bicycle.py

#Bicycle industry classes

class Bike_shop(object):
    def __init__(self, name, inventory = None):
        self.name = name
        self.margin = 0.2
        if None == inventory:
            self.inventory = []
        else:
            self.inventory = inventory
            
    def add_bicycle(self, bicycle):
        '''Adds bicycle to inventory'''
        for bike in self.inventory:
            if bike.model == bicycle.model:
                bike.weight = bicycle.weight
                bike.cost = bicycle.cost
                return

        self.inventory.append(bicycle)


    def show_inventory(self):
        for item in self.inventory:
            print("Name:{} | Weight:{} | Cost:{} \n".format(item.model, item.weight, item.cost))

    def filter_by_budget(self, budget):
        shortlist = []
        for item in self.inventory:
            if budget >= item.cost + (item.cost * self.margin):
                shortlist.append(item)

        return shortlist
        
    def remove_bicycle(self, model):
        '''Removes bicycle to inventory'''
        
    def sell_bicycle(self, model):
        '''Sells specific bike model to customer'''
        
        
class Bicycle(object):
    def __init__(self, model, weight, cost):
        self.model = model
        self.weight = weight
        self.cost = cost
        
class Customer(object):
    def __init__(self, name, budget, collection = None):
        '''Creates a customer with the default parameters.
        Checks if customer has a bike based on the value of collection.'''
        self.name = name
        self.budget = budget
        if None == collection:
            self.collection = {}
            self.has_bike = False
        else:
            self.collection = collection
            self.has_bike = True

main.py

from bicycle import *

# Bike_shop attributes - name, inv, margin (% as decimal)
# Bicycle attributes - model, weight (lbs.), cost ($)
# Customer attributes - name, budget ($), has_bike (bool)

shop1 = Bike_shop("Wheelz N' Stuff")
shop1.add_bicycle( Bicycle('Schwinn', 20, 49.99) )
shop1.add_bicycle( Bicycle('Trek', 15, 99.99) )
shop1.add_bicycle( Bicycle('Giant', 17, 149.99) )
shop1.add_bicycle( Bicycle('Fuji', 9, 399.99) )
shop1.add_bicycle( Bicycle('GT', 10, 449.99) )
shop1.add_bicycle( Bicycle('Kestrel', 10, 799.99) )

lance = Customer('Lance Armstrong', 1000, False)
dave = Customer('Dave Mirra', 500, False)
matt = Customer('Matt Hoffman', 200, False)

def retail_price(model):
    price = model.cost + model.cost * shop1.margin
    print('${}'.format(round(price, 2)))
    
#retail_price(bike_6)

def print_shortlist(shortlist):
    for item in shortlist:
        print("Name:{} | Weight:{} | Cost:{} \n".format(item.model, item.weight, item.cost))

if __name__ == "__main__":
    lance_shortlist = shop1.filter_by_budget(lance.budget)
    dave_shortlist = shop1.filter_by_budget(dave.budget)
    matt_shortlist = shop1.filter_by_budget(matt.budget)

    print("Lance can afford\n")
    print_shortlist(lance_shortlist)
    print("Dave can afford\n")
    print_shortlist(dave_shortlist)
    print("Matt can afford\n")
    print_shortlist(matt_shortlist)