This is a note for me, because I don't remember the nodeshape names and from time to time, I want to change them:

>>> node.setUserData("nodeshape", "trapezoid_up")

('rect', 'bone', 'bulge', 'bulge_down', 'burst', 'camera', 'chevron_down', 'chevron_up', 'cigar', 
'circle', 'clipped_left', 'clipped_right', 'cloud', 'diamond', 'ensign', 'gurgle', 'light', 'null'
, 'oval', 'peanut', 'pointy', 'slash', 'squared', 'star', 'tabbed_left', 'tabbed_right', 'tilted',
 'trapezoid_down', 'trapezoid_up', 'wave')