartz.startx.plist