Create maya key pairs

gistfile1.py

import maya.cmds as mc
objs = mc.ls(sl=1)

keyframes = mc.keyframe(objs,q=1)
fs = int( mc.playbackOptions(q=1, ast=1 ) )
fe = int( mc.playbackOptions(q=1, aet=1 ) )

keyframes = sorted( [k for k in set(keyframes) if k>=fs and k<=fe] )
for k in keyframes:
    mc.setKeyframe(objs,t=[k],i=True)

for a,b in zip(keyframes,keyframes[1:]):
    if b - a < 3:
        print b-a
        continue
    for o in objs:
        mc.copyKey(o,t=(a,a))
        mc.pasteKey(o,t=(b-1,b-1))