- # pickup half the number of ret artist
- ret_extra = MetaContainer(ret_extra[:max(4, len(ret))//2])
+ # tries to pickup less artist from extra art
+ if len(ret) < 4:
+ ret_extra = MetaContainer(ret_extra)
+ else:
+ ret_extra = MetaContainer(ret_extra[:max(4, len(ret))//2])