from maya import cmds
loc = cmds.spaceLocator(name="test")
loc_tx = "{0}.translateX".format(loc[0])
loc_vis = "{0}.visibility".format(loc[0])
# At Frame 1
cmds.currentTime(1)
cmds.setKeyframe(loc_tx, inTangentType="linear", outTangentType="linear")
cmds.setKeyframe(loc_vis, inTangentType="linear", outTangentType="linear")
# At Frame 10
cmds.currentTime(10)
cmds.setAttr(loc_tx, 10)
cmds.setKeyframe(loc_tx, inTangentType="linear", outTangentType="linear")
cmds.setAttr(loc_vis, 0)
cmds.setKeyframe(loc_vis, inTangentType="linear", outTangentType="linear") # This will still returns me in stepped tangent