Revert to Python 2.7.
Revert to Python 2.7.

oaelhara/numbbo,dtusar/coco,oaelhara/numbbo,NDManh/numbbo,NDManh/numbbo,dtusar/coco,NDManh/numbbo,NDManh/numbbo,NDManh/numbbo,oaelhara/numbbo,oaelhara/numbbo,dtusar/coco,dtusar/coco,oaelhara/numbbo,oaelhara/numbbo,oaelhara/numbbo,dtusar/coco,dtusar/coco,oaelhara/numbbo,oaelhara/numbbo,dtusar/coco,NDManh/numbbo,NDManh/numbbo,dtusar/coco,dtusar/coco,NDManh/numbbo,NDManh/numbbo