Are you referring to the spurs on each side of the vent?, if so both males and females have them.
The only accurate way to sex a Ball Python is by popping or probing, it takes practice best thing is to find someone near you willing to show you how it's done and than practice.
You can also watch the following
YouTube - 8 Ball Pythons - Popping Lessons
YouTube - Sexing Baby Ball Pythons - part 1