# Print the frame and value length of selected keys on a single curve
import pymel.core as pm
curve = pm.findKeyframe(c=True)
if len(curve) == 1: # only 1 curve selected
l_keys = pm.keyframe(q=True, selected=True, tc=True)
v_keys = pm.keyframe(q=True, selected=True, vc=True)
if len(l_keys) > 1: # at least 2 keys selected
key_length = abs(l_keys[-1] - l_keys[0])
key_value = abs(v_keys[-1] - v_keys[0])
print ("len: {}, val: {:.3f}".format(key_length, key_value)),
else:
pm.warning('Need to select at least 2 keys'),
else:
pm.warning('Select only 1 curve'),