Is it possible to render only keyframes from Dope-sheet? I want to render only keyframes from Dope-sheet without the in-between frames. Effectively creating hold of last keyframe till there is new keyframe by re-saving (not re-rendering) the previously rendered keyframe as next frame till I hit next keyframe. 

I am Aware of OpenGL render for quick test. But I am talking of final test.

I want to do this so that I can block out poses without interpolation. With Final render result it will help check lighting, materials and mesh deformations.

Is this possible?
Render all frames of the selected object(s) that have a keyframe:

import os
import bpy

original_frame = bpy.context.scene.frame_current
output_path = bpy.context.scene.render.filepath
start = bpy.context.scene.frame_start
end = bpy.context.scene.frame_end
frames = []

for obj in bpy.context.selected_objects:
    for fcurve in obj.animation_data.action.fcurves:
        for keyframe_point in fcurve.keyframe_points:
            x, y = keyframe_point.co
            if x &gt;= start and x &lt;= end and x not in frames:
                frames.append(x)

for frame in frames:
    bpy.context.scene.frame_current = frame
    bpy.context.scene.render.filepath = os.path.join(output_path, "%05d" % frame)
    bpy.ops.render.render(write_still=True)

bpy.context.scene.frame_current = original_frame
bpy.context.scene.render.filepath = output_path