FoodCalculator.py

class FoodCalculator:
  current_price = 0
  def __init__(self):
    pass
  def add_item(self,value):
    self.current_price = value #assign to instance variable
  def get_tax(self,tax_rate):
    return self.current_price*(tax_rate*0.01)
  def get_tip(self,taxP,tipP):
    after_tax = self.current_price+(0.01*taxP*self.current_price)
    return ((float(tipP)/float(100))*after_tax)
  def get_total_cost(self,taxP,tipP):
    after_tax = self.current_price+(0.01*taxP*self.current_price)
    after_tip = after_tax+(0.01*tipP*after_tax)
    return after_tip
fc = FoodCalculator()
fc.add_item(100)
print fc.get_tax(10)
print fc.get_tip(10,10)
print fc.get_total_cost(10,10)