I believe it means you have some sort of temptation in your life and its been an inward struggle deciding what to do. It can be anything from food cravings to cheating on someone. The snake represents temptation and in the dream and may help you figure out what to truly do by avoiding the snake
Having a snake dream can be positive and negative. From what I know, the negative part is that you have a fear or worry in life. It usually means you're scared or worried about something coming up. It could also mean knowledge and wisdom, so it basically depends on if the dream was good or bad I guess.