Ballistic Skill Calculator

def calc_bs(bs, mod):
    if mod == ("bad", "yes"):
        bs = bs - 10
        return bs
    if mod == ("good", "yes"):
        bs = bs + 10
        return bs
    if mod == ("double good", "yes"):
        bs = bs + 20
        return bs
    if mod == ("double bad", "yes"):
        bs = bs - 20
        return bs
    if mod == ("triple bad", "yes"):
        bs = bs - 30
        return bs
    if mod == ("triple good", "yes"):
        bs = bs + 30
        return bs
    else:
        return bs
    
aim = "good", "no"
aim_full = "double good", "no"
semi_auto = "good", "no"
full_auto = "double good", "no"
supp_fire = "double bad", "no"
enemy_ran = "double bad", "no"
surprise = "triple good", "no"
massive_target = "triple good", "no"
point_blank = "triple good", "no"
stunned = "double good", "no"
enormous_target = "double good", "no"
short_range = "good", "no"
hulking_target = "good", "no"
heavy_rain = "bad", "no"
scrawny_target = "bad", "no"
called_shot = "double bad", 'no'
target_in_melee = "double bad", 'no'
fog_mist = "double bad", 'no'
puny_target = 'double bad', 'no'
no_talent = "double bad", 'no'
miniscule_target = "triple bad", "no"
extreme_range = "triple bad", 'no'
target_concealed = "triple bad", 'no'
darkness = "triple bad", 'no'
bs = 30

part1 = calc_bs(calc_bs(calc_bs(calc_bs(calc_bs(bs,aim),aim_full),semi_auto),full_auto),supp_fire)
part2 = calc_bs(calc_bs(calc_bs(calc_bs(calc_bs(part1,enemy_ran),surprise),massive_target),point_blank),stunned)
part3 = calc_bs(calc_bs(calc_bs(calc_bs(calc_bs(part2, enormous_target), short_range), hulking_target), heavy_rain), scrawny_target)
part4 = calc_bs(calc_bs(calc_bs(calc_bs(calc_bs(part3, called_shot), target_in_melee), fog_mist), puny_target), no_talent)
part5 = calc_bs(calc_bs(calc_bs(calc_bs(part4, miniscule_target), extreme_range), target_concealed), darkness)
print part5

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